Nefmoto - User contributions [en]

ATR 1.60 (Exhaust Gas Temperature Control)

2012-05-22T19:52:31Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

atr-main exhaust gas temperature control overview

atr-atrbb detection of control range

atr-atrb exhaust gas temperature control for cylinder bank 1

atr-atrerb enabling exhaust gas temperature control for cylinder bank 1

atr-atrpi exhaust gas temperature proportional/integral control for cylinder bank 1

atr-atrb2 exhaust gas temperature control for cylinder bank 2

atr-atrerb2 enabling exhaust gas temperature control for cylinder bank 2

atr-atrpi2 exhaust gas temperature proportional/integral control for cylinder bank 2

atr-atrnl limp mode for exhaust gas temperature control

atr-atrko coordination of the control output

ATR 1.60 Function Description

Task:

Protection of components (manifold, turbocharger, etc.) by controlling the exhaust gas temperature.
By means of this control, the general enrichment at high load and speed
("full-load enrichment") can be reduced. When general mixture control
is insufficient, the exhaust gas temperature control enrichment must also be
invoked which leads to reduced fuel consumption.

Principle:

An excessively high exhaust gas temperature can be lowered by enriching the
air-fuel mixture. Through this enrichment, more fuel enters the cylinder than is
required for stoichiometric combustion of the fuel. The unburned fuel vaporises
on the cylinder walls and cools them, whereby the exhaust gas temperature
decreases. For this control, the exhaust gas temperature is measured using an
exhaust gas temperature sensor or estimated by an exhaust gas temperature
model.

As long as the exhaust temperature is below the threshold temperature, there is no
control. Thus, there is only a "down regulation" of the exhaust
temperature, not an "up regulation". If the desired temperature is reached
or exceeded, the control switches. To achieve an enrichment of the mixture, the
controller is adjusted to give a desired value of lambda in the
"rich" region. This enrichment decreases the exhaust gas temperature,
and the controller sets the desired exhaust temperature. When the exhaust temperature
drops back below the threshold temperature, the controller takes back the
enrichment. If enrichment is no longer required, control is switched off.

Overview of Codeword CATR:

{| border="1"
|-
|
Bit No.
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|-
|
|
|
|
|
|
|
|
|
*
|}
*If the value of bit 0 is set equal to 1, this enables exhaust gas temperature control.

ATRBB: Detection Control Range

This function detects the valid control range. Via the configuration byte CATR, the control can, in principle, be switched off. A valid range is usually present when the end of start conditions is detected (B_stend = 1), and the relative load (rl) lies above an applicable threshold rlatr. This control scheme is only available in the near-full load range (rl > rlatr) is active, since exhaust
temperatures are only likely to be high in this range. Once the range is exited, control is switched off, e.g. in the transition to idle to shorten the duration of the enrichment.

The valid control range is indicated by the flag B_atrb = 1.

ATRERB:
Enabling Exhaust Gas Temperature Control for Bank 1

The exhaust gas temperature control is a flip-flop on or off. The condition flag
B_atr = 1 indicates that control is active. If the exhaust gas temperature (tabg)
is greater than or equal to the applicable threshold value TABGSS, the control
is switched on. The control is switched off when enrichment is no longer
required. This is the case when the regulator output dlatr > 0. The
controller output dlatr for the exhaust temperature control is then set to
zero. It is possible to set a lean limit for the control scheme via the fixed
value LATRO. If the current set-lambda without add. If the current desired lambda
value without additional lamvoa parts above the limit LATRO (in the lean range)
there will be no control. In addition, there is no control if any of the
following conditions are met:

(a) No valid control range is detected (B_atrb = 0)

(b) Fuel injector cut-off condition is true (B_bevab = 1)

(c) The exhaust gas temperature sensor indicates an error (E_ats = 1)

(d) The exhaust gas temperature sensor is not ready (B_atsb = 0)

(e) Significant differences between the bank controller control variables were
found (E_atrd = 1).

If the engine reaches the rich running limit (B_lagf = 1) while exhaust gas
temperature control is active (B_atr = 1), a further enrichment attempt is prohibited
by the control scheme (B_atrsp = 1). The current value of the controller output
is recorded. However, an enrichment reduction is allowed.

ATRPI2: Exhaust Gas Temperature Proportional/Integral Control for Cylinder Bank 1

The exhaust gas temperature controller is configured as a PI controller, because
the "delta lambda controller" intervenes additively. ATRP and ATRI
are applied amplification factors for the P and I components. When control is
switched off (B_atr = 0) the controller output is set to zero. The integral
component in this case is set to equal the negative value of the proportional
component (dlatri = -dlatrp), so it follows
that the sum is zero. The controller output (dlatr) will be limited to
"rich" by the applicable limit DLATRMN. In this case, the integrator
is suspended. The exhaust gas temperature tabg falls below the threshold
temperature TABGSS or the control is turned off (B_atr = 0), the integrator will
be released. When the controller is inhibited (B_atrsp = 1), the last value of controller
output (dlatr) is recorded. The integral part is calculated so that the
controller output is constant even when a control error remains (dlatri = dlatr
- dlatrp).

ATRERB2: Enabling Exhaust Gas Temperature Control for Cylinder Bank 2

As per cylinder bank 1

ATRPI2: Exhaust Gas Temperature Proportional/Integral Control for Cylinder Bank 2

As per cylinder bank 1

ATRNL: Limp Mode for Exhaust Gas Temperature Control

In the event that an exhaust gas temperature sensor fails or is not ready, a limp mode variable (dlatrnl) is provided. The delta lambda target of interest for the limp mode is in the characteristic DLATRNL.

ATRKO: Control Output Coordination

If there is no error in the exhaust gas temperature sensors before, the controller
outputs dlatr or dlatr2 through the function outputs dlamatr or dlamatr2 are
transferred to lambda coordination. Once a sensor failure (E_ats = 1 or E_ats2
= 1) or the sensors are not operational (B_atsb = 0), or significant bank
differences of the controller variables (E_atrd = 1 or E_atrd2 = 1) is detected,
the ATR-control range (B_atrb = 1) the limp mode variable dlatrnl are
transferred to both banks of lambda coordination.

ATR 1.60 Application Notes

Requirements:

- Application of lambda control

Applications Tools:

VS100

Preassignment of the Parameters:

Erkennung Regelbereich:

- Codeword CATR = 01 (hexadecimal) = 1 (decimal) enable control

- Minimum load for exhaust gas temperature control map KFRLATR (x: engine
speed/rpm, y: intake air temperature/°C, z:%)

{| border="1"
|-
|
|
2000
|
3000
|
4000
|
5000
|
6000
|-
|
10
|
|
|
|
|
|-
|
35
|
|
|
|
|
|-
|
60
|
|
|
|
|
|-
|
85
|
|
|
|
|
|-
|
109
|
|
|
|
|
|}
Enable
exhaust gas temperature control for cylinder bank 1/bank 2:
- Threshold
exhaust gas temperature for exhaust gas temperature control: TABGSS(2) = 1000°C
- Desired
AFR upper limit for switching off exhaust gas temperature control: LATRO = 16.0
Exhaust
gas temperature control for cylinder bank 1/bank 2:
-
Threshold exhaust gas temperature for exhaust gas temperature control:
TABGSS(2) = 1000°C
- Gain
factor for proportional component exhaust gas temperature PI control: ATRP =
0.005 l/K
-
Gain factor for integral component for exhaust gas temperature PI control: ATRI
= 0.0005 l/(s ´ K)
-
Lower limit for exhaust gas temperature control: DLATRMN = -0.3
Exhaust
gas temperature control limp mode:
-
Delta lambda exhaust gas temperature control limp mode:

{| border="1"
|-
|
Engine
speed/rpm
|
2000
|
3000
|
4000
|
5000
|
6000
|-
|
DLATRNL
|
-0.10
|
-0.13
|
-0.17
|
-0.20
|
-0.23
|}
Procedure:
Switching off the Function:
To
prohibit exhaust gas temperature control set codeword CATR [Bit 0] equal to 0.
Affected
Functions:
%LAMKO
through dlamatr_w and dlamatr2_w

{| border="1"
|-
|
Parameter
|
Description
|-
|
ATRI
|
Gain factor (integral component), exhaust gas temperature control
|-
|
ATRP
|
Gain factor (proportional component), exhaust gas temperature control
|-
|
CATR
|
Configuration byte, exhaust gas temperature control
|-
|
DLATRMN
|
Lower limit for exhaust gas
temperature control
|-
|
DLATRNLN
|
Delta lambda in limp mode, exhaust gas temperature control
|-
|
KFRLATR
|
Minimum load for exhaust gas temperature control
|-
|
LATRO
|
Desired lambda upper limit, exhaust gas temperature control
|-
|
SY_STERVK
|
System constant condition flag for stereo pre-cat
|-
|
TABGSS
|
Exhaust gas temperature threshold for exhaust gas temperature control
|-
|
TABGSS2
|
Exhaust gas temperature threshold, exhaust gas temperature control, bank
2
|-
|
Variable
|
Description
|-
|
B_ATR
|
Condition flag for exhaust gas temperature control
|-
|
B_ATR2
|
Condition flag for exhaust gas temperature control, cylinder bank 2
|-
|
B_ATRB
|
Condition flag for valid operating range, exhaust gas temperature control
|-
|
B_ATRNL
|
Condition flag for limp mode in exhaust gas temperature control
|-
|
B ATRSP
|
Condition flag for exhaust gas temperature control disabled
|-
|
B_ATRSP2
|
Condition flag for exhaust gas temperature control disabled, cylinder
bank 2
|-
|
B_ATSB
|
Condition flag for exhaust gas temperature sensor ready
|-
|
B_BEVAB
|
Condition flag for fuel injector cut-off in cylinder bank 1
|-
|
B_BEVAB2
|
Condition flag for fuel injector cut-off in cylinder bank 2
|-
|
B_LALGF
|
Condition flag for "lambda rich" limit active
|-
|
B_LALGF2
|
Condition flag for "lambda rich" limit active
|-
|
B STEND
|
Condition flag for end of start conditions reached
|-
|
DLAMATR2_W
|
Delta lambda for exhaust gas temperature control, cylinder bank 2
|-
|
DLAMATR_W
|
Delta lambda for exhaust gas temperature control
|-
|
DLATR2_W
|
Delta lambda for exhaust gas temperature control, cylinder bank 2
|-
|
DLATRI2_W
|
Integral component, exhaust gas temperature PI control, cylinder bank 2
|-
|
DLATRI_W
|
Integral component, exhaust gas temperature PI control
|-
|
DLATRNL_W
|
Delta lambda in limp mode, exhaust gas temperature control
|-
|
DLATRP2_W
|
Proportional component, exhaust gas temperature PI control, cylinder bank
2
|-
|
DLATRP W
|
Proportional component, exhaust gas temperature PI control
|-
|
DLATR_W
|
Delta lambda, exhaust gas temperature control
|-
|
E_ATRD
|
Error flag: cylinder bank difference, exhaust gas temperature control
|-
|
E_ATRD2
|
Error flag: cylinder bank difference, exhaust gas temperature control bank
2
|-
|
E_ATS
|
Error flag: exhaust gas temperature sensor
|-
|
E_ATS2
|
Error flag: exhaust gas temperature sensor, cylinder bank 2
|-
|
LAMVOA2_W
|
Lambda pilot control without additive parts, cylinder bank 2
|-
|
LAMVOA_W
|
Lambda pilot control without additive parts
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
RLATR
|
Load threshold for exhaust gas temperature control
|-
|
TABG2_W
|
Exhaust gas temperature, cylinder bank 2
|-
|
TABG_W
|
Exhaust gas temperature
|-
|
TANS
|
Intake air temperature
|}

[[Category:ME7]]

ZWGRU 23.110 (Fundamental Ignition Angle)

2012-05-22T19:51:38Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

zwgru-zwgru

zwgru-zw-nws Sub-function ZW_NWS: Provision for binary or continously variable camshaft control

zwgru-dzw-nws Sub-function DZW_NWS: Provision for binary or continously variable camshaft control (delta-ignition angle)

ZWGRU 23.110 Function Description

The fundamental ignition angle is provided by the map KFZW. The sub-function ZW_NWS describes the provision for any necessary camshaft timing (NWS). For binary camshaft control, the factor fnwue switches seamlessly between the maps KFZW and KFZW2. In the case of continuously variable camshaft control which depends on the camshaft overlap angle wnwue, an ignition angle correction DZWNWSUE is added to KFZW. The currently valid camshaft control version is defined by the system constant SY_NWS in the software generation:

SY_NWS = 0: no camshaft control

SY_NWS = 1: binary camshaft control

SY_NWS = 2: continuously variable NWS

SY_NWS > 2: not defined.

The software is translated conditionally, i.e. only one variant is available in the EPROM. SY_NWS is not in the EPROM and cannot be applied. The same additive ignition angle correction is performed as when calculating the optimum ignition angle (see %MDBAS), i.e. exhaust gas recirculation and lambda dependence are considered. The temperature dependence is considered in a separate function (%ZWWL). The result is the ignition angle for cylinder bank 1 (zwref) which is also the reference for cylinder bank 2. For cylinder bank 2, the ignition angle offset dzwb2 is added to the ignition angle.

ZWGRU 23.110 Application Notes

The maps KFZW and KFZW2 are applied when the engine is warm for the respective camshaft control position, exhaust gas recirculation is inactive and lambda = 1. If the engine does not knock, the optimal ignition angle is input. For engine knock, the knock limit is input.

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CNOKT
|
Codeword for lower octane fuel
|-
|
CWZWBANK
|
Codeword for enabling cylinder-specific ignition
angle offsets
|-
|
DZWNWSUE
|
Delta ignition angle depending on camshaft overlap
angle
|-
|
KFDWSZ
|
Delta ignition angle for cylinder bank 1-specific
ignition advance; through camshaft control
|-
|
KFDWSZ2
|
Delta ignition angle for cylinder bank 2-specific
ignition advance; through camshaft control
|-
|
KFDZK
|
Delta ignition angle during knock
|-
|
KFDZWKG
|
Ignition angle correction by moving the knock limit
|-
|
KFSWKFZK
|
Ignition angle retardation threshold for switching
between ignition angle maps
|-
|
KFZW
|
Ignition angle map
|-
|
KFZW2
|
Ignition angle map, variant 2
|-
|
TMZIZWV
|
Engine temperature threshold for enabling
cylinder-specific ignition angle adjustment
|-
|
TSWKR
|
Time lag for summing ignition angle retardation
queries
|-
|
VZIZWV
|
Vehicle speed threshold for disabling
cylinder-specific ignition angle adjustment
|-
|
Variable
|
Description
|-
|
B_KFZK
|
Condition flag for anti-knock map
|-
|
B_KRDWS
|
Condition flag for knock control safety retardation
|-
|
B_NOZWE
|
Condition flag for no ignition angle intervention on
the engine torque structure
|-
|
C_INI
|
Condition flag for intialising ECU
|-
|
DZWB2
|
Ignition angle offset for cylinder bank 2
|-
|
DZWBANK
|
Cylinder-bank specific ignition angle offset
|-
|
DZWKG
|
Delta ignition angle for moving the knock limit
|-
|
DZWOAG
|
Exhaust gas recirculation rate-dependent ignition
angle correction of the optimum ignition angle
|-
|
DZWOL
|
Lambda-dependent ignition angle correction of the
optimum ignition angle
|-
|
DZWZK
|
Delta ignition angle during knock
|-
|
FNWUE
|
Weighting factor for ignition angle overlap (inlet)
|-
|
LAMBAS
|
Basic lambda
|-
|
NMOT
|
Engine speed
|-
|
NMOT W
|
Engine speed (Word)
|-
|
RL_W
|
Relative cylinder charge (Word)
|-
|
SY_NWS
|
System constant for camshaft control: none, binary
(on/off) or continuously variable
|-
|
SY_ZIZWV
|
''Text must be provided by Mrs Sauer''
|-
|
TMOT
|
Engine temperature
|-
|
VFZG
|
Vehicle speed
|-
|
WKRMA
|
Average of the ignition angle retardation during
knock control, general (in limp mode with safety)
|-
|
WNWUE
|
Camshaft overlap angle
|-
|
ZWGRU
|
Fundamental ignition angle
|-
|
ZWNWS
|
Fundamental ignition angle taking camshaft control
into consideration
|-
|
ZZYLZUE
|
ECU cylinder counter for ignition calculation
|}

[[Category:ME7]]

ZUE 282.130 (Fundamental Function - Ignition)

2012-05-22T19:50:45Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

zue-zue

zue- dzwll

ZUE 282.130 Function Description

The ignition angle (zwgru) from the fundamental ignition angle calculation is corrected by the warm-up angle (dzwwl) and the cylinder-specific knock control angle (dwkrz), and it follows that the basic ignition angle (zwbas) is identical with the earliest possible ignition angle. This ignition angle now forms the route in to the ignition engine torque implementation (MDZW), which provides the output ignition angle (zwsol). This ignition angle is now limited to the earliest or latest possible ignition angle. The resulting ignition angle (zwist) is corrected by the phase error which gives the output ignition angle (zwout).

For back-up protection of the ignition angles, the one’s complement (i.e. inverse binary value) of zwout is calculated which forms zwoutcpl. This then becomes the input variable of the function monitor.

The cylinder bank selective ignition angle adjustment is activated via the codeword CWDZWLL = 1.

The delta ignition angle (dzwll) corresponding to B_bankl2 is added to, or subtracted from zwsol.

ZUE 282.130 Application Notes

Three interfaces are provided for the application; the RAM cell vszw and the fixed value ZWAPPL ZW enable adjustment of application tools. Engagement of the torque functions can be disabled using the codeword CWMDAPP (bit 0), so that the applied ignition angle (zwbas) can be driven directly.

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CWZWBANK
|
Codeword for enabling cylinder-specific ignition angle offsets
|-
|
FZIZWV
|
Factor for torque correction via cylinder-specific ignition angle
adjustment
|-
|
KFDZWLL
|
Map for delta ignition angle during idle
|-
|
KLZWBSMN
|
Latest possible basic ignition angle
|-
|
TMZIZWV
|
Engine temperature threshold for enabling cylinder-specific ignition
angle adjustment
|-
|
VZIZWV
|
Vehicle speed threshold for disabling cylinder-specific ignition angle
adjustment
|-
|
WPHN
|
Phase response
|-
|
ZWAPPL
|
Application interface: ignition angle adjustment
|-
|
Variable
|
Description
|-
|
B_BANK2
|
Condition flag for cylinder bank 2
|-
|
B_LL
|
Condition flag for idle
|-
|
B_LLREIN
|
Condition flag for idle control active
|-
|
B_NOZWE
|
Condition flag for no ignition angle intervention in the torque structure
|-
|
B_SA
|
Condition flag for overrun fuel cut-off
|-
|
B_ZWAPPL
|
Condition flag for ignition angle application without torque intervention
|-
|
B_ZWKRA
|
Condition flag for ignition angle output during knock regulation
|-
|
CWDZWLL
|
Codeword for delta ignition angle during idle active
|-
|
DWKR
|
Cylinder-specific ignition angle retardation during knock control
|-
|
DZWBANK
|
Cylinder bank-specific ignition angle offset
|-
|
DZWOB
|
Delta ignition angle during overboost
|-
|
DZWWL
|
Delta ignition angle during warm-up
|-
|
DZWZK
|
Delta ignition angle during knock
|-
|
MISOLZ_W
|
Indicated resulting desired torque for ignition angle intervention
|-
|
MIZSOL_W
|
Indicated resulting desired torque for ignition angle intervention
|-
|
NMOT
|
Engine speed
|-
|
NSOL
|
Desired idle speed
|-
|
REDIST
|
Actual reduction stage
|-
|
RL
|
Relative cylinder charge
|-
|
SY_REDMX
|
System constant: maximum reduction stage
|-
|
SY_TDZW
|
System constant: additive ignition angle adaptation active
|-
|
SY TURBO
|
System constant: turbocharger
|-
|
SY_WMAX
|
System constant: earliest outputtable ignition angle
|-
|
SY_WMIN
|
System constant: latest outputtable ignition angle
|-
|
SY_ZIZWV
|
''Text must be provided by Mrs
Sauer''
|-
|
SZOUT_W
|
Closing time output
|-
|
TMOT
|
Engine temperature
|-
|
VFZG
|
Vehicle speed
|-
|
VSTDZW
|
Additive ignition angle adaption
|-
|
VSZW
|
Ignition angle correction adjusting system
|-
|
WKRDY
|
Ignition angle retardation via dynamic knock regulation
|-
|
WPHG
|
Ignition angle speed sensor phase correction
|-
|
ZNACHANZ
|
Number of ignitions in overrun
|-
|
ZWBAS
|
Basic ignition angle
|-
|
ZWDLLPRT
|
Ignition angle pointer with delta idle ignition angle
|-
|
ZWGRU
|
Fundamental ignition angle
|-
|
ZWIST
|
Actual ignition angle
|-
|
ZWOUT
|
Ignition angle output
|-
|
ZWOUTCPL
|
One’s complement of the ignition angles for function monitoring
|-
|
ZWOUTPRT
|
Ignition angle pointer
|-
|
ZWSOL
|
Desired ignition angle for torque intervention
|-
|
ZWSPAE
|
Latest ignition angle
|-
|
ZWSTT
|
Ignition angle during start
|-
|
ZWZYL1
|
Ignition angle for cylinder 1
|-
|
ZZYLZUE
|
Dwell angle-cylinder counter for calculating ignitions
|}

[[Category:ME7]]

RKTI 11.40 (Calculation of Injection Time ti from Relative Fuel Mass rk)

2012-05-22T19:49:14Z

TTQS:

RKTI 11.40 Function Description

ti_w represents a physical value of injection time which is correct also during start conditions. During start the physical value of ti_b1, ti_b2 and ti_tvu_w has to be corrected by the user by a factor of 8, because start quantisation of ti_b1 is internally corrected by dividing by 8 to store large ti-values into a ‘word’ variable instead of a ‘long’ variable.

Please see the ''funktionsrahmen'' for the following diagrams:

1. Battery correction of injection time for injection valves, calculation frkte (fuel mass into
injection time)

2. Calculation of ubatt correction of injector time for injectors

3. Correction for injected fuel mass if the reference pressure of the fuel rail pressure controller is not manifold pressure (i.e. with a returnless fuel rail).

4. Calculation of the injection time during start conditions

5. Calculation of the injection time after end of start conditions

This function calculates the effective injection time before fine tuning (tevfa_w, tevfa2_w) from the relative fuel mass (rk_w, rk2_w) and the factor frkte. With an ideal fuel supply system, tevfa_w + tvu_w, tevfa2_w + tvu_w should result in lambda of 1.0 in the combustion chamber, with pilot control to lambda = 1.0 and neutral values of all mixture adaptations.

In practice, a deviation in lambda may occur due to injector nonlinearities or pulses in the fuel system. This deviation is corrected using the map FKKVS as a function of engine speed (nmot_w) and effective injection time (tevfa_w or tevfa2_w). The corrected effective injection time is te_w or te2_w.
By adding the battery voltage correction for the injectors, the actuation time is calculated thus: ti_b1 = te_w + tvu_w. The function ACIFI controls the actuation times ti_b1 and ti_b2 for the associated injectors. In a single bank system (SY_stervk = false) the actuation times for bank 1 (ti_b1 or ti_b2) are forwarded to CIFI. In order to achieve the long injection times required during
starting conditions, the quantization times ti_b1, ti_b2 are increased by a factor of 8 which thus expands the range to 1677.696 ms. The same applies for the additive quantity ti_tvu_w.

Therefore, a 16 bit value is required for the interface to the function ACIFI. This is important for runtime reasons for normal operation. During start conditions, VS100 measurements of the physically indicated injection time are multiplied by a factor of 8. The resolution during start conditions for ti_b1, ti_b2 and ti_tvu_w is 25.6 microseconds, whereas in normal operation it is 3.2 microseconds.

The RAM cells ti_w and ti_2_w show the physically correct injection time during both start conditions and also normal operation with a resolution of 16 microseconds. The resolutions are valid for a 20 MHz processor.

The minimum injection time TEMIN or TEMINVA is set when outputs B_va = true, B_temin = true or B_temin2 = true. This serves to lock out the lambda control. The threshold value TEMINVA is differentiated from TEMIN with a cold engine when the wall film degradation is not properly emulated by the thinning-delay because te_w limits TEMIN. At higher speeds it is possible that the available theoretical maximum injection time is not sufficient to obtain the required target torque. Therefore, an injection time timx_w that is larger than the maximum possible injection time timxth_w is deployed until the desired torque is withdrawn and timx_w is not larger than timxth_w. For this purpose, the
control error dtimx_w is assigned to a PI controller. When the controller is active, the output controlled variable mitibgr_w represents the desired torque.
When the controller is inactive, mitibgr_w receives the value 100%. The desired torque in %MDBGRG is obtained by initializing with mifab_w and mitibgr_w. In order to avoid jumps in the nominal torque, the integrator of the integral component is initialized with mifab_w.

The controller is activated as soon as timx_w exceeds the speed-dependent threshold timxth_w. The controller remains in operation until timx_w < timxth_w AND mitibgr_w > mifab_w. See Applications Information.

RKTI 11.40 Application Notes

Calculation of the constant KRKTE:

KRKTE = (''rho''air x Vhcyl) / (100 x 14.7 x 1.67x10–5 x 1.05 x Qstat)

= (50.2624 x Vhcyl) / Qstat

Where:

''rho''air = air density (1.293 g/dm3 at 0°C and 1013 mbar)

Vhcyl = Volume of a cylinder hub in dm3

Qstat = injector constant with ''n''-heptane

1.05 = injector correction factor for petrol

14.7 = Stoichiometric air quantity at lambda = 1.0

1.67x10–5 = conversion factor minutes to milliseconds.

Calculation of the correction for fuel supply systems where the reference pressure of the fuel pressure regulator is ambient pressure:

FRLFSDP = SQRT[pdr_evmes/(pdr_akt + (pu - ps))]

Where:

pdr_evmes = absolute pressure in the fuel system before the injectors at the injector constant (Qstat) generally 3 bar

pdr_akt = actual fuel system pressure

pu = ambient pressure

ps = intake manifold pressure

For systems that take their reference pressure from the intake manifold pu - ps = 0 is used in the calculation above.

It then applies to the entire relationship FRLFSDP = Ö(pdr_evmes/pdr_akt)

For a fuel pressure of 3 bar, the results for FRLFSDP (where dpus = pu - ps) are as follows:

{| border="1"
|-
|
Naturally-aspirated Engine
|
Turbocharged Engine
|-
|
dpus/mbar
|
FRLFSDP
|
dpus/mbar
|
FRLFSDP
|-
|
0
|
1.0000
|
-1200*
|
1.2990
|-
|
100
|
0.9837
|
-1000
|
1.2247
|-
|
200
|
0.9682
|
-800
|
1.1678
|-
|
300
|
0.9535
|
-600
|
1.1180
|-
|
400
|
0.9393
|
-400
|
1.0742
|-
|
500
|
0.9258
|
-200
|
1.0351
|-
|
600
|
0.9129
|
0
|
1.0000
|-
|
700
|
0.9005
|
200
|
0.9682
|-
|
800
|
0.8885
|
400
|
0.9393
|-
|
|
|
600
|
0.9129
|-
|
|
|
800
|
0.8885
|}
*Boost pressure = 1800 mbar, ambient pressure = 600 mbar

For consistency reasons, 11 sampling points for vacuum and turbo are used with the turbo-values.

In the charge sampling and injection application in returnless fuel systems via the code word for the reference pressure for the fuel pressure regulator (CWPKAPP), the constant PSAPES (intake manifold pressure for injection application) is used as a substitute value where the modelled intake
manifold pressure ps_w has not been applied. Thus the manifold pressure can be set directly with a VS100 processor. With the VS20 processor, the pressure PSAPES can be changed with an adjustment factor between 0 and 2 via the RAM cell vsfpses (pses_w = PSAPES x vsfpses).

The initial value for PSAPES is 1013 mbar. If this value (in conjunction with a factor of 2 from vsfpses) does not define the maximum manifold pressure for turbocharged engines with VS20, the one-off value of PSAPES must be increased with VS100.

Initialization:

Map size in program development nmot x tevfa_w = 10 x 10

FKKVS: Sample points

{| border="1"
|-
|
Speed
|
800
|
1400
|
2000
|
2600
|
3200
|
3800
|
4400
|
5000
|
5600
|
6200
|
RPM
|-
|
Tevfa_w
|
1.5
|
2.5
|
3.5
|
4.5
|
5.5
|
6.5
|
7.5
|
8.5
|
9.5
|
10.5
|
ms
|-
|
Value
|
1.0
|
1.0
|
1.0
|
1.0
|
1.0
|
1.0
|
1.0
|
1.0
|
1.0
|
1.0
|
|}
The characteristic field FKKVS corrects errors in the fuel system (pulses in returnless fuel systems)

The map size of FKKVS can be extended to about nmot x tevfa_w = 10 x 10 to 16 x 10.

This is especially important to simplify the application for proportional systems. The speed sample points should match the number and values of the map KFPRG in the
function BGSRM.

TEMIN: 1 milliseconds

TEMINVA: 1 milliseconds so that overall, the same TEMIN is active

TEMINVA: 0 milliseconds so that it is inactive when the engine is cold and thinning delay B_va = true, te to TEMIN seated and so that the wall film is not broken down properly.

ti-resolution values are valid for a 20 MHz processor frequency. Otherwise thery must be converted thus: 20 MHz / (current processor frequency [MHz]).

Start:

ti_b1, ti_b2 25.6 microseconds. Measurements from VS100 must be multiplied by a factor of 8.

ti_tvu_w 25.6 microseconds. Measurements from VS100 must be multiplied by a factor of 8.

ti_w, ti2_w 16 microseconds.

te_w, te2_w not available.

Normal:

ti_b1, ti_b2 3.2 microseconds.

ti_tvu_w 3.2 microseconds.

ti_w, ti2_w 16 microseconds.

te_w, te2_w 3.2 microseconds.

First inputs:

ZTSPEV = 240 seconds

TVTSPEV

{| border="1"
|-
|
Etvmodev [°]
|
-20
|
0
|
100
|
120
|-
|
tvsp_w [ms]
|
0
|
0
|
0
|
0
|}
DMIL

CWDMIL

Bit 0 true: controller activated

Bit 0 false: controller deactivated

Bit 1 true: inputs B_ba and B_bag both active

KMITIBGR = 15 %/ms*s

PVMITIBGR = 0.8 %/ms

{| border="1"
|-
|
'''Variable'''
|
'''Description'''
|-
|
CWDMIL
|
Code word ti-continuous wave control RKTI
|-
|
CWPKAPP
|
Application code word for the fuel pressure
regulator pressure reference
|-
|
FKKVS
|
Correction factor for the fuel supply system
|-
|
FRLFSDP
|
Injection correction RLFS
|-
|
KMITIBGR
|
On-slope factor for the integration of dtimx_w
through torque limitation
|-
|
KRKTE
|
Conversion of relative fuel mass rk to
effective injection time te
|-
|
PSAPES
|
Intake manifold injection for application
|-
|
PVMITIBGR
|
Proportional gain factor for torque limitation
through continuous wave injection
|-
|
SY_STERVK
|
System constant condition: stereo before
catalytic converter
|-
|
TEMIN
|
minimum TE
|-
|
TEMINVA
|
minimum TE at VA
|-
|
TVTSPEV
|
Correction of the injection time depending on
evtmod
|-
|
TVUB
|
Voltage correction
|-
|
ZTSPEV
|
Time constant for filtering evtmod taking tvu-control
into account
|-
|
|
|-
|
B_BA
|
Acceleration enrichment condition (indicator)
|-
|
B_BAG
|
Strong acceleration enrichment condition
|-
|
B_ENIMITI
|
Integrator release condition for
torque limitation through continuous wave injection
|-
|
B_STEND
|
End of start condition
|-
|
B_TEMIN
|
TEMIN-limiting condition active, Bank 1
|-
|
B_TEMIN2
|
TEMIN-limiting condition active, Bank 2
|-
|
B_VA
|
Wall-film thinning delay condition (indicator)
|-
|
DPUS_W
|
Delta intake manifold pressure environment
|-
|
DTIMX_W
|
Difference between theoretical and maximum injection
time
|-
|
EVTMOD
|
Intake valve temperature models (temperature
model)
|-
|
EVTMODEV
|
Filtered value of evtmod taking into account
the formation of tvu_w
|-
|
FRKTE_W
|
Conversion factor relative fuel mass rk to
effective injection time te
|-
|
FTEK2_W
|
Correction factor for effective injection time,
Bank 2
|-
|
FTEK_W
|
Correction factor for effective injection time
|-
|
MIFAB_W
|
Limited indicated driver-desired torque
|-
|
MITIBGRI_W
|
I-component for torque limitation via
ti-control during continuous injection
|-
|
MITIBGRP_W
|
P-component for torque limitation
via ti-control during continuous injection
|-
|
MITIBGR_W
|
Torque limitation via ti-control during
continuous injection
|-
|
NMOT
|
Engine speed
|-
|
NMOT_W
|
Engine speed
|-
|
PS_W
|
Manifold Absolute Pressure (Word)
|-
|
PU_W
|
Ambient pressure
|-
|
RK2_W
|
Relative fuel mass, Bank2
|-
|
RK_W
|
Relative fuel mass
|-
|
TE2_W
|
Effective injection time Bank2 (word)
|-
|
TEVFA2_W
|
Effective injection time before trim (word)
|-
|
TEVFAKGE_W
|
Addressing map FKKVS with effective injection
time before fine-tuning
|-
|
TEVFA_W
|
Effective injection time before trim (word)
|-
|
TE W
|
Effective injection time (word)
|-
|
TI2_W
|
Injection time for cylinder 2 (word)
|-
|
TIMXTH_W
|
Theoretical maximum injection time
|-
|
TIMX_W
|
Maximum injection time
|-
|
TI B1
|
Injection time for injectors in Bank1
|-
|
TI_B2
|
Injection time for injectors in Bank2
|-
|
TI_TVU_W
|
Battery voltage-dependent
injection time correction CPU quantization
|-
|
TI_W
|
Injection time
|-
|
TVSP_W
|
Injection delay time depending on evtmod
|-
|
TVU_W
|
Battery voltage correction
|-
|
UB
|
Battery voltage
|-
|
VSFPSES
|
Adjustment factor for intake manifold pressure
for the injection application
|}

[[Category:ME7]]

MDZW 1.120 (Calculating Torque at the Desired Ignition Angle)

2012-05-22T19:48:08Z

TTQS:

MDZW 1.120 Function Description

When calculating the desired ignition angle there are three different cases:

1. Torque influence on the ignition angle active (B_zwvs = 1)

2. Switching off torque influence on the ignition angle (B_zwvs = 0, dmaufr_w> 0)

3. Torque influences inactive (B_nozwe = 1)

1. Active Torque Intervention

The enable condition (B_zwvs) condition is set and the switch-off condition for the ignition angle intervention (B_nozwe) is false. The desired ignition angle is calculated from the torque requirement for the ignition path mizsol_w. The perturbation ramp (dmaufr_w) is zero. The requested torque mizsol_w is converted into the desired efficiency etazws. This is done by dividing by the optimum torque, which is calculated by multiplying miopt_w with the efficiency etazaist. The desired efficiency (etazws) is converted via the inverse ignition angle efficiency characteristic DZWETA into a delta-ignition angle (dzws). The difference between the optimum ignition angle zwopt and dzws gives the desired ignition angle zwsol.

2. Switching off the Torque Influence

When switching off the torque intervention (B_zwvz = 1®0, see %MDKOG), the desired torque mizsol_w can jump to a higher value. This positive torque perturbation must be prevented for driveability reasons. This is done by eliminating the requirement B_zwvz. A perturbation ramp dmaufr_w is reset, which initialises the amplitude of the jump and runs down to zero with a speed-dependent rate. This ramp is subtracted from the input mizsol_w and ensures a smooth transition into a state without any intervention within the timeframe. In this state B_zwvs = false, the switch-off condition for the ignition angle intervention B_nozwe is set but only after the ramp.

A special case is the anti-judder feature intervention, in which B_zwvs, but not B_zwvz is set. When the anti-judder torque requirement is eliminated from input mizsol_w, there is no jump, so that the switch-off ramp in this case is not necessary.

3. Torque Influences Inactive

In this state, no requirement is active (B_zwvs = 0) and the ramp dmaufr_w is screened. The switch-off condition for the ignition angle intervention B_nozwe is set. In this case, the desired ignition angle zwsol for the ignition is not taken into account (c.f. %ZUE) so the calculation can be omitted.

MDZW 1.120 Application Notes

The values are in DMAUFN are preset to give a slope of approximately 5%/sec for all engine speeds.

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
DMAUFN
|
Delta torque control after engine torque intervention
|-
|
DZWETA
|
Inverse delta ignition angle efficiency
|-
|
Variable
|
Description
|-
|
B_NOZWE
|
Condition flag: no ignition angle intervention on the engine torque
structure
|-
|
B_ZWVS
|
Condition flag for fast external ignition angle intervention on the
torque interface
|-
|
B_ZWVZ
|
Condition flag for ignition angle intervention on the torque interface
|-
|
DMAUFR_W
|
Delta “up regulation” torque
|-
|
DZWS
|
Delta ignition angle between zwopt and zwsol
|-
|
ETAZAIST
|
Actual cylinder suppression efficiency
|-
|
ETAZWS
|
Desired ignition angle efficiency
|-
|
MIBAS_W
|
Indicated basic torque
|-
|
MIOPT_W
|
Optimum indicated torque
|-
|
MISOL_W
|
Indicated resulting desired torque
|-
|
MIZSOL_W
|
Indicated resulting desired torque for ignition angle intervention
|-
|
MIZWMN_W
|
Indicated engine torque at the latest ignition angle
|-
|
NMOT W
|
Engine speed
|-
|
REDIST
|
Actual reduction stage
|-
|
R SYN
|
Synchronisation grid
|-
|
ZWOPT
|
Optimum ignition angle
|-
|
ZWSOL
|
Desired ignition angle for torque intervention
|}

[[Category:ME7]]

MDZW 1.120 (Calculating Torque at the Desired Ignition Angle)

2012-05-22T19:47:27Z

TTQS:

MDZW 1.120 Function Description

When calculating the desired ignition angle there are three different cases:

1. Torque influence on the ignition angle active (B_zwvs = 1)

2. Switching off torque influence on the ignition angle (B_zwvs = 0, dmaufr_w> 0)

3. Torque influences inactive (B_nozwe = 1)

1. Active Torque Intervention

The enable condition (B_zwvs) condition is set and the switch-off condition for the ignition angle intervention (B_nozwe) is false. The desired ignition angle is calculated from the torque requirement for the ignition path mizsol_w. The perturbation ramp (dmaufr_w) is zero. The requested torque mizsol_w is converted into the desired efficiency etazws. This is done by dividing by the optimum torque, which is calculated by multiplying miopt_w with the efficiency etazaist. The desired efficiency (etazws) is converted via the inverse ignition angle efficiency characteristic DZWETA into a delta-ignition angle (dzws). The difference between the optimum ignition angle zwopt and dzws gives the desired ignition angle zwsol.

2. Switching off the Torque Influence

When switching off the torque intervention (B_zwvz = 1®0, see %MDKOG), the desired torque mizsol_w can jump to a higher value. This positive torque perturbation must be prevented for driveability reasons. This is done by eliminating the requirement B_zwvz. A perturbation ramp dmaufr_w is reset, which initialises the amplitude of the jump and runs down to zero with a speed-dependent rate. This ramp is subtracted from the input mizsol_w and ensures a smooth transition into a state without any intervention within the timeframe. In this state B_zwvs = false, the switch-off condition for the ignition angle intervention B_nozwe is set but only after the ramp.

A special case is the anti-judder feature intervention, in which B_zwvs, but not B_zwvz is set. When the anti-judder torque requirement is eliminated from input mizsol_w, there is no jump, so that the switch-off ramp in this case is not necessary.

3. Torque Influences Inactive

In this state, no requirement is active (B_zwvs = 0) and the ramp dmaufr_w is screened. The switch-off condition for the ignition angle intervention B_nozwe is set. In this case, the desired ignition angle zwsol for the ignition is not taken into account (c.f. %ZUE) so the calculation can be omitted.

MDZW 1.120 Application Notes

The values are in DMAUFN are preset to give a slope of approximately 5%/sec for all engine speeds.

{| border="1"
|-
|
Parameter
|
Description
|-
|
DMAUFN
|
Delta torque control after engine torque intervention
|-
|
DZWETA
|
Inverse delta ignition angle efficiency
|-
|
Variable
|
Description
|-
|
B_NOZWE
|
Condition flag: no ignition angle intervention on the engine torque
structure
|-
|
B_ZWVS
|
Condition flag for fast external ignition angle intervention on the
torque interface
|-
|
B_ZWVZ
|
Condition flag for ignition angle intervention on the torque interface
|-
|
DMAUFR_W
|
Delta “up regulation” torque
|-
|
DZWS
|
Delta ignition angle between zwopt and zwsol
|-
|
ETAZAIST
|
Actual cylinder suppression efficiency
|-
|
ETAZWS
|
Desired ignition angle efficiency
|-
|
MIBAS_W
|
Indicated basic torque
|-
|
MIOPT_W
|
Optimum indicated torque
|-
|
MISOL_W
|
Indicated resulting desired torque
|-
|
MIZSOL_W
|
Indicated resulting desired torque for ignition angle intervention
|-
|
MIZWMN_W
|
Indicated engine torque at the latest ignition angle
|-
|
NMOT W
|
Engine speed
|-
|
REDIST
|
Actual reduction stage
|-
|
R SYN
|
Synchronisation grid
|-
|
ZWOPT
|
Optimum ignition angle
|-
|
ZWSOL
|
Desired ignition angle for torque intervention
|}

[[Category:ME7]]

MDKOG 14.70 (Torque Coordination for Overall Interventions)

2012-05-22T19:46:10Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

mdkog-main Main function overview

mdkog-bbmdein Sub-function BBMDEIN: active torque intervention conditions

mdkog-bbzwein Sub-function BBZWEIN: active ignition angle intervention conditions

mdkog-mdbeg Sub-function MDBEG: limit of the indicated torque

mdkog-mdbeg-diag Sub-function MDBEG_DIAG: connection of the torque limit to the diagnosis

mdkog-mdabws Sub-function MDABWS: stalling

MDKOG 14.70 Function Description

Coordination of the Requested Engine Torques

Through the torque coordination calculation, the indicated desired engine torque (misol_w) is used to calculate the fade out stage and/or the ignition angle adjustment. The externally-requested indicated torques from the cruise control (miasrs_w) and transmission protection (migs_w) and the internal torque requirements (e.g. driver requested torque, maximum engine speed or maximum load) will be converted into an indicated desired engine torque (misolv_w) via either a minimum or maximum range.

The desired torque for the ignition path is dependent on the enable condition B_zwvz (cf. BBMDEIN):

- When ignition angle interventions are enabled, mizsolv_w is calculated as follows:

The upper limit of the desired torque, misolv_w, is given by the product of optimal internal torque
(including lambda influence) and ignition angle (miopt_w x etazwb), then the torque requirements of the idle control dmllr_w (only proportional and differential components) and the anti-judder feature, dmar_w are added.

- When ignition angle interventions are not required, the basic torque mibas_w is used as the desired torque which depends only on the stipulated ignition and mixture-application efficiencies. The anti-judder feature intervention is also considered in this case.

Sub-function BBMDEIN: Active Torque Intervention Conditions

In addition, via the traction control torque intervention, the condition flag B_msr is set so that overrun fuel cut-off is prohibited (see %MDRED). During cruise control intervention, the condition flag B_asr to cylinder suppression is possible (see %MDRED). The condition flag B_mdein is used to disable the misfire detection (see %DASE) and enable the anti-judder feature or idle speed control (for B_mdein = 0). The condition flags B_zwvz and B_zwvs are responsible for enabling the torque adjustment through ignition.

- B_zwvz is set when the time frame level detects the need for an intervention. This is the case at all operating points which require a torque reserve, i.e. idle, catalyst heating, short journeys and for the dashpot driveability functions, load shock attenuation, filtering for overrun fuel cut-off and short journeys. When the clutch is also immediately released to avoid revving the engine. All external intervention is detected by comparing mifa_w and misol_w.

An ignition angle enable can also be made via the code word CWMDKOG, when the desired the cylinder charge corresponds to the minimum cylinder charge. In addition, if the difference between the actual cylinder charge and the minimum cylinder charge is less than the delta value to be applied, data input to the code word for the ignition angle can be enabled.

- B_zwvs is set when either a timeframe intervention is submitted or a torque influence from the anti-judder feature is required. The desired value is not then switched to misol_w in the function %MDZW (torque influence on ignition), however, the influence is activated.

Sub-function MDABWS: Stalling

Should the engine speed during torque reduction through cruise control or transmission protection fall under NASNOTTM, miext is immediately set equal to MDIMX so that the two operations are prohibited. NASNOTKL is a function of engine temperature, tmot.

Sub-function BBZWEIN: Active Ignition Angle Intervention Conditions

see BBMDEIN

Sub-function MDBEG: limit of the indicated torque

The two torque variables and misolv_w and mizsolv_w are limited to the maximum indicated torque miszul_w (from %MDZUL). This is to ensure that monitoring in level 2 only becomes active when the desired (and possibly limited) torque is not converted correctly into an actual torque. The data input to KFMIZU will be aligned to the level 2 permitted torque. Particularly in the application phase this can prevent an unwanted torque monitoring response. By noting the value of B_mibeg it is possible to detect whether a limitation of the desired torque has been made.

To test the data monitoring, there is a counter cmibeg_w that counts the number of active limitations. The counter cmibeg_w is incremented with each rising edge of B_mibeg. The counter is not active when the driver releases the throttle pedal or the maximum value is reached (MAXWORD = 65,535). The value is cached and only an error path enable or a power failure resets it.

Sub-function MDBEG_DIAG: Connection of the Torque Limit to the Diagnosis

This function MDBEG_DIAG is part of the EGAS monitoring concept (level 1). The desired torque MDBEG is limited to a maximum permissible torque, miszul_w. If this limit is active, the bit B_mibeg is set. In certain operating conditions (e.g. very cold engine and idle), this level-1-limit will be active, but only for a short time. If the limit B_mibeg is active for a longer time (e.g. 10 minutes), there might be a fault in the system and a diagnostic entry is made.

MDKOG 14.70 Application Notes

Typical values:

MDIMX = 99.6%;

NASNOTKL

{| border="1"
|-
|
Engine temperature/°C
|
-30
|
0
|
30
|
60
|-
|
NASNOT
|
1500
|
900
|
600
|
600
|}

The engine speed threshold NASNOT must not be larger than 2550 rpm.

DELRL < 2%

THDMB = 1 sec

CWMDKOG = 2

{| border="1"
|-
|
Bit
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|-
|
CWMDKOG
|
*
|
*
|
*
|
*
|
Note 4
|
Note 3
|
Note 2
|
Note 1
|}
Note 1. Ignition angle enable with rlsol = rlmin

Note 2. Ignition angle enable with B_mibeg

Note 3. Ignition angle enable with rl - rlmin_w £ DELRL

Note 4. !B_mibegl kill data input

{| border="1"
|-
|
Parameter
|
Description
|-
|
CDCMDB
|
Codeword CARB: torque limitation desired torque
|-
|
CDKMDB
|
Codeword Client: torque limitation desired torque
|-
|
CDTMDB
|
Codeword Tester: torque limitation desired torque
|-
|
CLAMDB
|
Codeword Error Class: torque limitation desired torque
|-
|
CWMDKOG
|
Codeword: MDKOG: ignition angle retardation via vacuum limitation
|-
|
CWTEZW
|
Codeword: ignition angle intervention via fuel tank breather valve check
|-
|
CWZWVMX
|
Codeword: ignition angle intervention via speed limitation
|-
|
DELRL
|
Delta relative cylinder charge for enabling ignition angle intervention
|-
|
FFTMDB
|
Freeze frame table: torque limitation desired torque
|-
|
MDIMX
|
Maximum indicated engine torque
|-
|
NASNOTKL
|
Characteristic curve for stall protection speed threshold
|-
|
THDMB
|
Healing debounce time of the entry error in long-term torque limitation
|-
|
TMVER
|
Debounce time detection of a long-term torque limitation
|-
|
TSFMDB
|
Error summation period: torque limitation desired torque
|-
|
TVLDSZW
|
Duty cycle ignition angle enable via recharge effect
|-
|
TVMIBEG
|
Debounce time for ignition angle enable via torque limitation
|-
|
BLOKNR
|
DAMOS source for block number
|-
|
B_ASR
|
Condition flag: cruise control active
|-
|
B_BEMDB
|
Condition flag: tape end functions requirement torque limitation
|-
|
B_BKMDB
|
Condition flag: torque monitoring (long-term limitation) active
|-
|
B_CLMDB
|
Condition flag: cancellation of long-term torque limitation
|-
|
B_DASH
|
Condition flag: dashpot-adjustment limit active
|-
|
B_FIL
|
Condition flag: PT1-filter for overrun fuel cut-off/reinstatement active
|-
|
B_FTMDB
|
Condition flag: error input from tester for torque limitation
|-
|
B_KH
|
Condition flag: catalyst heating
|-
|
B_KUPPLV
|
Condition flag: delayed clutch actuation
|-
|
B_KW
|
Condition flag: catalyst keep warm
|-
|
B_LDSUA
|
Condition flag: charge air recirculation valve active (open)
|-
|
B_LL
|
Condition flag: idle
|-
|
B_LLREIN
|
Condition flag: idle control active
|-
|
B_LSD
|
Condition flag: positive load change damping active
|-
|
B_MDEIN
|
Condition flag: torque intervention active
|-
|
B_MDMIN
|
Condition flag: minimum achievable indicated torque achieved
|-
|
B_MGBGET
|
Condition flag: torque gradient limitation active
|-
|
B_MIBEG
|
Condition flag: torque limitation active
|-
|
B_MIBEGL
|
Condition flag: torque limitation cylinder charge path active
|-
|
B_MNMDB
|
Fehlertyp min.: torque monitoring long-term limitation
|-
|
B MSR
|
Condition flag for torque slip control
|-
|
B_MXMDB
|
Error type: maximum permissible desired torque is exceeded permanently
|-
|
B_NPMDB
|
Implausible error: torque monitoring long-term limitation
|-
|
B_PWF
|
Condition flag: power fail
|-
|
B_SA
|
Condition flag: overrun fuel cut-off
|-
|
B_SIMDB
|
Error type: torque monitoring long-term limitation
|-
|
B_STEND
|
Condition flag: end of start conditions achieved
|-
|
B_ZWGET
|
Ignition angle intervention through transmission intervention
|-
|
B_ZWNGET
|
Ignition angle intervention not through transmission intervention
|-
|
B_ZWVS
|
Condition flag: for quick exit of ignition angle intervention in the
torque interface
|-
|
B_ZWVZ
|
Condition flag: for ignition angle intervention in the torque interface
|-
|
B_ZWVZVB
|
Condition flag: for ignition angle intervention in the torque interface for
limitation
|-
|
CMIBEG_W
|
Counter for active limitations of the internal torques
|-
|
DFP_MDB
|
ECU internal error path number: torque monitoring long-term limitation
|-
|
DMAR_W
|
Delta engine speed (anti judder)
|-
|
DMLLR_W
|
Demanded torque change for idle control (P & D components)
|-
|
DMRKH
|
Torque reserve for catalyst heating
|-
|
DMRKT_W
|
Torque reserve for short journeys
|-
|
DMRLLR_W
|
Torque reserve for idle control
|-
|
DMZMS_W
|
Difference between the indicated desired torque and the allowed desired
torque
|-
|
ETAZWB
|
Ignition angle efficiency of the basic ignition angles
|-
|
E_MDB
|
Error flag: torque monitoring long-term limitation
|-
|
MIASRL_W
|
Indicated desired engine torque (cruise control), slow intervention
|-
|
MIASRS_W
|
Indicated desired engine torque (cruise control), fast intervention
|-
|
MIBAS W
|
Indicated basic torque
|-
|
MIBEG_W
|
Torque limit
|-
|
MIBGR_W
|
Indicated desired torque for input-dependent clutch torque limitation
|-
|
MIEXTV_W
|
For external demanded torque for stall protection
|-
|
MIEXT_W
|
For external (cruise control, transmission protection, etc.) demanded
indicated engine torque
|-
|
MIFAB_W
|
Limited indicated driver’s desired torque
|-
|
MIFA_W
|
Indicated driver’s desired torque
|-
|
MIGS_W
|
Indicated desired engine torque for transmission protection, fast
intervention
|-
|
MILRES_W
|
Torque requirement for air path with all reserves
|-
|
MIMAX_W
|
Maximum achievable indicated torque
|-
|
MIMSR W
|
Indicated desired engine torque, traction control
|-
|
MINMX_W
|
Torque requirement of the speed limiter
|-
|
MIOPT W
|
Optimum indicated torque
|-
|
MISOLP_W
|
Indicated desired torque for torque limitation, local variable
|-
|
MISOLV_W
|
Indicated resulting torque for torque limitation
|-
|
MISOL_W
|
Indicated resulting desired torque
|-
|
MISZUL_W
|
Maximum possible indicated torque
|-
|
MITEBG_W
|
Torque target for minimum filling fuel tank breather
|-
|
MIVMX_W
|
Indicated desired torque for speed control
|-
|
MIZSOLV_W
|
Indicated resulting desired torque for ignition angle intervention for torque
limitation
|-
|
MIZSOL_W
|
Indicated resulting desired torque for ignition angle intervention
|-
|
NASNOTTM
|
Speed threshold for stall protection as a function of engine speed
|-
|
NMOT
|
Engine speed
|-
|
RLMIN_W
|
Minimum possible relative cylinder charge
|-
|
RLSOL_W
|
Desired cylinder charge
|-
|
RL_W
|
Relative cylinder charge (word)
|-
|
SFPMDB
|
Error path status: torque monitoring, long-term limitation
|-
|
TMOT
|
Engine temperature
|-
|
WPED_W
|
Normalised throttle pedal angle
|-
|
Z_MDB
|
Cycle flag: torque limitation, long-term limitation
|}

[[Category:ME7]]

MDKOG 14.70 (Torque Coordination for Overall Interventions)

2012-05-22T19:42:47Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

mdkog-main Main function overview

mdkog-bbmdein Sub-function BBMDEIN: active torque intervention conditions

mdkog-bbzwein Sub-function BBZWEIN: active ignition angle intervention conditions

mdkog-mdbeg Sub-function MDBEG: limit of the indicated torque

mdkog-mdbeg-diag Sub-function MDBEG_DIAG: connection of the torque limit to the diagnosis

mdkog-mdabws Sub-function MDABWS: stalling

MDKOG 14.70 Function Description

Coordination of the Requested Engine Torques

Through the torque coordination calculation, the indicated desired engine torque (misol_w) is used to calculate the fade out stage and/or the ignition angle adjustment. The externally-requested indicated torques from the cruise control (miasrs_w) and transmission protection (migs_w) and the internal torque requirements (e.g. driver requested torque, maximum engine speed or maximum load) will be converted into an indicated desired engine torque (misolv_w) via either a minimum or maximum range.

The desired torque for the ignition path is dependent on the enable condition B_zwvz (cf. BBMDEIN):

- When ignition angle interventions are enabled, mizsolv_w is calculated as follows:

The upper limit of the desired torque, misolv_w, is given by the product of optimal internal torque
(including lambda influence) and ignition angle (miopt_w ´ etazwb), then the torque requirements of the idle control dmllr_w (only proportional and differential components) and the anti-judder feature, dmar_w are added.

- When ignition angle interventions are not required, the basic torque mibas_w is used as the desired torque which depends only on the stipulated ignition and mixture-application efficiencies. The anti-judder feature intervention is also considered in this case.

Sub-function BBMDEIN: Active Torque Intervention Conditions

In
addition, via the traction control torque intervention, the condition flag
B_msr is set so that overrun fuel cut-off is prohibited (see %MDRED). During
cruise control intervention, the condition flag B_asr to cylinder suppression
is possible (see %MDRED). The condition flag B_mdein is used to disable the
misfire detection (see %DASE) and enable the anti-judder feature or idle speed
control (for B_mdein = 0). The condition flags B_zwvz and B_zwvs are
responsible for enabling the torque adjustment through ignition.

-
B_zwvz is set when the time frame level detects the need for an intervention. This
is the case at all operating points which require a torque reserve, i.e. idle,
catalyst heating, short journeys and for the dashpot driveability functions,
load shock attenuation, filtering for overrun fuel cut-off and short journeys.
When the clutch is also immediately released to avoid revving the engine. All
external intervention is detected by comparing mifa_w and misol_w.

An
ignition angle enable can also be made via the code word CWMDKOG, when the
desired the cylinder charge corresponds to the minimum cylinder charge. In
addition, if the difference between the actual cylinder charge and the minimum
cylinder charge is less than the delta value to be applied, data input to the
code word for the ignition angle can be enabled.

-
B_zwvs is set when either a timeframe intervention is submitted or a torque
influence from the anti-judder feature is required. The desired value is not
then switched to misol_w in the function %MDZW (torque influence on ignition),
however, the influence is activated.

Sub-function MDABWS: Stalling

Should
the engine speed during torque reduction through cruise control or transmission
protection fall under NASNOTTM, miext is immediately set equal to MDIMX so that
the two operations are prohibited. NASNOTKL is a function of engine
temperature, tmot.

Sub-function
BBZWEIN: Active Ignition Angle Intervention Conditions

see
BBMDEIN

Sub-function
MDBEG: limit of the indicated torque

The
two torque variables and misolv_w mizsolv_w are limited to the maximum indicated
torque miszul_w (from %MDZUL). This is to ensure that monitoring in level 2
only becomes active when the desired (and possibly limited) torque is not
converted correctly into an actual torque. The data input to KFMIZU will be aligned
to the level 2 permitted torque. Particularly in the application phase this can
prevent an unwanted torque monitoring response. By noting the value of B_mibeg
it is possible to detect whether a limitation of the desired torque has been
made.

To
test the data monitoring, there is a counter cmibeg_w that counts the number of
active limitations. The counter cmibeg_w is incremented with each rising edge
of B_mibeg. The counter is not active when the driver releases the throttle
pedal or the maximum value is reached (MAXWORD = 65,535). The value is cached
and only an error path enable or a power failure resets it.

Sub-function MDBEG_DIAG: Connection of the Torque Limit to the Diagnosis

This function MDBEG_DIAG is part of the EGAS monitoring concept (level 1). The desired torque MDBEG is limited to a maximum permissible torque, miszul_w. If this limit is active, the bit B_mibeg is set. In certain operating conditions (e.g. very cold engine and idle), this level-1-limit will be active, but only for a short time. If the limit B_mibeg is active for a longer time (e.g. 10 minutes),
there might be a fault in the system and a diagnostic entry is made.

MDKOG
14.70 Application Notes

Typical values:

MDIMX = 99.6%;

NASNOTKL

{| border="1"
|-
|
Engine temperature/°C
|
-30
|
0
|
30
|
60
|-
|
NASNOT
|
1500
|
900
|
600
|
600
|}
The engine speed threshold NASNOT must not be larger than 2550 rpm.

DELRL < 2%

THDMB = 1 sec

CWMDKOG = 2

{| border="1"
|-
|
Bit
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|-
|
CWMDKOG
|
*
|
*
|
*
|
*
|
Note 4
|
Note 3
|
Note 2
|
Note 1
|}
Note 1. Ignition angle enable with rlsol = rlmin

Note 2. Ignition angle enable with B_mibeg

Note 3. Ignition angle enable with rl - rlmin_w £ DELRL

Note 4. !B_mibegl kill data input

{| border="1"
|-
|
Parameter
|
Description
|-
|
CDCMDB
|
Codeword CARB: torque limitation desired torque
|-
|
CDKMDB
|
Codeword Client: torque limitation desired torque
|-
|
CDTMDB
|
Codeword Tester: torque limitation desired torque
|-
|
CLAMDB
|
Codeword Error Class: torque limitation desired torque
|-
|
CWMDKOG
|
Codeword: MDKOG: ignition angle retardation via vacuum limitation
|-
|
CWTEZW
|
Codeword: ignition angle intervention via fuel tank breather valve check
|-
|
CWZWVMX
|
Codeword: ignition angle intervention via speed limitation
|-
|
DELRL
|
Delta relative cylinder charge for enabling ignition angle intervention
|-
|
FFTMDB
|
Freeze frame table: torque limitation desired torque
|-
|
MDIMX
|
Maximum indicated engine torque
|-
|
NASNOTKL
|
Characteristic curve for stall protection speed threshold
|-
|
THDMB
|
Healing debounce time of the entry error in long-term torque limitation
|-
|
TMVER
|
Debounce time detection of a long-term torque limitation
|-
|
TSFMDB
|
Error summation period: torque limitation desired torque
|-
|
TVLDSZW
|
Duty cycle ignition angle enable via recharge effect
|-
|
TVMIBEG
|
Debounce time for ignition angle enable via torque limitation
|-
|
BLOKNR
|
DAMOS source for block number
|-
|
B_ASR
|
Condition flag: cruise control active
|-
|
B_BEMDB
|
Condition flag: tape end functions requirement torque limitation
|-
|
B_BKMDB
|
Condition flag: torque monitoring (long-term limitation) active
|-
|
B_CLMDB
|
Condition flag: cancellation of long-term torque limitation
|-
|
B_DASH
|
Condition flag: dashpot-adjustment limit active
|-
|
B_FIL
|
Condition flag: PT1-filter for overrun fuel cut-off/reinstatement active
|-
|
B_FTMDB
|
Condition flag: error input from tester for torque limitation
|-
|
B_KH
|
Condition flag: catalyst heating
|-
|
B_KUPPLV
|
Condition flag: delayed clutch actuation
|-
|
B_KW
|
Condition flag: catalyst keep warm
|-
|
B_LDSUA
|
Condition flag: charge air recirculation valve active (open)
|-
|
B_LL
|
Condition flag: idle
|-
|
B_LLREIN
|
Condition flag: idle control active
|-
|
B_LSD
|
Condition flag: positive load change damping active
|-
|
B_MDEIN
|
Condition flag: torque intervention active
|-
|
B_MDMIN
|
Condition flag: minimum achievable indicated torque achieved
|-
|
B_MGBGET
|
Condition flag: torque gradient limitation active
|-
|
B_MIBEG
|
Condition flag: torque limitation active
|-
|
B_MIBEGL
|
Condition flag: torque limitation cylinder charge path active
|-
|
B_MNMDB
|
Fehlertyp min.: torque monitoring long-term limitation
|-
|
B MSR
|
Condition flag for torque slip control
|-
|
B_MXMDB
|
Error type: maximum permissible desired torque is exceeded permanently
|-
|
B_NPMDB
|
Implausible error: torque monitoring long-term limitation
|-
|
B_PWF
|
Condition flag: power fail
|-
|
B_SA
|
Condition flag: overrun fuel cut-off
|-
|
B_SIMDB
|
Error type: torque monitoring long-term limitation
|-
|
B_STEND
|
Condition flag: end of start conditions achieved
|-
|
B_ZWGET
|
Ignition angle intervention through transmission intervention
|-
|
B_ZWNGET
|
Ignition angle intervention not through transmission intervention
|-
|
B_ZWVS
|
Condition flag: for quick exit of ignition angle intervention in the
torque interface
|-
|
B_ZWVZ
|
Condition flag: for ignition angle intervention in the torque interface
|-
|
B_ZWVZVB
|
Condition flag: for ignition angle intervention in the torque interface for
limitation
|-
|
CMIBEG_W
|
Counter for active limitations of the internal torques
|-
|
DFP_MDB
|
ECU internal error path number: torque monitoring long-term limitation
|-
|
DMAR_W
|
Delta engine speed (anti judder)
|-
|
DMLLR_W
|
Demanded torque change for idle control (P & D components)
|-
|
DMRKH
|
Torque reserve for catalyst heating
|-
|
DMRKT_W
|
Torque reserve for short journeys
|-
|
DMRLLR_W
|
Torque reserve for idle control
|-
|
DMZMS_W
|
Difference between the indicated desired torque and the allowed desired
torque
|-
|
ETAZWB
|
Ignition angle efficiency of the basic ignition angles
|-
|
E_MDB
|
Error flag: torque monitoring long-term limitation
|-
|
MIASRL_W
|
Indicated desired engine torque (cruise control), slow intervention
|-
|
MIASRS_W
|
Indicated desired engine torque (cruise control), fast intervention
|-
|
MIBAS W
|
Indicated basic torque
|-
|
MIBEG_W
|
Torque limit
|-
|
MIBGR_W
|
Indicated desired torque for input-dependent clutch torque limitation
|-
|
MIEXTV_W
|
For external demanded torque for stall protection
|-
|
MIEXT_W
|
For external (cruise control, transmission protection, etc.) demanded
indicated engine torque
|-
|
MIFAB_W
|
Limited indicated driver’s desired torque
|-
|
MIFA_W
|
Indicated driver’s desired torque
|-
|
MIGS_W
|
Indicated desired engine torque for transmission protection, fast
intervention
|-
|
MILRES_W
|
Torque requirement for air path with all reserves
|-
|
MIMAX_W
|
Maximum achievable indicated torque
|-
|
MIMSR W
|
Indicated desired engine torque, traction control
|-
|
MINMX_W
|
Torque requirement of the speed limiter
|-
|
MIOPT W
|
Optimum indicated torque
|-
|
MISOLP_W
|
Indicated desired torque for torque limitation, local variable
|-
|
MISOLV_W
|
Indicated resulting torque for torque limitation
|-
|
MISOL_W
|
Indicated resulting desired torque
|-
|
MISZUL_W
|
Maximum possible indicated torque
|-
|
MITEBG_W
|
Torque target for minimum filling fuel tank breather
|-
|
MIVMX_W
|
Indicated desired torque for speed control
|-
|
MIZSOLV_W
|
Indicated resulting desired torque for ignition angle intervention for torque
limitation
|-
|
MIZSOL_W
|
Indicated resulting desired torque for ignition angle intervention
|-
|
NASNOTTM
|
Speed threshold for stall protection as a function of engine speed
|-
|
NMOT
|
Engine speed
|-
|
RLMIN_W
|
Minimum possible relative cylinder charge
|-
|
RLSOL_W
|
Desired cylinder charge
|-
|
RL_W
|
Relative cylinder charge (word)
|-
|
SFPMDB
|
Error path status: torque monitoring, long-term limitation
|-
|
TMOT
|
Engine temperature
|-
|
WPED_W
|
Normalised throttle pedal angle
|-
|
Z_MDB
|
Cycle flag: torque limitation, long-term limitation
|}

[[Category:ME7]]

MDFUE 8.50 (Setpoint for Air Mass from Load Torque)

2012-05-22T19:39:32Z

TTQS:

MDFUE 8.50 Function Description

See the ''funktionsrahmen'' for diagram mdfue.

The torque variable milsol_w, which is set on the charge path at the basic ignition angle and basic efficiency is converted into torque variable misopl1_w, which corresponds
to the optimum torque at lambda = 1. The map KFMIRL provides the cylinder charge which corresponds to this operating point.

This cylinder charge is limited to a minimum permitted value rlmin_w at which the condition B_mdmin is set for idle control which then stops the integrator. In the case of a turbocharger, there is a limit on the maximum permitted cylinder charge rlmax_w. This variable does not exist for naturally-aspirated engines!

The result is the desired cylinder charge rlsol_w.

Supplement to the application interface:

CWRLAPPL = 0: Function as before: rlsol generated from the limited KFMIRL.

CWRLAPPL bit 1 =1: rlsol_w = RLSOLAP

CWRLAPPL bit 2 =1: rlsol_w = wped_w x FWPEDRLS

Application Notes

The map KFMIRL is the inverse of map KFMIOP in the function MDBAS ''(it is understood that this is not a direct arithmetic inverse, but is intended to mean that the variables on the x, y & z axes are complementary)''. See MDBAS for application notes.

{| border="1"
|-
|
'''Parameter'''
|
'''Description'''
|-
|
CWRLAPPL
|
Code word:
default rlsol_w during applications phase
|-
|
FRLMNHO
|
Correction
factor for rlmin via altitude
|-
|
FWPEDRLS
|
Factor for
direct entry to the default rlsol from wped (application)
|-
|
KFMIRL
|
Map for
calculating target cylinder charge
|-
|
KFRLMN
|
Minimum
cylinder charge in firing mode
|-
|
KFRLMNSA
|
Minimum rl
during overrun fuel cut-off
|-
|
RLSOLAP
|
Target
cylinder charge for application calibration purposes
|-
|
ZKDRLSOL
|
Time constant
for drlsol-integrator
|-
|
'''Variable'''
|
'''Description'''
|-
|
B_MDMIN
|
Condition
flag: minimum achievable indicated torque reached
|-
|
B_SA
|
Condition
flag: overrun fuel cut-off active
|-
|
C_INI
|
ECU initialisation condition
|-
|
DRLSOLF_W
|
Filtered
change in target cylinder charge
|-
|
DRLSOL_W
|
Change in
target cylinder charge
|-
|
ETALAB
|
Lambda
efficiency without intervention with respect to the optimum torque at lambda =
1
|-
|
ETAZWBM
|
Average
ignition angle efficiency at the basic ignition angles
|-
|
FHO
|
Altitude correction factor
|-
|
MILSOL_W
|
Driver’s
requested torque for cylinder charge path
|-
|
MISOPL1_W
|
Target air
torque, back-calculated from lambda = 1 and zwopt
|-
|
NMOT
|
Engine speed
|-
|
NMOT_W
|
Engine speed (word)
|-
|
RLMAX_W
|
Maximum
achievable cylinder charge from the turbo
|-
|
RLMIN_W
|
Minimum permitted rl
|-
|
RLSOL_W
|
Target cylinder charger
|-
|
RLTEDTE_W
|
Relative
cylinder charge from the fuel tank breather valve determined from DTEV
|-
|
R_T10
|
Time graticule of 10 ms
|-
|
SY_TURBO
|
System constant: turbocharger
|-
|
TMOT
|
Engine temperature
|-
|
WPED W
|
Normalised throttle pedal angle
|}

MDFAW 12.260 (Driver Requested Torque)

2012-05-22T19:38:47Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

mdfaw-mdfaw MDFAW overview

mdfaw-pedchar Sub-function PEDCHAR: throttle pedal
characteristic

mdfaw-mrfmx Sub-function
MRFMX: maximum relative driver requested torque

mdfaw-dmlwhs Sub-function DMLWHS: indicated driver requested torque for
change limitation in the homogenous charge mode

mdfaw-dmfabeg Sub-function
DMFABEG: change limitation for the driver's requests

mdfaw-sawe Sub-function SAWE: change
limitation during overrun fuel cut-off & reinstatement

mdfaw-filsawe Sub-function FILSAWE: filter for change limitation during
overrun fuel cut-off & reinstatement

mdfaw-dashpot Sub-function DASHPOT: change limitation
during negative load change (dashpot)

mdfaw-fildash Sub-function
FILDASH: filter for dashpot

mdfaw-zdash Sub-function
ZDASH: filter time constant for dashpot

mdfaw-ebdash Sub-function EBDASH: switching
conditions for dashpot

mdfaw-mismeus Sub-function MISMEUS: change limitation during fast torque
intervention for operating mode changeover

mdfaw-lsd Sub-function LSD: Change limitation during positive load
changes (load change damping)

mdfaw-fillsd Sub-function FILLSD: filter for load
change damping

mdfaw-zlsd Sub-function ZLSD: filter time
constant for load change damping

mdfaw-pt2fil Sub-function PT2FIL: PT2-filter

mdfaw-eblsd Sub-function EBLSD: switching
conditions for load change damping

mdfaw-mdbg Sub-function
MDBG: torque change limitation

mdfaw-mifal Sub-function MIFAL: driver
requested torque for the cylinder charge path

mdfaw-fwmifal Sub-function FWMIFAL: excessive increase factor for driver
requested torque for the cylinder charge path during positive load changes

mdfaw-bits Sub-function BITS: Saving of
the significant bits in the flag byte mdfaw_bits

MDFAW 12.260 Function Description

The duty of this function is to calculate the driver’s requested torque as a function of accelerator pedal position (wped_w) and cruise control output (mrfgr_w). Separate values are provided for cylinder charge and ignition influences (mifal_w, mifa_w).

The throttle pedal characteristic is defined by maps, where through pedal position and engine speed, a factor (relative torque) is stored to help scale indicated torque between the minimum and maximum. The relative driver’s requested torque can have values greater than 100% (pedal crossover). For reverse gear, a separate map is available that can be used on vehicles with automatic transmission. To enhance driving
comfort, a change in the driver’s requested torque limit can take place under certain conditions (load changes, overrun fuel cut-off and reinstatement, transition from part load to idle and vice versa. See sub-function DMFABEG).

The idle condition (B_ll) is set when the relative driver’s requested torque drops below the threshold MRFALLU and is reset when the threshold MRFALLO is exceeded. The cruise control condition (B_fgr) is set when the cruise controller output is greater than the output of the pedal characteristic. The integral component of the idle control (dmllri_w) is included in the driver’s request.

The change limitation for the driver’s requested torque (sub-function DMFABEG) is used to improve ride comfort and overrun fuel cut-off and smooth resumption of positive and negative load changes. With that, a DT1-element filtered torque loss (dmverl_w) is added behind the change limitation around jumps in the clutch torque to damp the connection or disconnection of load.

Overrun fuel cut-off/reinstatement

Via a PT1-filter, down-regulation of the target torques starting from the actual torque at zero takes place by overrun fuel cut-off; smooth resumption by up-regulation of the target torques starting from mizwmn_w to mimin_w. The filter time constants for up-regulation and down-regulation can be chosen independently of each other. One more time constant is made available for hard resumption and leaving idle (under light throttle). The initialization of the filters on the overrun fuel cut-off to the actual torque is needed to avoid a jump in torque on enabling of the ignition angle interventions. The filtering is, or is not cancelled:

- During active dashpot,

- For active load shock absorption,

- In the test laboratory

- On a steep negative speed gradient (uncoupling of thrust or throttle),

- When the clutch is actuated (configurable via CWDMFAB)

- mrfa gradient at higher threshold (important during hard resumption and when leaving the idle),

- Upon reaching the basic ignition angles.

Dashpot

The change limitation for negative load changes (dashpot) is implemented using a
PT1-filter with gear and speed-dependent time constant. The PT1-filter runs at
a negative gradient of the unfiltered driver’s requested torque. The dashpot is
triggered when the difference between the filtered and unfiltered output value
exceeds a clutch-dependent and torque-dependent threshold, and cruise control
is not engaged. The trigger also always occurs at the transition to idle. The
PT1-filter triggered by the dashpot is initialized with the actual torque in
order to avoid a jump in torque during ignition angle interventions. The
dashpot is terminated when the difference between filtered and unfiltered value
falls below a gear-dependent threshold. As long as the dashpot is active, there
will not be any overrun fuel cut-off (see function %BBSAWE).

The driver’s desired torque for the cylinder charge influence mifal_w is calculated by a dashpot with its own PT1-filter that is initialized when the unfiltered driver’s desired torque drops below the trigger level. In this way, a steep initial drop is reached, which leads to the rapid closing of the throttle. Then a soft change is made to the target value. The dashpot can be active only when:

- The general dashpot-enable is done viaCWDMFAB Bit1,

- There is no commitment to overrun fuel cut-off,

- Load shock absorption is not active,

- There is the speed signal,

- The minimum speed is exceeded for dashpot,

- The clutch is not pressed,

- Start end is reached,

- The response is greater than zero,

- ASR intervention is not active,

- The cylinder charge is greater than the minimum charge.

Load Shock Absorption

The change limitation during positive load changes is realized with the help of a PT2 filter whose damping and time constant are gear- and speed-dependent. The PT2 filter runs with a positive gradient of the unfiltered driver’s requested torque. Load shock damping is triggered when the difference between unfiltered and filtered output value exceeds a gear- and clutch torque-dependent threshold. The PT2 filter is triggered when the load shock absorption is initialized with the actual torque or a speed-and gear-dependent initial value, to avoid a jump in torque upon enabling of the ignition angle interventions and to influence the response behavior. The load shock damping is terminated when the difference between the filtered and unfiltered value drops below a gear-dependent threshold.

The driver’s desired torque for the cylinder charge influence mifal_w with active load shock damping is calculated from a map which depends on the desired torque for the ignition influence (mifa_w) and on the gear, which is a limitation on the unfiltered target. Thus, the cylinder charge can be controlled so that there is no significant ignition angle intervention in order to set the desired torque curve.

The load shock damping can be active only when

- Load shock damping is generally enabled via CWDMFAB Bit 0,

- There is no idle

- For vehicles with CVT transmission, the torque gradient limitation is not active and the torque converter clutch is not open,

- The speed signal is present

- The minimum speed for load shock absorption is exceeded,

- The clutch is not actuated

- Cruise control is not engaged,

- Speed and speed limits are not active,

- End of start conditions is reached,

- The gear is greater than zero,

- No traction control intervention is active.

The PT2 filter is implemented with two integrators and feedback. There is also the possibility that the filter is initialized with a given value (iwflsd_w) if the condition B_iflsd is set.

MDFAW 12.260 Application Notes

CWDMFAB

Bit 0 0: Load shock damping deactivated

1: Load shock damping enabled

Bit 1 0: Dashpot deactivated

1: Dashpot enabled

Bit 2 0: Load shock damping with B_gwhs inactive

1: Load shock damping with B_kupplv inactive

Bit 3 0: Dashpot with B_gwhs inactive

1: Dashpot with B_kupplv inactive

Bit 4 0: Overrun fuel cut-off/reinstatement filter with B_kuppl active

1: Overrun fuel cut-off/reinstatement filter with B_kuppl inactive

Bit 5 0: Dashpot and load shock damping even with traction control intervention enabled

1: Dashpot and load shock damping with traction control intervention inactive

Bit 6 0: Dashpot triggering independently of B_ll

1: Dashpot triggering on positive edge of B_ll

Bit 7 0: Load shock damping and dashpot triggering via threshold inactive, until cruise control intervention

1: Load shock damping and dashpot triggering via threshold also possible during cruise control intervention

CWMDFAW

Bit 0 0: Initialization of migef_w when reinstating with miistoar_w

1: Initialization of migef_w when reinstating with 0 (for sequential reinstatement)

Bit 1 0: Initialization of mifal_w with dashpot with mivbeb_w

1: Initialization of mifal_w with dashpot with mibdp_w - dmdpo_w

Bit 2 0: Load shock damping with B_kupplv or B_gwhs inactive

1: Enable the load and shock damping independent of B_kupplv and B_gwhs

KFPEDL and KFPEDR must contain smaller values than KFPED at the same pedal value and the same speed so that the torque monitoring only depends on KFPED.

{| border="1"
|-
|
Parameter
|
Description
|-
|
CWDMFAB
|
Codeword ECU switch for change limitation
|-
|
CWMDFAW
|
Codeword for %MDFAW
|-
|
DMDPOSCH
|
Delta torque dashpot triggering in the shift operation
|-
|
DMDPUG
|
Delta torque dashpot end
|-
|
DMIFLSD
|
Delta torque for initialising filter load shock damping
|-
|
DMISMEUS
|
Delta indicated torque for change limitation by B_mismeus
|-
|
DMLSDUG
|
Delta torque end load shock damping
|-
|
DMRFAWEN
|
Threshold mrfa-gradient for deactivating PT1-filter during reinstatement
|-
|
DRLMINDP
|
Offset on rlmin for switching off dashpot
|-
|
FGMIFAL
|
Weighting factor for elevation via KFWMIFAL
|-
|
FGZLSD
|
Weighting for reduction via KFZLSD
|-
|
FKFPEDV
|
Factor for interpolation between the two pedal maps
|-
|
FKZDPTM
|
Correction factor time constant dashpot
|-
|
FLRMIFAL
|
Factor for driver requested torque cylinder charge path in low range
|-
|
FLRZDASH
|
Factor for dashpot time constant im low range
|-
|
FLRZLSD
|
Factor for load shock damping-time constant in low range
|-
|
FZDA1SCH
|
Dashpot time constant correction factor in shift operation
|-
|
FZDA2SCH
|
Dashpot time constant correction factor at small clutch torque in shifting
operation
|-
|
KFDLSD
|
Damping PT2-filter load shock damping
|-
|
KFDMDPO
|
Delta torque dashpot triggering
|-
|
KFDMLSDO
|
Delta torque triggering load shock damping
|-
|
KFDMLSDS
|
Delta torque triggering load shock damping after shifting operation
|-
|
KFMIFABG
|
Delta torque for gradient limitation
|-
|
KFMIFALS
|
Indicated driver requested torque for cylinder charge path during load
shock damping
|-
|
KFMILSD
|
Indicated torque initial value for load shock damping
|-
|
KFPED
|
Relative driver requested torque from throttle pedal
|-
|
KFPEDL
|
Relative driver requested torque at low speeds
|-
|
KFPEDR
|
Relative driver requested torque from throttle pedal for reverse gear
|-
|
KFWMIFAL
|
Excessive increase factor for cylinder charge path during load shock
damping
|-
|
KFWZLSD
|
Reduction factor for time constant load shock damping
|-
|
KFZDASH
|
Time constant PT1-filter dashpot
|-
|
KFZDASH2
|
Time constant PT1-filter dashpot at small clutch torque
|-
|
KFZLSD
|
Time constant PT2-filter load shock damping
|-
|
MDIMX
|
Maximum indicated engine torque
|-
|
MIFABGMX
|
Maximum value mifa_w for torque change limitation
|-
|
MIFALMF
|
Indicated driver requested torque for cylinder charge path with active
gradient limitation
|-
|
MKFADPN
|
Clutch torque for changeover of dashpot-filter time
|-
|
MKFADPN1
|
Clutch torque for changeover of dashpot-filter time for air conditioning
|-
|
MKMIFABG
|
Clutch torque for activating the torque change limitation
|-
|
MRFALLO
|
Upper idle threshold of the relative driver requested torques
|-
|
MRFALLU
|
Lower idle threshold of the relative driver requested torques
|-
|
MRFAVLN
|
Full load detection threshold for the relative driver requests
|-
|
NGFSAWE
|
Threshold speed gradient for overrun fuel cut-off/reinstatement filter
|-
|
SNM12MDUW
|
Sample point distribution for engine speed
|-
|
SWP16MDUW
|
Sample point distribution for throttle pedal angle
|-
|
SY_ASG
|
System constant: automated manual transmission present
|-
|
SY_BDE
|
System constant: petrol direct injection
|-
|
SY_CVT
|
System constant: continuously variably transmission present
|-
|
TDMFBSA
|
Time constant PT1-filter during overrun fuel cut-off
|-
|
TDMFBWE
|
Time constant PT1-filter during smooth reinstatement
|-
|
TDMFNSG
|
Filter time constant during target speed increase (continuously variably
transmission)
|-
|
TDMFWEMI
|
Filter time constant during hard reinstatement
|-
|
TDMLSDS
|
Time after clutch actuation with modified load shock damping trigger
|-
|
TVFSAWE
|
Delay time for resetting B_fil
|-
|
VDASH
|
Minimum speed for dashpot
|-
|
VLSD
|
Minimum speed for load shock damping
|-
|
Variable
|
Description
|-
|
B_CVT
|
Condition: continuously variable transmission
|-
|
B_DASH
|
Condition: dashpot change limitation active
|-
|
B_DASHV
|
Condition: dashpot delay
|-
|
B_DP
|
Condition: dashpot value greater than driver request (= 1)
|-
|
B_EDP
|
Condition: dashpot permission
|-
|
B_ELSD
|
Condition: load shock damping permission
|-
|
B_FAAN
|
Condition: functional requirement: general speed increase
|-
|
B_FGR
|
Condition: cruise control (Tempomat) active
|-
|
B_FIL
|
Condition: PT1-filter for overrun fuel cut-off/reinstatement active
|-
|
B_GWHS
|
Condition: gear change by manual switch
|-
|
B_IFLSD
|
Condition: initialising filter load shock damping
|-
|
B_KO
|
Condition: compressor enabled
|-
|
B KUPPL
|
Condition: clutch actuated
|-
|
B_KUPPLV
|
Condition: delayed clutch actuation
|-
|
B_LL
|
Condition: idle
|-
|
B_LLVFGR
|
Condition: idle forbidden by vehicle speed limiter
|-
|
B_LOWRA
|
Condition: Intermediate clutch for low range switch-off
|-
|
B_LS
|
Condition: load shock limitation without driver request (=1)
|-
|
B_LSD
|
Condition: positive load shock damping active
|-
|
B_MGBGAKT
|
Condition: torque gradient limitation active
|-
|
B_MGBGET
|
Condition: torque gradient limitation active
|-
|
B_MIFABG
|
Condition: mifa limitation
|-
|
B_MISMEUS
|
Condition: torque change limitation by B_smeus
|-
|
B MRPEDASG
|
Condition: changeover driver requested torque from AMS
|-
|
B_MRPFA
|
Condition: zeroing of mrped_w because of general speed increase
|-
|
B_NMAX
|
Condition: speed limiter active
|-
|
B_NMOT
|
Condition: engine speed: n > NMIN
|-
|
B_NSGET
|
Condition: torque requirement for CVT: position the pulley cone
|-
|
B_SA
|
Condition: overrun fuel cut-off
|-
|
B_SAB
|
Condition: overrun fuel cut-off standby
|-
|
B_SABFG
|
Condition: overrun fuel cut-off standby or enable
|-
|
B_STEND
|
Condition: end of start conditions reached
|-
|
B_TDMLSDS
|
Condition: time after clutch actuation with modified load shock damping
trigger
|-
|
B_TMISMEUS
|
Condition: trigger for torque filtering B_mismeus
|-
|
B VL
|
Condition: full load
|-
|
B_VMAX
|
Condition: speed limiter active
|-
|
B_VNULL
|
Condition: vehicle stopped
|-
|
B_WKAUF
|
Condition: torque converter open
|-
|
B_ZWSCH
|
Condition: ignition angle for stratified charge mode active
|-
|
DLSD_W
|
Damping PT2-filter in load shock damping
|-
|
DMBEBL_W
|
Delta torque for triggering load shock damping
|-
|
DMDPO_W
|
Delta torque dashpot triggering
|-
|
DMDPU_W
|
Delta torque dashpot end
|-
|
DMGBEG_W
|
Delta torque for gradient limitation
|-
|
DMLLRI_W
|
Required torque change from idle control (integral component)
|-
|
DMLSDO_W
|
Delta torque on triggering load shock damping
|-
|
DMLSDU_W
|
Delta torque at end of load shock damping
|-
|
DMLWHS_W
|
Delta torque during load alternation between homogeneous and stratified
charge modes
|-
|
DMRFAWE_W
|
Threshold mrfa-gradient for deactivating PT1-Filter during reinstatement
|-
|
DMVERL_W
|
Torque loss after DT1-Filter
|-
|
FKFPED
|
Factor for interpolation between the two pedal maps
|-
|
FWMIFAL
|
Excessive increase factor in cylinder charge path load shock damping
|-
|
FWZLSD
|
Reduction factor time constant load shock damping
|-
|
FZDASH
|
Factor time constant dashpot
|-
|
GANGI
|
Actual gear
|-
|
IWFLSD_W
|
Initialising value for filter load shock damping
|-
|
MDFAW_BITS
|
Flag byte for %MDFAW
|-
|
MDGRAD_W
|
Torque gradient limiting through the transmission
|-
|
MDSLWHOM_W
|
Load alternation torque loss in the homogeneous mode
|-
|
MDSLW_W
|
Torque loss: load alternation
|-
|
MDVERL W
|
Engine torque loss
|-
|
MIASRS_W
|
Indicated target engine torque traction control for fast intervention
|-
|
MIBAS_W
|
Indicated basic torque
|-
|
MIBDP_W
|
Indicated target engine torque dashpot
|-
|
MIBLSD_W
|
Limited indicated torque for load shock damping
|-
|
MIFA
|
Indicated driver requested engine torque
|-
|
MIFABG_W
|
Gradient-limited driver requested torque
|-
|
MIFAL_W
|
Indicated driver requested torque for torque coordination on the charge
path
|-
|
MIFA_W
|
Indicated driver requested engine torque
|-
|
MIGEF_W
|
Gefiltertes indicated driver requested torque
|-
|
MIISTOAR_W
|
Actual torque without anti-judder component
|-
|
MIMAX_W
|
Maximum permissible indicated torque
|-
|
MIMINHOM_W
|
Minimum torque for the homogeneous charge mode
|-
|
MIMIN_W
|
Minimum engine torque
|-
|
MINBEG_W
|
Indicated driver requested torque after / change limitation
|-
|
MISMEUS_W
|
Indicated torque during change limitation B_mismeus
|-
|
MIVBEB_W
|
Indicated torque before change limitation, upper limit of mimax_w
|-
|
MIVBEGVH_W
|
Indicated driver requested torque before maximum limit for homogeneous
charge mode
|-
|
MIVBEGV_W
|
Indicated driver requested torque before maximum limit
|-
|
MIVBEG_W
|
Indicated driver requested torque before change limitation
|-
|
MIZWMN_W
|
Indicateed engine torque at the latest igniton angle
|-
|
MKFADPN_W
|
Clutch torque for changeover dashpot-filter time
|-
|
MKFANB_W
|
Clutch torque from limited driver’s request
|-
|
MKFA_W
|
Driver requested torque (clutch) after change limitation
|-
|
MRFAMXAS W
|
Relative driver requested torque maximum value from automated manual
transmission
|-
|
MRFAMX_W
|
Relative driver requested torque maximum value
|-
|
MRFA_W
|
Relative driver requested torque from cruise control and throttle pedal
|-
|
MRFGR_W
|
Relative torque requirement from cruise control
|-
|
MRPEDASG W
|
Relative driver requested torque from automated manual transmission
|-
|
MRPEDL_W
|
Relative driver requested torque from the throttle pedal for less speed
|-
|
MRPEDS W
|
Relative driver requested torque from the throttle pedal for greater
speed
|-
|
MRPED_W
|
Relative driver requested torque
|-
|
NGFIL_W
|
Filtered speed gradient
|-
|
NMOT W
|
Engine speed
|-
|
RLMINDP_W
|
Minimum relative cylinder charge for dashpot switch off
|-
|
RLMIN_W
|
Minimum permitted relative load
|-
|
RL_W
|
Relative air charge (word)
|-
|
TMOT
|
Engine coolant temperature
|-
|
VFZG
|
Vehicle speed
|-
|
WPED_W
|
Normalised throttle pedal angle
|-
|
ZDASH1_W
|
Time constant PT1-filter dashpot
|-
|
ZDASH2_W
|
Time constant PT1-filter dashpot at small clutch torque
|-
|
ZDASH_W
|
Time constant dashpot
|-
|
ZLSDV_W
|
Time constant PT2-filter load shock damping before reduction
|-
|
ZLSD_W
|
Time constant PT2-filter load shock damping
|}

[[Category:ME7]]

MDBAS 8.30 (Calculation of the Basic Parameters for the Torque Interface)

2012-05-22T19:35:58Z

TTQS:

MDBAS 8.30 Function Description

See the ''funktionsrahmen'' for the following diagrams:

MDBAS MDBAS (included in this translation)

MDBAS ZW NWS

The optimum torque values mioptl1_w at lambda = 1 are calculated with the help of the map KFMIOP. This torque is corrected for the influence of lambda by multiplying by the lambda efficiency (etalab). The lambda efficiency is obtained from the characteristic line ETALAM. Multiplying by the ignition angle efficiency gives the basic torque mibas. This corresponds to the indicated torque that is set when the combustion takes place with the basic lambda (lambas) and the basic ignition angle (zwbas).

The optimum ignition angle at lambda = 1 is determined from the map KFZWOP. The sub-function ZW_NWS describes the influence on the optimum ignition angle of an existing camshaft timing adjustment. The equipment options are none, binary (on or off), or continuously variable camshaft timing adjustment. In the case of binary adjustment, the factor fnwue governs continuous switching between the maps KFZWOP and KFZWOP2. In the case of continuous camshaft timing adjustment which depends on the camshaft overlap angle (wnwue) an ignition angle correction is added to KFZWOP. The determined optimum ignition angle (zwoptl1) again applies for lambda = 1. The currently applicable camshaft timing adjustment type is defined by the system constant SY_NWS in SW generation:

SY_NWS = 0: no camshaft timing adjustment

SY_NWS = 1: binary camshaft timing adjustment

SY_NWS = 2: continuously variable camshaft timing adjustment

SY_NWS > 2: not defined.

The software is translated conditionally, i.e. there is only one variant in the EPROM. SY_NWS is not in the EPROM and can not be applied.

Additive corrections depending on lambda, the exhaust gas recirculation rate and engine temperature are included. The resulting ignition angle (zwopt) now forms the basis for the ignition angle efficiency calculation. The basic ignition angle efficiency is calculated using the characteristic ETADZW, the input value is obtained from the difference between zwopt and zwbas. This is followed by an averaging of the basic efficiencies across all cylinders and the result is the base efficiency etazwbm.

The ignition angle correction for exhaust gas recirculation operation can through the code word CWMDBAS either always be included or only included if B_agr = true. In the case of permanent inclusion, ignition angle jumps are avoided by switching off B_agr.

MDBAS 8.30 Application Notes

Exhaust gas recirculation should be inactive throughout all these measurements! Data input requires the following measurements to be made:

1. Operation at Lambda = 1:

Ignition angle fine tuning on an engine dynamometer at lambda = 1 with the engine at normal operating temperature at the following operating points:

Engine speed = 500, 750, 1000, 1250, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000 & 6500 rpm (if possible)

Relative cylinder charge = 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100%

Ignition angle fine turning begins at the ignition angle at which maximum torque is achieved (i.e. maximum brake torque, MBT) if not to drive at the knock limit. The ignition angle should now be retarded in steps of 4.5° crank angle until the latest mobile firing angle is achieved. The following data must be recorded at each point: engine speed (nmot), relative cylinder charge (rl), lambda, clutch torque and ignition angle.

2. Lambda Dependence

Ignition angle fine tuning through lambda at the following measuring points:

Engine speed = 1000, 2000, & 3000 rpm

Relative cylinder charge = 30, 50 & 70 %

Lambda = 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15 & 1.20

Measurements as above.

3. Drag Torque

The drag torque (engine braking) must be obtained at all the measuring points specified in 1. Measure on an engine dynamometer with no ignition and with the engine at its normal operating temperature.

4. Evaluation

Evaluation of the results takes place at K3/ESY4-Hes.

{| border="1"
|-
|
Parameter
|
Description
|-
|
AGRRMAX
|
Maximum possible exhaust gas recirculation rate
|-
|
CWMDBAS
|
Codeword to take account of the ignition angle correction for exhaust gas
recirculation operation
|-
|
DZWNWSUE
|
Delta ignition angle depending on camshaft angle
|-
|
DZWOLA
|
Lambda dependence of the optimum ignition angle relative to lambda = 1
|-
|
DZWOM
|
Temperature dependent offset of the optimum ignition angle
|-
|
ETADZW
|
Ignition angle efficiency dependence on delta ignition angle
|-
|
ETALAM
|
Lambda efficiency
|-
|
KFDZWOAGR
|
Offset of the optimum ignition angle with exhaust gas recirculation
operation
|-
|
KFMIOP
|
Optimum
engine torque map
|-
|
KFZWOP
|
Optimum ignition angle
|-
|
KFZWOP2
|
Optimum ignition angle variant 2
|-
|
Variable
|
Description
|-
|
AGRR
|
Exhaust gas recirculation rate
|-
|
B_AGR
|
Exhaust gas recirculation one condition
|-
|
DZWOAG
|
Exhaust gas recirculation rate dependent ignition angle correction of the
optimum ignition angle
|-
|
DZWOL
|
Lambda dependent ignition angle correction of the optimum ignition angle
|-
|
DZWOTM
|
Temperature dependent ignition angle correction of the optimum ignition
angle
|-
|
ETALAB
|
Lambda efficiency without intervention based on optimum torque at lambda
|-
|
ETATRMN
|
Minimum value of the cylinder barrel efficiency
|-
|
ETAZWB
|
Ignition angle efficiency of the basic ignition angles
|-
|
ETAZWBM
|
Mean ignition angle efficiency of the basic ignition angles
|-
|
FNWUE
|
Weighting factor for inlet camshaft overlap
|-
|
LAMBAS
|
Basic lambda
|-
|
MIBAS_W
|
Indicated basic torque
|-
|
MIOPTL1_W
|
Optimum indicated torque at lambda = 1
|-
|
MIOPT_W
|
Optimum indicated torque
|-
|
NMOT W
|
Engine speed
|-
|
RL_W
|
Relative cylinder charge (word)
|-
|
R_SYN
|
Synchro-raster
|-
|
SY_NWS
|
System constant for camshaft control: none, binary (on/off) or continuous
|-
|
TMOT
|
Engine (coolant) temperature
|-
|
WNWUE
|
Camshaft overlap angle
|-
|
ZWBAS
|
Basic ignition angle
|-
|
ZWOPT
|
Optimum ignition angle
|}

[[Category:ME7]]

MDBAS 8.30 (Calculation of the Basic Parameters for the Torque Interface)

2012-05-22T19:35:03Z

TTQS:

MDBAS 8.30 (Calculation of the Basic Parameters for the Torque Interface)

2012-05-22T19:33:55Z

TTQS:

MDBAS 8.30 (Calculation of the Basic Parameters for the Torque Interface)

2012-05-22T19:33:06Z

TTQS:

MDBAS 8.30 Function Description

See the ''funktionsrahmen'' for the following diagrams:

MDBAS MDBAS (included in this translation)

MDBAS ZW NWS

The optimum torque values mioptl1_w at lambda = 1 are calculated with the help of the map KFMIOP. This torque is corrected for the influence of lambda by multiplying by the lambda efficiency (etalab). The lambda efficiency is obtained from the characteristic line ETALAM. Multiplying by the ignition angle efficiency gives the basic torque mibas. This corresponds to the indicated torque that is set when the combustion takes place with the basic lambda (lambas) and the base ignition angle (zwbas).

The optimum ignition angle at lambda = 1 is determined from the map KFZWOP. The sub-function ZW_NWS describes the influence on the optimum ignition angle of an existing camshaft timing adjustment. The equipment options are none, binary (on or off), or continuously variable camshaft timing adjustment. In the case of binary adjustment, the factor fnwue governs continuous switching between the maps KFZWOP and KFZWOP2. In the case of continuous camshaft timing adjustment which depends on the camshaft overlap angle (wnwue) an ignition angle correction is added to KFZWOP. The determined optimum ignition angle (zwoptl1) again applies for lambda = 1. The currently applicable camshaft timing adjustment type is defined by the system constant SY_NWS in SW generation:

SY_NWS = 0: no camshaft timing adjustment

SY_NWS = 1: binary camshaft timing adjustment

SY_NWS = 2: continuously variable camshaft timing adjustment

SY_NWS > 2: not defined.

The software is translated conditionally, i.e. there is only one variant in the EPROM. SY_NWS is not in the EPROM and can not be applied.

Additive corrections depending on lambda, the exhaust gas recirculation rate and engine temperature are included. The resulting ignition angle (zwopt) now forms the basis for the ignition angle efficiency calculation. The basic ignition angle efficiency is calculated using the characteristic ETADZW, the input value is obtained from the difference between zwopt and zwbas. This is followed by an averaging of the basic efficiencies across all cylinders and the result is the base efficiency etazwbm.

The ignition angle correction for exhaust gas recirculation operation can through the code word CWMDBAS either always be included or only included if B_agr = true. In the case of permanent inclusion, ignition angle jumps are avoided by switching off B_agr.

MDBAS 8.30 Application Notes

Exhaust gas recirculation should be inactive throughout all these measurements! Data input requires the following measurements to be made:

1. Operation at Lambda = 1:

Ignition angle fine tuning on an engine dynamometer at lambda = 1 with the engine at normal operating temperature at the following operating points:

Engine speed = 500, 750, 1000, 1250, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000 & 6500 rpm (if possible)

Relative cylinder charge = 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100%

Ignition angle fine turning begins at the ignition angle at which maximum torque is achieved (i.e. maximum brake torque, MBT) if not to drive at the knock limit. The ignition angle should now be retarded in steps of 4.5° crank angle until the latest mobile firing angle is achieved. The following data must be recorded at each point: engine speed (nmot), relative cylinder charge (rl), lambda, clutch torque and ignition angle.

2. Lambda Dependence

Ignition angle fine tuning through lambda at the following measuring points:

Engine speed = 1000, 2000, & 3000 rpm

Relative cylinder charge = 30, 50 & 70 %

Lambda = 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15 & 1.20

Measurements as above.

3. Drag Torque

The drag torque (engine braking) must be obtained at all the measuring points specified in 1. Measure on an engine dynamometer with no ignition and with the engine at its normal operating temperature.

4. Evaluation

Evaluation of the results takes place at K3/ESY4-Hes.

{| border="1"
|-
|
Parameter
|
Description
|-
|
AGRRMAX
|
Maximum possible exhaust gas recirculation rate
|-
|
CWMDBAS
|
Codeword to take account of the ignition angle correction for exhaust gas
recirculation operation
|-
|
DZWNWSUE
|
Delta ignition angle depending on camshaft angle
|-
|
DZWOLA
|
Lambda dependence of the optimum ignition angle relative to lambda = 1
|-
|
DZWOM
|
Temperature dependent offset of the optimum ignition angle
|-
|
ETADZW
|
Ignition angle efficiency dependence on delta ignition angle
|-
|
ETALAM
|
Lambda efficiency
|-
|
KFDZWOAGR
|
Offset of the optimum ignition angle with exhaust gas recirculation
operation
|-
|
KFMIOP
|
Optimum
engine torque map
|-
|
KFZWOP
|
Optimum ignition angle
|-
|
KFZWOP2
|
Optimum ignition angle variant 2
|-
|
Variable
|
Description
|-
|
AGRR
|
Exhaust gas recirculation rate
|-
|
B_AGR
|
Exhaust gas recirculation one condition
|-
|
DZWOAG
|
Exhaust gas recirculation rate dependent ignition angle correction of the
optimum ignition angle
|-
|
DZWOL
|
Lambda dependent ignition angle correction of the optimum ignition angle
|-
|
DZWOTM
|
Temperature dependent ignition angle correction of the optimum ignition
angle
|-
|
ETALAB
|
Lambda efficiency without intervention based on optimum torque at lambda
|-
|
ETATRMN
|
Minimum value of the cylinder barrel efficiency
|-
|
ETAZWB
|
Ignition angle efficiency of the basic ignition angles
|-
|
ETAZWBM
|
Mean ignition angle efficiency of the basic ignition angles
|-
|
FNWUE
|
Weighting factor for inlet camshaft overlap
|-
|
LAMBAS
|
Basic lambda
|-
|
MIBAS_W
|
Indicated basic torque
|-
|
MIOPTL1_W
|
Optimum indicated torque at lambda = 1
|-
|
MIOPT_W
|
Optimum indicated torque
|-
|
NMOT W
|
Engine speed
|-
|
RL_W
|
Relative cylinder charge (word)
|-
|
R_SYN
|
Synchro-raster
|-
|
SY_NWS
|
System constant for camshaft control: none, binary (on/off) or continuous
|-
|
TMOT
|
Engine (coolant) temperature
|-
|
WNWUE
|
Camshaft overlap angle
|-
|
ZWBAS
|
Basic ignition angle
|-
|
ZWOPT
|
Optimum ignition angle
|}

[[Category:ME7]]

ARMD 10.40 (Torque-Based Anti-Jerk Function)

2012-05-22T19:28:07Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

armd-armd Main function

armd-kifz Subfunction KIFZ (amplification of vehicle model)

armd-flrar Subfunction FLRAR (amplification factor for modelling of external load)

armd-fdar Subfunction FDAR (amplification factor for anti-jerk intervention)

armd-nmoti Subfunction NMOTI

armd-ndfil Subfunction NDFIL (filtered engine speed difference)

armd-frgar Subfunction FRGAR

armd-iniarv Subfunction INIARV

armd-kup gw Subfunction KUPGW

armd-dmar Subfunction DMAR (delta torque anti-jerk)

armd-varss Subfunction VARSS

ARMD 10.40 Function Description

Function purpose

The anti-jerk function detects oscillations of the power train and damps them out by applying opposing-phase torque interventions. The torque intervention is converted into an ignition angle offset by the torque interface.

Desired phase position of the torque intervention

In order to damp the power train oscillation efficiently, the torque intervention should counteract engine speed oscillations. Thereby the same effect is achieved as if the attenuation coefficient of the drive shaft is increased.

Operation pattern of anti-jerk function

Basic idea: a reference speed without oscillation and corresponding to the driver’s demand is evaluated. The difference between desired and actual engine speed isolates the oscillation. A counteracting delta torque is set which is proportional to this oscillation.

The function is realized by a simple vehicle model consisting of an integrator with the constant kifz_w. The input to this integrator is the difference between the driver’s predetermined clutch torque mkar_w and the load torque mlast_w. The output from the integtrator is the modelled engine speed nmod_w. The engine speed difference ndiff_w between the modelled engine speed nmod_w and the actual engine speed nmot_w now forms the basis for the torque intervention as well as for the calculation of the load torque. The load torque is evaluated proportional to the engine speed difference and the factor flrar is taken from the corresponding characteristic line. The engine speed difference ndiff_w contains another offset besides the oscillation part.
This offset is filtered on a 50 ms scan timescale through a discrete second order low pass filter. (Coefficients of the nominator polynomial are denoted A0, A1 and A2 and of the denominator polynomial 1, B1 and B2.

The filtered offset ndfil_w is substracted from the differential engine speed and gives the engine speed oscillation ndar_w.
Proportionally to this engine speed and using the factor fdar, a delta torque as a torque intervention is calculated. If this intervention lays between the limits KFDMDARU and KFDMDARO, it is set to zero.

Activation Conditions

The model is always active, just the intervention can be switched off.

Application Notes

Conditions for calibration of anti-jerk

The basic calibration of the vehicle must have been done. This includes the transition compensation and all functions for the torque interface.

1. Evaluation of the integrator constant kifz_w and flrar

Coarse application:

Drive on the road (flat surface, no hills) at a constant speed in respective gear with the anti-jerk function deactivated (fdar=0).
Then execute a change in load and register the calculated coupling torque mkar_w and the engine speed nmot_w.

Evaluation of integrator constant as follows: at a load step the torque jump is approximately delta M (in %) and the speed approximately rises with constant gradient gradn (in RPM/s). Kifz_w is then calculated from the expression gradn/(delta M). A typical value for second gear is 4.6 x 100/MDNORM [RPM/(sx%)].

Fine application:

Driving on flat surface. Set the product kifz_w x flrar to a fixed value (recommendation: 15). Realization of load jumps with registration of mkar_w, mlast_w, nmot_w and ndiff_w. Vary the couple kifz_w and flrar (maintaining the product constant!) until ndiff_w remains approximately constant during a load jump.

In principle the following process is valid for the amplification factor flrar: high factors cause a reduction of the offset ndfil_w, but also a big phase advance of ndiff_w.

2. Evaluation of filter parameters

For a low pass filter with 50 ms scan rate, the transmission function has the form G(z) = Z(z)/N(z) where

Z(z) = A0 + A1z-1 + A2z-2

N(z) = 1 + B1z-1 + B2z-2

Select one of the low pass filters listed in the table below, according to the appearing jerk frequency:

{| border="1"
|-
|
TP No.
|
Limit freq.
|
A0
|
A1
|
A2
|
B1
|
B2
|-
|
1
|
0.67 Hz
|
0.0095
|
0.0191
|
0.0095
|
-1.7056
|
0.7437
|-
|
2
|
0.80 Hz
|
0.0134
|
0.0267
|
0.0134
|
-1.6475
|
0.7009
|-
|
3
|
1.00 Hz
|
0.0201
|
0.0402
|
0.0201
|
-1.5610
|
0.6414
|}

Low pass filter No. 3 is recommended. The attenuation of the jerk frequency is determined by the margin between the jerk frequency and the filter cut-off frequency. The bigger the filter cut-off frequency, the smaller the time the filter needs to stabilize.

Warning: modification of a single coefficient of G(z) is not permitted!

3. Evaluation of fdar

Recommendation is fdar = 0.67 x 100/MDNORM (%/RPM). Increase of attenuation by enlargement of fdar, reduction of fdar decreases the attenuation.

4. Thresholds KFDMDARO and KFDMDARU

In case the delta torque for the intervention is within these thresholds, it is set to zero. This avoids undesired ignition angle instability. Typical values are: KFDMDARU = -5 x 100/MDNORM [%], KFDMDARO = 5 x 100/MDNORM [%].

Abbreviations

{| border="1"
|-
|
A0
|
Transmission
coefficient
|-
|
A1
|
Transmission
coefficient
|-
|
A2
|
Transmission
coefficient
|-
|
B1
|
Transmission
coefficient
|-
|
B2
|
Transmission
coefficient
|-
|
CWARMD
|
Code
word anti jerk function
|-
|
DMARMX
|
Maximum
limit of the steady-state torque interventions of the anti-jerk function
|-
|
DNFILO
|
Upper
threshold of filter output gradient ndfil
|-
|
DVFZAR
|
Hysteresis
for vehicle speed limit during anti-jerk
|-
|
FLRAWG
|
Integrator
gain factor of the load controller during AT (throttle plate closed)
|-
|
FLRHG
|
Integrator
gain factor of the load controller
|-
|
FRARAWG
|
Integrator
gain factor during AT (throttle plate closed)
|-
|
FRARHG
|
Integrator
gain factor
|-
|
KFDMDADP
|
Upper
threshold for torque-intervention during dashpot
|-
|
KFDMDARO
|
Upper
threshold for torque intervention
|-
|
KFDMDAROS
|
Upper
threshold for steady-state torque intervention
|-
|
KIFZGAWG
|
Integrator
gain factor in the vehicle model with AT (throttle plate closed)
|-
|
KIFZGHG
|
Integrator
gain factor in the vehicle model with HG
|-
|
NARAO
|
Upper
engine speed threshold for anti-jerk function active
|-
|
NARASTG
|
RPM
threshold in higher gear for anti-jerk active
|-
|
NARLLGA
|
Speed
threshold for anti-jerk at idle
|-
|
NDFILOG
|
Threshold
for filter output ndfil
|-
|
NDIFFOG
|
Threshold
engine speed difference for initialization of anti-jerk during braking
|-
|
NVG
|
Factor
to calculate engine speed initialization
|-
|
NVMNG
|
Minimum
speed / velocity ratio
|-
|
NVMXG
|
Maximum
speed / velocity ratio
|-
|
SMK08MDSW
|
Anti-jerk
torque dependent basic point (number =8)
|-
|
TAREIN
|
Blocking
time for anti-jerk function
|-
|
TMAR
|
Lower
engine temperature threshold for anti-jerk release
|-
|
TMLAST
|
Blocking
time until the initialization of the anti-jerk is triggered at deceleration
|-
|
TVARS
|
Delay
time until anti-jerk is inactive again
|-
|
TVARSS
|
Delay
time for anti-jerk becoming inactive again in steady-state conditions
|-
|
TVKUPAR
|
Delay
time for clutch for anti-jerk function
|-
|
TVKUPHS
|
Delay
time for clutch switch during shifting in higher gear
|-
|
TVKUPRS
|
Delay
time for clutch switch during shifting in lower gear
|-
|
TZSPINI
|
Blocking
time for filter initialisation
|-
|
VARAU
|
Minimum
vehicle speed for anti-jerk active
|-
|
WPEDU
|
Pedal
lower threshold value for anti-jerk function
|-
|
B_AR
|
Condition:
anti-jerk active
|-
|
B_ARGF
|
Condition:
anti-jerk transition window
|-
|
B_AUTGET
|
Condition:
automatic gearbox
|-
|
B_BREMS
|
Condition:
brake operated
|-
|
B_DASHV
|
Condition:
dashpot delayed
|-
|
B_FGR
|
Condition:
driver's set engine torque determined by cruise control
|-
|
B_GFEN
|
Condition:
transition window
|-
|
B_GWHS
|
Condition:
gear change on manual transmission vehicle
|-
|
B_HPNMOT
|
Condition:
high-point speed oscillation
|-
|
B_INIAR
|
Condition:
initialization of anti-jerk function
|-
|
B_INIAR1
|
Condition:
provisional initialization of anti-jerk function
|-
|
B_INIARV
|
Condition:
initialization of the filter function is delayed
|-
|
B_KUPGW
|
Condition:
clutch applied until shifting of geanti-jerk is detected
|-
|
B_KUPPL
|
EGAS
Condition: clutch is disengaged
|-
|
B_LL
|
Condition:
idle
|-
|
B_LSD
|
Condition:
limitation of positive torque gradient active
|-
|
B_SA
|
Condition:
fuel cut-off
|-
|
B_STEND
|
Condition:
end of start reached
|-
|
B_TPNMOT
|
Condition:
low-point speed oscillation
|-
|
B_TVARS
|
Condition:
anti-jerking function dynamically active
|-
|
B_TVARSS
|
Condition:
anti-jerking function steady-state active
|-
|
B_WK
|
Condition:
converter lockup clutch closed
|-
|
DMAR_W
|
Delta
torque anti-jerk
|-
|
FDAR
|
Amplification
factor for anti-jerk intervention
|-
|
FLRAR
|
Amplification
factor for modelling of external load
|-
|
GANGI
|
Engaged
gear
|-
|
KIFZ_W
|
Amplification
of vehicle model
|-
|
MDBES_W
|
Acceleration
torque
|-
|
MDVERL_W
|
Resistant
torque of the engine
|-
|
MIFA_W
|
Desired
indicated engine torque
|-
|
MISOLV_W
|
Indicated
resultant nominal torque before torque limitation
|-
|
MKAR_W
|
Calculated
clutch torque for anti-jerk function
|-
|
MLAST_W
|
Estimated
load moment
|-
|
NDAR_W
|
RPM
difference for torque control
|-
|
NDFIL_W
|
Filtered
engine speed difference
|-
|
NDIFFOG_W
|
Threshold
engine speed difference for reset of anti-jerk during braking
|-
|
NDIFF_W
|
Engine
speed difference for ISC amplification
|-
|
NMODIV_W
|
Engine
speed for initialising ARMD calculated from velocity
|-
|
NMOD_W
|
Engine
speed from model
|-
|
NMOT_W
|
Actual
engine speed
|-
|
NVQUOT_W
|
Quotient
engine speed / vehicle speed
|-
|
TMOT
|
Engine
temperature
|-
|
VFZG
|
Vehicle
speed (km/h)
|-
|
VFZG_W
|
Vehicle
speed (km/h, word)
|-
|
WPED_W
|
Normalised
throttle pedal angle (word)
|}

ARMD 10.40 (Torque-Based Anti-Jerk Function)

2012-05-22T19:27:31Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

armd-armd Main function

armd-kifz Subfunction KIFZ (amplification of vehicle model)

armd-flrar Subfunction FLRAR (amplification factor for modelling of external load)

armd-fdar Subfunction FDAR (amplification factor for anti-jerk intervention)

armd-nmoti Subfunction NMOTI

armd-ndfil Subfunction NDFIL (filtered engine speed difference)

armd-frgar Subfunction FRGAR

armd-iniarv Subfunction INIARV

armd-kup gw Subfunction KUPGW

armd-dmar Subfunction DMAR (delta torque anti-jerk)

armd-varss Subfunction VARSS

ARMD 10.40 Function Description

Function purpose

The anti-jerk function detects oscillations of the power train and damps them out by applying opposing-phase torque interventions. The torque intervention is converted into an ignition angle offset by the torque interface.

Desired phase position of the torque intervention

In order to damp the power train oscillation efficiently, the torque intervention should counteract engine speed oscillations. Thereby the same effect is achieved as if the attenuation coefficient of the drive shaft is increased.

Operation pattern of anti-jerk function

Basic idea: a reference speed without oscillation and corresponding to the driver’s demand is evaluated. The difference between desired and actual engine speed isolates the oscillation. A counteracting delta torque is set which is proportional to this oscillation.

The function is realized by a simple vehicle model consisting of an integrator with the constant kifz_w. The input to this integrator is the difference between the driver’s predetermined clutch torque mkar_w and the load torque mlast_w. The output from the integtrator is the modelled engine speed nmod_w. The engine speed difference ndiff_w between the modelled engine speed nmod_w and the actual engine speed nmot_w now forms the basis for the torque intervention as well as for the calculation of the load torque. The load torque is evaluated proportional to the engine speed difference and the factor flrar is taken from the corresponding characteristic line. The engine speed difference ndiff_w contains another offset besides the oscillation part.
This offset is filtered on a 50 ms scan timescale through a discrete second order low pass filter. (Coefficients of the nominator polynomial are denoted A0, A1 and A2 and of the denominator polynomial 1, B1 and B2.

The filtered offset ndfil_w is substracted from the differential engine speed and gives the engine speed oscillation ndar_w.
Proportionally to this engine speed and using the factor fdar, a delta torque as a torque intervention is calculated. If this intervention lays between the limits KFDMDARU and KFDMDARO, it is set to zero.

Activation Conditions

The model is always active, just the intervention can be switched off.

Application Notes

Conditions for calibration of anti-jerk

The basic calibration of the vehicle must have been done. This includes the transition compensation and all functions for the torque interface.

1. Evaluation of the integrator constant kifz_w and flrar

Coarse application:

Drive on the road (flat surface, no hills) at a constant speed in respective gear with the anti-jerk function deactivated (fdar=0).
Then execute a change in load and register the calculated coupling torque mkar_w and the engine speed nmot_w.

Evaluation of integrator constant as follows: at a load step the torque jump is approximately delta M (in %) and the speed approximately rises with constant gradient gradn (in RPM/s). Kifz_w is then calculated from the expression gradn/(delta M). A typical value for second gear is 4.6 x 100/MDNORM [RPM/(sx%)].

Fine application:

Driving on flat surface. Set the product kifz_w x flrar to a fixed value (recommendation: 15). Realization of load jumps with registration of mkar_w, mlast_w, nmot_w and ndiff_w. Vary the couple kifz_w and flrar (maintaining the product constant!) until ndiff_w remains approximately constant during a load jump.

In principle the following process is valid for the amplification factor flrar: high factors cause a reduction of the offset ndfil_w, but also a big phase advance of ndiff_w.

2. Evaluation of filter parameters

For a low pass filter with 50 ms scan rate, the transmission function has the form G(z) = Z(z)/N(z) where

Z(z) = A0 + A1z-1 + A2z-2

N(z) = 1 + B1z-1 + B2z-2

Select one of the low pass filters listed in the table below, according to the appearing jerk frequency:

{| border="1"
|-
|
TP No.
|
Limit freq.
|
A0
|
A1
|
A2
|
B1
|
B2
|-
|
1
|
0.67 Hz
|
0.0095
|
0.0191
|
0.0095
|
-1.7056
|
0.7437
|-
|
2
|
0.80 Hz
|
0.0134
|
0.0267
|
0.0134
|
-1.6475
|
0.7009
|-
|
3
|
1.00 Hz
|
0.0201
|
0.0402
|
0.0201
|
-1.5610
|
0.6414
|}

Low pass filter No. 3 is recommended. The attenuation of the jerk frequency is determined by the margin between the jerk frequency and the filter cut-off frequency. The bigger the filter cut-off frequency, the smaller the time the filter needs to stabilize. Attenuation: modification of a single coefficient of G(z) is not permitted!

3. Evaluation of fdar

Recommendation is fdar = 0.67 x 100/MDNORM (%/RPM). Increase of attenuation by enlargement of fdar, reduction of fdar decreases the attenuation.

4. Thresholds KFDMDARO and KFDMDARU

In case the delta torque for the intervention is within these thresholds, it is set to zero. This avoids undesired ignition angle instability. Typical values are: KFDMDARU = -5 x 100/MDNORM [%], KFDMDARO = 5 x 100/MDNORM [%].

Abbreviations

{| border="1"
|-
|
A0
|
Transmission
coefficient
|-
|
A1
|
Transmission
coefficient
|-
|
A2
|
Transmission
coefficient
|-
|
B1
|
Transmission
coefficient
|-
|
B2
|
Transmission
coefficient
|-
|
CWARMD
|
Code
word anti jerk function
|-
|
DMARMX
|
Maximum
limit of the steady-state torque interventions of the anti-jerk function
|-
|
DNFILO
|
Upper
threshold of filter output gradient ndfil
|-
|
DVFZAR
|
Hysteresis
for vehicle speed limit during anti-jerk
|-
|
FLRAWG
|
Integrator
gain factor of the load controller during AT (throttle plate closed)
|-
|
FLRHG
|
Integrator
gain factor of the load controller
|-
|
FRARAWG
|
Integrator
gain factor during AT (throttle plate closed)
|-
|
FRARHG
|
Integrator
gain factor
|-
|
KFDMDADP
|
Upper
threshold for torque-intervention during dashpot
|-
|
KFDMDARO
|
Upper
threshold for torque intervention
|-
|
KFDMDAROS
|
Upper
threshold for steady-state torque intervention
|-
|
KIFZGAWG
|
Integrator
gain factor in the vehicle model with AT (throttle plate closed)
|-
|
KIFZGHG
|
Integrator
gain factor in the vehicle model with HG
|-
|
NARAO
|
Upper
engine speed threshold for anti-jerk function active
|-
|
NARASTG
|
RPM
threshold in higher gear for anti-jerk active
|-
|
NARLLGA
|
Speed
threshold for anti-jerk at idle
|-
|
NDFILOG
|
Threshold
for filter output ndfil
|-
|
NDIFFOG
|
Threshold
engine speed difference for initialization of anti-jerk during braking
|-
|
NVG
|
Factor
to calculate engine speed initialization
|-
|
NVMNG
|
Minimum
speed / velocity ratio
|-
|
NVMXG
|
Maximum
speed / velocity ratio
|-
|
SMK08MDSW
|
Anti-jerk
torque dependent basic point (number =8)
|-
|
TAREIN
|
Blocking
time for anti-jerk function
|-
|
TMAR
|
Lower
engine temperature threshold for anti-jerk release
|-
|
TMLAST
|
Blocking
time until the initialization of the anti-jerk is triggered at deceleration
|-
|
TVARS
|
Delay
time until anti-jerk is inactive again
|-
|
TVARSS
|
Delay
time for anti-jerk becoming inactive again in steady-state conditions
|-
|
TVKUPAR
|
Delay
time for clutch for anti-jerk function
|-
|
TVKUPHS
|
Delay
time for clutch switch during shifting in higher gear
|-
|
TVKUPRS
|
Delay
time for clutch switch during shifting in lower gear
|-
|
TZSPINI
|
Blocking
time for filter initialisation
|-
|
VARAU
|
Minimum
vehicle speed for anti-jerk active
|-
|
WPEDU
|
Pedal
lower threshold value for anti-jerk function
|-
|
B_AR
|
Condition:
anti-jerk active
|-
|
B_ARGF
|
Condition:
anti-jerk transition window
|-
|
B_AUTGET
|
Condition:
automatic gearbox
|-
|
B_BREMS
|
Condition:
brake operated
|-
|
B_DASHV
|
Condition:
dashpot delayed
|-
|
B_FGR
|
Condition:
driver's set engine torque determined by cruise control
|-
|
B_GFEN
|
Condition:
transition window
|-
|
B_GWHS
|
Condition:
gear change on manual transmission vehicle
|-
|
B_HPNMOT
|
Condition:
high-point speed oscillation
|-
|
B_INIAR
|
Condition:
initialization of anti-jerk function
|-
|
B_INIAR1
|
Condition:
provisional initialization of anti-jerk function
|-
|
B_INIARV
|
Condition:
initialization of the filter function is delayed
|-
|
B_KUPGW
|
Condition:
clutch applied until shifting of geanti-jerk is detected
|-
|
B_KUPPL
|
EGAS
Condition: clutch is disengaged
|-
|
B_LL
|
Condition:
idle
|-
|
B_LSD
|
Condition:
limitation of positive torque gradient active
|-
|
B_SA
|
Condition:
fuel cut-off
|-
|
B_STEND
|
Condition:
end of start reached
|-
|
B_TPNMOT
|
Condition:
low-point speed oscillation
|-
|
B_TVARS
|
Condition:
anti-jerking function dynamically active
|-
|
B_TVARSS
|
Condition:
anti-jerking function steady-state active
|-
|
B_WK
|
Condition:
converter lockup clutch closed
|-
|
DMAR_W
|
Delta
torque anti-jerk
|-
|
FDAR
|
Amplification
factor for anti-jerk intervention
|-
|
FLRAR
|
Amplification
factor for modelling of external load
|-
|
GANGI
|
Engaged
gear
|-
|
KIFZ_W
|
Amplification
of vehicle model
|-
|
MDBES_W
|
Acceleration
torque
|-
|
MDVERL_W
|
Resistant
torque of the engine
|-
|
MIFA_W
|
Desired
indicated engine torque
|-
|
MISOLV_W
|
Indicated
resultant nominal torque before torque limitation
|-
|
MKAR_W
|
Calculated
clutch torque for anti-jerk function
|-
|
MLAST_W
|
Estimated
load moment
|-
|
NDAR_W
|
RPM
difference for torque control
|-
|
NDFIL_W
|
Filtered
engine speed difference
|-
|
NDIFFOG_W
|
Threshold
engine speed difference for reset of anti-jerk during braking
|-
|
NDIFF_W
|
Engine
speed difference for ISC amplification
|-
|
NMODIV_W
|
Engine
speed for initialising ARMD calculated from velocity
|-
|
NMOD_W
|
Engine
speed from model
|-
|
NMOT_W
|
Actual
engine speed
|-
|
NVQUOT_W
|
Quotient
engine speed / vehicle speed
|-
|
TMOT
|
Engine
temperature
|-
|
VFZG
|
Vehicle
speed (km/h)
|-
|
VFZG_W
|
Vehicle
speed (km/h, word)
|-
|
WPED_W
|
Normalised
throttle pedal angle (word)
|}

ARMD 10.40 (Torque-Based Anti-Jerk Function)

2012-05-22T19:25:59Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

armd-armd Main function

armd-kifz Subfunction KIFZ (amplification of vehicle model)

armd-flrar Subfunction FLRAR (amplification factor for modelling of external load)

armd-fdar Subfunction FDAR (amplification factor for anti-jerk intervention)

armd-nmoti Subfunction NMOTI

armd-ndfil Subfunction NDFIL (filtered engine speed difference)

armd-frgar Subfunction FRGAR

armd-iniarv Subfunction INIARV

armd-kup gw Subfunction KUPGW

armd-dmar Subfunction DMAR (delta torque anti-jerk)

armd-varss Subfunction VARSS

ARMD 10.40 Function Description

Function purpose

The anti-jerk function detects oscillations of the power train and damps them out by applying opposing-phase torque interventions. The torque intervention is converted into an ignition angle offset by the torque interface.

Desired phase position of the torque intervention

In order to damp the power train oscillation efficiently, the torque intervention should counteract engine speed oscillations. Thereby the same effect is achieved as if the attenuation coefficient of the drive shaft is increased.

Operation pattern of anti-jerk function

Basic idea: a reference speed without oscillation and corresponding to the driver’s demand is evaluated. The difference between desired and actual engine speed isolates the oscillation. A counteracting delta torque is set which is proportional to this oscillation.

The function is realized by a simple vehicle model consisting of an integrator with the constant kifz_w. The input to this integrator is the difference between the driver’s predetermined clutch torque mkar_w and the load torque mlast_w. The output from the integtrator is the modelled engine speed nmod_w. The engine speed difference ndiff_w between the modelled engine speed nmod_w and the actual engine speed nmot_w now forms the basis for the torque intervention as well as for the calculation of the load torque. The load torque is evaluated proportional to the engine speed difference and the factor flrar is taken from the corresponding characteristic line. The engine speed difference ndiff_w contains another offset besides the oscillation part.
This offset is filtered on a 50 ms scan timescale through a discrete second order low pass filter. (Coefficients of the nominator polynomial are denoted A0, A1 and A2 and of the denominator polynomial 1, B1 and B2.

The filtered offset ndfil_w is substracted from the differential engine speed and gives the engine speed oscillation ndar_w.
Proportionally to this engine speed and using the factor fdar, a delta torque as a torque intervention is calculated. If this intervention lays between the limits KFDMDARU and KFDMDARO, it is set to zero.

Activation Conditions

The model is always active, just the intervention can be switched off.

Application Notes

Conditions for calibration of anti-jerk

The basic calibration of the vehicle must have been done. This includes the transition compensation and all functions for the torque interface.

1. Evaluation of the integrator constant kifz_w and flrar

Coarse application:

Drive on the road (flat surface, no hills) at a constant speed in respective gear with the anti-jerk function deactivated (fdar=0).
Then execute a change in load and register the calculated coupling torque mkar_w and the engine speed nmot_w.

Evaluation of integrator constant as follows: at a load step the torque jump is approximately delta M (in %) and the speed approximately rises with constant gradient gradn (in RPM/s). Kifz_w is then calculated from the expression gradn/(delta M). A typical value for second gear is 4.6 x 100/MDNORM [RPM/(sx%)].

Fine application:

Driving on flat surface. Set the product kifz_w x flrar to a fixed value (recommendation: 15). Realization of load jumps with registration of mkar_w, mlast_w, nmot_w and ndiff_w. Vary the couple kifz_w and flrar (maintaining the product constant!) until ndiff_w remains approximately constant during a load jump.

In principle the following process is valid for the amplification factor flrar: high factors cause a reduction of the offset ndfil_w, but also a big phase advance of ndiff_w.

2. Evaluation of filter parameters

Low pass filter in 50 ms scan rate: transmission function has the form G(z) = Z(z)/N(z) with

Z(z) = A0 + A1z-1 + A2z-2

N(z) = 1 + B1z-1 + B2z-2.

Select one of the low pass filters listed in the table below, according to the appearing jerk frequency:

{| border="1"
|-
|
TP No.
|
Limit freq.
|
A0
|
A1
|
A2
|
B1
|
B2
|-
|
1
|
0.67 Hz
|
0.0095
|
0.0191
|
0.0095
|
-1.7056
|
0.7437
|-
|
2
|
0.80 Hz
|
0.0134
|
0.0267
|
0.0134
|
-1.6475
|
0.7009
|-
|
3
|
1.00 Hz
|
0.0201
|
0.0402
|
0.0201
|
-1.5610
|
0.6414
|}

Low pass filter No. 3 is recommended. The attenuation of the jerk frequency is determined by the margin between the jerk frequency and the filter cut-off frequency. The bigger the filter cut-off frequency, the smaller the time the filter needs to stabilize. Attenuation: modification of a single coefficient of G(z) is not permitted!

3. Evaluation of fdar

Recommendation is fdar = 0.67 x 100/MDNORM (%/RPM). Increase of attenuation by enlargement of fdar, reduction of fdar decreases the attenuation.

4. Thresholds KFDMDARO and KFDMDARU

In case the delta torque for the intervention is within these thresholds, it is set to zero. This avoids undesired ignition angle instability. Typical values are: KFDMDARU = -5 x 100/MDNORM [%], KFDMDARO = 5 x 100/MDNORM [%].

Abbreviations

{| border="1"
|-
|
A0
|
Transmission
coefficient
|-
|
A1
|
Transmission
coefficient
|-
|
A2
|
Transmission
coefficient
|-
|
B1
|
Transmission
coefficient
|-
|
B2
|
Transmission
coefficient
|-
|
CWARMD
|
Code
word anti jerk function
|-
|
DMARMX
|
Maximum
limit of the steady-state torque interventions of the anti-jerk function
|-
|
DNFILO
|
Upper
threshold of filter output gradient ndfil
|-
|
DVFZAR
|
Hysteresis
for vehicle speed limit during anti-jerk
|-
|
FLRAWG
|
Integrator
gain factor of the load controller during AT (throttle plate closed)
|-
|
FLRHG
|
Integrator
gain factor of the load controller
|-
|
FRARAWG
|
Integrator
gain factor during AT (throttle plate closed)
|-
|
FRARHG
|
Integrator
gain factor
|-
|
KFDMDADP
|
Upper
threshold for torque-intervention during dashpot
|-
|
KFDMDARO
|
Upper
threshold for torque intervention
|-
|
KFDMDAROS
|
Upper
threshold for steady-state torque intervention
|-
|
KIFZGAWG
|
Integrator
gain factor in the vehicle model with AT (throttle plate closed)
|-
|
KIFZGHG
|
Integrator
gain factor in the vehicle model with HG
|-
|
NARAO
|
Upper
engine speed threshold for anti-jerk function active
|-
|
NARASTG
|
RPM
threshold in higher gear for anti-jerk active
|-
|
NARLLGA
|
Speed
threshold for anti-jerk at idle
|-
|
NDFILOG
|
Threshold
for filter output ndfil
|-
|
NDIFFOG
|
Threshold
engine speed difference for initialization of anti-jerk during braking
|-
|
NVG
|
Factor
to calculate engine speed initialization
|-
|
NVMNG
|
Minimum
speed / velocity ratio
|-
|
NVMXG
|
Maximum
speed / velocity ratio
|-
|
SMK08MDSW
|
Anti-jerk
torque dependent basic point (number =8)
|-
|
TAREIN
|
Blocking
time for anti-jerk function
|-
|
TMAR
|
Lower
engine temperature threshold for anti-jerk release
|-
|
TMLAST
|
Blocking
time until the initialization of the anti-jerk is triggered at deceleration
|-
|
TVARS
|
Delay
time until anti-jerk is inactive again
|-
|
TVARSS
|
Delay
time for anti-jerk becoming inactive again in steady-state conditions
|-
|
TVKUPAR
|
Delay
time for clutch for anti-jerk function
|-
|
TVKUPHS
|
Delay
time for clutch switch during shifting in higher gear
|-
|
TVKUPRS
|
Delay
time for clutch switch during shifting in lower gear
|-
|
TZSPINI
|
Blocking
time for filter initialisation
|-
|
VARAU
|
Minimum
vehicle speed for anti-jerk active
|-
|
WPEDU
|
Pedal
lower threshold value for anti-jerk function
|-
|
B_AR
|
Condition:
anti-jerk active
|-
|
B_ARGF
|
Condition:
anti-jerk transition window
|-
|
B_AUTGET
|
Condition:
automatic gearbox
|-
|
B_BREMS
|
Condition:
brake operated
|-
|
B_DASHV
|
Condition:
dashpot delayed
|-
|
B_FGR
|
Condition:
driver's set engine torque determined by cruise control
|-
|
B_GFEN
|
Condition:
transition window
|-
|
B_GWHS
|
Condition:
gear change on manual transmission vehicle
|-
|
B_HPNMOT
|
Condition:
high-point speed oscillation
|-
|
B_INIAR
|
Condition:
initialization of anti-jerk function
|-
|
B_INIAR1
|
Condition:
provisional initialization of anti-jerk function
|-
|
B_INIARV
|
Condition:
initialization of the filter function is delayed
|-
|
B_KUPGW
|
Condition:
clutch applied until shifting of geanti-jerk is detected
|-
|
B_KUPPL
|
EGAS
Condition: clutch is disengaged
|-
|
B_LL
|
Condition:
idle
|-
|
B_LSD
|
Condition:
limitation of positive torque gradient active
|-
|
B_SA
|
Condition:
fuel cut-off
|-
|
B_STEND
|
Condition:
end of start reached
|-
|
B_TPNMOT
|
Condition:
low-point speed oscillation
|-
|
B_TVARS
|
Condition:
anti-jerking function dynamically active
|-
|
B_TVARSS
|
Condition:
anti-jerking function steady-state active
|-
|
B_WK
|
Condition:
converter lockup clutch closed
|-
|
DMAR_W
|
Delta
torque anti-jerk
|-
|
FDAR
|
Amplification
factor for anti-jerk intervention
|-
|
FLRAR
|
Amplification
factor for modelling of external load
|-
|
GANGI
|
Engaged
gear
|-
|
KIFZ_W
|
Amplification
of vehicle model
|-
|
MDBES_W
|
Acceleration
torque
|-
|
MDVERL_W
|
Resistant
torque of the engine
|-
|
MIFA_W
|
Desired
indicated engine torque
|-
|
MISOLV_W
|
Indicated
resultant nominal torque before torque limitation
|-
|
MKAR_W
|
Calculated
clutch torque for anti-jerk function
|-
|
MLAST_W
|
Estimated
load moment
|-
|
NDAR_W
|
RPM
difference for torque control
|-
|
NDFIL_W
|
Filtered
engine speed difference
|-
|
NDIFFOG_W
|
Threshold
engine speed difference for reset of anti-jerk during braking
|-
|
NDIFF_W
|
Engine
speed difference for ISC amplification
|-
|
NMODIV_W
|
Engine
speed for initialising ARMD calculated from velocity
|-
|
NMOD_W
|
Engine
speed from model
|-
|
NMOT_W
|
Actual
engine speed
|-
|
NVQUOT_W
|
Quotient
engine speed / vehicle speed
|-
|
TMOT
|
Engine
temperature
|-
|
VFZG
|
Vehicle
speed (km/h)
|-
|
VFZG_W
|
Vehicle
speed (km/h, word)
|-
|
WPED_W
|
Normalised
throttle pedal angle (word)
|}

ARMD 10.40 (Torque-Based Anti-Jerk Function)

2012-05-22T19:25:05Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

armd-armd Main function

armd-kifz Subfunction KIFZ (amplification of vehicle model)

armd-flrar Subfunction FLRAR (amplification factor for modelling of external load)

armd-fdar Subfunction FDAR (amplification factor for anti-jerk intervention)

armd-nmoti Subfunction NMOTI

armd-ndfil Subfunction NDFIL (filtered engine speed difference)

armd-frgar Subfunction FRGAR

armd-iniarv Subfunction INIARV

armd-kup gw Subfunction KUPGW

armd-dmar Subfunction DMAR (delta torque anti-jerk)

armd-varss Subfunction VARSS

ARMD 10.40 Function Description

Function purpose

The anti-jerk function detects oscillations of the power train and damps them out by applying opposing-phase torque interventions. The torque intervention is converted into an ignition angle offset by the torque interface.

Desired phase position of the torque intervention

In order to damp the power train oscillation efficiently, the torque intervention should counteract engine speed oscillations. Thereby the same effect is achieved as if the attenuation coefficient of the drive shaft is increased.

Operation pattern of anti-jerk function

Basic idea: a reference speed without oscillation and corresponding to the driver’s demand is evaluated. The difference between desired and actual engine speed isolates the oscillation. A counteracting delta torque is set which is proportional to this oscillation.

The function is realized by a simple vehicle model consisting of an integrator with the constant kifz_w. The input to this integrator is the difference between the driver’s predetermined clutch torque mkar_w and the load torque mlast_w. The output from the integtrator is the modelled engine speed nmod_w. The engine speed difference ndiff_w between the modelled engine speed nmod_w and the actual engine speed nmot_w now forms the basis for the torque intervention as well as for the calculation of the load torque. The load torque is evaluated proportional to the engine speed difference and the factor flrar is taken from the corresponding characteristic line. The engine speed difference ndiff_w contains another offset besides the oscillation part.
This offset is filtered on a 50 ms scan timescale through a discrete second order low pass filter. (Coefficients of the nominator polynomial are denoted A0, A1 and A2 and of the denominator polynomial 1, B1 and B2.

The filtered offset ndfil_w is substracted from the differential engine speed and gives the engine speed oscillation ndar_w.
Proportionally to this engine speed and using the factor fdar, a delta torque as a torque intervention is calculated. If this intervention lays between the limits KFDMDARU and KFDMDARO, it is set to zero.

Activation Conditions

The model is always active, just the intervention can be switched off.

Application Notes

Conditions for calibration of anti-jerk

The basic calibration of the vehicle must have been done. This includes the transition compensation and all functions for the torque interface.

1. Evaluation of the integrator constant kifz_w and flrar

Coarse application:

Drive on the road (flat surface, no hills) at a constant speed in respective gear with the anti-jerk function deactivated (fdar=0).
Then execute a change in load and register the calculated coupling torque mkar_w and the engine speed nmot_w.

Evaluation of integrator constant as follows: at a load step the torque jump is approximately delta M (in %) and the speed approximately rises with constant gradient gradn (in RPM/s). Kifz_w is then calculated from the expression gradn/(delta M). A typical value for second gear is 4.6 x 100/MDNORM [RPM/(sx%)].

Fine application:

Driving on flat surface. Set the product kifz_w x flrar to a fixed value (recommendation: 15). Realization of load jumps with registration of mkar_w, mlast_w, nmot_w and ndiff_w. Vary the couple kifz_w and flrar (maintaining the product constant!) until ndiff_w remains approximately constant during a load jump.

In principle the following process is valid for the amplification factor flrar: high factors cause a reduction of the offset ndfil_w, but also a big phase advance of ndiff_w.

2. Evaluation of filter parameters

Low pass filter in 50 ms scan rate: transmission function has the form G(z) = Z(z)/N(z) with

Z(z) = A0 + A1z-1 + A2z-2
N(z) = 1 + B1z-1 + B2z-2.

Select one of the low pass filters listed in the table below, according to the appearing jerk frequency:

{| border="1"
|-
|
TP No.
|
Limit freq.
|
A0
|
A1
|
A2
|
B1
|
B2
|-
|
1
|
0.67 Hz
|
0.0095
|
0.0191
|
0.0095
|
-1.7056
|
0.7437
|-
|
2
|
0.80 Hz
|
0.0134
|
0.0267
|
0.0134
|
-1.6475
|
0.7009
|-
|
3
|
1.00 Hz
|
0.0201
|
0.0402
|
0.0201
|
-1.5610
|
0.6414
|}

Low pass filter No. 3 is recommended. The attenuation of the jerk frequency is determined by the margin between the jerk frequency and the filter cut-off frequency. The bigger the filter cut-off frequency, the smaller the time the filter needs to stabilize. Attenuation: modification of a single coefficient of G(z) is not permitted!

3. Evaluation of fdar

Recommendation is fdar = 0.67 x 100/MDNORM (%/RPM). Increase of attenuation by enlargement of fdar, reduction of fdar decreases the attenuation.

4. Thresholds KFDMDARO and KFDMDARU

In case the delta torque for the intervention is within these thresholds, it is set to zero. This avoids undesired ignition angle instability. Typical values are: KFDMDARU = -5 x 100/MDNORM [%], KFDMDARO = 5 x 100/MDNORM [%].

Abbreviations

{| border="1"
|-
|
A0
|
Transmission
coefficient
|-
|
A1
|
Transmission
coefficient
|-
|
A2
|
Transmission
coefficient
|-
|
B1
|
Transmission
coefficient
|-
|
B2
|
Transmission
coefficient
|-
|
CWARMD
|
Code
word anti jerk function
|-
|
DMARMX
|
Maximum
limit of the steady-state torque interventions of the anti-jerk function
|-
|
DNFILO
|
Upper
threshold of filter output gradient ndfil
|-
|
DVFZAR
|
Hysteresis
for vehicle speed limit during anti-jerk
|-
|
FLRAWG
|
Integrator
gain factor of the load controller during AT (throttle plate closed)
|-
|
FLRHG
|
Integrator
gain factor of the load controller
|-
|
FRARAWG
|
Integrator
gain factor during AT (throttle plate closed)
|-
|
FRARHG
|
Integrator
gain factor
|-
|
KFDMDADP
|
Upper
threshold for torque-intervention during dashpot
|-
|
KFDMDARO
|
Upper
threshold for torque intervention
|-
|
KFDMDAROS
|
Upper
threshold for steady-state torque intervention
|-
|
KIFZGAWG
|
Integrator
gain factor in the vehicle model with AT (throttle plate closed)
|-
|
KIFZGHG
|
Integrator
gain factor in the vehicle model with HG
|-
|
NARAO
|
Upper
engine speed threshold for anti-jerk function active
|-
|
NARASTG
|
RPM
threshold in higher gear for anti-jerk active
|-
|
NARLLGA
|
Speed
threshold for anti-jerk at idle
|-
|
NDFILOG
|
Threshold
for filter output ndfil
|-
|
NDIFFOG
|
Threshold
engine speed difference for initialization of anti-jerk during braking
|-
|
NVG
|
Factor
to calculate engine speed initialization
|-
|
NVMNG
|
Minimum
speed / velocity ratio
|-
|
NVMXG
|
Maximum
speed / velocity ratio
|-
|
SMK08MDSW
|
Anti-jerk
torque dependent basic point (number =8)
|-
|
TAREIN
|
Blocking
time for anti-jerk function
|-
|
TMAR
|
Lower
engine temperature threshold for anti-jerk release
|-
|
TMLAST
|
Blocking
time until the initialization of the anti-jerk is triggered at deceleration
|-
|
TVARS
|
Delay
time until anti-jerk is inactive again
|-
|
TVARSS
|
Delay
time for anti-jerk becoming inactive again in steady-state conditions
|-
|
TVKUPAR
|
Delay
time for clutch for anti-jerk function
|-
|
TVKUPHS
|
Delay
time for clutch switch during shifting in higher gear
|-
|
TVKUPRS
|
Delay
time for clutch switch during shifting in lower gear
|-
|
TZSPINI
|
Blocking
time for filter initialisation
|-
|
VARAU
|
Minimum
vehicle speed for anti-jerk active
|-
|
WPEDU
|
Pedal
lower threshold value for anti-jerk function
|-
|
B_AR
|
Condition:
anti-jerk active
|-
|
B_ARGF
|
Condition:
anti-jerk transition window
|-
|
B_AUTGET
|
Condition:
automatic gearbox
|-
|
B_BREMS
|
Condition:
brake operated
|-
|
B_DASHV
|
Condition:
dashpot delayed
|-
|
B_FGR
|
Condition:
driver's set engine torque determined by cruise control
|-
|
B_GFEN
|
Condition:
transition window
|-
|
B_GWHS
|
Condition:
gear change on manual transmission vehicle
|-
|
B_HPNMOT
|
Condition:
high-point speed oscillation
|-
|
B_INIAR
|
Condition:
initialization of anti-jerk function
|-
|
B_INIAR1
|
Condition:
provisional initialization of anti-jerk function
|-
|
B_INIARV
|
Condition:
initialization of the filter function is delayed
|-
|
B_KUPGW
|
Condition:
clutch applied until shifting of geanti-jerk is detected
|-
|
B_KUPPL
|
EGAS
Condition: clutch is disengaged
|-
|
B_LL
|
Condition:
idle
|-
|
B_LSD
|
Condition:
limitation of positive torque gradient active
|-
|
B_SA
|
Condition:
fuel cut-off
|-
|
B_STEND
|
Condition:
end of start reached
|-
|
B_TPNMOT
|
Condition:
low-point speed oscillation
|-
|
B_TVARS
|
Condition:
anti-jerking function dynamically active
|-
|
B_TVARSS
|
Condition:
anti-jerking function steady-state active
|-
|
B_WK
|
Condition:
converter lockup clutch closed
|-
|
DMAR_W
|
Delta
torque anti-jerk
|-
|
FDAR
|
Amplification
factor for anti-jerk intervention
|-
|
FLRAR
|
Amplification
factor for modelling of external load
|-
|
GANGI
|
Engaged
gear
|-
|
KIFZ_W
|
Amplification
of vehicle model
|-
|
MDBES_W
|
Acceleration
torque
|-
|
MDVERL_W
|
Resistant
torque of the engine
|-
|
MIFA_W
|
Desired
indicated engine torque
|-
|
MISOLV_W
|
Indicated
resultant nominal torque before torque limitation
|-
|
MKAR_W
|
Calculated
clutch torque for anti-jerk function
|-
|
MLAST_W
|
Estimated
load moment
|-
|
NDAR_W
|
RPM
difference for torque control
|-
|
NDFIL_W
|
Filtered
engine speed difference
|-
|
NDIFFOG_W
|
Threshold
engine speed difference for reset of anti-jerk during braking
|-
|
NDIFF_W
|
Engine
speed difference for ISC amplification
|-
|
NMODIV_W
|
Engine
speed for initialising ARMD calculated from velocity
|-
|
NMOD_W
|
Engine
speed from model
|-
|
NMOT_W
|
Actual
engine speed
|-
|
NVQUOT_W
|
Quotient
engine speed / vehicle speed
|-
|
TMOT
|
Engine
temperature
|-
|
VFZG
|
Vehicle
speed (km/h)
|-
|
VFZG_W
|
Vehicle
speed (km/h, word)
|-
|
WPED_W
|
Normalised
throttle pedal angle (word)
|}

ARMD 10.40 (Torque-Based Anti-Jerk Function)

2012-05-22T19:23:27Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

armd-armd Main function

armd-kifz Subfunction KIFZ (amplification of vehicle model)

armd-flrar Subfunction FLRAR (amplification factor for modelling of external load)

armd-fdar Subfunction FDAR (amplification factor for anti-jerk intervention)

armd-nmoti Subfunction NMOTI

armd-ndfil Subfunction NDFIL (filtered engine speed difference)

armd-frgar Subfunction FRGAR

armd-iniarv Subfunction INIARV

armd-kup gw Subfunction KUPGW

armd-dmar Subfunction DMAR (delta torque anti-jerk)

armd-varss Subfunction VARSS

ARMD 10.40 Function Description

Function purpose

The anti-jerk function detects oscillations of the power train and damps them out by applying opposing-phase torque interventions. The torque intervention is converted into an ignition angle offset by the torque interface.

Desired phase position of the torque intervention

In order to damp the power train oscillation efficiently, the torque intervention should counteract engine speed oscillations. Thereby the same effect is achieved as if the attenuation coefficient of the drive shaft is increased.

Operation pattern of anti-jerk function

Basic idea: a reference speed without oscillation and corresponding to the driver’s demand is evaluated. The difference between desired and actual engine speed isolates the oscillation. A counteracting delta torque is set which is proportional to this oscillation.

The function is realized by a simple vehicle model consisting of an integrator with the constant kifz_w. The input to this integrator is the difference between the driver’s predetermined clutch torque mkar_w and the load torque mlast_w. The output from the integtrator is the modelled engine speed nmod_w. The engine speed difference ndiff_w between the modelled engine speed nmod_w and the actual engine speed nmot_w now forms the basis for the torque intervention as well as for the calculation of the load torque. The load torque is evaluated proportional to the engine speed difference and the factor flrar is taken from the corresponding characteristic line. The engine speed difference ndiff_w contains another offset besides the oscillation part.
This offset is filtered on a 50 ms scan timescale through a discrete second order low pass filter. (Coefficients of the nominator polynomial are denoted A0, A1 and A2 and of the denominator polynomial 1, B1 and B2.

The filtered offset ndfil_w is substracted from the differential engine speed and gives the engine speed oscillation ndar_w.
Proportionally to this engine speed and using the factor fdar, a delta torque as a torque intervention is calculated. If this intervention lays between the limits KFDMDARU and KFDMDARO, it is set to zero.

Activation Conditions

The model is always active, just the intervention can be switched off.

Application Notes

Conditions for calibration of anti-jerk

The basic calibration of the vehicle must have been done. This includes the transition compensation and all functions for the torque interface.

1. Evaluation of the integrator constant kifz_w and flrar

Coarse application:
Drive on the road (flat surface, no hills) at a constant speed in respective gear with the anti-jerk function deactivated (fdar=0).
Then execute a change in load and register the calculated coupling torque mkar_w and the engine speed nmot_w.

Evaluation of integrator constant as follows: at a load step the torque jump is approximately delta M (in %) and the speed approximately rises with constant gradient gradn (in RPM/s). Kifz_w is then calculated from the expression gradn/(delta M). A typical value for second gear is 4.6 x 100/MDNORM [RPM/(sx%)].

Fine application:
Driving on flat surface. Set the product kifz_w x flrar to a fixed value (recommendation: 15). Realization of load jumps with registration of mkar_w, mlast_w, nmot_w and ndiff_w. Vary the couple kifz_w and flrar (maintaining the product constant!) until ndiff_w remains approximately constant during a load jump.

In principle the following process is valid for the amplification factor flrar: high factors cause a reduction of the offset ndfil_w, but also a big phase advance of ndiff_w.

2. Evaluation of filter parameters
Low pass filter in 50 ms scan rate: transmission function has the form G(z) = Z(z)/N(z) with

Z(z) = A0 + A1z-1 + A2z-2
N(z) = 1 + B1z-1 + B2z-2.

Select one of the low pass filters listed in the table below, according to the appearing jerk frequency:

{| border="1"
|-
|
TP No.
|
Limit freq.
|
A0
|
A1
|
A2
|
B1
|
B2
|-
|
1
|
0.67 Hz
|
0.0095
|
0.0191
|
0.0095
|
-1.7056
|
0.7437
|-
|
2
|
0.80 Hz
|
0.0134
|
0.0267
|
0.0134
|
-1.6475
|
0.7009
|-
|
3
|
1.00 Hz
|
0.0201
|
0.0402
|
0.0201
|
-1.5610
|
0.6414
|}

Low pass filter No. 3 is recommended. The attenuation of the jerk frequency is determined by the margin between the jerk frequency and the filter cut-off frequency. The bigger the filter cut-off frequency, the smaller the time the filter needs to stabilize. Attenuation: modification of a single coefficient of G(z) is not permitted!

3. Evaluation of fdar

Recommendation is fdar = 0.67 x 100/MDNORM (%/RPM). Increase of attenuation by enlargement of fdar, reduction of fdar decreases the attenuation.

4. Thresholds KFDMDARO and KFDMDARU

In case the delta torque for the intervention is within these thresholds, it is set to zero. This avoids undesired ignition angle instability. Typical values are: KFDMDARU = -5 x 100/MDNORM [%], KFDMDARO = 5 x 100/MDNORM [%].

Abbreviations

{| border="1"
|-
|
A0
|
Transmission
coefficient
|-
|
A1
|
Transmission
coefficient
|-
|
A2
|
Transmission
coefficient
|-
|
B1
|
Transmission
coefficient
|-
|
B2
|
Transmission
coefficient
|-
|
CWARMD
|
Code
word anti jerk function
|-
|
DMARMX
|
Maximum
limit of the steady-state torque interventions of the anti-jerk function
|-
|
DNFILO
|
Upper
threshold of filter output gradient ndfil
|-
|
DVFZAR
|
Hysteresis
for vehicle speed limit during anti-jerk
|-
|
FLRAWG
|
Integrator
gain factor of the load controller during AT (throttle plate closed)
|-
|
FLRHG
|
Integrator
gain factor of the load controller
|-
|
FRARAWG
|
Integrator
gain factor during AT (throttle plate closed)
|-
|
FRARHG
|
Integrator
gain factor
|-
|
KFDMDADP
|
Upper
threshold for torque-intervention during dashpot
|-
|
KFDMDARO
|
Upper
threshold for torque intervention
|-
|
KFDMDAROS
|
Upper
threshold for steady-state torque intervention
|-
|
KIFZGAWG
|
Integrator
gain factor in the vehicle model with AT (throttle plate closed)
|-
|
KIFZGHG
|
Integrator
gain factor in the vehicle model with HG
|-
|
NARAO
|
Upper
engine speed threshold for anti-jerk function active
|-
|
NARASTG
|
RPM
threshold in higher gear for anti-jerk active
|-
|
NARLLGA
|
Speed
threshold for anti-jerk at idle
|-
|
NDFILOG
|
Threshold
for filter output ndfil
|-
|
NDIFFOG
|
Threshold
engine speed difference for initialization of anti-jerk during braking
|-
|
NVG
|
Factor
to calculate engine speed initialization
|-
|
NVMNG
|
Minimum
speed / velocity ratio
|-
|
NVMXG
|
Maximum
speed / velocity ratio
|-
|
SMK08MDSW
|
Anti-jerk
torque dependent basic point (number =8)
|-
|
TAREIN
|
Blocking
time for anti-jerk function
|-
|
TMAR
|
Lower
engine temperature threshold for anti-jerk release
|-
|
TMLAST
|
Blocking
time until the initialization of the anti-jerk is triggered at deceleration
|-
|
TVARS
|
Delay
time until anti-jerk is inactive again
|-
|
TVARSS
|
Delay
time for anti-jerk becoming inactive again in steady-state conditions
|-
|
TVKUPAR
|
Delay
time for clutch for anti-jerk function
|-
|
TVKUPHS
|
Delay
time for clutch switch during shifting in higher gear
|-
|
TVKUPRS
|
Delay
time for clutch switch during shifting in lower gear
|-
|
TZSPINI
|
Blocking
time for filter initialisation
|-
|
VARAU
|
Minimum
vehicle speed for anti-jerk active
|-
|
WPEDU
|
Pedal
lower threshold value for anti-jerk function
|-
|
B_AR
|
Condition:
anti-jerk active
|-
|
B_ARGF
|
Condition:
anti-jerk transition window
|-
|
B_AUTGET
|
Condition:
automatic gearbox
|-
|
B_BREMS
|
Condition:
brake operated
|-
|
B_DASHV
|
Condition:
dashpot delayed
|-
|
B_FGR
|
Condition:
driver's set engine torque determined by cruise control
|-
|
B_GFEN
|
Condition:
transition window
|-
|
B_GWHS
|
Condition:
gear change on manual transmission vehicle
|-
|
B_HPNMOT
|
Condition:
high-point speed oscillation
|-
|
B_INIAR
|
Condition:
initialization of anti-jerk function
|-
|
B_INIAR1
|
Condition:
provisional initialization of anti-jerk function
|-
|
B_INIARV
|
Condition:
initialization of the filter function is delayed
|-
|
B_KUPGW
|
Condition:
clutch applied until shifting of geanti-jerk is detected
|-
|
B_KUPPL
|
EGAS
Condition: clutch is disengaged
|-
|
B_LL
|
Condition:
idle
|-
|
B_LSD
|
Condition:
limitation of positive torque gradient active
|-
|
B_SA
|
Condition:
fuel cut-off
|-
|
B_STEND
|
Condition:
end of start reached
|-
|
B_TPNMOT
|
Condition:
low-point speed oscillation
|-
|
B_TVARS
|
Condition:
anti-jerking function dynamically active
|-
|
B_TVARSS
|
Condition:
anti-jerking function steady-state active
|-
|
B_WK
|
Condition:
converter lockup clutch closed
|-
|
DMAR_W
|
Delta
torque anti-jerk
|-
|
FDAR
|
Amplification
factor for anti-jerk intervention
|-
|
FLRAR
|
Amplification
factor for modelling of external load
|-
|
GANGI
|
Engaged
gear
|-
|
KIFZ_W
|
Amplification
of vehicle model
|-
|
MDBES_W
|
Acceleration
torque
|-
|
MDVERL_W
|
Resistant
torque of the engine
|-
|
MIFA_W
|
Desired
indicated engine torque
|-
|
MISOLV_W
|
Indicated
resultant nominal torque before torque limitation
|-
|
MKAR_W
|
Calculated
clutch torque for anti-jerk function
|-
|
MLAST_W
|
Estimated
load moment
|-
|
NDAR_W
|
RPM
difference for torque control
|-
|
NDFIL_W
|
Filtered
engine speed difference
|-
|
NDIFFOG_W
|
Threshold
engine speed difference for reset of anti-jerk during braking
|-
|
NDIFF_W
|
Engine
speed difference for ISC amplification
|-
|
NMODIV_W
|
Engine
speed for initialising ARMD calculated from velocity
|-
|
NMOD_W
|
Engine
speed from model
|-
|
NMOT_W
|
Actual
engine speed
|-
|
NVQUOT_W
|
Quotient
engine speed / vehicle speed
|-
|
TMOT
|
Engine
temperature
|-
|
VFZG
|
Vehicle
speed (km/h)
|-
|
VFZG_W
|
Vehicle
speed (km/h, word)
|-
|
WPED_W
|
Normalised
throttle pedal angle (word)
|}

ARMD 10.40 (Torque-Based Anti-Jerk Function)

2012-05-22T19:20:47Z

TTQS: Created page with "See the ''funktionsrahmen'' for the following diagrams: armd-armd Main function armd-kifz Subfunction KIFZ (amplification of vehicle model) armd-flrar Subfunction FLRAR (amplif..."

See the ''funktionsrahmen'' for the following diagrams:

armd-armd Main function
armd-kifz Subfunction KIFZ (amplification of
vehicle model)
armd-flrar Subfunction FLRAR (amplification
factor for modelling of external load)
armd-fdar Subfunction FDAR (amplification factor
for anti-jerk intervention)
armd-nmoti Subfunction NMOTI
armd-ndfil Subfunction NDFIL (filtered engine
speed difference)
armd-frgar Subfunction FRGAR
armd-iniarv Subfunction INIARV
armd-kup gw Subfunction
KUPGW
armd-dmar Subfunction DMAR (delta torque anti-jerk)
armd-varss Subfunction VARSS

ARMD 10.40 Function Description
Function purpose
The anti-jerk function detects oscillations of the power train and damps them out by applying opposing-phase torque interventions. The torque intervention is converted into an ignition angle offset by the torque interface.

Desired phase position of the torque intervention
In order to damp the power train oscillation efficiently, the torque intervention should counteract engine speed oscillations. Thereby the same effect is achieved as if the attenuation coefficient of the drive shaft is increased.

Operation pattern of anti-jerk function
Basic idea: a reference speed without oscillation and corresponding to the driver’s demand is evaluated. The difference between desired and actual engine speed isolates the oscillation. A counteracting delta torque is set which is proportional to this oscillation.
The function is realized by a simple vehicle model consisting of an integrator with the constant kifz_w. The input to this integrator is the difference between the driver’s predetermined clutch torque mkar_w and the load torque mlast_w. The output from the integtrator is the modelled engine speed nmod_w. The engine speed difference ndiff_w between the modelled engine speed nmod_w and the actual engine speed nmot_w now forms the basis for the torque intervention as well as for the calculation of the load torque. The load torque is evaluated proportional to the engine speed difference and the factor flrar is taken from the corresponding characteristic line. The engine speed difference ndiff_w contains another offset besides the oscillation part.
This offset is filtered on a 50 ms scan timescale through a discrete second order low pass filter. (Coefficients of the nominator polynomial are denoted A0, A1 and A2 and of the denominator polynomial 1, B1 and B2.
The filtered offset ndfil_w is substracted from the differential engine speed and gives the engine speed oscillation ndar_w.
Proportionally to this engine speed and using the factor fdar, a delta torque as a torque intervention is calculated. If this intervention lays between the limits KFDMDARU and KFDMDARO, it is set to zero.

Activation Conditions
The model is always active, just the intervention can be switched off.

Application Notes

Conditions for calibration of anti-jerk The basic calibration of the vehicle must have been done. This includes the transition compensation and all functions for the torque interface.

1. Evaluation of the integrator constant kifz_w and flrar

Coarse application:
Drive on the road (flat surface, no hills) at a constant speed in respective gear with the anti-jerk function deactivated (fdar=0).
Then execute a change in load and register the calculated coupling torque mkar_w and the engine speed nmot_w.
Evaluation of integrator constant as follows: at a load step the torque jump is approximately delta M (in %) and the speed approximately rises with constant gradient gradn (in RPM/s). Kifz_w is then calculated from the expression gradn/(delta M). A typical value for second gear is 4.6 × 100/MDNORM [RPM/(sx%)].

Fine application:
Driving on flat surface. Set the product kifz_w x flrar to a fixed value (recommendation: 15). Realization of load jumps with registration of mkar_w, mlast_w, nmot_w and ndiff_w. Vary the couple kifz_w and flrar (maintaining the product constant!) until ndiff_w remains approximately constant during a load jump.

In principle the following process is valid for the amplification factor flrar: high factors cause a reduction of the offset ndfil_w, but also a big phase advance of ndiff_w.

2. Evaluation of filter parameters
Low pass filter in 50 ms scan rate: transmission function has the form G(z) = Z(z)/N(z) with

Z(z) = A0 + A1xz-1 + A2xz-2
N(z) = 1 + B1xz-1 + B2xz-2.

Select one of the low pass filters listed in the table below, according to the appearing jerk frequency:

{| border="1"
|-
|
TP No.
|
Limit freq.
|
A0
|
A1
|
A2
|
B1
|
B2
|-
|
1
|
0.67 Hz
|
0.0095
|
0.0191
|
0.0095
|
-1.7056
|
0.7437
|-
|
2
|
0.80 Hz
|
0.0134
|
0.0267
|
0.0134
|
-1.6475
|
0.7009
|-
|
3
|
1.00 Hz
|
0.0201
|
0.0402
|
0.0201
|
-1.5610
|
0.6414
|}

Low pass filter No. 3 is recommended. The attenuation of the jerk frequency is determined by the margin between the jerk frequency and the filter cut-off frequency. The bigger the filter cut-off frequency, the smaller the time the filter needs to stabilize. Attenuation: modification of a single coefficient of G(z) is not permitted!

3. Evaluation of fdar
Recommendation is fdar = 0.67 × 100/MDNORM (%/RPM). Increase of attenuation by enlargement of fdar, reduction of fdar decreases the attenuation.

4. Thresholds KFDMDARO and KFDMDARU

In case the delta torque for the intervention is within these thresholds, it is set to zero. This avoids undesired ignition angle instability. Typical values are: KFDMDARU = -5 × 100/MDNORM [%], KFDMDARO = 5 × 100/MDNORM [%].

Abbreviations

{| border="1"
|-
|
A0
|
Transmission
coefficient
|-
|
A1
|
Transmission
coefficient
|-
|
A2
|
Transmission
coefficient
|-
|
B1
|
Transmission
coefficient
|-
|
B2
|
Transmission
coefficient
|-
|
CWARMD
|
Code
word anti jerk function
|-
|
DMARMX
|
Maximum
limit of the steady-state torque interventions of the anti-jerk function
|-
|
DNFILO
|
Upper
threshold of filter output gradient ndfil
|-
|
DVFZAR
|
Hysteresis
for vehicle speed limit during anti-jerk
|-
|
FLRAWG
|
Integrator
gain factor of the load controller during AT (throttle plate closed)
|-
|
FLRHG
|
Integrator
gain factor of the load controller
|-
|
FRARAWG
|
Integrator
gain factor during AT (throttle plate closed)
|-
|
FRARHG
|
Integrator
gain factor
|-
|
KFDMDADP
|
Upper
threshold for torque-intervention during dashpot
|-
|
KFDMDARO
|
Upper
threshold for torque intervention
|-
|
KFDMDAROS
|
Upper
threshold for steady-state torque intervention
|-
|
KIFZGAWG
|
Integrator
gain factor in the vehicle model with AT (throttle plate closed)
|-
|
KIFZGHG
|
Integrator
gain factor in the vehicle model with HG
|-
|
NARAO
|
Upper
engine speed threshold for anti-jerk function active
|-
|
NARASTG
|
RPM
threshold in higher gear for anti-jerk active
|-
|
NARLLGA
|
Speed
threshold for anti-jerk at idle
|-
|
NDFILOG
|
Threshold
for filter output ndfil
|-
|
NDIFFOG
|
Threshold
engine speed difference for initialization of anti-jerk during braking
|-
|
NVG
|
Factor
to calculate engine speed initialization
|-
|
NVMNG
|
Minimum
speed / velocity ratio
|-
|
NVMXG
|
Maximum
speed / velocity ratio
|-
|
SMK08MDSW
|
Anti-jerk
torque dependent basic point (number =8)
|-
|
TAREIN
|
Blocking
time for anti-jerk function
|-
|
TMAR
|
Lower
engine temperature threshold for anti-jerk release
|-
|
TMLAST
|
Blocking
time until the initialization of the anti-jerk is triggered at deceleration
|-
|
TVARS
|
Delay
time until anti-jerk is inactive again
|-
|
TVARSS
|
Delay
time for anti-jerk becoming inactive again in steady-state conditions
|-
|
TVKUPAR
|
Delay
time for clutch for anti-jerk function
|-
|
TVKUPHS
|
Delay
time for clutch switch during shifting in higher gear
|-
|
TVKUPRS
|
Delay
time for clutch switch during shifting in lower gear
|-
|
TZSPINI
|
Blocking
time for filter initialisation
|-
|
VARAU
|
Minimum
vehicle speed for anti-jerk active
|-
|
WPEDU
|
Pedal
lower threshold value for anti-jerk function
|-
|
B_AR
|
Condition:
anti-jerk active
|-
|
B_ARGF
|
Condition:
anti-jerk transition window
|-
|
B_AUTGET
|
Condition:
automatic gearbox
|-
|
B_BREMS
|
Condition:
brake operated
|-
|
B_DASHV
|
Condition:
dashpot delayed
|-
|
B_FGR
|
Condition:
driver's set engine torque determined by cruise control
|-
|
B_GFEN
|
Condition:
transition window
|-
|
B_GWHS
|
Condition:
gear change on manual transmission vehicle
|-
|
B_HPNMOT
|
Condition:
high-point speed oscillation
|-
|
B_INIAR
|
Condition:
initialization of anti-jerk function
|-
|
B_INIAR1
|
Condition:
provisional initialization of anti-jerk function
|-
|
B_INIARV
|
Condition:
initialization of the filter function is delayed
|-
|
B_KUPGW
|
Condition:
clutch applied until shifting of geanti-jerk is detected
|-
|
B_KUPPL
|
EGAS
Condition: clutch is disengaged
|-
|
B_LL
|
Condition:
idle
|-
|
B_LSD
|
Condition:
limitation of positive torque gradient active
|-
|
B_SA
|
Condition:
fuel cut-off
|-
|
B_STEND
|
Condition:
end of start reached
|-
|
B_TPNMOT
|
Condition:
low-point speed oscillation
|-
|
B_TVARS
|
Condition:
anti-jerking function dynamically active
|-
|
B_TVARSS
|
Condition:
anti-jerking function steady-state active
|-
|
B_WK
|
Condition:
converter lockup clutch closed
|-
|
DMAR_W
|
Delta
torque anti-jerk
|-
|
FDAR
|
Amplification
factor for anti-jerk intervention
|-
|
FLRAR
|
Amplification
factor for modelling of external load
|-
|
GANGI
|
Engaged
gear
|-
|
KIFZ_W
|
Amplification
of vehicle model
|-
|
MDBES_W
|
Acceleration
torque
|-
|
MDVERL_W
|
Resistant
torque of the engine
|-
|
MIFA_W
|
Desired
indicated engine torque
|-
|
MISOLV_W
|
Indicated
resultant nominal torque before torque limitation
|-
|
MKAR_W
|
Calculated
clutch torque for anti-jerk function
|-
|
MLAST_W
|
Estimated
load moment
|-
|
NDAR_W
|
RPM
difference for torque control
|-
|
NDFIL_W
|
Filtered
engine speed difference
|-
|
NDIFFOG_W
|
Threshold
engine speed difference for reset of anti-jerk during braking
|-
|
NDIFF_W
|
Engine
speed difference for ISC amplification
|-
|
NMODIV_W
|
Engine
speed for initialising ARMD calculated from velocity
|-
|
NMOD_W
|
Engine
speed from model
|-
|
NMOT_W
|
Actual
engine speed
|-
|
NVQUOT_W
|
Quotient
engine speed / vehicle speed
|-
|
TMOT
|
Engine
temperature
|-
|
VFZG
|
Vehicle
speed (km/h)
|-
|
VFZG_W
|
Vehicle
speed (km/h, word)
|-
|
WPED_W
|
Normalised
throttle pedal angle (word)
|}

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2012-05-22T19:20:23Z

TTQS:

=NefMoto Wiki - Welcome!=
The NefMoto site is a collective body of VW/Audi ME7 ECU tuning information.

==Overview==
*[[Getting Started]]

==Flashing==
*[[NefMoto ECU Flashing Software]] - Free, fast and reliable ECU flashing
*[[ECU Bench Flashing]]
*[[Galletto 1260 Flashing Cable]] - Recover a failed flash in [[ECU Boot Mode|boot mode]]

==Software Tools==
*[http://www.nefariousmotorsports.com/wiki/index.php/NefMoto_ECU_Flashing_Software NefMoto]
*[[Me7 Logger]]
**[[GUI for Me7 Logger]]
**[[Innovate LC1 / ME7 Logger]]
*[http://www.nefariousmotorsports.com/forum/index.php/topic,447.0title,.html ME7Check]
**[http://nefariousmotorsports.com/forum/index.php/topic,447.msg9477.html#msg9477 Gui for ME7Check]
*[[ECUxPlot]]
*[[ME7_95040 EEPROM programmer - Read over OBD / (Boot mode Write)]]
*[[Findmap v0.3b]]
*[http://nefariousmotorsports.com/forum/index.php?action=dlattach;topic=639.0;attach=720 Galletto 1260]

==Motronic 7 (ME7.x) Breakdown==
*[http://s4wiki.com/wiki/Tuning S4Wiki.org Tuning guide] <- A must read!
*[[Funktionsrahmen|Bosch ME7.x Funktionsrahmen]]
*[[Checksums]]
*[[ME7 Tuning Information]]
*[[ME7 Communication Protocol Information]]
Manually translated modules
*[[ARMD 10.40 (Torque-Based Anti-Jerk Function)]]
*[[ATM 33.50 (Exhaust Gas Temperature Model)]]
*[[ATR 1.60 (Exhaust Gas Temperature Control)]]
*[[BGSRM 17.10 (Cylinder Charge Detection, Intake Manifold Model)]]
*[[FUEDK 21.90 (Cylinder Charge Control, Calculating Target Throttle Angle)]]
*[[GGHFM 57.60 (MAF Meter System Pulsations)]]
*[[KRDY 17.120 (Dynamic Knock Control)]]
*[[KRRA 15.130 (Knock Control with Individual Cylinder Retard)]]
*[[LAMBTS 2.120 (Lambda for Component Protection)]]
*[[LAMFAW 7.100 (Driver's Requested Lambda)]]
*[[LAMKO 9.80 (Lambda Coordination)]]
*[[LDRLMX 3.100 (Calculation of LDR Maximum Cylinder Charge rlmax)]]
*[[LDRPID 25.10 (Charge Pressure Regulation PID Control)]]
*[[LRSHK 9.20 (Continuous Post-Catalyst Lambda Control)]]
*[[MDBAS 8.30 (Calculation of the Basic Parameters for the Torque Interface)]]
*[[MDFAW 12.260 (Driver Requested Torque)]]
*[[MDFUE 8.50 (Setpoint for Air Mass from Load Torque)]]
*[[MDKOG 14.70 (Torque Coordination for Overall Interventions)]]
*[[MDZW 1.120 (Calculating Torque at the Desired Ignition Angle)]]
*[[RKTI 11.40 (Calculation of Injection Time ti from Relative Fuel Mass rk)]]
*[[SLS 88.150 (Secondary Air Control)]]
*[[ZUE 282.130 (Fundamental Function - Ignition)]]
*[[ZWGRU 23.110 (Fundamental Ignition Angle)]]

==Motronic MED9 Breakdown==

*[[MED9 Abbreviations in English (A-C)]]
*[[MED9 Abbreviations in English (D-F)]]
*[[MED9 Abbreviations in English (G-L)]]
*[[MED9 Abbreviations in English (M-Q)]]
*[[MED9 Abbreviations in English (R-S)]]
*[[MED9 Abbreviations in English (T)]]
*[[MED9 Abbreviations in English (U-Z)]]
*[http://nefariousmotorsports.com/forum/index.php?topic=1353.0 Download all as Excel workbook]

==Development==
*[[Reverse Engineering Generic Guide]]
*[[Camden's ME7.5 Reverse Engineering]]
*[[ECU pin outs]]

==Vehicle Information==
*[[Volkswagen]]
*[[Audi]]

KRRA 15.130 (Knock Control with Individual Cylinder Retard)

2012-05-03T18:30:50Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

krra-main KRRA: knock control including steady state adaptation

krra-bbkrra BBKRRA: release of knock control and adaptation

krra-bbkr BBKR: release of knock control and adaptation

krra-bb-krdws BB-KRDWS: condition for safety retard of ignition

krra-bb-lzf BB-LZF: release of leading cylinder function

krra-lzist LZIST: determination of led and leading cylinders

krra-uewkr UEWKR: overwrite ignition retard of led cylinders

krra-wkral WKRAL: Update of the cylinder selective ignition retard at adaptation area change (wkra -- > wkr)

krra-wkrber WKRBER: Calculation of ignition retard

krra-krvf FRUEHVERST: Release of ignition advance adjustment

krra-wkri WKRI: calculation of the average ignition retard

krra-begwkr BEGWKR: limitation of ignition retard after reading adaptation map

krra-stkra STKRA: Detection of load- and speed range

krra-kr-adap KR_ADAP: Adaptation of ignition retard

krra-vswkr VSWKR: Ignition adjustment with VS2x

krra-kr-freeze KR-FREEZE: calculation of ignition retard for frozen knock control

krra-initialise Initialise function

Note: The cylinder-specific variables wkr, dwkrz, wkra and zkrvf are indicated in the following description through a control variable (i) - like in the ECU code, for example wkr(i). The corresponding RAM-cell which can be read via VS100 is marked by _i, for example: wkr_i.

The Knock Control cylinder counter zzylkr serves as control variable (except wkra). The following applies to it:

zzylkr = 1 ... SY_ZYLZA ASCET-Model
zzylkr = 0 ... SY_ZYLZA-1 ECU-Code

See also the Application Notes section in this module.

KRRA 15.130 Function Description

Function of Knock Control

The KRRA module includes calculation of the cylinder-specific change of ignition angle of the knock control and adaptive calculation of the cylinder-specific retarding wkr(i) (WKRBER) with storage in an adaptation characteristic map wkra(i) (KR ADAP). The input values of the adaptation map are current cylinder number, engine speed and load (STKRA).

The value of the retarding dwkrz(i) which is passed on to the ignition comes to dependent on the operating condition (BBKC):

1. B_kr & !B_krdws & !B_llr dwkrz(i) = wkr(i)

2. B_kr & B_krdws dwkrz(i) = krdwsw KRDWS – Safety retarding see modules DKRS, DKRNT and DKRTP

3. B_kr & !B_krdws & B_llr dwkrz(i) = wkrm wkrm – average retard over all cylinders

4. !B_kr & (!)B_krdws dwkrz(i) = 0

Condition for active Knock Control without exhaust gas recirculation B_kr: ((rl > LKRN) v B_krldy) & (tmot > TMKR) &

B_stend & (nmot > NKRF) Condition for active Knock Control with exhaust gas recirculation B_kr: (( rl > LKRAGRN) v B_krldy) & (tmot > TMKR) &

B_stend & (nmot > NKRF) Condition for active adaptation: B_kra : B_kr & (tmot > TMKRA)

The lower speed threshold NKRF should prevent the engine stalling at low speed by Knock Control-Ignition Angle-intervention.

Co-ordination of the Ignition Angle for Torque Management

When knock control is active, the earliest cylinder-specific ignition angle results:

KFZW + dwkrz(i) + wkrdy (wkrdy is derived dynamically from module KRDY, included in module ZUE)

There are two types of control action:

1. Output ignition angle = KFZW + dwkrz(i) + wkrdy --> B_zwkraa = 1 --> knock control algorithm remains unchanged.

2. Output ignition angle < KFZW + dwkrz(i) + wkrdy --> B_zwkraa = 0 --> advancing algorithm of wkr(i) is frozen and knock
control adaptation is disabled. (due to exhaust gas reasons, Stability Program operation, idle control, etc.)

In module ZUE the bit B zwkra is formed synchronously to the ignition angle output and it is then stored in the corresponding position in bit array zwkrafld. E.g. B_zwkraa is then determined from zwkrafld as follows:
SW cylinder counter

{| border="1"
|-
|
(zzylkr)
|
5
|
4
|
3
|
2
|
1
|
0
|
|-
|
B_zwkra
|
1
|
1
|
0
|
1
|
0
|
0
|
zwkrafld = 25 + 24
+ 22 = 52
|}

B_zwkraa (zzylkr = 3) = 0 (= false)

Please note: Signs of the ignition angle (in degrees crankshaft (°KW)) according to mathematical convention.

KFZW > 0 (with TDC as the point of reference, ignition "before" DTC means mathematically positive angles KFZW)
dwkrz(i) £ 0 ("retard" timing with regard to the basis ignition angle means mathematically negative dwkrz(i))

Retarding of the ignition angle without adaptation (WKRBER)

If B_kr and !B_kra are set the knock control operates as follows:

If a knocking combustion (B_kl) is detected in module KRKE then the ignition angle of the corresponding cylinder i is adjusted by
retarding it by an amount KRFKN per knock event. If the engine is in the Knock Control-steady-state operation, is adjusted by retarding it by an amount KRFKLN per knock event. This cylinder-individual retarding is added independently of load and engine speed in the RAM area wkr(i).

For engine smoothness reasons and in order to avoid spurious misfire detections, the retarding is limited in each calculation to a
range around the mean value wkrm of the latest given SY_ZYLZA retardings wkr(i), given by wkrm plus/minus a freely selectable threshold. This threshold DWKRMSN is a characteristic line over the engine speed.

Additionally the retarding is limited in wkr(i) towards retard to KRMXN and towards advance to 0°.

wkr is a RAM-area in which a RAM-cell is reserved for each cylinder.

If the “Knock Control active” operating range of the engine is left (!B kr) then the latest present retarding remains stored in
wkr(i) until the “Knock Control active” range is entered again. The same applies for wkrm.

In the “Knock Control not-active” range of the engine zero is passed on to module ZUE as adjustment value dwkrz(i).

If the ignition is switched off, the retardings in wkr(i) are set equal to zero.

Advancing of the ignition angle (WKRBER & FRUEHVERST)

The retardings from wkr(i) are cancelled on a cylinder-specific basis if B_kr is set and if a cylinder-specific advancing
counter zkrvf(i) has reached zero.

During each knock event B_kl, the cylinder-specific counter zkrvf(i) is populated with the value KRVFN. Each non-knocking combustion in cylinder i for which in addition B zwkraa = 1 applies (i.e. the given ignition angle was limited by Knock Control) decrements zkrvf(i) by 1. When zkrvf(i) = 0 is reached, the retarding in wkr(i) assigned to the corresponding cylinder is
decremented by one quantization step and the counter is again populated with KRVFN.

During each timing towards advance, the wkr(i) are limited to the mean value wkrm of the latest given retarding SY_ZYLZA minus a
freely selectable threshold DWKRMSN or to the value zero.

If the “Knock Control active” operating range of the engine is left (!B_kr) the latest available counter values remain stored in zkrvf(i) until the “Knock Control active” range is entered again.

If the ignition is switched off, the counter values inzkrvf(i) are set equal to zero.

If changed engine operating conditions result in a reduced tendency to knock, a quicker advancing of the wkr(i) is performed until
the first knock event occurs after the beginning of this quick advancing. In this case, the counters zkrvf(i) are started when KRVFSN < KRVFN. The condition for the start of the quick advancing is either the transition from reading adaptation values wkra(i) to wkr(i) or the termination of a dynamic phase or a negative load range shift.

There should be no quick advance during dynamic operation (B_krldya / B_krndy = 1).

Knock Control Steady-State Mode

In Knock Control steady-state mode, the ignition angle per knock event is retarded by the value KRFKLN or KRFKN. So that the knock
frequency at different retards is not too high, the Knock Control steady-state mode advance adjustment speed adjusted by KRLVFKN.

The Knock Control steady-state operation is indicated by B_krstatb. This bit is set if |drl| < DRLKRSTMX and |ngfil| < NGKRSTMX
for TVKRSTAT seconds.

Retarding of the ignition angle with adaptation (KR ADAP)

B_kra = B_kr & (tmot > TMKRA) --> Adaptation active

B_krafrz = B_kra & ((rl < lkraw) || (tmot < TMKRAS) || (nmot < NKRAMIN) || (nmot > NKRAMX) || B_asr || B_nmax ||
B_vmax) --> Learning the adaptation values is prohibited

The adaptation ensures that also for strongly map-dependent varying retardings the knock frequency does not increase in case
of quick changes of the map ranges. For this purpose, when adaptation is active, the current retards under certain conditions are written in a load-speed-dependent adaptation map (see Storage) or overwritten with the values stored in the map (see Read). Read access to the adaptation map is only enabled when the engine temperature is stable and when there is a significant knock control demand (i.e. TMKRA >= TMKR), whereas the knock control must be activated even at low knock control demands (worst case conditions). Write accesses to the adaptation map are enabled until the second temperature threshold (TMKRAS ³ TMKRA) and the second load threshold (LKRAN >= LKRN) are exceeded. This prevents, on the one hand, spurious adaptation due to retardings during warm-up and on the other hand, a learning of the adaptation value to 0 at lower loads.

A RAM cell is reserved in the adaptation map wkra for each load- and speed range per cylinder. The load and speed limits are removed for administration labels (KRAL1-3N or KRAN1-4). The values stored there will be used as the limiting values in case of increasing load or speed.

In case of decreasing load or engine speed, an adjustable hysteresis (KRALH, KRANH) is subtracted from these values.

The current load range is stored in stkrlx, the speed range in stkrnx.

When the ignition is switched off all values remain stored in wkra. If the supply voltage of the ECU is disconnected the values are
lost. After the supply voltage of the ECU has been reconnected all values are set to 0.

DIAGRAM

For the indexing of the wkra(i) - RAM-cells the following specification is used in the SW:
i = zzylkr + (8 x stkrnx) + (40 x stkrlx zzylkr) = 0...7, so at the maximum, 8 cylinders can be represented.

stkrnx = 0...4, 5 engine speed ranges

stkrlx = 0...3, 4 load ranges (value of 0 is notwithstanding the ASCET-Model!)

The wkra of the current adaptation range can be obtained from the RAM cells wkraa_i, i = 0 ... SY_ZYLZA-1

Adaptation - Learning Conditions:

The following conditions update the adaptation map:

1. During each knock event, the ignition angle retard wkr of the cylinder in which the knock event occurred, is increased by an
offset KRDWKLA then stored in the current load-speed range of the adaptation map when this sum (wkr + KRDWKLA) is later than the value stored in wkra.

2. If the current retard wkr(i) is at least KRDWA earlier than the last value stored in the adaptation map and advance adjustment
counter zkrvf (i) = 0, the ignition angle retard is changed to KRDWSA towards advance in the adaptation map.

3. If the current retard wkr(i) = 0 and the advance adjustment counter zkrvf (i) = 0, wkra (i) is changed by KRDWSA towards advance.

The adaptation of the characteristic map is only performed during steady-state operation and during not active safety retarding (B
krdws=0). When idle control is active, the steady-state adaptation is also blocked, because the control is via the average wkrm retardation.

In order to avoid the unjustified adaptation of large amounts of retardation, further writing to the adaptation map (combined into
B_krafrz) is prohibited under the following conditions:

- tmot < TMKRAS error identifiers due to extraneous noise during warm-up.

- nmot > NKRAMAX error identifiers due to extraneous noise from the dump valve.

- nmot < NKRAMIN error identifiers due to extraneous noise from the drivetrain.

- B_asr = 1 transient engine conditions via fast ignition angle-intervention, possibly error identifiers.

- B_nmax = 1 ditto

- B_vmax = 1 ditto

Writing is also prohibited when

- rl < LKRAN

Adaptation – Read Conditions

During active adaptation the retarding of all cylinders wkr(i) is overwritten by the values from wkra(i) if one of the
following conditions is fulfilled:

1. Transition from !B_kra to B_kra

2. Load range changes with dynamic response (B_krl/ndyn = 1)

3. Engine speed changes with dynamic response (B_krl/ndyn = 1)

4. Entering or exiting idle control

During overwriting of wkr(i) with wkra(i), ignition angle jumps towards advance can happen (e.g adaptation has not yet settled in all adaptation ranges) which may give rise to undesirable results (judder, knock). For this reason, early ignition angle changes will be limited via overwriting KRDWAA. KRDWAA = 0 means that ignition angle jumps towards advance will be prevented. KRDWAA = KRMXN means that ignition angle jumps towards advance within the scope of the maximum Knock Control range are permitted.

Knock Control in the case of Active Dynamic Response (KRRA, KR_ADAP, BBKR)

In case of active dynamic response (B_krldy, B_krldya, B_krndy, see module KRDY) the further adaptation of the steady-state values
wkra(i) is blocked. A change of the adaptation ranges leads to an updating of wkr(i) with the values adjusted in wkra(i).

Each knocking combustion (B_kl), like so far, leads to a retarding by KRFKN and is therefore added to the cylinder-individual
retarding in wkr(i).

In addition to B_krldya, an adaptive dynamic derivative action wkrdy (see module KRDY) is added. For the fastest possible inclusion of this derivative action for dynamic response detection, an auxiliary bit B_wkrdyw set in module KRDY triggers the corresponding updating of all dwkrz_i included in wkrdy in the next KR-time frame. This algorithm is not shown in the ASCET images.

Knock Control during Active Idle Control (KRRA)

When idle control is active (B_llr = 1) cylinder-specific knock detection and control of the retardings wkr(i) still occurs. However, at ignition, the average retardation wkrm is output (dwkrz(i) = wkrm for all i).

In this way, additional idle disturbance via Knock Control-ignition angle intervention is avoided. During activation or deactivation of idle control respectively, the adaptation map is read.

Knock Control Above NKRMAX (BBKR, WKRBER)

Errors can frequently occur at high speeds due to noise (e.g. valve lift). Therefore, in order to avoid unduly large amounts of retarding, there is a speed threshold, NKRMAX, above which the de facto knock control is disabled! Instead, wkr(i) is permanently overwritten with the adapted values of the current adaptation range wkra(i) + an offset. This offset (krfkw - KRDWKLA) is implemented so that a margin from krfkw to the knock limit in this adaptation range is maintained. However, the prerequisites for this are a nearly constant knock limit within the respective adaptation areas and the presence of a current
adaptation value.

Please apply this function with the utmost care!

Optional Leading Cylinder (LZ)

The leading cylinder function is enabled:

- On exceeding a cylinder-specific speed threshold KRNLZ[i], above which the cylinder has poor knock detection, this cylinder is led by the cylinder with a good knock detection.

- For systems with two knock sensors, if an error has been detected for the knock sensors. (The one knock sensor associated cylinder are hereafter referred to as a group.) The cylinders of the group concerned are then led by the cylinders of the group
having a good working knock sensor. On exceeding KRNLZ [i], the safety retardation will be activated for all of the cylinders. This mitigation measure will be turned off via the codeword CWKRNLR. If an error is detected, a sensor immediately activates the security retardation.

Leading Cylinder Function when Engine Speed > KRNLZ, Without Knock Sensor Error

The corresponding leading and led cylinders are selected via the elements LZFUER_0 to _k (k = SY_ZYLZA - 1), of the blocks of constants LZFUER. The leading cylinder (LZ) is indicated by set bits in the bytes to LZFUER_0 _k.

The elements i = 0 to k of the constants LZFUER are selected via the cylinder block counter zzylkr in Knock Control, i.e. LZFUER_i belongs to zzylkr = i the cylinder counter counts the combustion within an AS. The connection between zzylkr and physical cylinder is given by the firing sequence. Accordingly, the bits 0-7 of LZFUER_i refer to zzylkr indexed combustion.

During activation of the lead cylinder function in this case, the contents of LZFUER is copied into the RAM-array LZIST (loop from i = 0 ... SY_ZYLZA-1 on a 100 ms time frame). Thus LZIST will contain the most current association between leading and led
cylinders.

For example:

6 cylinder engine with firing sequence zzylkr = 0 1 2 3 4 5

Physical cylinders: 1 4 3 6 2 5

Block of constants LZFUER

Led cyl. Bit 7 6 5 4 3 2 1 0 <-- (leading cylinder)

LZFUER_0 0 0 0 0 0 0 0 0 -- > 00 -- > physical cylinder 1 will not be led, i.e. separate knock detection

LZFUER_1 0 0 0 0 1 0 0 0 -- > 08 -- > physical cylinder 4 will be led by cylinder 6

LZFUER_2 0 0 0 0 1 0 0 1 -- > 09 -- > physical cylinder 3 will be led by phys. cylinder 6 or 1 (late selection)

LZFUER_3 0 0 0 0 0 0 0 0 -- > 00 -- > physical cylinder 6 will not be led, i.e. separate knock detection

LZFUER_4 0 0 0 0 1 0 0 0 -- > 08 -- > physical cylinder 2 will be led by cylinder 6

LZFUER_5 0 0 0 0 1 0 0 0 -- > 08 -- > physical cylinder 5 will be led by cylinder 6

A led cylinder may not be defined as a lead cylinder for itself, i.e. the bit i in LZFUER_i must be "0"

In the lead cylinder function, the following active measures are taken:

1. The knock detection will continue unchanged

2. The knock control and adaptation of the leading cylinder continues unchanged

3. For a led cylinder i, the retardation of the latest i assigned to leading cylinders j plus a cylinder-specific offset WKRLZOF_i is used as a late adjustment: wkr_i is overwritten in the background program with wkr_j + WKRLZOF_i. The adaptation continues unchanged. The adapted (and possibly incorrect) values for led cylinders arising because of 6 are not output.

If the code word CWKRLZFK = 1, the retard for the led cylinder is determined according to the following minimum selection:

wkr_i = MIN (wkr_i,

wkr_j) + WKRLZOF_i

4. Detected knock for the led cylinders has no effect: the retardation per knock is set to zero for the cylinder.

If the code word CWKRLZFK = 1, wkr_i will be retarded according to krfkw in the led cylinders and also the cylinders in which knock is detected, regardless of the leading cylinder function.

5. An independent advance for led cylinder is suppressed: the step width of the counter zkrvf_i for the led cylinder i is set continuously in the background program KRVFN.

If the code word CWKRLZFK = 1, the step width counter zkrvf_i is not overwritten for the led cylinder i.

Thus, an advance of wkr_i independent of the leading cylinder is possible. But because this results in an earlier ignition angle than with the leading cylinder, wkr_i will be overwritten with the ignition angle-adjustment of the leading cylinder. Thus, the earliest possible ignition angle for the led cylinder is given by the leading cylinder’s ignition angle + offset.

6. When reading from the adaptation maps, ignition angle changes towards advance are limited to 0° crank angle, rather than KRDWAA.

Leading Cylinder Function With Knock Sensor Error and Engine Speed < KRNLZ

If the knock sensor in group 2 is off (B_kseb2 = 1), then the cylinder of group 2 is led by group 1 according to the measures described in points 1 to 6 above. Instead of the individual cylinder offsets WKRLZOF_i, a global offset, WKRLZOFEKS is applied to the led cylinder. In this case, the content of LZB1 is copied into the RAM array LZIST (see above).

If the knock sensor in group 1 from (B_kseb1 = 1), then the cylinder of group 1 is led by group 2 according to the measures described in points 1 to 6 above. Instead of the individual cylinder offsets WKRLZOF_i, a global offset, WKRLZOFEKS is applied to the led cylinder. In this case, the content of LZB2 is copied into the RAM array LZIST (see above).

If both knock sensors are off (B_kseb1 = 1 & B_kseb2 = 1), the safety retardation is activated (B_krdws = 1).

Through the elements LZBi_0 to LZBi_k (k = SY_ZYLZA - 1) of the constant blocks LZBi (i = 1,2) the corresponding leading and led cylinders are selected.

The leading cylinder (LZ) is indicated by set bits in the bytes LZBi_0 to LZBi_k.

The elements n = 0 to k of the constant block are selected by the cylinder counter zzylkr in the Knock Control function, i.e. LZBi_n is zzylkr = n. The cylinder counter counts the firing within an AS. The connection between zzylkr and the physical cylinder is given by the firing sequence. Accordingly, the bits 0-7 of LZBi_n refer to zzylkr by indexed combustion

For example:

6 cylinder engine with firing sequence zzylkr = 0 1 2 3 4 5

Physical cylinders: 1 4 3 6 2 5

Constant block LZB1

Led cyl. Bit 7 6 5 4 3 2 1 0 <-- leading cylinder

LZB1_0 0 0 0 0 0 0 0 0 = 0

LZB1_1 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder 4 is led by the cylinders of group 1

LZB1_2 0 0 0 0 0 0 0 0 = 0

LZB1_3 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder 6 is led by the cylinders of group 1

LZB1_4 0 0 0 0 0 0 0 0 = 0

LZB1_5 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder 5 is led by the cylinders of group 1

Constant block LZB2

Led cyl. Bit 7 6 5 4 3 2 1 0 <-- leading cylinder

LZB2_0 0 0 1 0 1 0 1 0 = 42 -- > physical cylinder 1 is led by the cylinders of group 2

LZB2_1 0 0 0 0 0 0 0 0 = 0

LZB2_2 0 0 1 0 1 0 1 0 = 42 -- > physical cylinder 3 is led by the cylinders of group 2

LZB2_3 0 0 0 0 0 0 0 0 = 0

LZB2_4 0 0 1 0 1 0 1 0 = 42 -- > physical cylinder is led by the cylinders of group 2

LZB2_5 0 0 0 0 0 0 0 0 = 0

A led cylinder may not be defined as a lead cylinder for itself, i.e. the bit i in LZBi_n must be "0"

Safety Retardation During Active Knock Control (KRRA)

The knock control system hardware (sensors and signal processing IC CC195) is continuously monitored using the diagnostic functions DKRNT, DKRTP and DKRS. When errors are detected, the corresponding error flags E_ * are set, resulting in setting B_krdws to trigger the safety retardation. Resetting of B_krdws after detection of error healing and hence the withdrawal of the safety retardation may only happen with "knock control not active" (to prevent torque jumps).

Other system errors that lead to triggering of the safety retardation are:

- Lack of synchronization (B_synph = 0)

For systems with two or more knock sensors (KSZA > 1), in the absence of general synchronization safety retardation will be switched on.

For systems with only one knock sensor (KSZA = 1) and without active leading cylinder function, knock detection in the absence of synchronization will be performed with the most sensitive knock detection threshold (B_krnl = 1 --> emergency knock detection
– see also module KRKE), the knock control system continues unchanged.

The operation of the leading cylinder function sets the synchronization of the system (B_synph = 1) mandatory in advance. It follows that in absence of synchronization and active leading cylinder function in safety retardation (B_krdws = 1) it must be switched, regardless of how many knock sensors the system has.

In the absence of synchronization, an emergency operation of the engine by using dual ignition per SW (mirroring the ignition --> Half firing interval) can occur. In the case of an odd number of cylinders, the required sychronisation between the Knock Control measurement windows and combustion is no longer necessarily given. It must, even for systems with a knock sensor, be switched to safety retardation. A value of > 1 is therefore input to KSZA.

- Emergency tachometer (B_nldg = 1)

During speed-sensor emergency operation, the measurement window cannot be output with the required accuracy. Therefore security retardation is activated. To prevent unnecessary setting of safety flags B_krdws after an ECU reset, the setting of c_inisyn is
blocked for 3 seconds. If the Knock Control safety flag, B krdws, is set (see modules DKRS, DKRNT and DKRTP), dwkrz(i) and wkrma are overwritten by KRDWS if the knock control is active.

wkra(i), wkr(i) and wkrm are not updated as long as B krdws is set.

If B krdws is again reset dwkrz(i) is overwritten by wkr(i), wkrma by wkrm.

Application Notes

Cylinder-specific and load/engine speed range-dependent values are marked by (i) in the description corresponding to their realization in the ECU-code, e.g. wkr(i). The corresponding RAM-cell which can be read via VS100 is indicated in the ASCET-image by i, e.g. wkr i.

The cylinder counter zzylkr generated in module GGKS serves as control variable for the index i of the cylinder-individual RAM-cells (wkr(i), dwkrz(i), zkrvf(i), with the exception of wkra(i), see above).

Knock Control can be switched off via the label TMKR:

TMKR > tmot --> !B_kr

For the application the following typical values are suggested:

KRFKN -3 °crank is a value for the retarding of the ignition angle. Experience shows that it is a sufficient value to safely run the engine at the knock limit with stabilized adaptation.

KRMXN -12 °crank is a value which is sufficient for most applications. When fixing this characteristic line it must be noted though that the engine can be operated absolutely knock-free with the programmed value under worst-case conditions (i.e. engine speed, ambient temperature and fuel with lowest octane number).

In the process attention must be paid to the maximum permitted exhaust gas temperature.

KRVFN approx. 4 sec/°KW advancing is a typical value. The control speed of Knock Control during quasi-steady-state engine running results from this characteristic line in connection with KRFKN. The aim here is to determine a time constant which is larger than the thermal time constant of the engine so as to avoid a thermal strain.

When adjusting KRVFN it must be taken into consideration that the thermal strain of the engine increases with increasing engine speed so that a larger period should be chosen for higher engine speeds.

KRVFN = 1 Inc. * n / (120 * x) with 1 Inc. in °KW
n in rpm
x in °KW/sec - "speed" for the advance adjustment

KRVFSN to be adjusted dependent of KRDWKLA in order to enable a quick advancing of the adaptation map values in case of changed
operating conditions without provoking an increased knock frequency.

KRDWKLA = -3 °KW: approx

1 sec/°KW advancing or approx. 1/4 x KRVFN

KRDWKLA = 0 °KW: approx

2 sec/°KW advancing or approx. 1/2 x KRVFN

TMKR approx. 40°C is the value during which on many engines knocking combustions can already occur

TMKRA: Below an engine temperature threshold TMKRA it is not useful to update wkra since experience has shown that within this
operating range the knock tendency of the engine is very low. If adaptation would be permitted the necessary values learned in the normal operating range would be lost which means that the knock frequency is again increased when this operating range is reached again. Usually this engine temperature threshold lies at TMKRA = 80°C

LKRN approx. 30% rl is a typical value. The lowest load threshold during which knocking combustions can occur is stored in this
characteristic line.

LKRAN can be parameterized with values > LKRN, so the adaptation will only happen when there is a significant Knock Control demand; LKRAN is ineffective when parameterized with values <= LKRN

KRDWKLA 0 °KW <= |KRDWKLA| <= |KRFKN|

KRDWA |KRDWA| >= |KRDWKLA|

KRDWSA 0 °KW < |KRDWSA| und |KRDWSA| <= |KRDWA| - |KRDWKLA|

The following sets of parameters can be recommended:

{| border="1"
|-
|
KRDWKLA/°KW
|
KRDWA/°KW
|
KRDWSA/°KW
|
|-
|
0
|
2.25
|
2.25
|
--> Adaptation up to the knock limit
|-
|
-1.5
|
3.0
|
1.5
|
--> Adaptation up to the knock limit + a safety margin of 1.5 °crank
|-
|
-3.0
|
4.5
|
1.5
|
--> Adaptation up to the knock limit + a safety margin of 3 °crank
|}

KRWKRAIN = 0 °crank ... KRMXN, when interpretation of the ignition angle-KF close to the knock limit a value < 0°crank is recommended.

KRDWAA = 0; ignition angle jumps towards advance via reading of the adaptation values are prevented.

KRDWAA = min(KRMXN); ignition angle jumps towards advance are permitted within the scope of the maximum knock control range.

0 > KRDWAA > min(KRMXN) ignition angle jumps towards advance are limited to KRDWAA.

DWKRMSN approx. -3 °KW is a typical value to maintain the engine smoothness and to avoid spurious misfire detection; if the values get smaller the cylinder-individual character of the knock control is increasingly lost.

KRDWSN around -12 °crank, knock must be avoided under worst case conditions.

KRALH in order to avoid a judder at the range limits, a hysteresis was introduced for decreasing load. Typical value for KRALH = 3%

KRANH in order to avoid a judder at the range limits, a hysteresis was introduced for decreasing engine speed. Typical value for KRANH = 120 rpm.

NKRAMIN equal to the speed, up to which error flags by mechanical noise and vibration arise from the drive train. If the function is not required then set NKRAMIN = 0.

NKRAMAX equal to the speed above which there can be error flags (e.g., valve lift) which particularly applies when NKRAMAX > KRAN4 so actually in the upper speed range, values can be adapted, otherwise there is considerable risk of freezing the Knock Control by overwriting with NKRMAX. If the function is not required then set NKRAMAX to the maximum value.

NKRMAX equal to the speed above which there can be error flags (e.g., valve lift) which particularly applies when NKRMAX > KRAN4 and NKRMAX >= NKRAMAX so actually in the upper speed range, values can be adapted, otherwise there is considerable risk of freezing the Knock Control by overwriting with NKRMAX. If the function is not required then set NKRMAX to the maximum value.

CWKRNLR = 1 additional mitigation measure for systems with two knock sensors with knock sensor error is active. CWKRNLR = 0 ... is not active

Particular attention when determining the ignition angle maps requires knowledge of the area in which an enrichment function (lambda <1) is active since the knock limit will shift because of the enrichment.

To ensure the stabilty of Knock Control is not jeopardized, the ignition angle structure and the enrichment function must be adjusted so that a uniform margin to the knock limit is maintained (<3° crank) across the entire operating range of the
engine.

The existence of some values/RAMs is determined by the representation in ASCET (block hierarchy, course of control). They are not
realized in the SW resp. they cannot be measured definitely by means of VS100 due to their special realization:

- B wkral cannot be measured definitely.

- B krvf is not realized.

- zkrvf(i)=0 cannot be measured, this state can only be detected indirectly via the performed RESET of the counter from zkrvf(i) = 1 to zkrvf(i) = KRVF(S)N.

- zzylkral is not realized.

Distinguishing between wkrm/wkrma

wkrm represents the mean value of the each time SY_ZYLZA latest calculated wkr(i) (possibly incl. mean value vswzm) while wkrma
represents the mean value of the dwkrz(i) (without wkrdy) which was passed on to the ignition during the SY ZYLZA latest combustions.

Adaptation characteristic map wkra

When choosing the map values a compromise has to be achieved between the possibly varying knock tendency of the engine at different
load and engine speed ranges and the time by which the characteristic map is updated during normal driving.

If the adaptation map wkra is chosen to be too large (i.e. many relative load-engine speed-ranges) a longer period will be needed in order to update all ranges.

Thus in case of changed operating conditions which lead to a larger knock tendency it is inevitable that the knock frequency increases.

Generally a characteristic map with three load and five engine speed ranges is sufficient for wkra. In this map a RAM-cell is
provided for each load/ engine speed range per cylinder.

(Example 4-cylinder-engine: 3 x 5 x 4 = 60 RAM-cells for wkra)

For the indexing of the wkra(i) - RAM-cells the following specification is used in the SW:

i = zzylkr + 8 x stkrnx + 40 x stkrlx (zzylkr = 0...7, so at the max. 8 cylinders can be represented).

The number of adaptation ranges can be varied according to special customer requirements but at the maximum to 4 x 8 load/engine speed ranges (change of above-mentioned indexing may possibly be necessary).

Cylinder-individual ignition angle timing with VS20

By means of VS20 a cylinder-individual additional timing vszw(i) can be performed (see also modules VS and VERST) so that the
following applies:

dwkrz(i) = wkr(i) + wkrdy + vszwkr(i) if B_kr & !B_krdws

{| border="1"
|-
|
Label
|
Timing Range
|
Quantization
|
Initialization/neutral value
|-
|
vszwkr_1
|
see
module VS_VERST
|
0.75° crank
|

0° crank
|-
|
Vszwkr_8
|
see module VS_VERST
|
|
|}

i = 0 ... SY ZYLZA - 1

Attention:

1. No automatic limitation of vszwkr(i) is performed - please pay attention to engine and catalyst protection during the timing!
2. The earliest possible ignition angle determined by the Knock Control is under all circumstances, i.e. it is possible that the
minimum permitted ignition angle may be undershot (due to temperature reasons see modules ZUE and ZWMIN). Please pay attention to engine and catalyst protection!

Abbreviations

{| border="1"
|-
|
CWKRLZFK
|
Code
word: knock detection is not switched off for led cylinders
|-
|
CWKRNLR
|
Code word: limp home in case of 1 out of 2 knock
sensors fails
|-
|
CWKRRA
|
Code
word for the function KRRA
|-
|
DRLKRSTMX
|
Maximum
drl in Knock Control steady-state operation
|-
|
DWKRMSN
|
Delta ignition angle Knock Control margin from
mean retarding
|-
|
KRAL1N
|
load range for Knock Control adaptation maps 1
|-
|
KRAL2N
|
load range for Knock Control adaptation maps 2
|-
|
KRAL3N
|
load range for adaptation Knock Control maps 3
|-
|
KRALH
|
Load hysteresis for Knock Control adaptation maps
|-
|
KRAN1
|
speed range for Knock Control adaptation maps,
sample range 1
|-
|
KRAN2
|
speed range for Knock Control adaptation maps,
sample range 2
|-
|
KRAN3
|
speed range for Knock Control adaptation maps,
sample range 3
|-
|
KRAN4
|
speed range for Knock Control adaptation maps,
sample range 4
|-
|
KRANH
|
Engine speed hysteresis for Knock Control
adaptation maps
|-
|
KRDWA
|
knock control difference current ignition angle
to adaptation map
|-
|
KRDWAA
|
Permissible
ignition angle jump towards advance when reading adaptation values
|-
|
KRDWKLA
|
The SV-learning value for KR adaptation after
knocking detected
|-
|
KRDWSA
|
The FV-learning value for KR adation when
wkra-wkr > KRDWA
|-
|
KRDWSN
|
knock control delta angle safety
|-
|
KRFKLN
|
Retard
per knock event at a slow advance
|-
|
KRFKN
|
retard step knock occurrence
|-
|
KRLMDY
|
Read if change of load range: always or only if
dynamic active
|-
|
KRMXN
|
maximum retard adjustment
|-
|
KRNLZAR
|
cylinder individual speed limit for lead by
leading cylinder
|-
|
KRNMDY
|
Read if change of speed range: always or only if
dynamic active
|-
|
KRVFN
|
number of firings/cyl. or time for ignition
advancing
|-
|
KRVFSN
|
number of firings/cyl. or delay-time during fast
ignition advancing of the Knock Control
|-
|
KSZA
|
Knock sensor number
|-
|
LKRAGRN
|
Load
threshold knock control with Exhaust Gas Recirculation
|-
|
LKRAN
|
Load
threshold knock control adaptation
|-
|
LKRN
|
load-signal threshold knock control
|-
|
LZB1
|
Lead
cylinder assignment: Bank 1 leads to Bank 2 with error KS 2
|-
|
LZB2
|
Lead
cylinder assignment: Bank 2 leads to Bank 1 with error KS 2
|-
|
LZFUER
|
Lead cylinder assignment
|-
|
NGKRSTMX
|
maximum speed
gradient in the Knock Control steady-state operation
|-
|
NKRAMAX
|
Upper
engine speed limit for freezing Knock Control adaptation
|-
|
NKRAMIN
|
Lower
engine speed limit for freezing Knock Control adaptation
|-
|
NKRF
|
Engine
speed threshold for Knock Control release
|-
|
NKRMAX
|
Upper
engine speed limit for freezing Knock Control adaptation
|-
|
SENZZYL0
|
|-
|
SNM16KRUB
|
Data point distribution engine speed, 16 data points
|-
|
SY_ZYLZA
|
System constant: number of cylinders
|-
|
TMKR
|
Engine-temperature threshold to enable Knock
Control
|-
|
TMKRA
|
Engine temperature threshold for adaptive Knock
Control
|-
|
TMKRAS
|
Temperature threshold for releasing write
access to the adaptation map
|-
|
TVKRSTAT
|
Knock
Control delay time steady-state operation
|-
|
WKRLZOF
|
Constant bloack: ignition retard offset for leed
cylinder
|-
|
WKRLZOFEKS
|
Ignition retard offset for led cylinders in case
of knock sensor error
|-
|
B_ADRKRA
|
Condition
flag: Knock Control adaptation
values reset errors in memory
|-
|
B_AGR
|
Condition
flag: Exhaust Gas Recirculation
|-
|
B ASR
|
Condition
flag: ASR active
|-
|
B_KL
|
Condition flag: knock detected
|-
|
B_KR
|
Condition flag for knock control active
|-
|
B_KRA
|
condition for active Knock Control adaptation
|-
|
B_KRAFRZ
|
Condition
flag: Knock Control adaptation is frozen
|-
|
B_KRDWS
|
Condition flag: knock control safety ignition
retarding
|-
|
B_KRFDKS
|
Condition flag: enable knock sensor diagnosis
|-
|
B_KRFRZ
|
Condition
flag: Knock Control adaptation is frozen
|-
|
B_KRLDY
|
Condition flag: load dynamics for knock detection
active
|-
|
B_KRLDYA
|
Condition flag: load dynamics retard and dynamics
adaptation active
|-
|
B_KRLDYN
|
Condition
flag: load dynamics for steady-state adaptation active
|-
|
B_KRLZ
|
Condition flag: knock control lead-cylinder function
active
|-
|
B_KRNDY
|
Condition flag: speed dynamics for knock
detection active
|-
|
B_KRNDYN
|
Condition
flag: speed dynamics for steady-state adaptation is active
|-
|
B_KRNL
|
Condition flag: emergency operation of knock
detection for emergency operation of phase sensor
|-
|
B_KRNLR
|
Condition
flag: emergency knock control for V6 or V8 with two knock sensors and error
in one knock sensor
|-
|
B_KRSTATB
|
Condition
flag: steady-state Knock Control operation
|-
|
B_KRVF
|
Condition flag: adjustment of Knock Control
ignition timing to a less retarded value
|-
|
B_KRWA
|
Condition
flag: Knock Control at stop
|-
|
B_KSEB1
|
Condition
flag: KS-error Bank 1
|-
|
B_KSEB2
|
Condition
flag: KS-error Bank 2
|-
|
B_LLR
|
Condition
flag: idle control
|-
|
B_NLDG
|
Condition flag: limp-home function speed sensor
|-
|
B_NMAX
|
Condition
flag: speed limit active
|-
|
B_PWF
|
Condition flag: power fail
|-
|
B_STEND
|
Condition flag: end of start
|-
|
B_SYNPH
|
Condition flag: synchronization phase
|-
|
B_TMKR
|
Condition flag: engine temperature (tmot) for
knock control achieved
|-
|
B_VMAX
|
Condition
flag: VMAX control active
|-
|
B_WKRAL
|
Condition flag: to read wkr from knock control
adaptation map
|-
|
B_ZWKRAA
|
Condition flag: ignition angle of the Knock
Control is given
|-
|
B_ZWKRUM
|
Condition flag: fast ignition advance Knock
Control
|-
|
DFP_KRNT
|
internal failure path number: knck control zero
test
|-
|
DFP_KROF
|
internal failure path number: knock control
offset
|-
|
DFP_KRTP
|
internal failure path number: knock control test
pulse
|-
|
DFP_KS1
|
internal failure path number: knock sensor 1
|-
|
DFP_KS2
|
internal failure path number: knock sensor 2
|-
|
DFP_KS3
|
internal failure path number: kncok sensor 3
|-
|
DFP_KS4
|
internal failure path number: knock sensor 4
|-
|
DRL_W
|
Change
in cylinder fill
|-
|
DWKR
|
cylinder-specific ignition-timing retardation
|-
|
DWKRMSW
|
current value for mean value limitation of the
retarding
|-
|
DWKRZ
|
cyl.-spec. ignition-timing retardation with
retardation for dynamics
|-
|
E_KRNT
|
error flag: knock control zero test
|-
|
E_KROF
|
Errorflag: knock control offset
|-
|
E_KRTP
|
error flag: knock control test pulse
|-
|
E_KS1
|
error flag: knock sensor 1
|-
|
E_KS1H
|
auxiliary error flag KS1
|-
|
E_KS2
|
error flag: knock sensor 2
|-
|
E_KS2H
|
auxiliary error flag KS2
|-
|
E_KS3
|
error flag: knock sensor 3
|-
|
E_KS3H
|
auxiliary errorflag KS3
|-
|
E_KS4
|
error flag: knock sensor 4
|-
|
E_KS4H
|
auxiliary error flag KS4
|-
|
KRAL1W
|
current value load adaptation range 1
|-
|
KRAL2W
|
current value load adaptation range 2
|-
|
KRAL3W
|
current value load adaptation range 3
|-
|
KRDWSW
|
momentan characteristic-value for safety retard
|-
|
KRFKW
|
current value of KRFKN
|-
|
KRLZN
|
Cylinder-specific speed threshold of lead
cylinder function exceeded
|-
|
KRMXW
|
current value for retard limitation of the
retarding
|-
|
KRVFSW
|
initialization value for quick advancing
|-
|
KRVFW
|
initialization value for normal advancing
|-
|
LKRAW
|
Current
value of the load threshold knock control-adaptation
|-
|
LKRW
|
Current value of the load threshold knock control
|-
|
LZIST
|
Array: instantaneous assignment of leading and led
cylinders
|-
|
NGFIL_W
|
Filtered
speed gradient
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative air charge
|-
|
STKRAX
|
Index for Knock Control adaptation map
|-
|
STKRLX
|
Load range adaptation map Knock Control
|-
|
STKRNX
|
Speed range adaptation map Knock Control
|-
|
TMOT
|
Engine temperature
|-
|
TPNT_AKTIV
|
Activation of Knock Control functions
|-
|
VSZWKR
|
Cylinder-specific adjustment of ignition angle by
VS2x
|-
|
VSZWM
|
Average value of adjustment ignition angle with
VS2x
|-
|
WKR
|
Cylinder-specific ignition retarding value knock
control
|-
|
WKRA
|
Adaptation map of wkr, speed- and load-dependent
|-
|
WKRAA
|
Monitor
for the wkra of the current adaptation ranges, wkra_0, _1…
|-
|
WKRATST
|
wkra updated in real time
|-
|
WKRM
|
Average value of individual ignition retarting by
knocking
|-
|
WKRMA
|
Average value of ignition retarding by KC,
generally(limpe home with safety)
|-
|
WKR_TST
|
cylinder-individual ignition angle retarding,
druming
|-
|
ZKRVF
|
counter determines the frequency of the
cylinder-individual ignition angle adv

|-
|
ZWKRAFLD
|
bit pattern of the cylinder-individually stored
B-zwkra
|-
|
ZZYLKR
|
cylinder counter Knock Control
|}

KRRA 15.130 (Knock Control with Individual Cylinder Retard)

2012-05-02T23:12:43Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

krra-main KRRA: knock control including steady state adaptation

krra-bbkrra BBKRRA: release of knock control and adaptation

krra-bbkr BBKR: release of knock control and adaptation

krra-bb-krdws BB-KRDWS: condition for safety retard of ignition

krra-bb-lzf BB-LZF: release of leading cylinder function

krra-lzist LZIST: determination of led and leading cylinders

krra-uewkr UEWKR: overwrite ignition retard of led cylinders

krra-wkral WKRAL: Update of the cylinder selective ignition retard at adaptation area change (wkra -- > wkr)

krra-wkrber WKRBER: Calculation of ignition retard

krra-krvf FRUEHVERST: Release of ignition advance adjustment

krra-wkri WKRI: calculation of the average ignition retard

krra-begwkr BEGWKR: limitation of ignition retard after reading adaptation map

krra-stkra STKRA: Detection of load- and speed range

krra-kr-adap KR_ADAP: Adaptation of ignition retard

krra-vswkr VSWKR: Ignition adjustment with VS2x

krra-kr-freeze KR-FREEZE: calculation of ignition retard for frozen knock control

krra-initialise Initialise function

Note:
The cylinder-specific variables wkr, dwkrz, wkra and zkrvf are indicated in the following description through a control variable (i) - like in the ECU code, for example wkr(i). The corresponding RAM-cell which can be read via VS100 is marked by _i, for example: wkr_i

The Knock Control cylinder counter zzylkr serves as control variable (except wkra)

The following applies to it:

zzylkr = 1 ... SY_ZYLZA ASCET-Model
zzylkr = 0 ... SY_ZYLZA-1 ECU-Code

See also the Application Notes section in this module

KRRA 15.130 Function Description

Function of Knock Control

The KRRA module includes calculation of the cylinder-specific change of ignition angle of the knock control and adaptive calculation of the cylinder-specific retarding wkr(i) (WKRBER) with storage in an adaptation characteristic map wkra(i) (KR ADAP). The input values of the adaptation map are current cylinder number, engine speed and load (STKRA)

The value of the retarding dwkrz(i) which is passed on to the ignition comes to dependent on the operating condition (BBKC):

1. B_kr & !B_krdws & !B_llr dwkrz(i) = wkr(i)

2. B_kr & B_krdws dwkrz(i) = krdwsw KRDWS – Safety retarding see modules DKRS, DKRNT and DKRTP

3. B_kr & !B_krdws & B_llr dwkrz(i) = wkrm wkrm – average retard over all cylinders

4. !B_kr & (!)B_krdws dwkrz(i) = 0

Condition for active Knock Control without exhaust gas recirculation B_kr: ((rl > LKRN) v B_krldy) & (tmot > TMKR) &

B_stend & (nmot > NKRF) Condition for active Knock Control with exhaust gas recirculation B_kr: (( rl > LKRAGRN) v B_krldy) & (tmot > TMKR) &

B_stend & (nmot > NKRF) Condition for active adaptation: B_kra : B_kr & (tmot > TMKRA)

The lower speed threshold NKRF should prevent the engine stalling at low speed by Knock Control-Ignition Angle-intervention

Co-ordination of the Ignition Angle for Torque Management

When knock control is active, the earliest cylinder-specific ignition angle results:
KFZW + dwkrz(i) + wkrdy (wkrdy is derived dynamically from module KRDY, included in module ZUE)

There are two types of control action:

1. Output ignition angle = KFZW + dwkrz(i) + wkrdy --> B_zwkraa = 1 --> knock control algorithm remains unchanged

2. Output ignition angle < KFZW + dwkrz(i) + wkrdy --> B_zwkraa = 0 --> advancing algorithm of wkr(i) is frozen and knock
control adaptation is disabled. (due to exhaust gas reasons, Stability Program operation, idle control, etc.)

In module ZUE the bit B zwkra is formed synchronously to the ignition angle output and it is then stored in the corresponding position in bit array zwkrafld. E.g. B_zwkraa is then determined from zwkrafld as follows:
SW cylinder counter

{| border="1"
|-
|
(zzylkr)
|
5
|
4
|
3
|
2
|
1
|
0
|
|-
|
B_zwkra
|
1
|
1
|
0
|
1
|
0
|
0
|
zwkrafld = 25 + 24
+ 22 = 52
|}

B_zwkraa (zzylkr = 3) = 0 (= false)

Please note: Signs of the ignition angle (in degrees crankshaft (°KW)) according to mathematical convention

KFZW > 0 (with TDC as the point of reference, ignition "before" DTC means mathematically positive angles KFZW)
dwkrz(i) £ 0 ("retard" timing with regard to the basis ignition angle means mathematically negative dwkrz(i))

Retarding of the ignition angle without adaptation (WKRBER)

If B_kr and !B_kra are set the knock control operates as follows:

If a knocking combustion (B_kl) is detected in module KRKE then the ignition angle of the corresponding cylinder i is adjusted by
retarding it by an amount KRFKN per knock event. If the engine is in the Knock Control-steady-state operation, is adjusted by retarding it by an amount KRFKLN per knock event. This cylinder-individual retarding is added independently of load and engine speed in the RAM area wkr(i)

For engine smoothness reasons and in order to avoid spurious misfire detections, the retarding is limited in each calculation to a
range around the mean value wkrm of the latest given SY_ZYLZA retardings wkr(i), given by wkrm plus/minus a freely selectable threshold. This threshold DWKRMSN is a characteristic line over the engine speed

Additionally the retarding is limited in wkr(i) towards retard to KRMXN and towards advance to 0°

wkr is a RAM-area in which a RAM-cell is reserved for each cylinder.

If the “Knock Control active” operating range of the engine is left (!B kr) then the latest present retarding remains stored in
wkr(i) until the “Knock Control active” range is entered again. The same applies for wkrm.

In the “Knock Control not-active” range of the engine zero is passed on to module ZUE as adjustment value dwkrz(i).

If the ignition is switched off, the retardings in wkr(i) are set equal to zero.

Advancing of the ignition angle (WKRBER & FRUEHVERST)

The retardings from wkr(i) are cancelled on a cylinder-specific basis if B_kr is set and if a cylinder-specific advancing
counter zkrvf(i) has reached zero.

During each knock event B_kl, the cylinder-specific counter zkrvf(i) is populated with the value KRVFN. Each non-knocking combustion in cylinder i for which in addition B zwkraa = 1 applies (i.e. the given ignition angle was limited by Knock Control) decrements zkrvf(i) by 1. When zkrvf(i) = 0 is reached, the retarding in wkr(i) assigned to the corresponding cylinder is
decremented by one quantization step and the counter is again populated with KRVFN.

During each timing towards advance, the wkr(i) are limited to the mean value wkrm of the latest given retarding SY_ZYLZA minus a
freely selectable threshold DWKRMSN or to the value zero.

If the “Knock Control active” operating range of the engine is left (!B_kr) the latest available counter values remain stored in zkrvf(i) until the “Knock Control active” range is entered again.

If the ignition is switched off, the counter values inzkrvf(i) are set equal to zero.

If changed engine operating conditions result in a reduced tendency to knock, a quicker advancing of the wkr(i) is performed until
the first knock event occurs after the beginning of this quick advancing. In this case, the counters zkrvf(i) are started when KRVFSN < KRVFN. The condition for the start of the quick advancing is either the transition from reading adaptation values wkra(i) to wkr(i) or the termination of a dynamic phase or a negative load range shift.

There should be no quick advance during dynamic operation (B_krldya / B_krndy = 1).

Knock Control Steady-State Mode

In Knock Control steady-state mode, the ignition angle per knock event is retarded by the value KRFKLN or KRFKN. So that the knock
frequency at different retards is not too high, the Knock Control steady-state mode advance adjustment speed adjusted by KRLVFKN.

The Knock Control steady-state operation is indicated by B_krstatb. This bit is set if |drl| < DRLKRSTMX and |ngfil| < NGKRSTMX
for TVKRSTAT seconds.

Retarding of the ignition angle with adaptation (KR ADAP)

B_kra = B_kr & (tmot > TMKRA) --> Adaptation active

B_krafrz = B_kra & ((rl < lkraw) || (tmot < TMKRAS) || (nmot < NKRAMIN) || (nmot > NKRAMX) || B_asr || B_nmax ||
B_vmax) --> Learning the adaptation values is prohibited

The adaptation ensures that also for strongly map-dependent varying retardings the knock frequency does not increase in case
of quick changes of the map ranges. For this purpose, when adaptation is active, the current retards under certain conditions are written in a load-speed-dependent adaptation map (see Storage) or overwritten with the values stored in the map (see Read). Read access to the adaptation map is only enabled when the engine temperature is stable and when there is a significant knock control requirement (i.e. TMKRA >= TMKR), whereas the knock control must be activated even at low knock control requirements (worst case conditions). Write accesses to the adaptation map are enabled until the second temperature threshold (TMKRAS ³ TMKRA) and the second load threshold (LKRAN >= LKRN) are exceeded. This prevents, on the one hand, spurious adaptation due to retardings during warm-up and on the other hand, a learning of the adaptation value to 0 at lower loads.

A RAM cell is reserved in the adaptation map wkra for each load- and speed range per cylinder. The load and speed limits are removed for administration labels (KRAL1-3N or KRAN1-4). The values stored there will be used as the limiting values in case of increasing load or speed.

In case of decreasing load or engine speed, an adjustable hysteresis (KRALH, KRANH) is subtracted from these values

The current load range is stored in stkrlx, the speed range in stkrnx.

When the ignition is switched off all values remain stored in wkra. If the supply voltage of the ECU is disconnected the values are
lost. After the supply voltage of the ECU has been reconnected all values are set to 0.

DIAGRAM

For the indexing of the wkra(i) - RAM-cells the following specification is used in the SW:
i = zzylkr + (8 x stkrnx) + (40 x stkrlx zzylkr) = 0...7, so at the maximum, 8 cylinders can be represented

stkrnx = 0...4, 5 engine speed ranges

stkrlx = 0...3, 4 load ranges (value of 0 is notwithstanding the ASCET-Model!)

The wkra of the current adaptation range can be obtained from the RAM cells wkraa_i, i = 0 ... SY_ZYLZA-1

Adaptation - Learning Conditions:

The following conditions update the adaptation map:

1. During each knock event, the ignition angle retard wkr of the cylinder in which the knock event occurred, is increased by an
offset KRDWKLA then stored in the current load-speed range of the adaptation map when this sum (wkr + KRDWKLA) is later than the value stored in wkra.

2. If the current retard wkr(i) is at least KRDWA earlier than the last value stored in the adaptation map and advance adjustment
counter zkrvf (i) = 0, the ignition angle retard is changed to KRDWSA towards advance in the adaptation map.

3. If the current retard wkr(i) = 0 and the advance adjustment counter zkrvf (i) = 0, wkra (i) is changed by KRDWSA towards advance.

The adaptation of the characteristic map is only performed during steady-state operation and during not active safety retarding (B
krdws=0). When idle control is active, the steady-state adaptation is also blocked, because the control is via the average wkrm retardation.

In order to avoid the unjustified adaptation of large amounts of retardation, further writing to the adaptation map (combined into
B_krafrz) is prohibited under the following conditions:

- tmot < TMKRAS error identifiers due to extraneous noise during warm-up

- nmot > NKRAMAX error identifiers due to extraneous noise from the dump valve

- nmot < NKRAMIN error identifiers due to extraneous noise from the drivetrain

- B_asr = 1 transient engine conditions via fast ignition angle-intervention, possibly error identifiers

- B_nmax = 1 ditto

- B_vmax = 1 ditto

Writing is also prohibited when

- rl < LKRAN

Adaptation – Read Conditions

During active adaptation the retarding of all cylinders wkr(i) is overwritten by the values from wkra(i) if one of the
following conditions is fulfilled:

1. Transition from !B_kra to B_kra

2. Load range changes with dynamic response (B_krl/ndyn = 1)

3. Engine speed changes with dynamic response (B_krl/ndyn = 1)

4. Entering or exiting idle control

During overwriting of wkr(i) with wkra(i), ignition angle jumps away from advance can happen (e.g adaptation has not yet settled in all adaptation ranges) which may give rise to undesirable results (judder, knock). For this reason, early ignition angle changes will be limited via overwriting KRDWAA. KRDWAA = 0 means that ignition angle jumps away from advance will be prevented. KRDWAA = KRMXN means that ignition angle jumps away from advance within the scope of the maximum Knock Control range are permitted.

Knock Control in the case of Active Dynamic Response (KRRA, KR_ADAP, BBKR)

In case of active dynamic response (B_krldy, B_krldya, B_krndy, see module KRDY) the further adaptation of the steady-state values
wkra(i) is blocked. A change of the adaptation ranges leads to an updating of wkr(i) with the values adjusted in wkra(i).

Each knocking combustion (B_kl), like so far, leads to a retarding by KRFKN and is therefore added to the cylinder-individual
retarding in wkr(i).

In addition to B_krldya, an adaptive dynamic derivative action wkrdy (see module KRDY) is added. For the fastest possible inclusion of this derivative action for dynamic response detection, an auxiliary bit B_wkrdyw set in module KRDY triggers the corresponding updating of all dwkrz_i included in wkrdy in the next KR-time frame. This algorithm is not shown in the ASCET images.

Knock Control during Active Idle Control (KRRA)

When idle control is active (B_llr = 1) cylinder-specific knock detection and control of the retardings wkr(i) still occurs. However, at ignition, the average retardation wkrm is output (dwkrz(i) = wkrm for all i).

In this way, additional idle disturbance via KR-ZW-intervention is avoided. During activation or deactivation of idle control respectively, the adaptation map is read.

Knock Control Above NKRMAX (BBKR, WKRBER)

Errors can frequently occur at high speeds due to noise (e.g. valve lift). Therefore, in order to avoid unduly large amounts of retarding, there is a speed threshold, NKRMAX, above which the de facto knock control is disabled! Instead, wkr(i) is permanently overwritten with the adapted values of the current adaptation range wkra(i) + an offset. This offset (krfkw - KRDWKLA) is implemented so that a margin from krfkw to the knock limit in this adaptation range is maintained. However, the prerequisites for this are a nearly constant knock limit within the respective adaptation areas and the presence of a current
adaptation value.

Please apply this function with the utmost care!

Optional Leading Cylinder (LZ)

The leading cylinder function is enabled:
- On exceeding a
cylinder-specific speed threshold KRNLZ[i], above which the cylinder has poor
knock detection, this cylinder is led by the cylinder with a good knock
detection

- For systems with two
knock sensors, if an error has been detected for the knock sensors. (The one
knock sensor associated cylinder are hereafter referred to as a group.) The
cylinders of the group concerned are then led by the cylinders of the group
having a good working knock sensor. On exceeding KRNLZ [i], the safety
retardation will be activated for all of the cylinders. This mitigation measure
will be turned off via the codeword CWKRNLR. If an error is detected, a sensor
immediately activates the security retardation

Leading Cylinder Function
when Engine Speed > KRNLZ, Without Knock Sensor Error
The corresponding leading and led cylinders are selected via the elements
LZFUER_0 to _k (k = SY_ZYLZA - 1), of the blocks of constants LZFUER. The leading cylinder (LZ) is indicated by set bits in
the bytes to
LZFUER_0 _k

The elements i = 0 to k
of the constants LZFUER are selected via the cylinder
block counter zzylkr in Knock Control, i.e. LZFUER_i belongs to zzylkr = i the
cylinder counter counts the combustion within an AS. The connection between
zzylkr and physical
cylinder is given by the firing sequence. Accordingly, the bits 0-7 of LZFUER_i
refer to zzylkr indexed combustion

During activation of the
lead cylinder function in this case, the contents of LZFUER is copied into the
RAM-array LZIST (loop from i = 0 ... SY_ZYLZA-1 on a 100 ms time frame). Thus
LZIST will contain the most current association between leading and led
cylinders

For example:

6 cylinder engine with firing sequence zzylkr = 0 1 2 3 4 5

Physical cylinders: 1 4 3 6 2 5
Block of constants LZFUER

Led cyl. Bit 7 6 5 4 3 2 1 0 <-- (leading cylinder)

LZFUER_0 0 0 0 0 0 0 0 0 -- > 00 -- > physical cylinder 1 will not be led, i.e. separate knock detection

LZFUER_1 0 0 0 0 1 0 0 0 -- > 08 -- > physical cylinder 4 will be led by cylinder 6

LZFUER_2 0 0 0 0 1 0 0 1 -- > 09 -- > physical cylinder 3 will be led by phys. cylinder 6 or 1 (late selection)

LZFUER_3 0 0 0 0 0 0 0 0 -- > 00 -- > physical cylinder 6 will not be led, i.e. separate knock detection

LZFUER_4 0 0 0 0 1 0 0 0 -- > 08 -- > physical cylinder 2 will be led by cylinder 6

LZFUER_5 0 0 0 0 1 0 0 0 -- > 08 -- > physical cylinder 5 will be led by cylinder 6

A led cylinder may not be defined as a lead cylinder for itself, i.e. the bit i in LZFUER_i must be "0"

In the lead cylinder function, the following active measures are taken:

1. The knock detection will continue unchanged

2. The knock control and adaptation of the leading cylinder continues unchanged

3. For a led cylinder i, the
retardation of the latest i assigned to leading cylinders j plus a
cylinder-specific offset WKRLZOF_i is used as a late adjustment: wkr_i is
overwritten in the background program with wkr_j + WKRLZOF_i. The adaptation
continues unchanged. The adapted (and possibly incorrect) values for led cylinders arising because of 6 are not output.

If the code word CWKRLZFK = 1, the retard for the led cylinder is determined according to the following
minimum selection:

wkr_i = MIN (wkr_i,

wkr_j) + WKRLZOF_i

4. Detected knock for the led cylinders has no effect: the retardation per knock is set to zero for the
cylinder.

If the code word CWKRLZFK = 1, wkr_i will be retarded according to krfkw in the led cylinders and also the cylinders in which knock is detected, regardless of the leading cylinder function

5. An independent advance for led cylinder is suppressed: the step width of the counter zkrvf_i for the led cylinder i is set continuously in the background program KRVFN.

If the code word CWKRLZFK
= 1, the step width counter zkrvf_i is not overwritten for the led cylinder i

Thus, an advance of wkr_i independent of the leading cylinder is possible. But
because this results in an earlier ignition angle than with the leading
cylinder, wkr_i will be overwritten with the ignition angle-adjustment of the
leading cylinder. Thus, the earliest possible ignition angle for the led
cylinder is given by the leading cylinder’s ignition angle + offset

6. When reading from the adaptation maps, ignition angle changes away from advance are limited to 0° crank angle, rather than KRDWAA.

Leading Cylinder Function With Knock Sensor Error and Engine Speed < KRNLZ

If the knock sensor in group 2 is off (B_kseb2 = 1), then the cylinder of group 2 is led by group 1 according to the measures described in points 1 to 6 above. Instead of the individual cylinder offsets WKRLZOF_i, a global offset, WKRLZOFEKS is applied to the led cylinder. In this case, the content of LZB1 is copied into the RAM array LZIST (see above)

If the knock sensor in group 1 from (B_kseb1 = 1), then the cylinder of group 1 is led by group 2 according to the measures described in points 1 to 6 above. Instead of the individual cylinder offsets WKRLZOF_i, a global offset, WKRLZOFEKS is applied to the led cylinder. In this case, the content of LZB2 is copied into the RAM array LZIST (see above)

If both knock sensors are off (B_kseb1 = 1 & B_kseb2 = 1), the safety retardation is activated (B_krdws = 1)

Through the elements LZBi_0 to LZBi_k (k = SY_ZYLZA - 1) of the constant blocks LZBi (i = 1,2) the corresponding leading and led cylinders are selected.

The leading cylinder (LZ) is indicated by set bits in the bytes LZBi_0 to LZBi_k.

The elements n = 0 to k of the constant block are selected by the cylinder counter zzylkr in the Knock Control function, i.e. LZBi_n is zzylkr = n. is one of the cylinder burns the counter counts within an AS. The connection between zzylkr and the physical cylinder is given by the firing sequence. Accordingly, the bits 0-7 of LZBi_n refer to zzylkr by indexed combustion

For example:

6 cylinder engine with firing sequence zzylkr = 0 1 2 3 4 5

Physical cylinders: 1 4 3 6 2 5

Constant block LZB1

Led cyl. Bit 7 6 5 4 3 2 1 0 <-- leading cylinder

LZB1_0 0 0 0 0 0 0 0 0 = 0

LZB1_1 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder 4 is led by the cylinders of group 1

LZB1_2 0 0 0 0 0 0 0 0 = 0

LZB1_3 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder 6 is led by the cylinders of group 1

LZB1_4 0 0 0 0 0 0 0 0 = 0

LZB1_5 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder 5 is led by the cylinders of group 1

Constant block LZB2

Led cyl. Bit 7 6 5 4 3 2 1 0 <-- leading cylinder

LZB2_0 0 0 1 0 1 0 1 0 = 42 -- > physical cylinder 1 is led by the cylinders of group 2

LZB2_1 0 0 0 0 0 0 0 0 = 0

LZB2_2 0 0 1 0 1 0 1 0 = 42 -- > physical cylinder 3 is led by the cylinders of group 2

LZB2_3 0 0 0 0 0 0 0 0 = 0

LZB2_4 0 0 1 0 1 0 1 0 = 42 -- > physical cylinder is led by the cylinders of group 2

LZB2_5 0 0 0 0 0 0 0 0 = 0

A led cylinder may not be defined as a lead cylinder for itself, i.e. the bit i in LZBi_n must be
"0"

Safety Retardation During Active Knock Control (KRRA)

The knock control system hardware (sensors and signal processing IC CC195) is continuously monitored using the diagnostic functions DKRNT, DKRTP and DKRS. When errors are detected, the corresponding error flags E_ * are set, resulting in setting B_krdws to trigger the safety retardation. Resetting of B_krdws after detection of error healing and hence the withdrawal of the safety retardation may only happen with "knock control not active" (to prevent torque jumps).

Other system errors that lead to triggering of the safety retardation are:

- Lack of synchronization (B_synph = 0)

For systems with two or more knock sensors (KSZA > 1), in the absence of general synchronization safety retardation will be switched on

For systems with only one
knock sensor (KSZA = 1) and without active leading cylinder function, knock
detection in the absence of synchronization will be performed with the most
sensitive knock detection threshold (B_krnl = 1 = > emergency knock detection
– see also module KRKE), the knock control system continues unchanged.

The operation of the
leading cylinder function sets the synchronization of the system (B_synph = 1)
mandatory in advance. It follows that in absence of synchronization and active
leading cylinder function in safety retardation (B_krdws = 1) it must be switched,
regardless of how many knock sensors the system has.

In the absence of
synchronization, an emergency operation of the engine by using dual ignition
per SW (mirroring the ignition = > Half firing interval) can occur. In the
case of an odd number of cylinders, the required sychronisation between the
Knock Control measurement windows and combustion is no longer necessarily
given. It must, even for systems with a knock sensor, be switched to safety
retardation. A value of > 1 is therefore input to KSZA.

- Emergency tachometer (B_nldg = 1)

During speed-sensor
emergency operation, the measurement window cannot be output with the required
accuracy. Therefore security retardation is activated. To prevent unnecessary
setting of safety flags B_krdws after an ECU reset, the setting of c_inisyn is
blocked for 3 seconds. If the Knock
Control safety flag, B krdws, is set (see modules DKRS, DKRNT and DKRTP),
dwkrz(i) and wkrma are overwritten by KRDWS if the knock control is active.

wkra(i), wkr(i) and wkrm are not updated as long as B
krdws is set.

If B krdws is again reset dwkrz(i) is overwritten by
wkr(i), wkrma by wkrm.

Application Notes

Cylinder-specific and load/engine speed
range-dependent values are marked by (i) in the description corresponding to
their realization in the ECU-code, e.g. wkr(i). The corresponding RAM-cell
which can be read via VS100 is indicated in the ASCET-image by i, e.g. wkr i

The cylinder counter zzylkr generated in module GGKS
serves as control variable for the index i of the cylinder-individual RAM-cells
(wkr(i), dwkrz(i), zkrvf(i), with the exception of wkra(i), see above)

Knock Control can be switched off via the label TMKR:
TMKR > tmot == > !B_kr
For the application the following typical values are
suggested:
KRFKN -3 °crank is a
value for the retarding of the ignition angle. Experience shows that it is a
sufficient value to safely run the engine at the knock limit with stabilized
adaptation

KRMXN -12 °crank is a
value which is sufficient for most applications. When fixing this
characteristic line it must be noted though that the engine can be operated
absolutely knock-free with the programmed value under worst-case conditions
(i.e. engine speed, ambient temperature and fuel with lowest octane number)

In the process attention must be paid to the maximum
permitted exhaust gas temperature

KRVFN approx. 4 sec/°KW
advancing is a typical value. The control speed of Knock Control during
quasi-steady-state engine running results from this characteristic line in
connection with KRFKN. The aim here is to determine a time constant which is
larger than the thermal time constant of the engine so as to avoid a thermal
strain.

When adjusting KRVFN it must be taken into
consideration that the thermal strain of the engine increases with increasing
engine speed so that a larger period should be chosen for higher engine speeds.

KRVFN = 1 Inc. * n / (120 * x) with 1 Inc. in °KW
n in rpm
x in °KW/sec - "speed" for the advance adjustment

KRVFSN to be adjusted dependent of KRDWKLA in order to
enable a quick advancing of the adaptation map values in case of changed
operating conditions without provoking an increased knock frequency.

KRDWKLA = -3 °KW: approx

1 sec/°KW advancing or approx. 1/4 x KRVFN

KRDWKLA = 0 °KW: approx

2 sec/°KW advancing or approx. 1/2 x KRVFN
TMKR approx. 40VC is the value during which on many
engines knocking combustions can already occur

TMKRA: Below an engine temperature threshold TMKRA it
is not useful to update wkra since experience has shown that within this
operating range the knock tendency of the engine is very low. If adaptation
would be permitted the necessary values learned in the normal operating range
would be lost which means that the knock frequency is again increased when this
operating range is reached again

Usually this engine temperature threshold lies at
TMKRA = 80°C

LKRN approx. 30% rl is a typical value. The lowest
load threshold during which knocking combustions can occur is stored in this
characteristic line

LKRAN can be parameterized with values > LKRN,
so the adaptation will only happen when there is a significant Knock Control
demand; LKRAN is ineffective when parameterized with values <=
LKRN

KRDWKLA 0 °KW <= |KRDWKLA| <= |KRFKN|

KRDWA |KRDWA| >= |KRDWKLA|

KRDWSA 0 °KW < |KRDWSA| und |KRDWSA| <= |KRDWA| - |KRDWKLA|

The following sets of
parameters can be recommended:

{| border="1"
|-
|
KRDWKLA/°KW
|
KRDWA/°KW
|
KRDWSA/°KW
|
|-
|
0
|
2.25
|
2.25
|
= > Adaptation up to the knock limit
|-
|
-1.5
|
3.0
|
1.5
|
= > Adaptation up to the knock limit + a
safety margin of 1.5 °crank
|-
|
-3.0
|
4.5
|
1.5
|
= > Adaptation up to the knock limit + a
safety margin of 3 °crank
|}

KRWKRAIN = 0 °crank ... KRMXN, when
interpretation of the ignition angle-KF close to the knock limit a value < 0
°crank is recommended

KRDWAA = 0; ignition angle jumps away from advance via reading of the
adaptation values are prevented
= min(KRMXN); ignition angle jumps away from advance are
permitted within the scope of the maximum knock control range
0 > KRDWAA > min(KRMXN)
ignition angle jumps away from advance are limited to KRDWAA

DWKRMSN approx. -3 °KW is a
typical value to maintain the engine smoothness and to avoid misfire
misdetection; if the values get smaller the cylinder-individual character of
the knock control is increasingly lost

KRDWSN around -12 °crank, knock
must be avoided under worst case conditions
KRALH in order to avoid a judder at the range limits,
a hysteresis was introduced for decreasing load

Typical value for KRALH = 3%

KRANH in order to avoid a judder at the range limits,
a hysteresis was introduced for decreasing engine speed

Typical value for KRANH = 120 rpm

NKRAMIN equal to the speed, up to which error flags by
mechanical noise and vibration arise from the drive train. If the function is
not required then set NKRAMIN = 0

NKRAMAX equal to the
speed above which there can be error flags (e.g., valve lift) which
particularly applies when NKRAMAX > KRAN4 so actually in the upper speed
range, values can be adapted, otherwise there is
considerable risk of freezing the Knock Control by overwriting with NKRMAX. If
the function is not required then set NKRAMAX to the maximum value.

NKRMAX equal to the speed
above which there can be error flags (e.g., valve lift) which particularly
applies when NKRMAX > KRAN4 and NKRMAX >= NKRAMAX so actually in the
upper speed range, values can be adapted,
otherwise there is considerable risk of freezing the Knock Control by
overwriting with NKRMAX. If the function is not required then set NKRMAX to the
maximum value.

CWKRNLR = 1 additional
mitigation measure for systems with two knock sensors with knock sensor error
is active. CWKRNLR = 0 ... is not active

Particular attention when
determining the ignition angle maps requires knowledge of the area in which an
enrichment function (lambda <1) is active since the knock limit will shift
because of the enrichment.

To ensure the stabilty of
Knock Control is not jeopardized, the ignition angle structure and the
enrichment function must be adjusted so that a uniform margin to the knock
limit is maintained (<3° crank) across the entire operating range of the
engine.

The existence of some values/RAMs is determined by the
representation in ASCET (block hierarchy, course of control). They are not
realized in the SW resp. they cannot be measured definitely by means of VS100
due to their special realization:

- B wkral cannot be measured definitely

- B krvf is not realized

- zkrvf(i)=0 cannot be measured, this state can only
be detected indirectly via the performed RESET of the counter from zkrvf(i) = 1
to zkrvf(i) = KRVF(S)N

- zzylkral is not realized

Distinguishing between wkrm/wkrma

wkrm represents the mean value of the each time SY
ZYLZA latest calculated wkr(i) (possibly incl. mean value vswzm) while wkrma
represents the mean value of the dwkrz(i) (without wkrdy) which was passed on
to the ignition during the SY ZYLZA latest combustions

Adaptation characteristic map wkra
When choosing the map values a compromise has to be
achieved between the possibly varying knock tendency of the engine at different
load and engine speed ranges and the time by which the characteristic map is
updated during normal driving

If the adaptation map wkra is chosen to be too large
(i.e. many relative load-engine speed-ranges) a longer period will be needed in
order to update all ranges

Thus in case of changed operating conditions which
lead to a larger knock tendency it is inevitable that the knock frequency
increases

Generally a characteristic map with three load and
five engine speed ranges is sufficient for wkra. In this map a RAM-cell is
provided for each load/ engine speed range per cylinder

(Example 4-cylinder-engine: 3 x 5 x 4
= 60 RAM-cells for wkra)
For the indexing of the wkra(i) - RAM-cells the
following specification is used in the SW:
i = zzylkr + 8 x stkrnx + 40 x stkrlx (zzylkr = 0...7,
so at the max. 8 cylinders can be represented)
The number of adaptation ranges can be varied
according to special customer requirements but at the maximum to 4 x 8
load/engine speed ranges (change of above-mentioned indexing may possibly be
necessary)

Cylinder-individual ignition angle timing with VS20
By means of VS20 a cylinder-individual additional
timing vszw(i) can be performed (see also modules VS and VERST) so that the
following applies:
dwkrz(i) = wkr(i) + wkrdy + vszwkr(i) if B kr & !B
krdws

{| border="1"
|-
|
Label
|
Timing Range
|
Quantization
|
Initialization/neutral value
|-
|
vszwkr_1
|
see
module VS_VERST
|
0.75
°crank
|

0
°crank
|-
|
Vszwkr_8
|
see
module VS_VERST
|
|
|}
i = 0 ... SY ZYLZA - 1
Attention:
1. No automatic limitation of vszwkr(i) is performed -
please pay attention to engine and catalyst protection during the timing!
2. The earliest possible ignition angle determined by
the Knock Control is under all circumstances, i.e. it is possible that the
minimum permitted ignition angle may be undershot (due to temperature reasons

see modules ZUE and ZWMIN). Please pay attention to engine and catalyst
protection!
Abbreviations

{| border="1"
|-
|
CWKRLZFK
|
Code
word: knock detection is not switched off for led cylinders
|-
|
CWKRNLR
|
Code word: limp home in case of 1 out of 2 knock
sensors fails
|-
|
CWKRRA
|
Code
word for the function KRRA
|-
|
DRLKRSTMX
|
Maximum
drl in Knock Control steady-state operation
|-
|
DWKRMSN
|
Delta ignition angle Knock Control margin from
mean retarding
|-
|
KRAL1N
|
load range for Knock Control adaptation maps 1
|-
|
KRAL2N
|
load range for Knock Control adaptation maps 2
|-
|
KRAL3N
|
load range for adaptation Knock Control maps 3
|-
|
KRALH
|
Load hysteresis for Knock Control adaptation maps
|-
|
KRAN1
|
speed range for Knock Control adaptation maps,
sample range 1
|-
|
KRAN2
|
speed range for Knock Control adaptation maps,
sample range 2
|-
|
KRAN3
|
speed range for Knock Control adaptation maps,
sample range 3
|-
|
KRAN4
|
speed range for Knock Control adaptation maps,
sample range 4
|-
|
KRANH
|
Engine speed hysteresis for Knock Control
adaptation maps
|-
|
KRDWA
|
knock control difference current ignition angle
to adaptation map
|-
|
KRDWAA
|
Permissible
ignition angle jump towards advance when reading adaptation values
|-
|
KRDWKLA
|
The SV-learning value for KR adaptation after
knocking detected
|-
|
KRDWSA
|
The FV-learning value for KR adation when
wkra-wkr > KRDWA
|-
|
KRDWSN
|
knock control delta angle safety
|-
|
KRFKLN
|
Retard
per knock event at a slow advance
|-
|
KRFKN
|
retard step knock occurrence
|-
|
KRLMDY
|
Read if change of load range: always or only if
dynamic active
|-
|
KRMXN
|
maximum retard adjustment
|-
|
KRNLZAR
|
cylinder individual speed limit for lead by
leading cylinder
|-
|
KRNMDY
|
Read if change of speed range: always or only if
dynamic active
|-
|
KRVFN
|
number of firings/cyl. or time for ignition
advancing
|-
|
KRVFSN
|
number of firings/cyl. or delay-time during fast
ignition advancing of the Knock Control
|-
|
KSZA
|
Knock sensor number
|-
|
LKRAGRN
|
Load
threshold knock control with Exhaust Gas Recirculation
|-
|
LKRAN
|
Load
threshold knock control adaptation
|-
|
LKRN
|
load-signal threshold knock control
|-
|
LZB1
|
Lead
cylinder assignment: Bank 1 leads to Bank 2 with error KS 2
|-
|
LZB2
|
Lead
cylinder assignment: Bank 2 leads to Bank 1 with error KS 2
|-
|
LZFUER
|
Lead cylinder assignment
|-
|
NGKRSTMX
|
maximum speed
gradient in the Knock Control steady-state operation
|-
|
NKRAMAX
|
Upper
engine speed limit for freezing Knock Control adaptation
|-
|
NKRAMIN
|
Lower
engine speed limit for freezing Knock Control adaptation
|-
|
NKRF
|
Engine
speed threshold for Knock Control release
|-
|
NKRMAX
|
Upper
engine speed limit for freezing Knock Control adaptation
|-
|
SENZZYL0
|
|-
|
SNM16KRUB
|
Data point distribution engine speed, 16 data points
|-
|
SY_ZYLZA
|
System constant: number of cylinders
|-
|
TMKR
|
Engine-temperature threshold to enable Knock
Control
|-
|
TMKRA
|
Engine temperature threshold for adaptive Knock
Control
|-
|
TMKRAS
|
Temperature threshold for releasing write
access to the adaptation map
|-
|
TVKRSTAT
|
Knock
Control delay time steady-state operation
|-
|
WKRLZOF
|
Constant bloack: ignition retard offset for leed
cylinder
|-
|
WKRLZOFEKS
|
Ignition retard offset for led cylinders in case
of knock sensor error
|-
|
B_ADRKRA
|
Condition
flag: Knock Control adaptation
values reset errors in memory
|-
|
B_AGR
|
Condition
flag: Exhaust Gas Recirculation
|-
|
B ASR
|
Condition
flag: ASR active
|-
|
B_KL
|
Condition flag: knock detected
|-
|
B_KR
|
Condition flag for knock control active
|-
|
B_KRA
|
condition for active Knock Control adaptation
|-
|
B_KRAFRZ
|
Condition
flag: Knock Control adaptation is frozen
|-
|
B_KRDWS
|
Condition flag: knock control safety ignition
retarding
|-
|
B_KRFDKS
|
Condition flag: enable knock sensor diagnosis
|-
|
B_KRFRZ
|
Condition
flag: Knock Control adaptation is frozen
|-
|
B_KRLDY
|
Condition flag: load dynamics for knock detection
active
|-
|
B_KRLDYA
|
Condition flag: load dynamics retard and dynamics
adaptation active
|-
|
B_KRLDYN
|
Condition
flag: load dynamics for steady-state adaptation active
|-
|
B_KRLZ
|
Condition flag: knock control lead-cylinder function
active
|-
|
B_KRNDY
|
Condition flag: speed dynamics for knock
detection active
|-
|
B_KRNDYN
|
Condition
flag: speed dynamics for steady-state adaptation is active
|-
|
B_KRNL
|
Condition flag: emergency operation of knock
detection for emergency operation of phase sensor
|-
|
B_KRNLR
|
Condition
flag: emergency knock control for V6 or V8 with two knock sensors and error
in one knock sensor
|-
|
B_KRSTATB
|
Condition
flag: steady-state Knock Control operation
|-
|
B_KRVF
|
Condition flag: adjustment of Knock Control
ignition timing to a less retarded value
|-
|
B_KRWA
|
Condition
flag: Knock Control at stop
|-
|
B_KSEB1
|
Condition
flag: KS-error Bank 1
|-
|
B_KSEB2
|
Condition
flag: KS-error Bank 2
|-
|
B_LLR
|
Condition
flag: idle control
|-
|
B_NLDG
|
Condition flag: limp-home function speed sensor
|-
|
B_NMAX
|
Condition
flag: speed limit active
|-
|
B_PWF
|
Condition flag: power fail
|-
|
B_STEND
|
Condition flag: end of start
|-
|
B_SYNPH
|
Condition flag: synchronization phase
|-
|
B_TMKR
|
Condition flag: engine temperature (tmot) for
knock control achieved
|-
|
B_VMAX
|
Condition
flag: VMAX control active
|-
|
B_WKRAL
|
Condition flag: to read wkr from knock control
adaptation map
|-
|
B_ZWKRAA
|
Condition flag: ignition angle of the Knock
Control is given
|-
|
B_ZWKRUM
|
Condition flag: fast ignition advance Knock
Control
|-
|
DFP_KRNT
|
internal failure path number: knck control zero
test
|-
|
DFP_KROF
|
internal failure path number: knock control
offset
|-
|
DFP_KRTP
|
internal failure path number: knock control test
pulse
|-
|
DFP_KS1
|
internal failure path number: knock sensor 1
|-
|
DFP_KS2
|
internal failure path number: knock sensor 2
|-
|
DFP_KS3
|
internal failure path number: kncok sensor 3
|-
|
DFP_KS4
|
internal failure path number: knock sensor 4
|-
|
DRL_W
|
Change
in cylinder fill
|-
|
DWKR
|
cylinder-specific ignition-timing retardation
|-
|
DWKRMSW
|
current value for mean value limitation of the
retarding
|-
|
DWKRZ
|
cyl.-spec. ignition-timing retardation with
retardation for dynamics
|-
|
E_KRNT
|
error flag: knock control zero test
|-
|
E_KROF
|
Errorflag: knock control offset
|-
|
E_KRTP
|
error flag: knock control test pulse
|-
|
E_KS1
|
error flag: knock sensor 1
|-
|
E_KS1H
|
auxiliary error flag KS1
|-
|
E_KS2
|
error flag: knock sensor 2
|-
|
E_KS2H
|
auxiliary error flag KS2
|-
|
E_KS3
|
error flag: knock sensor 3
|-
|
E_KS3H
|
auxiliary errorflag KS3
|-
|
E_KS4
|
error flag: knock sensor 4
|-
|
E_KS4H
|
auxiliary error flag KS4
|-
|
KRAL1W
|
current value load adaptation range 1
|-
|
KRAL2W
|
current value load adaptation range 2
|-
|
KRAL3W
|
current value load adaptation range 3
|-
|
KRDWSW
|
momentan characteristic-value for safety retard
|-
|
KRFKW
|
current value of KRFKN
|-
|
KRLZN
|
Cylinder-specific speed threshold of lead
cylinder function exceeded
|-
|
KRMXW
|
current value for retard limitation of the
retarding
|-
|
KRVFSW
|
initialization value for quick advancing
|-
|
KRVFW
|
initialization value for normal advancing
|-
|
LKRAW
|
Current
value of the load threshold knock control-adaptation
|-
|
LKRW
|
Current value of the load threshold knock control
|-
|
LZIST
|
Array: instantaneous assignment of leading and led
cylinders
|-
|
NGFIL_W
|
Filtered
speed gradient
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative air charge
|-
|
STKRAX
|
Index for Knock Control adaptation map
|-
|
STKRLX
|
Load range adaptation map Knock Control
|-
|
STKRNX
|
Speed range adaptation map Knock Control
|-
|
TMOT
|
Engine temperature
|-
|
TPNT_AKTIV
|
Activation of Knock Control functions
|-
|
VSZWKR
|
Cylinder-specific adjustment of ignition angle by
VS2x
|-
|
VSZWM
|
Average value of adjustment ignition angle with
VS2x
|-
|
WKR
|
Cylinder-specific ignition retarding value knock
control
|-
|
WKRA
|
Adaptation map of wkr, speed- and load-dependent
|-
|
WKRAA
|
Monitor
for the wkra of the current adaptation ranges, wkra_0, _1…
|-
|
WKRATST
|
wkra updated in real time
|-
|
WKRM
|
Average value of individual ignition retarting by
knocking
|-
|
WKRMA
|
Average value of ignition retarding by KC,
generally(limpe home with safety)
|-
|
WKR_TST
|
cylinder-individual ignition angle retarding,
druming
|-
|
ZKRVF
|
counter determines the frequency of the
cylinder-individual ignition angle adv

|-
|
ZWKRAFLD
|
bit pattern of the cylinder-individually stored
B-zwkra
|-
|
ZZYLKR
|
cylinder counter Knock Control
|}

KRRA 15.130 (Knock Control with Individual Cylinder Retard)

2012-05-02T23:03:43Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

krra-main KRRA: knock control including steady state adaptation

krra-bbkrra BBKRRA: release of knock control and adaptation

krra-bbkr BBKR: release of knock control and adaptation

krra-bb-krdws BB-KRDWS: condition for safety retard of ignition

krra-bb-lzf BB-LZF: release of leading cylinder function

krra-lzist LZIST: determination of led and leading cylinders

krra-uewkr UEWKR: overwrite ignition retard of led cylinders

krra-wkral WKRAL: Update of the cylinder selective ignition retard at adaptation area change (wkra -- > wkr)

krra-wkrber WKRBER: Calculation of ignition retard

krra-krvf FRUEHVERST: Release of ignition advance adjustment

krra-wkri WKRI: calculation of the average ignition retard

krra-begwkr BEGWKR: limitation of ignition retard after reading adaptation map

krra-stkra STKRA: Detection of load- and speed range

krra-kr-adap KR_ADAP: Adaptation of ignition retard

krra-vswkr VSWKR: Ignition adjustment with VS2x

krra-kr-freeze KR-FREEZE: calculation of ignition retard for frozen knock control

krra-initialise Initialise function

Note:
The cylinder-specific variables wkr, dwkrz, wkra and zkrvf are indicated in the following description through a control variable (i) - like in the ECU code, for example wkr(i). The corresponding RAM-cell which can be read via VS100 is marked by _i, for example: wkr_i

The Knock Control cylinder counter zzylkr serves as control variable (except wkra)

The following applies to it:

zzylkr = 1 ... SY_ZYLZA ASCET-Model
zzylkr = 0 ... SY_ZYLZA-1 ECU-Code

See also the Application Notes section in this module

KRRA 15.130 Function Description

Function of Knock Control

The KRRA module includes calculation of the cylinder-specific change of ignition angle of the knock control and adaptive calculation of the cylinder-specific retarding wkr(i) (WKRBER) with storage in an adaptation characteristic map wkra(i) (KR ADAP). The input values of the adaptation map are current cylinder number, engine speed and load (STKRA)

The value of the retarding dwkrz(i) which is passed on to the ignition comes to dependent on the operating condition (BBKC):

1. B_kr & !B_krdws & !B_llr dwkrz(i) = wkr(i)

2. B_kr & B_krdws dwkrz(i) = krdwsw KRDWS – Safety retarding see modules DKRS, DKRNT and DKRTP

3. B_kr & !B_krdws & B_llr dwkrz(i) = wkrm wkrm – average retard over all cylinders

4. !B_kr & (!)B_krdws dwkrz(i) = 0

Condition for active Knock Control without exhaust gas recirculation B_kr: ((rl > LKRN) v B_krldy) & (tmot > TMKR) &

B_stend & (nmot > NKRF) Condition for active Knock Control with exhaust gas recirculation B_kr: (( rl > LKRAGRN) v B_krldy) & (tmot > TMKR) &

B_stend & (nmot > NKRF) Condition for active adaptation: B_kra : B_kr & (tmot > TMKRA)

The lower speed threshold NKRF should prevent the engine stalling at low speed by Knock Control-Ignition Angle-intervention

Co-ordination of the Ignition Angle for Torque Management

When knock control is active, the earliest cylinder-specific ignition angle results:
KFZW + dwkrz(i) + wkrdy (wkrdy is derived dynamically from module KRDY, included in module ZUE)

There are two types of control action:

1. Output ignition angle = KFZW + dwkrz(i) + wkrdy --> B_zwkraa = 1 --> knock control algorithm remains unchanged

2. Output ignition angle < KFZW + dwkrz(i) + wkrdy --> B_zwkraa = 0 --> advancing algorithm of wkr(i) is frozen and knock
control adaptation is disabled. (due to exhaust gas reasons, Stability Program operation, idle control, etc.)

In module ZUE the bit B zwkra is formed synchronously to the ignition angle output and it is then stored in the corresponding position in bit array zwkrafld. E.g. B_zwkraa is then determined from zwkrafld as follows:
SW cylinder counter

{| border="1"
|-
|
(zzylkr)
|
5
|
4
|
3
|
2
|
1
|
0
|
|-
|
B_zwkra
|
1
|
1
|
0
|
1
|
0
|
0
|
zwkrafld = 25 + 24
+ 22 = 52
|}

B_zwkraa (zzylkr = 3) = 0 (= false)

Please note: Signs of the ignition angle (in degrees crankshaft (°KW)) according to mathematical convention

KFZW > 0 (with TDC as the point of reference, ignition "before" DTC means mathematically positive angles KFZW)
dwkrz(i) £ 0 ("retard" timing with regard to the basis ignition angle means mathematically negative dwkrz(i))

Retarding of the ignition angle without adaptation (WKRBER)

If B_kr and !B_kra are set the knock control operates as follows:

If a knocking combustion (B_kl) is detected in module KRKE then the ignition angle of the corresponding cylinder i is adjusted by
retarding it by an amount KRFKN per knock event. If the engine is in the Knock Control-steady-state operation, is adjusted by retarding it by an amount KRFKLN per knock event. This cylinder-individual retarding is added independently of load and engine speed in the RAM area wkr(i)

For engine smoothness reasons and in order to avoid spurious misfire detections, the retarding is limited in each calculation to a
range around the mean value wkrm of the latest given SY_ZYLZA retardings wkr(i), given by wkrm plus/minus a freely selectable threshold. This threshold DWKRMSN is a characteristic line over the engine speed

Additionally the retarding is limited in wkr(i) towards retard to KRMXN and towards advance to 0°

wkr is a RAM-area in which a RAM-cell is reserved for each cylinder.

If the “Knock Control active” operating range of the engine is left (!B kr) then the latest present retarding remains stored in
wkr(i) until the “Knock Control active” range is entered again. The same applies for wkrm.

In the “Knock Control not-active” range of the engine zero is passed on to module ZUE as adjustment value dwkrz(i).

If the ignition is switched off, the retardings in wkr(i) are set equal to zero.

Advancing of the ignition angle (WKRBER & FRUEHVERST)

The retardings from wkr(i) are cancelled on a cylinder-specific basis if B_kr is set and if a cylinder-specific advancing
counter zkrvf(i) has reached zero.

During each knock event B_kl, the cylinder-specific counter zkrvf(i) is populated with the value KRVFN. Each non-knocking combustion in cylinder i for which in addition B zwkraa = 1 applies (i.e. the given ignition angle was limited by Knock Control) decrements zkrvf(i) by 1. When zkrvf(i) = 0 is reached, the retarding in wkr(i) assigned to the corresponding cylinder is
decremented by one quantization step and the counter is again populated with KRVFN.

During each timing towards advance, the wkr(i) are limited to the mean value wkrm of the latest given retarding SY_ZYLZA minus a
freely selectable threshold DWKRMSN or to the value zero.

If the “Knock Control active” operating range of the engine is left (!B_kr) the latest available counter values remain stored in zkrvf(i) until the “Knock Control active” range is entered again.

If the ignition is switched off, the counter values inzkrvf(i) are set equal to zero.

If changed engine operating conditions result in a reduced tendency to knock, a quicker advancing of the wkr(i) is performed until
the first knock event occurs after the beginning of this quick advancing. In this case, the counters zkrvf(i) are started when KRVFSN < KRVFN. The condition for the start of the quick advancing is either the transition from reading adaptation values wkra(i) to wkr(i) or the termination of a dynamic phase or a negative load range shift.

There should be no quick advance during dynamic operation (B_krldya / B_krndy = 1).

Knock Control Steady-State Mode

In Knock Control steady-state mode, the ignition angle per knock event is retarded by the value KRFKLN or KRFKN. So that the knock
frequency at different retards is not too high, the Knock Control steady-state mode advance adjustment speed adjusted by KRLVFKN.

The Knock Control steady-state operation is indicated by B_krstatb. This bit is set if |drl| < DRLKRSTMX and |ngfil| < NGKRSTMX
for TVKRSTAT seconds.

Retarding of the ignition angle with adaptation (KR ADAP)

B_kra = B_kr & (tmot > TMKRA) --> Adaptation active

B_krafrz = B_kra & ((rl < lkraw) || (tmot < TMKRAS) || (nmot < NKRAMIN) || (nmot > NKRAMX) || B_asr || B_nmax ||
B_vmax) --> Learning the adaptation values is prohibited

The adaptation ensures that also for strongly map-dependent varying retardings the knock frequency does not increase in case
of quick changes of the map ranges. For this purpose, when adaptation is active, the current retards under certain conditions are written in a load-speed-dependent adaptation map (see Storage) or overwritten with the values stored in the map (see Read). Read access to the adaptation map is only enabled when the engine temperature is stable and when there is a significant knock control requirement (i.e. TMKRA >= TMKR), whereas the knock control must be activated even at low knock control requirements (worst case conditions). Write accesses to the adaptation map are enabled until the second temperature threshold (TMKRAS ³ TMKRA) and the second load threshold (LKRAN >= LKRN) are exceeded. This prevents, on the one hand, spurious adaptation due to retardings during warm-up and on the other hand, a learning of the adaptation value to 0 at lower loads.

A RAM cell is reserved in the adaptation map wkra for each load- and speed range per cylinder. The load and speed limits are removed for administration labels (KRAL1-3N or KRAN1-4). The values stored there will be used as the limiting values in case of increasing load or speed.

In case of decreasing load or engine speed, an adjustable hysteresis (KRALH, KRANH) is subtracted from these values

The current load range is stored in stkrlx, the speed range in stkrnx.

When the ignition is switched off all values remain stored in wkra. If the supply voltage of the ECU is disconnected the values are
lost. After the supply voltage of the ECU has been reconnected all values are set to 0.

DIAGRAM

For the indexing of the wkra(i) - RAM-cells the following specification is used in the SW:
i = zzylkr + (8 x stkrnx) + (40 x stkrlx zzylkr) = 0...7, so at the maximum, 8 cylinders can be represented

stkrnx = 0...4, 5 engine speed ranges

stkrlx = 0...3, 4 load ranges (value of 0 is notwithstanding the ASCET-Model!)

The wkra of the current adaptation range can be obtained from the RAM cells wkraa_i, i = 0 ... SY_ZYLZA-1

Adaptation - Learning Conditions:

The following conditions update the adaptation map:

1. During each knock event, the ignition angle retard wkr of the cylinder in which the knock event occurred, is increased by an
offset KRDWKLA then stored in the current load-speed range of the adaptation map when this sum (wkr + KRDWKLA) is later than the value stored in wkra.

2. If the current retard wkr(i) is at least KRDWA earlier than the last value stored in the adaptation map and advance adjustment
counter zkrvf (i) = 0, the ignition angle retard is changed to KRDWSA towards advance in the adaptation map.

3. If the current retard wkr(i) = 0 and the advance adjustment counter zkrvf (i) = 0, wkra (i) is changed by KRDWSA towards advance.

The adaptation of the characteristic map is only performed during steady-state operation and during not active safety retarding (B
krdws=0). When idle control is active, the steady-state adaptation is also blocked, because the control is via the average wkrm retardation.

In order to avoid the unjustified adaptation of large amounts of retardation, further writing to the adaptation map (combined into
B_krafrz) is prohibited under the following conditions:

- tmot < TMKRAS error identifiers due to extraneous noise during warm-up

- nmot > NKRAMAX error identifiers due to extraneous noise from the dump valve

- nmot < NKRAMIN error identifiers due to extraneous noise from the drivetrain

- B_asr = 1 transient engine conditions via fast ignition angle-intervention, possibly error identifiers

- B_nmax = 1 ditto

- B_vmax = 1 ditto

Writing is also prohibited when

- rl < LKRAN

Adaptation – Read Conditions

During active adaptation the retarding of all cylinders wkr(i) is overwritten by the values from wkra(i) if one of the
following conditions is fulfilled:

1. Transition from !B_kra to B_kra

2. Load range changes with dynamic response (B_krl/ndyn = 1)

3. Engine speed changes with dynamic response (B_krl/ndyn = 1)

4. Entering or exiting idle control

During overwriting of wkr(i) with wkra(i), ignition angle jumps away from advance can happen (e.g adaptation has not yet settled in all adaptation ranges) which may give rise to undesirable results (judder, knock). For this reason, early ignition angle changes will be limited via overwriting KRDWAA. KRDWAA = 0 means that ignition angle jumps away from advance will be prevented. KRDWAA = KRMXN means that ignition angle jumps away from advance within the scope of the maximum Knock Control range are permitted.

Knock Control in the case of Active Dynamic Response (KRRA, KR_ADAP, BBKR)

In case of active dynamic response (B_krldy, B_krldya, B_krndy, see module KRDY) the further adaptation of the steady-state values
wkra(i) is blocked. A change of the adaptation ranges leads to an updating of wkr(i) with the values adjusted in wkra(i).

Each knocking combustion (B_kl), like so far, leads to a retarding by KRFKN and is therefore added to the cylinder-individual
retarding in wkr(i).

In addition to B_krldya, an adaptive dynamic derivative action wkrdy (see module KRDY) is added. For the fastest possible inclusion of this derivative action for dynamic response detection, an auxiliary bit B_wkrdyw set in module KRDY triggers the corresponding updating of all dwkrz_i included in wkrdy in the next KR-time frame. This algorithm is not shown in the ASCET images.

Knock Control during Active Idle Control (KRRA)

When idle control is active (B_llr = 1) cylinder-specific knock detection and control of the retardings wkr(i) still occurs. However, at ignition, the average retardation wkrm is output (dwkrz(i) = wkrm for all i).

In this way, additional idle disturbance via KR-ZW-intervention is avoided. During activation or deactivation of idle control respectively, the adaptation map is read.

Knock Control Above NKRMAX (BBKR, WKRBER)

Errors can frequently occur at high speeds due to noise (e.g. valve lift). Therefore, in order to avoid unduly large amounts of retarding, there is a speed threshold, NKRMAX, above which the de facto knock control is disabled! Instead, wkr(i) is permanently overwritten with the adapted values of the current adaptation range wkra(i) + an offset. This offset (krfkw - KRDWKLA) is implemented so that a margin from krfkw to the knock limit in this adaptation range is maintained. However, the prerequisites for this are a nearly constant knock limit within the respective adaptation areas and the presence of a current
adaptation value.

Please apply this function with the utmost care!

Optional Leading Cylinder (LZ)

The leading cylinder function is enabled:
- On exceeding a
cylinder-specific speed threshold KRNLZ[i], above which the cylinder has poor
knock detection, this cylinder is led by the cylinder with a good knock
detection

- For systems with two
knock sensors, if an error has been detected for the knock sensors. (The one
knock sensor associated cylinder are hereafter referred to as a group.) The
cylinders of the group concerned are then led by the cylinders of the group
having a good working knock sensor. On exceeding KRNLZ [i], the safety
retardation will be activated for all of the cylinders. This mitigation measure
will be turned off via the codeword CWKRNLR. If an error is detected, a sensor
immediately activates the security retardation

Leading Cylinder Function
when Engine Speed > KRNLZ, Without Knock Sensor Error
The corresponding leading and led cylinders are selected via the elements
LZFUER_0 to _k (k = SY_ZYLZA - 1), of the blocks of constants LZFUER. The leading cylinder (LZ) is indicated by set bits in
the bytes to
LZFUER_0 _k

The elements i = 0 to k
of the constants LZFUER are selected via the cylinder
block counter zzylkr in Knock Control, i.e. LZFUER_i belongs to zzylkr = i the
cylinder counter counts the combustion within an AS. The connection between
zzylkr and physical
cylinder is given by the firing sequence. Accordingly, the bits 0-7 of LZFUER_i
refer to zzylkr indexed combustion

During activation of the
lead cylinder function in this case, the contents of LZFUER is copied into the
RAM-array LZIST (loop from i = 0 ... SY_ZYLZA-1 on a 100 ms time frame). Thus
LZIST will contain the most current association between leading and led
cylinders

For example:
6 cylinder engine with
firing sequence zzylkr = 0 1 2 3 4 5
Physical cylinders: 1 4 3 6 2 5
Block of constants LZFUER
Led cyl. Bit 7 6 5 4 3 2 1 0 <-- (leading cylinder)
LZFUER_0 0 0 0 0 0 0 0 0 -- > 00 -- > physical
cylinder 1 will not be led, i.e. separate knock detection
LZFUER_1 0 0 0 0 1 0 0 0 -- > 08 -- > physical
cylinder 4 will be led by cylinder 6
LZFUER_2 0 0 0 0 1 0 0 1 -- > 09 -- > physical cylinder
3 will be led by phys. cylinder 6 or 1 (late selection)
LZFUER_3 0 0 0 0 0 0 0 0 -- > 00 -- > physical
cylinder 6 will not be led, i.e. separate knock detection
LZFUER_4 0 0 0 0 1 0 0 0 -- > 08 -- > physical
cylinder 2 will be led by cylinder 6
LZFUER_5 0 0 0 0 1 0 0 0 -- > 08 -- > physical
cylinder 5 will be led by cylinder 6
A led cylinder may not be
defined as a lead cylinder for itself, i.e. the bit i in LZFUER_i must be
"0"

In the lead cylinder function, the following active measures are taken:

1. The knock detection will continue unchanged

2. The knock control and adaptation of the leading cylinder continues unchanged

3. For a led cylinder i, the
retardation of the latest i assigned to leading cylinders j plus a
cylinder-specific offset WKRLZOF_i is used as a late adjustment: wkr_i is
overwritten in the background program with wkr_j + WKRLZOF_i. The adaptation
continues unchanged. The adapted (and possibly incorrect) values for led cylinders arising because of 6 are not output

If the code word CWKRLZFK
= 1, the retard for the led cylinder is determined according to the following
minimum selection:
wkr_i = MIN (wkr_i,
wkr_j) + WKRLZOF_i
4. Detected knock for the
led cylinders has no effect: the retardation per knock is set to zero for the
cylinder

If the code word CWKRLZFK
= 1, wkr_i will be retarded according to krfkw in the led cylinders and also
the cylinders in which knock is detected, regardless of the leading cylinder
function

5. An independent advance
for led cylinder is suppressed: the step width of the counter zkrvf_i for the
led cylinder i is set continuously in the background program KRVFN

If the code word CWKRLZFK
= 1, the step width counter zkrvf_i is not overwritten for the led cylinder i

Thus, an advance of wkr_i independent of the leading cylinder is possible. But
because this results in an earlier ignition angle than with the leading
cylinder, wkr_i will be overwritten with the ignition angle-adjustment of the
leading cylinder. Thus, the earliest possible ignition angle for the led
cylinder is given by the leading cylinder’s ignition angle + offset

6. When reading from the
adaptation maps, ignition angle changes away from advance are limited to 0°
crank angle, rather than KRDWAA

Leading Cylinder Function
With Knock Sensor Error and Engine Speed < KRNLZ
If the knock sensor in
group 2 is off (B_kseb2 = 1), then the cylinder of group 2 is led by group 1
according to the measures described in points 1 to 6 above. Instead of the
individual cylinder offsets WKRLZOF_i, a global offset, WKRLZOFEKS is applied
to the led cylinder. In this case, the content of LZB1 is copied into the RAM
array LZIST (see above)

If the knock sensor in
group 1 from (B_kseb1 = 1), then the cylinder of group 1 is led by group 2
according to the measures described in points 1 to 6 above. Instead of the
individual cylinder offsets WKRLZOF_i, a global offset, WKRLZOFEKS is applied
to the led cylinder. In this case, the content of LZB2 is copied into the RAM
array LZIST (see above)

If both knock sensors are
off (B_kseb1 = 1 & B_kseb2 = 1), the safety retardation is activated
(B_krdws = 1)

Through the elements
LZBi_0 to LZBi_k (k = SY_ZYLZA - 1) of the constant
blocks LZBi (i = 1,2) the corresponding leading and led cylinders are selected

The leading cylinder (LZ) is indicated by set bits in the bytes LZBi_0 to LZBi_k

The elements n = 0 to k
of the constant block are selected by the cylinder
counter zzylkr in the Knock Control function, i.e. LZBi_n is zzylkr = n. is one
of the cylinder burns the counter counts within an AS. The connection between
zzylkr and the physical cylinder is given by the firing sequence. Accordingly, the
bits 0-7 of LZBi_n refer to zzylkr by indexed combustion

For example:
6 cylinder engine with
firing sequence zzylkr = 0 1 2 3 4 5
Physical cylinders: 1 4 3 6 2 5
Constant block LZB1
Led cyl. Bit 7 6 5 4 3 2 1 0 <-- leading cylinder
LZB1_0 0 0 0 0 0 0 0 0 = 0
LZB1_1 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder
4 is led by the cylinders of group 1
LZB1_2 0 0 0 0 0 0 0 0 = 0
LZB1_3 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder
6 is led by the cylinders of group 1
LZB1_4 0 0 0 0 0 0 0 0 = 0
LZB1_5 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder
5 is led by the cylinders of group 1
Constant block LZB2
Led cyl. Bit 7 6 5 4 3 2 1 0 <-- leading cylinder
LZB2_0 0 0 1 0 1 0 1 0 = 42 -- > physical
cylinder 1 is led by the cylinders of group 2
LZB2_1 0 0 0 0 0 0 0 0 = 0
LZB2_2 0 0 1 0 1 0 1 0 = 42 -- > physical
cylinder 3 is led by the cylinders of group 2
LZB2_3 0 0 0 0 0 0 0 0 = 0
LZB2_4 0 0 1 0 1 0 1 0 = 42 -- > physical
cylinder is led by the cylinders of group 2
LZB2_5 0 0 0 0 0 0 0 0 = 0
A led cylinder may not be
defined as a lead cylinder for itself, i.e. the bit i in LZBi_n must be
"0"

Safety Retardation During
Active Knock Control (KRRA)
The knock control system hardware
(sensors and signal processing IC CC195) is continuously monitored using the
diagnostic functions DKRNT, DKRTP and DKRS. When errors are detected, the corresponding
error flags E_ * are set, resulting in setting B_krdws to trigger the safety
retardation. Resetting of B_krdws after detection of error healing and hence
the withdrawal of the safety retardation may only happen with "knock
control not active" (to prevent torque jumps)

Other system errors that
lead to triggering of the safety retardation are:
- Lack of synchronization
(B_synph = 0)
For systems with two or
more knock sensors (KSZA > 1), in the absence of general synchronization
safety retardation will be switched on

For systems with only one
knock sensor (KSZA = 1) and without active leading cylinder function, knock
detection in the absence of synchronization will be performed with the most
sensitive knock detection threshold (B_krnl = 1 = > emergency knock detection
– see also module KRKE), the knock control system continues unchanged

The operation of the
leading cylinder function sets the synchronization of the system (B_synph = 1)
mandatory in advance. It follows that in absence of synchronization and active
leading cylinder function in safety retardation (B_krdws = 1) it must be switched,
regardless of how many knock sensors the system has

In the absence of
synchronization, an emergency operation of the engine by using dual ignition
per SW (mirroring the ignition = > Half firing interval) can occur. In the
case of an odd number of cylinders, the required sychronisation between the
Knock Control measurement windows and combustion is no longer necessarily
given. It must, even for systems with a knock sensor, be switched to safety
retardation. A value of > 1 is therefore input to KSZA

- Emergency tachometer
(B_nldg = 1)
During speed-sensor
emergency operation, the measurement window cannot be output with the required
accuracy. Therefore security retardation is activated. To prevent unnecessary
setting of safety flags B_krdws after an ECU reset, the setting of c_inisyn is
blocked for 3 seconds. If the Knock
Control safety flag, B krdws, is set (see modules DKRS, DKRNT and DKRTP),
dwkrz(i) and wkrma are overwritten by KRDWS if the knock control is active

wkra(i), wkr(i) and wkrm are not updated as long as B
krdws is set

If B krdws is again reset dwkrz(i) is overwritten by
wkr(i), wkrma by wkrm

Application Notes
Cylinder-specific and load/engine speed
range-dependent values are marked by (i) in the description corresponding to
their realization in the ECU-code, e.g. wkr(i). The corresponding RAM-cell
which can be read via VS100 is indicated in the ASCET-image by i, e.g. wkr i

The cylinder counter zzylkr generated in module GGKS
serves as control variable for the index i of the cylinder-individual RAM-cells
(wkr(i), dwkrz(i), zkrvf(i), with the exception of wkra(i), see above)

Knock Control can be switched off via the label TMKR:
TMKR > tmot == > !B_kr
For the application the following typical values are
suggested:
KRFKN -3 °crank is a
value for the retarding of the ignition angle. Experience shows that it is a
sufficient value to safely run the engine at the knock limit with stabilized
adaptation

KRMXN -12 °crank is a
value which is sufficient for most applications. When fixing this
characteristic line it must be noted though that the engine can be operated
absolutely knock-free with the programmed value under worst-case conditions
(i.e. engine speed, ambient temperature and fuel with lowest octane number)

In the process attention must be paid to the maximum
permitted exhaust gas temperature

KRVFN approx. 4 sec/°KW
advancing is a typical value. The control speed of Knock Control during
quasi-steady-state engine running results from this characteristic line in
connection with KRFKN. The aim here is to determine a time constant which is
larger than the thermal time constant of the engine so as to avoid a thermal
strain

When adjusting KRVFN it must be taken into
consideration that the thermal strain of the engine increases with increasing
engine speed so that a larger period should be chosen for higher engine speeds

KRVFN = 1 Inc. * n / (120 * x) with 1 Inc. in °KW
n in rpm
x in °KW/sec - "speed" for
the advance adjustment
KRVFSN to be adjusted dependent of KRDWKLA in order to
enable a quick advancing of the adaptation map values in case of changed
operating conditions without provoking an increased knock frequency

KRDWKLA = -3 °KW: approx

1 sec/°KW advancing or approx. 1/4 ´ KRVFN
KRDWKLA = 0 °KW: approx

2 sec/°KW advancing or approx. 1/2 ´ KRVFN
TMKR approx. 40VC is the value during which on many
engines knocking combustions can already occur

TMKRA: Below an engine temperature threshold TMKRA it
is not useful to update wkra since experience has shown that within this
operating range the knock tendency of the engine is very low. If adaptation
would be permitted the necessary values learned in the normal operating range
would be lost which means that the knock frequency is again increased when this
operating range is reached again

Usually this engine temperature threshold lies at
TMKRA = 80°C

LKRN approx. 30% rl is a typical value. The lowest
load threshold during which knocking combustions can occur is stored in this
characteristic line

LKRAN can be parameterized with values > LKRN,
so the adaptation will only happen when there is a significant Knock Control
demand; LKRAN is ineffective when parameterized with values <=
LKRN

KRDWKLA 0 °KW
<= |KRDWKLA| <= |KRFKN|
KRDWA |KRDWA| >=
|KRDWKLA|
KRDWSA 0 °KW <
|KRDWSA| und |KRDWSA| <= |KRDWA| - |KRDWKLA|
The following sets of
parameters can be recommended:

{| border="1"
|-
|
KRDWKLA/°KW
|
KRDWA/°KW
|
KRDWSA/°KW
|
|-
|
0
|
2.25
|
2.25
|
= > Adaptation up to the knock limit
|-
|
-1.5
|
3.0
|
1.5
|
= > Adaptation up to the knock limit + a
safety margin of 1.5 °crank
|-
|
-3.0
|
4.5
|
1.5
|
= > Adaptation up to the knock limit + a
safety margin of 3 °crank
|}
KRWKRAIN = 0 °crank ... KRMXN, when
interpretation of the ignition angle-KF close to the knock limit a value < 0
°crank is recommended
KRDWAA = 0; ignition angle jumps away from advance via reading of the
adaptation values are prevented
= min(KRMXN); ignition angle jumps away from advance are
permitted within the scope of the maximum knock control range
0 > KRDWAA > min(KRMXN)
ignition angle jumps away from advance are limited to KRDWAA
DWKRMSN approx. -3 °KW is a
typical value to maintain the engine smoothness and to avoid misfire
misdetection; if the values get smaller the cylinder-individual character of
the knock control is increasingly lost

KRDWSN around -12 °crank, knock
must be avoided under worst case conditions
KRALH in order to avoid a judder at the range limits,
a hysteresis was introduced for decreasing load

Typical value for KRALH = 3%

KRANH in order to avoid a judder at the range limits,
a hysteresis was introduced for decreasing engine speed

Typical value for KRANH = 120 rpm

NKRAMIN equal to the speed, up to which error flags by
mechanical noise and vibration arise from the drive train. If the function is
not required then set NKRAMIN = 0
NKRAMAX equal to the
speed above which there can be error flags (e.g., valve lift) which
particularly applies when NKRAMAX > KRAN4 so actually in the upper speed
range, values can be adapted, otherwise there is
considerable risk of freezing the Knock Control by overwriting with NKRMAX. If
the function is not required then set NKRAMAX to the maximum value

NKRMAX equal to the speed
above which there can be error flags (e.g., valve lift) which particularly
applies when NKRMAX > KRAN4 and NKRMAX >= NKRAMAX so actually in the
upper speed range, values can be adapted,
otherwise there is considerable risk of freezing the Knock Control by
overwriting with NKRMAX. If the function is not required then set NKRMAX to the
maximum value

CWKRNLR = 1 additional
mitigation measure for systems with two knock sensors with knock sensor error
is active. CWKRNLR = 0 ... is not active

Particular attention when
determining the ignition angle maps requires knowledge of the area in which an
enrichment function (lambda <1) is active since the knock limit will shift
because of the enrichment

To ensure the stabilty of
Knock Control is not jeopardized, the ignition angle structure and the
enrichment function must be adjusted so that a uniform margin to the knock
limit is maintained (<3° crank) across the entire operating range of the
engine

The existence of some values/RAMs is determined by the
representation in ASCET (block hierarchy, course of control). They are not
realized in the SW resp. they cannot be measured definitely by means of VS100
due to their special realization:
- B wkral cannot be measured definitely
- B krvf is not realized
- zkrvf(i)=0 cannot be measured, this state can only
be detected indirectly via the performed RESET of the counter from zkrvf(i) = 1
to zkrvf(i) = KRVF(S)N
- zzylkral is not realized
Distinguishing between wkrm/wkrma
wkrm represents the mean value of the each time SY
ZYLZA latest calculated wkr(i) (possibly incl. mean value vswzm) while wkrma
represents the mean value of the dwkrz(i) (without wkrdy) which was passed on
to the ignition during the SY ZYLZA latest combustions

Adaptation characteristic map wkra
When choosing the map values a compromise has to be
achieved between the possibly varying knock tendency of the engine at different
load and engine speed ranges and the time by which the characteristic map is
updated during normal driving

If the adaptation map wkra is chosen to be too large
(i.e. many relative load-engine speed-ranges) a longer period will be needed in
order to update all ranges

Thus in case of changed operating conditions which
lead to a larger knock tendency it is inevitable that the knock frequency
increases

Generally a characteristic map with three load and
five engine speed ranges is sufficient for wkra. In this map a RAM-cell is
provided for each load/ engine speed range per cylinder

(Example 4-cylinder-engine: 3 ´ 5 ´ 4
= 60 RAM-cells for wkra)
For the indexing of the wkra(i) - RAM-cells the
following specification is used in the SW:
i = zzylkr + 8 ´ stkrnx + 40 ´ stkrlx (zzylkr = 0...7,
so at the max. 8 cylinders can be represented)
The number of adaptation ranges can be varied
according to special customer requirements but at the maximum to 4 x 8
load/engine speed ranges (change of above-mentioned indexing may possibly be
necessary)

Cylinder-individual ignition angle timing with VS20
By means of VS20 a cylinder-individual additional
timing vszw(i) can be performed (see also modules VS and VERST) so that the
following applies:
dwkrz(i) = wkr(i) + wkrdy + vszwkr(i) if B kr & !B
krdws

{| border="1"
|-
|
Label
|
Timing Range
|
Quantization
|
Initialization/neutral value
|-
|
vszwkr_1
|
see
module VS_VERST
|
0.75
°crank
|
0
°crank
|-
|
Vszwkr_8
|
see
module VS_VERST
|
|
|}
i = 0 ... SY ZYLZA - 1
Attention:
1. No automatic limitation of vszwkr(i) is performed -
please pay attention to engine and catalyst protection during the timing!
2. The earliest possible ignition angle determined by
the Knock Control is under all circumstances, i.e. it is possible that the
minimum permitted ignition angle may be undershot (due to temperature reasons

see modules ZUE and ZWMIN). Please pay attention to engine and catalyst
protection!
Abbreviations

{| border="1"
|-
|
CWKRLZFK
|
Code
word: knock detection is not switched off for led cylinders
|-
|
CWKRNLR
|
Code word: limp home in case of 1 out of 2 knock
sensors fails
|-
|
CWKRRA
|
Code
word for the function KRRA
|-
|
DRLKRSTMX
|
Maximum
drl in Knock Control steady-state operation
|-
|
DWKRMSN
|
Delta ignition angle Knock Control margin from
mean retarding
|-
|
KRAL1N
|
load range for Knock Control adaptation maps 1
|-
|
KRAL2N
|
load range for Knock Control adaptation maps 2
|-
|
KRAL3N
|
load range for adaptation Knock Control maps 3
|-
|
KRALH
|
Load hysteresis for Knock Control adaptation maps
|-
|
KRAN1
|
speed range for Knock Control adaptation maps,
sample range 1
|-
|
KRAN2
|
speed range for Knock Control adaptation maps,
sample range 2
|-
|
KRAN3
|
speed range for Knock Control adaptation maps,
sample range 3
|-
|
KRAN4
|
speed range for Knock Control adaptation maps,
sample range 4
|-
|
KRANH
|
Engine speed hysteresis for Knock Control
adaptation maps
|-
|
KRDWA
|
knock control difference current ignition angle
to adaptation map
|-
|
KRDWAA
|
Permissible
ignition angle jump towards advance when reading adaptation values
|-
|
KRDWKLA
|
The SV-learning value for KR adaptation after
knocking detected
|-
|
KRDWSA
|
The FV-learning value for KR adation when
wkra-wkr > KRDWA
|-
|
KRDWSN
|
knock control delta angle safety
|-
|
KRFKLN
|
Retard
per knock event at a slow advance
|-
|
KRFKN
|
retard step knock occurrence
|-
|
KRLMDY
|
Read if change of load range: always or only if
dynamic active
|-
|
KRMXN
|
maximum retard adjustment
|-
|
KRNLZAR
|
cylinder individual speed limit for lead by
leading cylinder
|-
|
KRNMDY
|
Read if change of speed range: always or only if
dynamic active
|-
|
KRVFN
|
number of firings/cyl. or time for ignition
advancing
|-
|
KRVFSN
|
number of firings/cyl. or delay-time during fast
ignition advancing of the Knock Control
|-
|
KSZA
|
Knock sensor number
|-
|
LKRAGRN
|
Load
threshold knock control with Exhaust Gas Recirculation
|-
|
LKRAN
|
Load
threshold knock control adaptation
|-
|
LKRN
|
load-signal threshold knock control
|-
|
LZB1
|
Lead
cylinder assignment: Bank 1 leads to Bank 2 with error KS 2
|-
|
LZB2
|
Lead
cylinder assignment: Bank 2 leads to Bank 1 with error KS 2
|-
|
LZFUER
|
Lead cylinder assignment
|-
|
NGKRSTMX
|
maximum speed
gradient in the Knock Control steady-state operation
|-
|
NKRAMAX
|
Upper
engine speed limit for freezing Knock Control adaptation
|-
|
NKRAMIN
|
Lower
engine speed limit for freezing Knock Control adaptation
|-
|
NKRF
|
Engine
speed threshold for Knock Control release
|-
|
NKRMAX
|
Upper
engine speed limit for freezing Knock Control adaptation
|-
|
SENZZYL0
|
|-
|
SNM16KRUB
|
Data point distribution engine speed, 16 data points
|-
|
SY_ZYLZA
|
System constant: number of cylinders
|-
|
TMKR
|
Engine-temperature threshold to enable Knock
Control
|-
|
TMKRA
|
Engine temperature threshold for adaptive Knock
Control
|-
|
TMKRAS
|
Temperature threshold for releasing write
access to the adaptation map
|-
|
TVKRSTAT
|
Knock
Control delay time steady-state operation
|-
|
WKRLZOF
|
Constant bloack: ignition retard offset for leed
cylinder
|-
|
WKRLZOFEKS
|
Ignition retard offset for led cylinders in case
of knock sensor error
|-
|
B_ADRKRA
|
Condition
flag: Knock Control adaptation
values reset errors in memory
|-
|
B_AGR
|
Condition
flag: Exhaust Gas Recirculation
|-
|
B ASR
|
Condition
flag: ASR active
|-
|
B_KL
|
Condition flag: knock detected
|-
|
B_KR
|
Condition flag for knock control active
|-
|
B_KRA
|
condition for active Knock Control adaptation
|-
|
B_KRAFRZ
|
Condition
flag: Knock Control adaptation is frozen
|-
|
B_KRDWS
|
Condition flag: knock control safety ignition
retarding
|-
|
B_KRFDKS
|
Condition flag: enable knock sensor diagnosis
|-
|
B_KRFRZ
|
Condition
flag: Knock Control adaptation is frozen
|-
|
B_KRLDY
|
Condition flag: load dynamics for knock detection
active
|-
|
B_KRLDYA
|
Condition flag: load dynamics retard and dynamics
adaptation active
|-
|
B_KRLDYN
|
Condition
flag: load dynamics for steady-state adaptation active
|-
|
B_KRLZ
|
Condition flag: knock control lead-cylinder function
active
|-
|
B_KRNDY
|
Condition flag: speed dynamics for knock
detection active
|-
|
B_KRNDYN
|
Condition
flag: speed dynamics for steady-state adaptation is active
|-
|
B_KRNL
|
Condition flag: emergency operation of knock
detection for emergency operation of phase sensor
|-
|
B_KRNLR
|
Condition
flag: emergency knock control for V6 or V8 with two knock sensors and error
in one knock sensor
|-
|
B_KRSTATB
|
Condition
flag: steady-state Knock Control operation
|-
|
B_KRVF
|
Condition flag: adjustment of Knock Control
ignition timing to a less retarded value
|-
|
B_KRWA
|
Condition
flag: Knock Control at stop
|-
|
B_KSEB1
|
Condition
flag: KS-error Bank 1
|-
|
B_KSEB2
|
Condition
flag: KS-error Bank 2
|-
|
B_LLR
|
Condition
flag: idle control
|-
|
B_NLDG
|
Condition flag: limp-home function speed sensor
|-
|
B_NMAX
|
Condition
flag: speed limit active
|-
|
B_PWF
|
Condition flag: power fail
|-
|
B_STEND
|
Condition flag: end of start
|-
|
B_SYNPH
|
Condition flag: synchronization phase
|-
|
B_TMKR
|
Condition flag: engine temperature (tmot) for
knock control achieved
|-
|
B_VMAX
|
Condition
flag: VMAX control active
|-
|
B_WKRAL
|
Condition flag: to read wkr from knock control
adaptation map
|-
|
B_ZWKRAA
|
Condition flag: ignition angle of the Knock
Control is given
|-
|
B_ZWKRUM
|
Condition flag: fast ignition advance Knock
Control
|-
|
DFP_KRNT
|
internal failure path number: knck control zero
test
|-
|
DFP_KROF
|
internal failure path number: knock control
offset
|-
|
DFP_KRTP
|
internal failure path number: knock control test
pulse
|-
|
DFP_KS1
|
internal failure path number: knock sensor 1
|-
|
DFP_KS2
|
internal failure path number: knock sensor 2
|-
|
DFP_KS3
|
internal failure path number: kncok sensor 3
|-
|
DFP_KS4
|
internal failure path number: knock sensor 4
|-
|
DRL_W
|
Change
in cylinder fill
|-
|
DWKR
|
cylinder-specific ignition-timing retardation
|-
|
DWKRMSW
|
current value for mean value limitation of the
retarding
|-
|
DWKRZ
|
cyl.-spec. ignition-timing retardation with
retardation for dynamics
|-
|
E_KRNT
|
error flag: knock control zero test
|-
|
E_KROF
|
Errorflag: knock control offset
|-
|
E_KRTP
|
error flag: knock control test pulse
|-
|
E_KS1
|
error flag: knock sensor 1
|-
|
E_KS1H
|
auxiliary error flag KS1
|-
|
E_KS2
|
error flag: knock sensor 2
|-
|
E_KS2H
|
auxiliary error flag KS2
|-
|
E_KS3
|
error flag: knock sensor 3
|-
|
E_KS3H
|
auxiliary errorflag KS3
|-
|
E_KS4
|
error flag: knock sensor 4
|-
|
E_KS4H
|
auxiliary error flag KS4
|-
|
KRAL1W
|
current value load adaptation range 1
|-
|
KRAL2W
|
current value load adaptation range 2
|-
|
KRAL3W
|
current value load adaptation range 3
|-
|
KRDWSW
|
momentan characteristic-value for safety retard
|-
|
KRFKW
|
current value of KRFKN
|-
|
KRLZN
|
Cylinder-specific speed threshold of lead
cylinder function exceeded
|-
|
KRMXW
|
current value for retard limitation of the
retarding
|-
|
KRVFSW
|
initialization value for quick advancing
|-
|
KRVFW
|
initialization value for normal advancing
|-
|
LKRAW
|
Current
value of the load threshold knock control-adaptation
|-
|
LKRW
|
Current value of the load threshold knock control
|-
|
LZIST
|
Array: instantaneous assignment of leading and led
cylinders
|-
|
NGFIL_W
|
Filtered
speed gradient
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative air charge
|-
|
STKRAX
|
Index for Knock Control adaptation map
|-
|
STKRLX
|
Load range adaptation map Knock Control
|-
|
STKRNX
|
Speed range adaptation map Knock Control
|-
|
TMOT
|
Engine temperature
|-
|
TPNT_AKTIV
|
Activation of Knock Control functions
|-
|
VSZWKR
|
Cylinder-specific adjustment of ignition angle by
VS2x
|-
|
VSZWM
|
Average value of adjustment ignition angle with
VS2x
|-
|
WKR
|
Cylinder-specific ignition retarding value knock
control
|-
|
WKRA
|
Adaptation map of wkr, speed- and load-dependent
|-
|
WKRAA
|
Monitor
for the wkra of the current adaptation ranges, wkra_0, _1…
|-
|
WKRATST
|
wkra updated in real time
|-
|
WKRM
|
Average value of individual ignition retarting by
knocking
|-
|
WKRMA
|
Average value of ignition retarding by KC,
generally(limpe home with safety)
|-
|
WKR_TST
|
cylinder-individual ignition angle retarding,
druming
|-
|
ZKRVF
|
counter determines the frequency of the
cylinder-individual ignition angle adv

|-
|
ZWKRAFLD
|
bit pattern of the cylinder-individually stored
B-zwkra
|-
|
ZZYLKR
|
cylinder counter Knock Control
|}

KRRA 15.130 (Knock Control with Individual Cylinder Retard)

2012-05-02T23:01:46Z

TTQS:

KRRA 15.130 (Knock Control with Individual Cylinder Retard)

2012-05-02T22:52:56Z

TTQS: Created page with "See the ''funktionsrahmen'' for the following diagrams: krra-main KRRA: knock control including steady state adaptation krra-bbkrra BBKRRA: release of knock control and adaptat..."

See the ''funktionsrahmen'' for the following diagrams:

krra-main KRRA: knock control including steady state adaptation

krra-bbkrra BBKRRA: release of knock control and adaptation

krra-bbkr BBKR: release of knock control and adaptation

krra-bb-krdws BB-KRDWS: condition for safety retard of ignition

krra-bb-lzf BB-LZF: release of leading cylinder function

krra-lzist LZIST: determination of led and leading cylinders

krra-uewkr UEWKR: overwrite ignition retard of led cylinders

krra-wkral WKRAL: Update of the cylinder selective ignition retard at adaptation area change (wkra -- > wkr)

krra-wkrber WKRBER: Calculation of ignition retard

krra-krvf FRUEHVERST: Release of ignition advance adjustment

krra-wkri WKRI: calculation of the average ignition retard

krra-begwkr BEGWKR: limitation of ignition retard after reading adaptation map

krra-stkra STKRA: Detection of load- and speed range

krra-kr-adap KR_ADAP: Adaptation of ignition retard

krra-vswkr VSWKR: Ignition adjustment with VS2x

krra-kr-freeze KR-FREEZE: calculation of ignition retard for frozen knock control

krra-initialise Initialise function

Note:
The cylinder-specific variables wkr, dwkrz, wkra and zkrvf are indicated in the following description through a control variable (i) - like in the ECU code, for example wkr(i). The corresponding RAM-cell which can be read via VS100 is marked by _i, for example: wkr_i

The Knock Control cylinder counter zzylkr serves as control variable (except wkra)

The following applies to it:
zzylkr = 1 ... SY_ZYLZA ASCET-Model
zzylkr
= 0 ... SY_ZYLZA-1 ECU-Code

See also the Application Notes section in this module

KRRA 15.130 Function Description

Function of Knock Control

The KRRA module includes calculation of the cylinder-specific change of ignition angle of the knock control and adaptive calculation of the cylinder-specific retarding wkr(i) (WKRBER) with storage in an adaptation characteristic map wkra(i) (KR ADAP). The input values of the adaptation map are current cylinder number, engine speed and load (STKRA)

The value of the retarding dwkrz(i) which is passed on to the ignition comes to dependent on the operating condition (BBKC):

1. B_kr & !B_krdws & !B_llr dwkrz(i) = wkr(i)

2. B_kr & B_krdws dwkrz(i) = krdwsw KRDWS – Safety retarding see modules DKRS, DKRNT and DKRTP

3. B_kr & !B_krdws & B_llr dwkrz(i) = wkrm wkrm – average retard over all cylinders

4. !B_kr & (!)B_krdws dwkrz(i) = 0
Condition for active Knock Control without exhaust gas recirculation B_kr: ((rl > LKRN) v B_krldy) & (tmot > TMKR) &
B_stend & (nmot > NKRF) Condition for active Knock Control with exhaust gas
recirculation B_kr: (( rl > LKRAGRN) v B_krldy) & (tmot > TMKR) &
B_stend & (nmot > NKRF)
Condition for active adaptation: B_kra : B_kr & (tmot > TMKRA)
The lower speed threshold NKRF should prevent the engine stalling at low speed by Knock Control-Ignition Angle-intervention

Co-ordination of the Ignition Angle for Torque Management

When knock control is active, the earliest cylinder-specific ignition angle results:
KFZW + dwkrz(i) + wkrdy (wkrdy is derived dynamically from module KRDY, included in module ZUE)
There are two types of control action:
1. Output ignition angle = KFZW + dwkrz(i) + wkrdy --> B_zwkraa = 1 --> knock control algorithm
remains unchanged
2. Output ignition angle < KFZW + dwkrz(i) + wkrdy --> B_zwkraa = 0 --> advancing algorithm of wkr(i) is frozen and knock
control adaptation is disabled. (due to exhaust gas reasons, Stability Program
operation, idle control, etc.)
In module ZUE the bit B zwkra is formed synchronously to the ignition angle output and it is then stored in the corresponding position in bit array zwkrafld. E.g. B_zwkraa is then determined from zwkrafld
as follows:
SW cylinder counter

{| border="1"
|-
|
(zzylkr)
|
5
|
4
|
3
|
2
|
1
|
0
|
|-
|
B_zwkra
|
1
|
1
|
0
|
1
|
0
|
0
|
zwkrafld = 25 + 24
+ 22 = 52
|}
B_zwkraa (zzylkr = 3) = 0 (= false)
Please note: Signs of the ignition angle (in degrees
crankshaft (°KW)) according to mathematical convention

KFZW > 0 (with TDC as the point of reference,
ignition "before" DTC means mathematically positive angles KFZW)
dwkrz(i) £ 0 ("retard" timing with regard to the basis ignition angle
means mathematically negative dwkrz(i) )
Retarding of the ignition angle without adaptation
(WKRBER)
If B_kr and !B_kra are set the knock control operates
as follows:
If a knocking combustion (B_kl) is detected in module
KRKE then the ignition angle of the corresponding cylinder i is adjusted by
retarding it by an amount KRFKN per knock event. If the engine is in the Knock
Control-steady-state operation, is adjusted by retarding it by an amount KRFKLN
per knock event. This cylinder-individual retarding is added independently of
load and engine speed in the RAM-area wkr(i)

For engine smoothness reasons and in order to avoid
spurious misfire detections, the retarding is limited in each calculation to a
range around the mean value wkrm of the latest given SY_ZYLZA retardings
wkr(i), given by wkrm plus/minus a freely selectable threshold

This threshold DWKRMSN is a characteristic line over
the engine speed

Additionally the retarding is limited in wkr(i)
towards retard to KRMXN and towards advance to 0°

wkr is a RAM-area in which a RAM-cell is reserved for each cylinder

If the “Knock Control active” operating range of the
engine is left (!B kr) then the latest present retarding remains stored in
wkr(i) until the “Knock Control active” range is entered again. The same
applies for wkrm

In the “Knock Control not-active” range of the engine
zero is passed on to module ZUE as adjustment value dwkrz(i)

If the ignition is switched off, the retardings in
wkr(i) are set equal to zero

Advancing of the ignition angle (WKRBER &
FRUEHVERST)
The retardings from wkr(i) are cancelled on a
cylinder-specific basis if B_kr is set and if a cylinder-specific advancing
counter zkrvf(i) has reached zero

During each knock event B_kl, the cylinder-specific
counter zkrvf(i) is populated with the value KRVFN. Each non-knocking combustion
in cylinder i for which in addition B zwkraa = 1 applies (i.e. the given ignition
angle was limited by Knock Control) decrements zkrvf(i) by 1. When zkrvf(i) = 0
is reached, the retarding in wkr(i) assigned to the corresponding cylinder is
decremented by one quantization step and the counter is again populated with
KRVFN

During each timing towards advance, the wkr(i) are
limited to the mean value wkrm of the latest given retarding SY_ZYLZA minus a
freely selectable threshold DWKRMSN or to the value zero

If the “Knock Control active” operating range of the
engine is left (!B_kr) the latest available counter values remain stored in zkrvf(i)
until the “Knock Control active” range is entered again

If the ignition is switched off, the counter values in
zkrvf(i) are set equal to zero

If changed engine operating conditions result in a
reduced tendency to knock, a quicker advancing of the wkr(i) is performed until
the first knock event occurs after the beginning of this quick advancing. In
this case, the counters zkrvf(i) are started when KRVFSN < KRVFN. The
condition for the start of the quick advancing is either the transition from reading
adaptation values wkra(i) to wkr(i) or the termination of a dynamic phase or
a negative load range shift

There should be no quick advance during dynamic
operation (B_krldya / B_krndy = 1)

Knock Control Steady-State Mode
In Knock Control steady-state mode, the ignition angle
per knock event is retarded by the value KRFKLN or KRFKN. So that the knock
frequency at different retards is not too high, the Knock Control steady-state
mode advance adjustment speed adjusted by KRLVFKN

The Knock Control steady-state operation is indicated
by B_krstatb. This bit is set if |drl| < DRLKRSTMX and |ngfil| < NGKRSTMX
for TVKRSTAT seconds

Retarding of the ignition angle with adaptation (KR
ADAP)
B_kra = B_kr & (tmot > TMKRA) --> Adaptation active
B_krafrz = B_kra & ((rl < lkraw) || (tmot <
TMKRAS) || (nmot < NKRAMIN) || (nmot > NKRAMX) || B_asr || B_nmax ||
B_vmax) --> Learning the
adaptation values is prohibited
The adaptation ensures that also for strongly
map-dependent varying retardings the knock frequency does not increase in case
of quick changes of the map ranges. For this purpose, when adaptation is
active, the current retards under certain conditions are written in a load-speed-dependent
adaptation map (see Storage) or overwritten with the values stored in the
map (see Read). Read access to the adaptation map is only enabled when the engine temperature is stable and when there
is a significant knock control requirement (i.e. TMKRA ³ TMKR), whereas the knock control must be activated
even at low knock control requirements (worst case conditions). Write accesses to
the adaptation map are enabled until the second temperature threshold (TMKRAS ³ TMKRA) and the second load threshold (LKRAN ³ LKRN) are exceeded. This prevents, on the one hand,
spurious adaptation due to retardings during warm-up and on the other hand, a
learning of the adaptation value to 0 at lower loads

A RAM cell is reserved in the adaptation map wkra for
each load- and speed range per cylinder. The load and speed limits are removed
for administration labels (KRAL1-3N or KRAN1-4). The values stored there will
be used as the limiting values in case of increasing load or speed

In case of decreasing load or engine speed, an adjustable hysteresis
(KRALH, KRANH) is subtracted from these
values

The current load range is stored in stkrlx, the speed
range in stkrnx

When the ignition is switched off all values remain
stored in wkra. If the supply voltage of the ECU is disconnected the values are
lost. After the supply voltage of the ECU has been reconnected all values are
set to 0

DIAGRAM
For the indexing of the wkra(i) - RAM-cells the
following specification is used in the SW:
i = zzylkr + (8 ´ stkrnx) + (40 ´ stkrlx zzylkr) = 0...7,
so at the maximum, 8 cylinders can be represented
stkrnx = 0...4, 5 engine speed ranges
stkrlx = 0...3, 4 load ranges (value of 0 is
notwithstanding the ASCET-Model!)
The wkra of the current adaptation range can be
obtained from the RAM cells wkraa_i, i = 0 ... SY_ZYLZA-1

Adaptation - Learning Conditions:
The following conditions update the adaptation map:
1. During each knock event, the ignition angle retard
wkr of the cylinder in which the knock event occurred, is increased by an
offset KRDWKLA then stored in the current load-speed range of the adaptation
map when this sum (wkr + KRDWKLA) is later than the value stored in wkra

2. If the current retard wkr(i) is at least KRDWA
earlier than the last value stored in the adaptation map and advance adjustment
counter zkrvf (i) = 0, the ignition angle retard is changed to KRDWSA towards
advance in the adaptation map

3. If the current retard wkr(i) = 0 and the advance
adjustment counter zkrvf (i) = 0, wkra (i) is changed by KRDWSA towards advance

The adaptation of the characteristic map is only
performed during steady-state operation and during not active safety retarding (B
krdws=0). When idle control is active, the steady-state adaptation is also
blocked, because the control is via the average wkrm retardation

In order to avoid the unjustified adaptation of large
amounts of retardation, further writing to the adaptation map (combined into
B_krafrz) is prohibited under the following conditions:
- tmot < TMKRAS error identifiers due to extraneous
noise during warm-up
- nmot > NKRAMAX error identifiers due to
extraneous noise from the dump valve
- nmot < NKRAMIN error identifiers due to
extraneous noise from the drivetrain
- B_asr = 1 transient engine conditions via fast ignition
angle-intervention, possibly error identifiers
- B_nmax = 1 ditto
- B_vmax = 1 ditto
Writing is also
prohibited when
- rl < LKRAN
Adaptation – Read Conditions
During active adaptation the retarding of all
cylinders wkr(i) is overwritten by the values from wkra(i) if one of the
following conditions is fulfilled:
1. Transition from !B_kra to B_kra
2. Load range changes
with dynamic response (B_krl/ndyn = 1)
3. Engine speed changes
with dynamic response (B_krl/ndyn = 1)
4. Entering or exiting
idle control
During overwriting of
wkr(i) with wkra(i), ignition angle jumps away from advance can happen (e.g

adaptation has not yet settled in all adaptation ranges) which may give rise to
undesirable results (judder, knock). For this reason, early ignition angle
changes will be limited via overwriting KRDWAA. KRDWAA = 0 means that ignition
angle jumps away from advance will be prevented. KRDWAA = KRMXN means that ignition
angle jumps away from advance within the scope of the maximum Knock Control
range are permitted

Knock Control in the case of Active Dynamic Response
(KRRA, KR_ADAP, BBKR)
In case of active dynamic response (B_krldy, B_krldya,
B_krndy, see module KRDY) the further adaptation of the steady-state values
wkra(i) is blocked. A change of the adaptation ranges leads to an updating of
wkr(i) with the values adjusted in wkra(i)

Each knocking combustion (B_kl), like so far, leads to
a retarding by KRFKN and is therefore added to the cylinder-individual
retarding in wkr(i)

In addition to B_krldya,
an adaptive dynamic derivative action wkrdy (see module KRDY) is added. For the
fastest possible inclusion of this derivative action for dynamic response
detection, an auxiliary bit B_wkrdyw set in module KRDY triggers the
corresponding updating of all dwkrz_i included in wkrdy in the next KR-time
frame. This algorithm is not shown in the ASCET images

Knock Control during
Active Idle Control (KRRA)
When idle control is
active (B_llr = 1) cylinder-specific knock detection and control of the
retardings wkr(i) still occurs. However, at ignition, the average retardation
wkrm is output (dwkrz(i) = wkrm for all i)

In this way, additional
idle disturbance via KR-ZW-intervention is avoided. During activation or
deactivation of idle control respectively, the adaptation map is read

Knock Control Above
NKRMAX (BBKR, WKRBER)
Errors can frequently
occur at high speeds due to noise (e.g. valve lift). Therefore, in order to
avoid unduly large amounts of retarding, there is a speed threshold, NKRMAX,
above which the de facto knock control is disabled! Instead, wkr(i) is
permanently overwritten with the adapted values of
the current adaptation range wkra(i) + an offset. This offset (krfkw - KRDWKLA)
is implemented so that a margin from krfkw to the knock limit in this adaptation range
is maintained. However, the prerequisites for this are a nearly constant knock
limit within the respective adaptation areas and the presence of a current
adaptation value

Please apply this
function with the utmost care!
Optional Leading Cylinder
(LZ)
The leading cylinder
function is enabled:
- On exceeding a
cylinder-specific speed threshold KRNLZ[i], above which the cylinder has poor
knock detection, this cylinder is led by the cylinder with a good knock
detection

- For systems with two
knock sensors, if an error has been detected for the knock sensors. (The one
knock sensor associated cylinder are hereafter referred to as a group.) The
cylinders of the group concerned are then led by the cylinders of the group
having a good working knock sensor. On exceeding KRNLZ [i], the safety
retardation will be activated for all of the cylinders. This mitigation measure
will be turned off via the codeword CWKRNLR. If an error is detected, a sensor
immediately activates the security retardation

Leading Cylinder Function
when Engine Speed > KRNLZ, Without Knock Sensor Error
The corresponding leading and led cylinders are selected via the elements
LZFUER_0 to _k (k = SY_ZYLZA - 1), of the blocks of constants LZFUER. The leading cylinder (LZ) is indicated by set bits in
the bytes to
LZFUER_0 _k

The elements i = 0 to k
of the constants LZFUER are selected via the cylinder
block counter zzylkr in Knock Control, i.e. LZFUER_i belongs to zzylkr = i the
cylinder counter counts the combustion within an AS. The connection between
zzylkr and physical
cylinder is given by the firing sequence. Accordingly, the bits 0-7 of LZFUER_i
refer to zzylkr indexed combustion

During activation of the
lead cylinder function in this case, the contents of LZFUER is copied into the
RAM-array LZIST (loop from i = 0 ... SY_ZYLZA-1 on a 100 ms time frame). Thus
LZIST will contain the most current association between leading and led
cylinders

For example:
6 cylinder engine with
firing sequence zzylkr = 0 1 2 3 4 5
Physical cylinders: 1 4 3 6 2 5
Block of constants LZFUER
Led cyl. Bit 7 6 5 4 3 2 1 0 <-- (leading cylinder)
LZFUER_0 0 0 0 0 0 0 0 0 -- > 00 -- > physical
cylinder 1 will not be led, i.e. separate knock detection
LZFUER_1 0 0 0 0 1 0 0 0 -- > 08 -- > physical
cylinder 4 will be led by cylinder 6
LZFUER_2 0 0 0 0 1 0 0 1 -- > 09 -- > physical cylinder
3 will be led by phys. cylinder 6 or 1 (late selection)
LZFUER_3 0 0 0 0 0 0 0 0 -- > 00 -- > physical
cylinder 6 will not be led, i.e. separate knock detection
LZFUER_4 0 0 0 0 1 0 0 0 -- > 08 -- > physical
cylinder 2 will be led by cylinder 6
LZFUER_5 0 0 0 0 1 0 0 0 -- > 08 -- > physical
cylinder 5 will be led by cylinder 6
A led cylinder may not be
defined as a lead cylinder for itself, i.e. the bit i in LZFUER_i must be
"0"

In the lead cylinder
function, the following active measures are taken:
1. The knock detection
will continue unchanged

2. The knock control and
adaptation of the leading cylinder continues unchanged

3. For a led cylinder i, the
retardation of the latest i assigned to leading cylinders j plus a
cylinder-specific offset WKRLZOF_i is used as a late adjustment: wkr_i is
overwritten in the background program with wkr_j + WKRLZOF_i. The adaptation
continues unchanged. The adapted (and possibly incorrect) values for led cylinders arising because of 6 are not output

If the code word CWKRLZFK
= 1, the retard for the led cylinder is determined according to the following
minimum selection:
wkr_i = MIN (wkr_i,
wkr_j) + WKRLZOF_i
4. Detected knock for the
led cylinders has no effect: the retardation per knock is set to zero for the
cylinder

If the code word CWKRLZFK
= 1, wkr_i will be retarded according to krfkw in the led cylinders and also
the cylinders in which knock is detected, regardless of the leading cylinder
function

5. An independent advance
for led cylinder is suppressed: the step width of the counter zkrvf_i for the
led cylinder i is set continuously in the background program KRVFN

If the code word CWKRLZFK
= 1, the step width counter zkrvf_i is not overwritten for the led cylinder i

Thus, an advance of wkr_i independent of the leading cylinder is possible. But
because this results in an earlier ignition angle than with the leading
cylinder, wkr_i will be overwritten with the ignition angle-adjustment of the
leading cylinder. Thus, the earliest possible ignition angle for the led
cylinder is given by the leading cylinder’s ignition angle + offset

6. When reading from the
adaptation maps, ignition angle changes away from advance are limited to 0°
crank angle, rather than KRDWAA

Leading Cylinder Function
With Knock Sensor Error and Engine Speed < KRNLZ
If the knock sensor in
group 2 is off (B_kseb2 = 1), then the cylinder of group 2 is led by group 1
according to the measures described in points 1 to 6 above. Instead of the
individual cylinder offsets WKRLZOF_i, a global offset, WKRLZOFEKS is applied
to the led cylinder. In this case, the content of LZB1 is copied into the RAM
array LZIST (see above)

If the knock sensor in
group 1 from (B_kseb1 = 1), then the cylinder of group 1 is led by group 2
according to the measures described in points 1 to 6 above. Instead of the
individual cylinder offsets WKRLZOF_i, a global offset, WKRLZOFEKS is applied
to the led cylinder. In this case, the content of LZB2 is copied into the RAM
array LZIST (see above)

If both knock sensors are
off (B_kseb1 = 1 & B_kseb2 = 1), the safety retardation is activated
(B_krdws = 1)

Through the elements
LZBi_0 to LZBi_k (k = SY_ZYLZA - 1) of the constant
blocks LZBi (i = 1,2) the corresponding leading and led cylinders are selected

The leading cylinder (LZ) is indicated by set bits in the bytes LZBi_0 to LZBi_k

The elements n = 0 to k
of the constant block are selected by the cylinder
counter zzylkr in the Knock Control function, i.e. LZBi_n is zzylkr = n. is one
of the cylinder burns the counter counts within an AS. The connection between
zzylkr and the physical cylinder is given by the firing sequence. Accordingly, the
bits 0-7 of LZBi_n refer to zzylkr by indexed combustion

For example:
6 cylinder engine with
firing sequence zzylkr = 0 1 2 3 4 5
Physical cylinders: 1 4 3 6 2 5
Constant block LZB1
Led cyl. Bit 7 6 5 4 3 2 1 0 <-- leading cylinder
LZB1_0 0 0 0 0 0 0 0 0 = 0
LZB1_1 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder
4 is led by the cylinders of group 1
LZB1_2 0 0 0 0 0 0 0 0 = 0
LZB1_3 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder
6 is led by the cylinders of group 1
LZB1_4 0 0 0 0 0 0 0 0 = 0
LZB1_5 0 0 0 1 0 1 0 1 = 21 -- > physical cylinder
5 is led by the cylinders of group 1
Constant block LZB2
Led cyl. Bit 7 6 5 4 3 2 1 0 <-- leading cylinder
LZB2_0 0 0 1 0 1 0 1 0 = 42 -- > physical
cylinder 1 is led by the cylinders of group 2
LZB2_1 0 0 0 0 0 0 0 0 = 0
LZB2_2 0 0 1 0 1 0 1 0 = 42 -- > physical
cylinder 3 is led by the cylinders of group 2
LZB2_3 0 0 0 0 0 0 0 0 = 0
LZB2_4 0 0 1 0 1 0 1 0 = 42 -- > physical
cylinder is led by the cylinders of group 2
LZB2_5 0 0 0 0 0 0 0 0 = 0
A led cylinder may not be
defined as a lead cylinder for itself, i.e. the bit i in LZBi_n must be
"0"

Safety Retardation During
Active Knock Control (KRRA)
The knock control system hardware
(sensors and signal processing IC CC195) is continuously monitored using the
diagnostic functions DKRNT, DKRTP and DKRS. When errors are detected, the corresponding
error flags E_ * are set, resulting in setting B_krdws to trigger the safety
retardation. Resetting of B_krdws after detection of error healing and hence
the withdrawal of the safety retardation may only happen with "knock
control not active" (to prevent torque jumps)

Other system errors that
lead to triggering of the safety retardation are:
- Lack of synchronization
(B_synph = 0)
For systems with two or
more knock sensors (KSZA > 1), in the absence of general synchronization
safety retardation will be switched on

For systems with only one
knock sensor (KSZA = 1) and without active leading cylinder function, knock
detection in the absence of synchronization will be performed with the most
sensitive knock detection threshold (B_krnl = 1 = > emergency knock detection
– see also module KRKE), the knock control system continues unchanged

The operation of the
leading cylinder function sets the synchronization of the system (B_synph = 1)
mandatory in advance. It follows that in absence of synchronization and active
leading cylinder function in safety retardation (B_krdws = 1) it must be switched,
regardless of how many knock sensors the system has

In the absence of
synchronization, an emergency operation of the engine by using dual ignition
per SW (mirroring the ignition = > Half firing interval) can occur. In the
case of an odd number of cylinders, the required sychronisation between the
Knock Control measurement windows and combustion is no longer necessarily
given. It must, even for systems with a knock sensor, be switched to safety
retardation. A value of > 1 is therefore input to KSZA

- Emergency tachometer
(B_nldg = 1)
During speed-sensor
emergency operation, the measurement window cannot be output with the required
accuracy. Therefore security retardation is activated. To prevent unnecessary
setting of safety flags B_krdws after an ECU reset, the setting of c_inisyn is
blocked for 3 seconds. If the Knock
Control safety flag, B krdws, is set (see modules DKRS, DKRNT and DKRTP),
dwkrz(i) and wkrma are overwritten by KRDWS if the knock control is active

wkra(i), wkr(i) and wkrm are not updated as long as B
krdws is set

If B krdws is again reset dwkrz(i) is overwritten by
wkr(i), wkrma by wkrm

Application Notes
Cylinder-specific and load/engine speed
range-dependent values are marked by (i) in the description corresponding to
their realization in the ECU-code, e.g. wkr(i). The corresponding RAM-cell
which can be read via VS100 is indicated in the ASCET-image by i, e.g. wkr i

The cylinder counter zzylkr generated in module GGKS
serves as control variable for the index i of the cylinder-individual RAM-cells
(wkr(i), dwkrz(i), zkrvf(i), with the exception of wkra(i), see above)

Knock Control can be switched off via the label TMKR:
TMKR > tmot == > !B_kr
For the application the following typical values are
suggested:
KRFKN -3 °crank is a
value for the retarding of the ignition angle. Experience shows that it is a
sufficient value to safely run the engine at the knock limit with stabilized
adaptation

KRMXN -12 °crank is a
value which is sufficient for most applications. When fixing this
characteristic line it must be noted though that the engine can be operated
absolutely knock-free with the programmed value under worst-case conditions
(i.e. engine speed, ambient temperature and fuel with lowest octane number)

In the process attention must be paid to the maximum
permitted exhaust gas temperature

KRVFN approx. 4 sec/°KW
advancing is a typical value. The control speed of Knock Control during
quasi-steady-state engine running results from this characteristic line in
connection with KRFKN. The aim here is to determine a time constant which is
larger than the thermal time constant of the engine so as to avoid a thermal
strain

When adjusting KRVFN it must be taken into
consideration that the thermal strain of the engine increases with increasing
engine speed so that a larger period should be chosen for higher engine speeds

KRVFN = 1 Inc. * n / (120 * x) with 1 Inc. in °KW
n in rpm
x in °KW/sec - "speed" for
the advance adjustment
KRVFSN to be adjusted dependent of KRDWKLA in order to
enable a quick advancing of the adaptation map values in case of changed
operating conditions without provoking an increased knock frequency

KRDWKLA = -3 °KW: approx

1 sec/°KW advancing or approx. 1/4 ´ KRVFN
KRDWKLA = 0 °KW: approx

2 sec/°KW advancing or approx. 1/2 ´ KRVFN
TMKR approx. 40VC is the value during which on many
engines knocking combustions can already occur

TMKRA: Below an engine temperature threshold TMKRA it
is not useful to update wkra since experience has shown that within this
operating range the knock tendency of the engine is very low. If adaptation
would be permitted the necessary values learned in the normal operating range
would be lost which means that the knock frequency is again increased when this
operating range is reached again

Usually this engine temperature threshold lies at
TMKRA = 80°C

LKRN approx. 30% rl is a typical value. The lowest
load threshold during which knocking combustions can occur is stored in this
characteristic line

LKRAN can be parameterized with values > LKRN,
so the adaptation will only happen when there is a significant Knock Control
demand; LKRAN is ineffective when parameterized with values <=
LKRN

KRDWKLA 0 °KW
<= |KRDWKLA| <= |KRFKN|
KRDWA |KRDWA| >=
|KRDWKLA|
KRDWSA 0 °KW <
|KRDWSA| und |KRDWSA| <= |KRDWA| - |KRDWKLA|
The following sets of
parameters can be recommended:

{| border="1"
|-
|
KRDWKLA/°KW
|
KRDWA/°KW
|
KRDWSA/°KW
|
|-
|
0
|
2.25
|
2.25
|
= > Adaptation up to the knock limit
|-
|
-1.5
|
3.0
|
1.5
|
= > Adaptation up to the knock limit + a
safety margin of 1.5 °crank
|-
|
-3.0
|
4.5
|
1.5
|
= > Adaptation up to the knock limit + a
safety margin of 3 °crank
|}
KRWKRAIN = 0 °crank ... KRMXN, when
interpretation of the ignition angle-KF close to the knock limit a value < 0
°crank is recommended
KRDWAA = 0; ignition angle jumps away from advance via reading of the
adaptation values are prevented
= min(KRMXN); ignition angle jumps away from advance are
permitted within the scope of the maximum knock control range
0 > KRDWAA > min(KRMXN)
ignition angle jumps away from advance are limited to KRDWAA
DWKRMSN approx. -3 °KW is a
typical value to maintain the engine smoothness and to avoid misfire
misdetection; if the values get smaller the cylinder-individual character of
the knock control is increasingly lost

KRDWSN around -12 °crank, knock
must be avoided under worst case conditions
KRALH in order to avoid a judder at the range limits,
a hysteresis was introduced for decreasing load

Typical value for KRALH = 3%

KRANH in order to avoid a judder at the range limits,
a hysteresis was introduced for decreasing engine speed

Typical value for KRANH = 120 rpm

NKRAMIN equal to the speed, up to which error flags by
mechanical noise and vibration arise from the drive train. If the function is
not required then set NKRAMIN = 0
NKRAMAX equal to the
speed above which there can be error flags (e.g., valve lift) which
particularly applies when NKRAMAX > KRAN4 so actually in the upper speed
range, values can be adapted, otherwise there is
considerable risk of freezing the Knock Control by overwriting with NKRMAX. If
the function is not required then set NKRAMAX to the maximum value

NKRMAX equal to the speed
above which there can be error flags (e.g., valve lift) which particularly
applies when NKRMAX > KRAN4 and NKRMAX >= NKRAMAX so actually in the
upper speed range, values can be adapted,
otherwise there is considerable risk of freezing the Knock Control by
overwriting with NKRMAX. If the function is not required then set NKRMAX to the
maximum value

CWKRNLR = 1 additional
mitigation measure for systems with two knock sensors with knock sensor error
is active. CWKRNLR = 0 ... is not active

Particular attention when
determining the ignition angle maps requires knowledge of the area in which an
enrichment function (lambda <1) is active since the knock limit will shift
because of the enrichment

To ensure the stabilty of
Knock Control is not jeopardized, the ignition angle structure and the
enrichment function must be adjusted so that a uniform margin to the knock
limit is maintained (<3° crank) across the entire operating range of the
engine

The existence of some values/RAMs is determined by the
representation in ASCET (block hierarchy, course of control). They are not
realized in the SW resp. they cannot be measured definitely by means of VS100
due to their special realization:
- B wkral cannot be measured definitely
- B krvf is not realized
- zkrvf(i)=0 cannot be measured, this state can only
be detected indirectly via the performed RESET of the counter from zkrvf(i) = 1
to zkrvf(i) = KRVF(S)N
- zzylkral is not realized
Distinguishing between wkrm/wkrma
wkrm represents the mean value of the each time SY
ZYLZA latest calculated wkr(i) (possibly incl. mean value vswzm) while wkrma
represents the mean value of the dwkrz(i) (without wkrdy) which was passed on
to the ignition during the SY ZYLZA latest combustions

Adaptation characteristic map wkra
When choosing the map values a compromise has to be
achieved between the possibly varying knock tendency of the engine at different
load and engine speed ranges and the time by which the characteristic map is
updated during normal driving

If the adaptation map wkra is chosen to be too large
(i.e. many relative load-engine speed-ranges) a longer period will be needed in
order to update all ranges

Thus in case of changed operating conditions which
lead to a larger knock tendency it is inevitable that the knock frequency
increases

Generally a characteristic map with three load and
five engine speed ranges is sufficient for wkra. In this map a RAM-cell is
provided for each load/ engine speed range per cylinder

(Example 4-cylinder-engine: 3 ´ 5 ´ 4
= 60 RAM-cells for wkra)
For the indexing of the wkra(i) - RAM-cells the
following specification is used in the SW:
i = zzylkr + 8 ´ stkrnx + 40 ´ stkrlx (zzylkr = 0...7,
so at the max. 8 cylinders can be represented)
The number of adaptation ranges can be varied
according to special customer requirements but at the maximum to 4 x 8
load/engine speed ranges (change of above-mentioned indexing may possibly be
necessary)

Cylinder-individual ignition angle timing with VS20
By means of VS20 a cylinder-individual additional
timing vszw(i) can be performed (see also modules VS and VERST) so that the
following applies:
dwkrz(i) = wkr(i) + wkrdy + vszwkr(i) if B kr & !B
krdws

{| border="1"
|-
|
Label
|
Timing Range
|
Quantization
|
Initialization/neutral value
|-
|
vszwkr_1
|
see
module VS_VERST
|
0.75
°crank
|
0
°crank
|-
|
Vszwkr_8
|
see
module VS_VERST
|
|
|}
i = 0 ... SY ZYLZA - 1
Attention:
1. No automatic limitation of vszwkr(i) is performed -
please pay attention to engine and catalyst protection during the timing!
2. The earliest possible ignition angle determined by
the Knock Control is under all circumstances, i.e. it is possible that the
minimum permitted ignition angle may be undershot (due to temperature reasons

see modules ZUE and ZWMIN). Please pay attention to engine and catalyst
protection!
Abbreviations

{| border="1"
|-
|
CWKRLZFK
|
Code
word: knock detection is not switched off for led cylinders
|-
|
CWKRNLR
|
Code word: limp home in case of 1 out of 2 knock
sensors fails
|-
|
CWKRRA
|
Code
word for the function KRRA
|-
|
DRLKRSTMX
|
Maximum
drl in Knock Control steady-state operation
|-
|
DWKRMSN
|
Delta ignition angle Knock Control margin from
mean retarding
|-
|
KRAL1N
|
load range for Knock Control adaptation maps 1
|-
|
KRAL2N
|
load range for Knock Control adaptation maps 2
|-
|
KRAL3N
|
load range for adaptation Knock Control maps 3
|-
|
KRALH
|
Load hysteresis for Knock Control adaptation maps
|-
|
KRAN1
|
speed range for Knock Control adaptation maps,
sample range 1
|-
|
KRAN2
|
speed range for Knock Control adaptation maps,
sample range 2
|-
|
KRAN3
|
speed range for Knock Control adaptation maps,
sample range 3
|-
|
KRAN4
|
speed range for Knock Control adaptation maps,
sample range 4
|-
|
KRANH
|
Engine speed hysteresis for Knock Control
adaptation maps
|-
|
KRDWA
|
knock control difference current ignition angle
to adaptation map
|-
|
KRDWAA
|
Permissible
ignition angle jump towards advance when reading adaptation values
|-
|
KRDWKLA
|
The SV-learning value for KR adaptation after
knocking detected
|-
|
KRDWSA
|
The FV-learning value for KR adation when
wkra-wkr > KRDWA
|-
|
KRDWSN
|
knock control delta angle safety
|-
|
KRFKLN
|
Retard
per knock event at a slow advance
|-
|
KRFKN
|
retard step knock occurrence
|-
|
KRLMDY
|
Read if change of load range: always or only if
dynamic active
|-
|
KRMXN
|
maximum retard adjustment
|-
|
KRNLZAR
|
cylinder individual speed limit for lead by
leading cylinder
|-
|
KRNMDY
|
Read if change of speed range: always or only if
dynamic active
|-
|
KRVFN
|
number of firings/cyl. or time for ignition
advancing
|-
|
KRVFSN
|
number of firings/cyl. or delay-time during fast
ignition advancing of the Knock Control
|-
|
KSZA
|
Knock sensor number
|-
|
LKRAGRN
|
Load
threshold knock control with Exhaust Gas Recirculation
|-
|
LKRAN
|
Load
threshold knock control adaptation
|-
|
LKRN
|
load-signal threshold knock control
|-
|
LZB1
|
Lead
cylinder assignment: Bank 1 leads to Bank 2 with error KS 2
|-
|
LZB2
|
Lead
cylinder assignment: Bank 2 leads to Bank 1 with error KS 2
|-
|
LZFUER
|
Lead cylinder assignment
|-
|
NGKRSTMX
|
maximum speed
gradient in the Knock Control steady-state operation
|-
|
NKRAMAX
|
Upper
engine speed limit for freezing Knock Control adaptation
|-
|
NKRAMIN
|
Lower
engine speed limit for freezing Knock Control adaptation
|-
|
NKRF
|
Engine
speed threshold for Knock Control release
|-
|
NKRMAX
|
Upper
engine speed limit for freezing Knock Control adaptation
|-
|
SENZZYL0
|
|-
|
SNM16KRUB
|
Data point distribution engine speed, 16 data points
|-
|
SY_ZYLZA
|
System constant: number of cylinders
|-
|
TMKR
|
Engine-temperature threshold to enable Knock
Control
|-
|
TMKRA
|
Engine temperature threshold for adaptive Knock
Control
|-
|
TMKRAS
|
Temperature threshold for releasing write
access to the adaptation map
|-
|
TVKRSTAT
|
Knock
Control delay time steady-state operation
|-
|
WKRLZOF
|
Constant bloack: ignition retard offset for leed
cylinder
|-
|
WKRLZOFEKS
|
Ignition retard offset for led cylinders in case
of knock sensor error
|-
|
B_ADRKRA
|
Condition
flag: Knock Control adaptation
values reset errors in memory
|-
|
B_AGR
|
Condition
flag: Exhaust Gas Recirculation
|-
|
B ASR
|
Condition
flag: ASR active
|-
|
B_KL
|
Condition flag: knock detected
|-
|
B_KR
|
Condition flag for knock control active
|-
|
B_KRA
|
condition for active Knock Control adaptation
|-
|
B_KRAFRZ
|
Condition
flag: Knock Control adaptation is frozen
|-
|
B_KRDWS
|
Condition flag: knock control safety ignition
retarding
|-
|
B_KRFDKS
|
Condition flag: enable knock sensor diagnosis
|-
|
B_KRFRZ
|
Condition
flag: Knock Control adaptation is frozen
|-
|
B_KRLDY
|
Condition flag: load dynamics for knock detection
active
|-
|
B_KRLDYA
|
Condition flag: load dynamics retard and dynamics
adaptation active
|-
|
B_KRLDYN
|
Condition
flag: load dynamics for steady-state adaptation active
|-
|
B_KRLZ
|
Condition flag: knock control lead-cylinder function
active
|-
|
B_KRNDY
|
Condition flag: speed dynamics for knock
detection active
|-
|
B_KRNDYN
|
Condition
flag: speed dynamics for steady-state adaptation is active
|-
|
B_KRNL
|
Condition flag: emergency operation of knock
detection for emergency operation of phase sensor
|-
|
B_KRNLR
|
Condition
flag: emergency knock control for V6 or V8 with two knock sensors and error
in one knock sensor
|-
|
B_KRSTATB
|
Condition
flag: steady-state Knock Control operation
|-
|
B_KRVF
|
Condition flag: adjustment of Knock Control
ignition timing to a less retarded value
|-
|
B_KRWA
|
Condition
flag: Knock Control at stop
|-
|
B_KSEB1
|
Condition
flag: KS-error Bank 1
|-
|
B_KSEB2
|
Condition
flag: KS-error Bank 2
|-
|
B_LLR
|
Condition
flag: idle control
|-
|
B_NLDG
|
Condition flag: limp-home function speed sensor
|-
|
B_NMAX
|
Condition
flag: speed limit active
|-
|
B_PWF
|
Condition flag: power fail
|-
|
B_STEND
|
Condition flag: end of start
|-
|
B_SYNPH
|
Condition flag: synchronization phase
|-
|
B_TMKR
|
Condition flag: engine temperature (tmot) for
knock control achieved
|-
|
B_VMAX
|
Condition
flag: VMAX control active
|-
|
B_WKRAL
|
Condition flag: to read wkr from knock control
adaptation map
|-
|
B_ZWKRAA
|
Condition flag: ignition angle of the Knock
Control is given
|-
|
B_ZWKRUM
|
Condition flag: fast ignition advance Knock
Control
|-
|
DFP_KRNT
|
internal failure path number: knck control zero
test
|-
|
DFP_KROF
|
internal failure path number: knock control
offset
|-
|
DFP_KRTP
|
internal failure path number: knock control test
pulse
|-
|
DFP_KS1
|
internal failure path number: knock sensor 1
|-
|
DFP_KS2
|
internal failure path number: knock sensor 2
|-
|
DFP_KS3
|
internal failure path number: kncok sensor 3
|-
|
DFP_KS4
|
internal failure path number: knock sensor 4
|-
|
DRL_W
|
Change
in cylinder fill
|-
|
DWKR
|
cylinder-specific ignition-timing retardation
|-
|
DWKRMSW
|
current value for mean value limitation of the
retarding
|-
|
DWKRZ
|
cyl.-spec. ignition-timing retardation with
retardation for dynamics
|-
|
E_KRNT
|
error flag: knock control zero test
|-
|
E_KROF
|
Errorflag: knock control offset
|-
|
E_KRTP
|
error flag: knock control test pulse
|-
|
E_KS1
|
error flag: knock sensor 1
|-
|
E_KS1H
|
auxiliary error flag KS1
|-
|
E_KS2
|
error flag: knock sensor 2
|-
|
E_KS2H
|
auxiliary error flag KS2
|-
|
E_KS3
|
error flag: knock sensor 3
|-
|
E_KS3H
|
auxiliary errorflag KS3
|-
|
E_KS4
|
error flag: knock sensor 4
|-
|
E_KS4H
|
auxiliary error flag KS4
|-
|
KRAL1W
|
current value load adaptation range 1
|-
|
KRAL2W
|
current value load adaptation range 2
|-
|
KRAL3W
|
current value load adaptation range 3
|-
|
KRDWSW
|
momentan characteristic-value for safety retard
|-
|
KRFKW
|
current value of KRFKN
|-
|
KRLZN
|
Cylinder-specific speed threshold of lead
cylinder function exceeded
|-
|
KRMXW
|
current value for retard limitation of the
retarding
|-
|
KRVFSW
|
initialization value for quick advancing
|-
|
KRVFW
|
initialization value for normal advancing
|-
|
LKRAW
|
Current
value of the load threshold knock control-adaptation
|-
|
LKRW
|
Current value of the load threshold knock control
|-
|
LZIST
|
Array: instantaneous assignment of leading and led
cylinders
|-
|
NGFIL_W
|
Filtered
speed gradient
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative air charge
|-
|
STKRAX
|
Index for Knock Control adaptation map
|-
|
STKRLX
|
Load range adaptation map Knock Control
|-
|
STKRNX
|
Speed range adaptation map Knock Control
|-
|
TMOT
|
Engine temperature
|-
|
TPNT_AKTIV
|
Activation of Knock Control functions
|-
|
VSZWKR
|
Cylinder-specific adjustment of ignition angle by
VS2x
|-
|
VSZWM
|
Average value of adjustment ignition angle with
VS2x
|-
|
WKR
|
Cylinder-specific ignition retarding value knock
control
|-
|
WKRA
|
Adaptation map of wkr, speed- and load-dependent
|-
|
WKRAA
|
Monitor
for the wkra of the current adaptation ranges, wkra_0, _1…
|-
|
WKRATST
|
wkra updated in real time
|-
|
WKRM
|
Average value of individual ignition retarting by
knocking
|-
|
WKRMA
|
Average value of ignition retarding by KC,
generally(limpe home with safety)
|-
|
WKR_TST
|
cylinder-individual ignition angle retarding,
druming
|-
|
ZKRVF
|
counter determines the frequency of the
cylinder-individual ignition angle adv

|-
|
ZWKRAFLD
|
bit pattern of the cylinder-individually stored
B-zwkra
|-
|
ZZYLKR
|
cylinder counter Knock Control
|}

KRDY 17.120 (Dynamic Knock Control)

2012-05-02T22:32:46Z

TTQS:

KRDY 17.120 Function Description

See the ''funktionsrahmen'' for the following diagrams:

krdy-krdy KRDY: Overview of Dynamic Knock Control

krdy-bb-dyn BB_DYN: Detection of Load- and Engine Speed Dynamic, Enable Adaptation

krdy-dlast DLAST: Determination of the Load Gradient

krdy-bb-dyna BB_DYNA: Detection of Load- and Engine Speed Dynamic for Steady-State Adaptation

krdy-dyn-adap DYN_ADAP: Adaptation of Dynamic Response Derivation

Function Description

Dynamic Load Response

The dynamic load response is characterized by two phenomena:

- Increased knock tendency (at the equivalent temperature)

- Rapid increase in noise level which are counteracted by the following measures:

- Additional ignition retard (dynamic response derivation wkrdy at B_krldya = 1)

- Faster tracking of the reference level and increased knock detection thresholds (at B_krldy = 1, see module KRKE)

Detection of the Dynamic Load Response and Enabling the Dynamic Response Adaptation (BB_DYN)

The load dynamic response is triggered by the positive load difference drlkrdy (load gradient, see DLAST).

If the difference between two successive samples (drlkrdy) during an acceleration of the load signal is greater than the 1st dynamic detection threshold KFDYES, the timer is set to the initial value zldy AZKRLDYN and bit B_krldyv = 1.

As soon as drlkrdy < KFDYES, zldy is decremented by 1 increment per cycle. When zldy = 0, B_krldyv is reset.

(For the set / reset with B_krldy, the procedure is basically the same but with AZKELDYN as a starting value for the counter zldyke.)

As long as zldy > 0 and TMKR < tmot £ TMDYNA, only the condition B_krldyv = 1 applies. Additionally, when tmot > TMDYNA, the condition B_krldya = 1 applies and thus a dynamic derivative wkrdy is output. The down-regulation of wkrdy starts with resetting B_krldyv. If wkrdy is down-regulated to 0, B_krldya will also be reset. At idle (B_ll), no dynamics are detected (e.g. LLR).

Set- and Reset Conditions for the Dynamic Load Response Bits

See the ''funktionsrahmen''for the diagrams

Determination of the Load Gradients drlkrdy (DLAST)

To determine the load gradient, a load signal generated by the charge detection (rl or drl) or a predicted load signal (drlp
or rlp) is used. Bit 0 of the code word CWKR is used to switch between actual and predicted load signal.

The dynamic load response must be detected in a 10 ms time interval and triggered. The instantaneously available load signals are
calculated in real time.

The applicable speed threshold NKRUM describes the bounding range in which the time interval is less than 10 ms. Below the speed
threshold NKRUM, drlkrdy comes from the real-time delta load signals from the detected or predicted load (drl or drlp). Above NKRUM, drlkrdy comes from the difference between the load signals rl or rlp sampled at 10 ms intervals.

Because of this switchover, oversampling of rlp and rl is avoided in the range below NKRUM.

Influence of the Dynamic Load Response on Knock Detection

During active load dynamics B_krldy, the following functions take effect:

1. The cylinder-selective reference level calculations are carried out with the label KRFTP3 (see module KRKE) --> Faster tracking of the reference level.

2. The knock detection thresholds kew(i)w can be increased by a factor FKELDY. The result is corrected knock detection thresholds kek(i) (see module KRKE).

Influence of the Dynamic Load Response on Knock Control

3. For each detected knocking combustion, the ignition angle is retarded by the value KRFKN on a cylinder-specific basis (see module KRRA).

When steady-state knock control adaptation is enabled, the stored ignition angle retards are read from the current adaptation map range each time. In contrast however, write access to the stead-state adaptation map, is forbidden (see module KRRA).

As long as tmot =< TMDYNA, there is no additional dynamic retarding of the ignition angle!

Dynamic Load Adaptation (DYN_ADAP)

If dynamic load response is triggered when tmot > TMDYNA --> B_krldya, the following functions additionally take effect:

4. Adaptive dynamic retarding of the ignition angle for all cylinders (modules KRDY and KRRA). In addition to the steady-state cylinder-selective knock control retarding, the ignition angle for all cylinders is retarded when dynamic response is detected for the time zldy > 0, to wkrdya(stkrnx) + KLDYMNT(evtmod) = starting value of wkrdy. If zldy = 0, this additional dynamic retardation wkrdy is reduced by one increment per DYAVF combustion events.

5.1 If dynamic load response is triggered without exceeding the second dynamic response threshold (KFDYES < drlkrdy < KFDYES + KFDYESOF >= B_krldya), then the retard adaptation (BB_DYN) is enabled for the initial value (wkrdy) of the dynamic response retarding. I.e. by heavy knocking B_kldystk, a new adaptation of wkrdya is performed for the next dynamic procedure (wkrdya (new) = wkrdya (old) + DYADS limited to DYADMX). In the case of purely normal knock (B_kldynrm), and also if no knock occurs (DYN_ADAP) the adaptation value remains unchanged.

5.2 If the second dynamic response threshold is also exceeded (drlkrdy > KFDYES + KFDYESOF >= B_krldya & B_krldyf), then in addition to the measures from 4 and 5.1, the adaptation of the dynamic response retarding is enabled to advance (BB_DYN).

During the active dynamic phase (B_krldyf = 1), two counters zzwdykr and zzwdymd are started. For each set bit B_zwkraa = 1 (i.e. the ignition angle from knock control is output) zzwdykr is incremented. For each bit not set B_zwkraa = 0 (i.e. the ignition angle from the torque interface was output) zzwdymd is incremented. At the end of the dynamic phase (B_krldyf = 0) the ratio is zzwdykr / (zzwdykr + zzwdymd) is determined; the two counters zzwdykr and zzwdymd are then reset to zero (DYN_ADAP).

If no knocking combustion occurs during the active dynamic phase (B_krldyf = 1), which is detected by the knock detection threshold kek (see module KRKE, B_kl), and zzwdykr / (zzwdykr + zzwdymd) >= PZWKRA (adjustable constant), then the initial value of the adaptive dynamic response derivation wkrdya is adjusted towards advance by 1 increment but is limited to the value DYAMNV.

The RAM area wkrdya is divided into 5 speed ranges stkrnx.

{| border="1"
|-
|
stkrnx =
|
0
|
1
|
2
|
3
|
4
|
|-
|
wkrdya
|
|
|
|
|
|-
|
Speed sample points
|
|
KRAN1
|
KRAN2
|
KRAN3
|
KRAN4
|
|-
|
|
<---------+
|
|
|
+---------> nmot (rpm)
|-
|
|
Hysteresis KRANH
|
|
|-
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|}

The engine speed ranges are identical to those of the steady-state adaptation characteristic map (see module KRRA). The engine speed limits apply with increasing engine speed.

The engine speed hysteresis KRANH is deducted only with decreasing speed (same as module KRRA).

The dynamic response derivation is recalculated for each write to the RAM area wkrdya and then into the engine speed range which is valid at the time of triggering of the dynamic response trigger point (! B_krldya --> B_krldya). It is then available as wkrdy for the next dynamic procedure which starts in this engine speed range.

When the ignition is turned off, all retardings are stored in the RAM area wkrdya until the engine is restarted.
After a ‘power cut’ of the RAM area, DYAMNV is initialized with wkrdya.

Engine Speed Dynamic Response

If the engine temperature tmot > TMKR and the engine speed gradient ngas_w are larger than the engine speed dynamic response detection threshold DNKRDYSN then the timer zndy is set to the initial value AZKRNDYN.

If ngas_w < DNKRDYSN, zndy is decremented up to zero for each ignition event in cylinder 1. The condition B krndy=1 applies until zndy > 0.

As long as B krndy = 1 the following applies:

1. The cylinder-selective reference level calculations are performed with the label KRFTP2 (see module KRKE) --> faster tracking of the reference level.

2. The knock detection thresholds ke(i)w are increased by the factor FKENDY. Corrected knock detection thresholds kek(i) result (see module KRKE).

3. For each detected knocking combustion, the ignition angle is retarded by the value KRFKN cylinder-selectively (see module KRRA).
When steady-state adaptation is enabled, the stored retardings are read from the current adaptation map range each time in case of range changes. Write access to the characteristic map of the steady-state adaptation is, however, forbidden (see module KRRA).

The triggering of the dynamic load response may also take place during active engine speed dynamic response and vice versa. It is decided in modules KRKE and KRRA respectively which of the introduced measures takes priority.

Application Notes

The application aim of dynamic load response is adjustment that optimizes performance with no audible “dynamic knocking” in the vehicle.

The adjustment should be performed under “worst-case conditions” (summer temperatures and fuel with lowest enabled octane number).

The following values taken from experience can be used for an approximate calibration:

TMKR approx. 40°C

TMDYNA approx. 80°C

AZKELDYN should be chosen so that error labels via the load-dependent noise recording are avoided

AZKRLDYN should be chosen in such a way that the dynamic condition approx. 300-600 ms applies. Guidance values are: 2-5 working cycles (AS) at 1000 rpm and 15-25 working cycles at 6000 rpm.

DYADMX approx. -8 ... -10 °crank

FKELDYA 1.2 - 1.3

DYAVF should be chosen such that during each working cycle adjustment to advance is performed by approx. 4 increments at most (so

DYAVF must be equal to or exceed no. of cylinders / 4, DYAVF is an integer and DYAVF > 0 is demanded!)
The greater the DYAVF then the smaller the down-regulation of speed will be

CWKR bit 0 = 1 as long as load prediction is not available or not stable

NKRUM = 4000 rpm for SY_ZYLZA = 3

NKRUM = 3000 rpm for SY_ZYLZA = 4

NKRUM = 2400 rpm for SY_ZYLZA = 5

NKRUM = 2000 rpm for SY_ZYLZA = 6

NKRUM = 1500 rpm for SY_ZYLZA = 8

NKRUM = 1200 rpm for SY_ZYLZA = 10

NKRUM = 1000 rpm for

SY_ZYLZA = 12

The application aim of engine speed dynamic response is avoiding misdetections due to a very fast increase in engine speed resulting in abrupt noise increase (especially critical: gear shifting on powerful vehicles with automatic gearbox)

NGKRWN approx. 500 - 1000 rpm/s;

AZKRNDYN should be chosen such that the dynamic response condition approx. 300-600 ms applies. Guidance values are: 2-5 working cycles at 1000 rpm and 15-25 working cycles at 6000 rpm.

Abbreviations

{| border="1"
|-
|
AZKELDYN
|
Ignition per cylinder for load dynamics --> knock detection
|-
|
AZKRLDYN
|
Number of ignition per cylinder during knock control load dynamic
|-
|
AZKRNDYN
|
Number of ignition for knock control engine speed
dynamic
|-
|
CWKR
|
Code word for knock control
|-
|
CWTIPIN
|
Codeword for tip-in function
|-
|
DRLKRAN
|
Detection threshold dynamic load response for steady-state
adaptation
|-
|
DYADMXN
|
Maximum value of dynamic response derivation
|-
|
DYADS
|
Additive retarding per cycle through adaptation
dynamics
|-
|
DYAFVS
|
Advance step for deactivation of dynamic response
|-
|
DYAMNV
|
Minimum value of dynamic response derivation
|-
|
DYAVF
|
Deactivation period for dynamics retardation
|-
|
DZWTIN
|
Delta ignition angle at tip-in
|-
|
FKELDYA
|
Correction factor for knock detection threshold for
adaptation of load dynamics
|-
|
KFDYES
|
Threshold for dynamic presetting values
|-
|
KFDYMNT
|
Pilot-controlled dynamic derivation
|-
|
KFDYRS
|
Dynamic derivation detection threshold
|-
|
KFDYRSOF
|
Offset threshold for dynamic presetting values
|-
|
NGKRAWN
|
Speed gradient threshold for dynamic
detection KRRA
|-
|
NGKRWN
|
Speed gradient threshold for dynamic
detection
|-
|
NKRUM
|
Revolution threshold for change of delta load signal
for load dynamics
|-
|
PZWKRA
|
Percentage frequency of ignition angle output by
knock control during dynamic adaptation
|-
|
TMDYNA
|
Engine temperature threshold to enable load dynamic
adaptation
|-
|
ZDRLKRA
|
Time constant for low-pass load gradient in knock
control
|-
|
ZNGKRA
|
Time constant for low-pass engine speed gradient
|-
|
'''Variable'''
|
'''Description'''
|-
|
B_DRLKRDY
|
Flag for n > NKRUM
|-
|
B_KL
|
Condition: knock detected
|-
|
B_KLDYNRM
|
Condition: normal knocking with adapted load dynamic
|-
|
B_KLDYSTK
|
Condition: heavy knocking with adapted load dynamic
|-
|
B_KRDWS
|
Condition: knock control safety ignition retarding
|-
|
B_KRLDY
|
Condition: load dynamics for knock detection active
|-
|
B_KRLDYA
|
Condition: load dynamics retard and dynamics
adaptation active
|-
|
B_KRLDYF
|
Condition: adaptation load dynamics retard towards
advance enabled
|-
|
B_KRLDYN
|
Condition: load dynamic for steady-state adaptation
active
|-
|
B_KRLDYV
|
Condition: threshold for additional load dynamics
retard exceeded
|-
|
B_KRNDY
|
Condition: speed dynamics for knock detection active
|-
|
B_KRNDYN
|
Condition: engine speed dynamics for steady-state
adaptation active
|-
|
B_KUPPL
|
EGAS Condition: clutch is disengaged
|-
|
B_LL
|
Condition: idle
|-
|
B_MF
|
Condition: measurement window
|-
|
B_TIPIN
|
Condition: tip-in detected
|-
|
B_TMKR
|
Condition: engine temperature (tmot) for knock
control reached
|-
|
B_VNULL
|
Condition: vehicle at standstill
|-
|
B_ZWKRAA
|
Condition: ignition angle is output from knock
control
|-
|
C_PWF
|
ECU condition: Power fail-initializing
|-
|
DRLKRAV
|
Actual value of DRLKRAN
|-
|
DRLKRDY
|
Load gradient for activating knock control load
dynamics
|-
|
DRLKRRA
|
Load gradient for selecting steady-state adaptation
|-
|
DRLP_W
|
Delta predicted load for injection time calculation
(word)
|-
|
DRL_W
|
Charge change (Word)
|-
|
DYESV
|
Current value of load dynamic response detection
threshold
|-
|
DYMNTV
|
Minimum additive dynamic derivation of KL
|-
|
DYRSOFV
|
Actual value of the offset for load dynamics
detection threshold
|-
|
DYRSV
|
Actual value of the load dynamics detection
threshold
|-
|
EVTMOD
|
Modelled inlet valve temperature (temperature model)
|-
|
GANGI
|
Engaged gear
|-
|
KEK
|
Knock detection threshold corrected
|-
|
LKRNEW
|
Value of load at time t
|-
|
LKROLD
|
Value of load at time t-dt
|-
|
NGAS_W
|
Engine speed gradient during one working cycle
|-
|
NGKRAF_W
|
Instantaneous value of threshold speed dynamics
|-
|
NGKRAV_W
|
Actual value of the engine speed dynamic threshold
|-
|
NGKRV_W
|
Actual value of the engine speed dynamic threshold
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
RLP_W
|
Relative cylinder charge predicted for injection
calculation (Word)
|-
|
RL_W
|
Relative air charge (Word)
|-
|
R_T10
|
10 ms time frame
|-
|
R_T100
|
100 ms time frame
|-
|
STKRNX
|
Speed range adaption map knock control
|-
|
STUETZ
|
Engine speed adaptation range during triggering of
the load dynamic
|-
|
TMOT
|
Engine temperature
|-
|
VIRKR
|
Ratio: integrator/ reference level knock control
|-
|
WKRDY
|
Ignition retard during dynamic-function of knock control
|-
|
WKRDYA
|
Adapted ignition timing for dynamic knock control
|-
|
ZALDY
|
Ignition counter for deactivation of load dynamics
|-
|
ZLDY
|
Ignition counter for load dynamic
|-
|
ZLDYKE
|
Ignition counter for load dynamics ®
knock detection
|-
|
ZNDY
|
Ignition counter for rpm-dynamics
|-
|
ZZWDYKR
|
Ignition counter for knock control with bit B_zwkra
= 1 set during dynamic knock control
|-
|
ZZWDYMD
|
Ignition counter for knock control with bit B.zwkra =
0 not set during dynamic knock control
|-
|
ZZYLKR
|
cylinder counter Knock Control
|}

KRDY 17.120 (Dynamic Knock Control)

2012-05-02T22:28:47Z

TTQS:

KRDY 17.120 Function Description

See the ''funktionsrahmen'' for the following diagrams:

krdy-krdy KRDY: Overview of Dynamic Knock Control

krdy-bb-dyn BB_DYN: Detection of Load- and Engine Speed Dynamic, Enable Adaptation

krdy-dlast DLAST: Determination of the Load Gradient

krdy-bb-dyna BB_DYNA: Detection of Load- and Engine Speed Dynamic for Steady-State Adaptation

krdy-dyn-adap DYN_ADAP: Adaptation of Dynamic Response Derivation

Function Description

Dynamic Load Response

The dynamic load response is characterized by two phenomena:

- Increased knock tendency (at the equivalent temperature)

- Rapid increase in noise level which are by the following measures:

- Additional ignition retard (dynamic response derivation wkrdy at B_krldya = 1)

- Faster tracking of the reference level and increased knock detection thresholds (at B_krldy = 1, see module KRKE)

Detection of the Dynamic Load Response and Enabling the Dynamic Response Adaptation (BB_DYN)

The load dynamic response is triggered by the positive load difference drlkrdy (load gradient, see DLAST).

If the difference between two successive samples (drlkrdy) during an acceleration of the load signal is greater than the 1st dynamic detection threshold KFDYES, the timer is set to the initial value zldy AZKRLDYN and bit B_krldyv = 1.

As soon as drlkrdy < KFDYES, zldy is decremented by 1 increment per cycle. When zldy = 0, B_krldyv is reset.

(For the set / reset with B_krldy, the procedure is basically the same but with AZKELDYN as a starting value for the counter zldyke.)

As long as zldy > 0 and TMKR < tmot £ TMDYNA, only the condition B_krldyv = 1 applies. Additionally, when tmot > TMDYNA, the condition B_krldya = 1 applies and thus a dynamic derivative wkrdy is output. The down-regulation of wkrdy
starts with resetting B_krldyv. If wkrdy is down-regulated to 0, B_krldya will also be reset. At idle (B_ll), no dynamics are detected (e.g. LLR).

Set- and Reset Conditions for the Dynamic Load Response Bits
See the ''funktionsrahmen''for the diagrams

Determination of the Load Gradients drlkrdy (DLAST)
To determine the load gradient, a load signal generated by the charge detection (rl or drl) or a predicted load signal (drlp
or rlp) is used. Bit 0 of the code word CWKR is used to switch between actual and predicted load signal.

The dynamic load response must be detected in a 10 ms time interval and triggered. The instantaneously available load signals are
calculated in real time.

The applicable speed threshold NKRUM describes the bounding range in which the time interval is less than 10 ms. Below the speed
threshold NKRUM, drlkrdy comes from the real-time delta load signals from the detected or predicted load (drl or drlp). Above NKRUM, drlkrdy comes from the difference between the load signals rl or rlp sampled at 10 ms intervals.

Because of this switchover, oversampling of rlp and rl is avoided in the range below NKRUM.

Influence of the Dynamic Load Response on Knock Detection

During active load dynamics B_krldy, the following functions take effect:

1. The cylinder-selective reference level calculations are carried out with the label KRFTP3 (see module KRKE) --> Faster tracking of the reference level.

2. The knock detection thresholds kew(i)w can be increased by a factor FKELDY. The result is corrected knock detection thresholds kek(i) (see module KRKE).

Influence of the Dynamic Load Response on Knock Control
3. For each detected knocking combustion, the ignition angle is retarded by the value KRFKN on a cylinder-specific basis (see module KRRA).

When steady-state knock control adaptation is enabled, the stored ignition angle retards are read from the current adaptation map range each time. In contrast however, write access to the stead-state adaptation map, is forbidden (see module KRRA).

As long as tmot =< TMDYNA, there is no additional dynamic retarding of the ignition angle!

Dynamic Load Adaptation (DYN_ADAP)

If dynamic load response is triggered when tmot > TMDYNA --> B_krldya, the following functions additionally take effect:

4. Adaptive dynamic retarding of the ignition angle for all cylinders (modules KRDY and KRRA). In addition to the steady-state cylinder-selective knock control retarding, the ignition angle for all cylinders is retarded when dynamic response is detected for the time zldy > 0, to wkrdya(stkrnx) + KLDYMNT(evtmod) = starting value of wkrdy. If zldy = 0, this additional dynamic retardation wkrdy is reduced by one increment per DYAVF combustion events.

5.1 If dynamic load response is triggered without exceeding the second dynamic response threshold (KFDYES < drlkrdy < KFDYES + KFDYESOF >= B_krldya), then the retard adaptation (BB_DYN) is enabled for the initial value (wkrdy) of the dynamic response retarding. I.e. by heavy knocking B_kldystk, a new adaptation of wkrdya is performed for the next dynamic procedure (wkrdya (new) = wkrdya (old) + DYADS limited to DYADMX). In the case of purely normal knock (B_kldynrm), and also if no knock occurs (DYN_ADAP) the adaptation value remains unchanged.

5.2 If the second dynamic response threshold is also exceeded (drlkrdy > KFDYES + KFDYESOF ³ B_krldya & B_krldyf), then in addition to the measures from 4 and 5.1, the adaptation of the dynamic response retarding is enabled to advance (BB_DYN).

During the active dynamic phase (B_krldyf = 1), two counters zzwdykr and zzwdymd are started. For each set bit B_zwkraa = 1 (i.e. the ignition angle from knock control is output) zzwdykr is incremented. For each bit not set B_zwkraa = 0 (i.e. the ignition angle from the torque interface was output) zzwdymd is incremented. At the end of the dynamic phase (B_krldyf = 0) the ratio is zzwdykr / (zzwdykr + zzwdymd) is determined; the two counters zzwdykr and zzwdymd are then reset to zero (DYN_ADAP).

If no knocking combustion occurs during the active dynamic phase (B_krldyf = 1), which is detected by the knock detection threshold kek (see module KRKE, B_kl), and zzwdykr / (zzwdykr + zzwdymd) >= PZWKRA (adjustable constant), then the initial value of the adaptive dynamic response derivation wkrdya is adjusted towards advance by 1 increment but is limited to the value DYAMNV.

The RAM area wkrdya is divided into 5 speed ranges stkrnx.

{| border="1"
|-
|
stkrnx =
|
0
|
1
|
2
|
3
|
4
|
|-
|
wkrdya
|
|
|
|
|
|-
|
Speed sample points
|
|
KRAN1
|
KRAN2
|
KRAN3
|
KRAN4
|
|-
|
|
<---------+
|
|
|
+---------> nmot (rpm)
|-
|
|
Hysteresis KRANH
|
|
|-
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|}

The engine speed ranges are identical to those of the steady-state adaptation characteristic map (see module KRRA). The engine speed limits apply with increasing engine speed.

The engine speed hysteresis KRANH is deducted only with decreasing speed (same as module KRRA).

The dynamic response derivation is recalculated for each write to the RAM area wkrdya and then into the engine speed range which is valid at the time of triggering of the dynamic response trigger point (! B_krldya --> B_krldya). It is then available as wkrdy for the next dynamic procedure which starts in this engine speed range.

When the ignition is turned off, all retardings are stored in the RAM area wkrdya until the engine is restarted.
After a ‘power cut’ of the RAM area, DYAMNV is initialized with wkrdya.

Engine Speed Dynamic Response

If the engine temperature tmot > TMKR and the engine speed gradient ngas_w are larger than the engine speed dynamic response detection threshold DNKRDYSN then the timer zndy is set to the initial value AZKRNDYN.

If ngas_w < DNKRDYSN, zndy is decremented up to zero for each ignition event in cylinder 1. The condition B krndy=1 applies until zndy > 0.

As long as B krndy = 1 the following applies:

1. The cylinder-selective reference level calculations are performed with the label KRFTP2 (see module KRKE) --> faster tracking of the reference level.

2. The knock detection thresholds ke(i)w are increased by the factor FKENDY. Corrected knock detection thresholds kek(i) result (see module KRKE).

3. For each detected knocking combustion, the ignition angle is retarded by the value KRFKN cylinder-selectively (see module KRRA).
When steady-state adaptation is enabled, the stored retardings are read from the current adaptation map range each time in case of range changes. Write access to the characteristic map of the steady-state adaptation is, however, forbidden (see module KRRA).

The triggering of the dynamic load response may also take place during active engine speed dynamic response and vice versa. It is decided in modules KRKE and KRRA respectively which of the introduced measures takes priority.

Application Notes

The application aim of dynamic load response is adjustment that optimizes performance with no audible “dynamic knocking” in the vehicle.

The adjustment should be performed under “worst-case conditions” (summer temperatures and fuel with lowest enabled octane number).

The following values taken from experience can be used for a rough adjustment:

TMKR approx. 40°C

TMDYNA approx. 80°C

AZKELDYN should be chosen so that error labels via the load-dependent noise recording are avoided

AZKRLDYN should be chosen in such a way that the dynamic condition approx. 300-600 ms applies. Guidance values are: 2-5 working cycles (AS) at 1000 rpm and 15-25 working cycles at 6000 rpm.

DYADMX approx. -8 ... -10 °crank

FKELDYA 1.2 - 1.3

DYAVF should be chosen such that during each working cycle adjustment to advance is performed by approx. 4 increments at most (so

DYAVF must be equal to or exceed no. of cylinders / 4, DYAVF is an integer and DYAVF > 0 is demanded!)
The greater the DYAVF then the smaller the down-regulation of speed will be

CWKR bit 0 = 1 as long as load prediction is not available or not stable

NKRUM = 4000 rpm for SY_ZYLZA = 3

NKRUM = 3000 rpm for SY_ZYLZA = 4

NKRUM = 2400 rpm for SY_ZYLZA = 5

NKRUM = 2000 rpm for SY_ZYLZA = 6

NKRUM = 1500 rpm for SY_ZYLZA = 8

NKRUM = 1200 rpm for SY_ZYLZA = 10

NKRUM = 1000 rpm for

SY_ZYLZA = 12

The application aim of engine speed dynamic response is avoiding misdetections due to a very fast increase in engine speed resulting in abrupt noise increase (especially critical: gear shifting on powerful vehicles with automatic gearbox)

NGKRWN approx. 500 - 1000 rpm/s;

AZKRNDYN should be chosen such that the dynamic response condition approx. 300-600 ms applies. Guidance values are: 2-5 working cycles at 1000 rpm and 15-25 working cycles at 6000 rpm.

Abbreviations

{| border="1"
|-
|
AZKELDYN
|
Ignition per cylinder for load dynamics --> knock detection
|-
|
AZKRLDYN
|
Number of ignition per cylinder during knock control load dynamic
|-
|
AZKRNDYN
|
Number of ignition for knock control engine speed
dynamic
|-
|
CWKR
|
Code word for knock control
|-
|
CWTIPIN
|
Codeword for tip-in function
|-
|
DRLKRAN
|
Detection threshold dynamic load response for steady-state
adaptation
|-
|
DYADMXN
|
Maximum value of dynamic response derivation
|-
|
DYADS
|
Additive retarding per cycle through adaptation
dynamics
|-
|
DYAFVS
|
Advance step for deactivation of dynamic response
|-
|
DYAMNV
|
Minimum value of dynamic response derivation
|-
|
DYAVF
|
Deactivation period for dynamics retardation
|-
|
DZWTIN
|
Delta ignition angle at tip-in
|-
|
FKELDYA
|
Correction factor for knock detection threshold for
adaptation of load dynamics
|-
|
KFDYES
|
Threshold for dynamic presetting values
|-
|
KFDYMNT
|
Pilot-controlled dynamic derivation
|-
|
KFDYRS
|
Dynamic derivation detection threshold
|-
|
KFDYRSOF
|
Offset threshold for dynamic presetting values
|-
|
NGKRAWN
|
Speed gradient threshold for dynamic
detection KRRA
|-
|
NGKRWN
|
Speed gradient threshold for dynamic
detection
|-
|
NKRUM
|
Revolution threshold for change of delta load signal
for load dynamics
|-
|
PZWKRA
|
Percentage frequency of ignition angle output by
knock control during dynamic adaptation
|-
|
TMDYNA
|
Engine temperature threshold to enable load dynamic
adaptation
|-
|
ZDRLKRA
|
Time constant for low-pass load gradient in knock
control
|-
|
ZNGKRA
|
Time constant for low-pass engine speed gradient
|-
|
'''Variable'''
|
'''Description'''
|-
|
B_DRLKRDY
|
Flag for n > NKRUM
|-
|
B_KL
|
Condition: knock detected
|-
|
B_KLDYNRM
|
Condition: normal knocking with adapted load dynamic
|-
|
B_KLDYSTK
|
Condition: heavy knocking with adapted load dynamic
|-
|
B_KRDWS
|
Condition: knock control safety ignition retarding
|-
|
B_KRLDY
|
Condition: load dynamics for knock detection active
|-
|
B_KRLDYA
|
Condition: load dynamics retard and dynamics
adaptation active
|-
|
B_KRLDYF
|
Condition: adaptation load dynamics retard towards
advance enabled
|-
|
B_KRLDYN
|
Condition: load dynamic for steady-state adaptation
active
|-
|
B_KRLDYV
|
Condition: threshold for additional load dynamics
retard exceeded
|-
|
B_KRNDY
|
Condition: speed dynamics for knock detection active
|-
|
B_KRNDYN
|
Condition: engine speed dynamics for steady-state
adaptation active
|-
|
B_KUPPL
|
EGAS Condition: clutch is disengaged
|-
|
B_LL
|
Condition: idle
|-
|
B_MF
|
Condition: measurement window
|-
|
B_TIPIN
|
Condition: tip-in detected
|-
|
B_TMKR
|
Condition: engine temperature (tmot) for knock
control reached
|-
|
B_VNULL
|
Condition: vehicle at standstill
|-
|
B_ZWKRAA
|
Condition: ignition angle is output from knock
control
|-
|
C_PWF
|
ECU condition: Power fail-initializing
|-
|
DRLKRAV
|
Actual value of DRLKRAN
|-
|
DRLKRDY
|
Load gradient for activating knock control load
dynamics
|-
|
DRLKRRA
|
Load gradient for selecting steady-state adaptation
|-
|
DRLP_W
|
Delta predicted load for injection time calculation
(word)
|-
|
DRL_W
|
Charge change (Word)
|-
|
DYESV
|
Current value of load dynamic response detection
threshold
|-
|
DYMNTV
|
Minimum additive dynamic derivation of KL
|-
|
DYRSOFV
|
Actual value of the offset for load dynamics
detection threshold
|-
|
DYRSV
|
Actual value of the load dynamics detection
threshold
|-
|
EVTMOD
|
Modelled inlet valve temperature (temperature model)
|-
|
GANGI
|
Engaged gear
|-
|
KEK
|
Knock detection threshold corrected
|-
|
LKRNEW
|
Value of load at time t
|-
|
LKROLD
|
Value of load at time t-dt
|-
|
NGAS_W
|
Engine speed gradient during one working cycle
|-
|
NGKRAF_W
|
Instantaneous value of threshold speed dynamics
|-
|
NGKRAV_W
|
Actual value of the engine speed dynamic threshold
|-
|
NGKRV_W
|
Actual value of the engine speed dynamic threshold
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
RLP_W
|
Relative cylinder charge predicted for injection
calculation (Word)
|-
|
RL_W
|
Relative air charge (Word)
|-
|
R_T10
|
10 ms time frame
|-
|
R_T100
|
100 ms time frame
|-
|
STKRNX
|
Speed range adaption map knock control
|-
|
STUETZ
|
Engine speed adaptation range during triggering of
the load dynamic
|-
|
TMOT
|
Engine temperature
|-
|
VIRKR
|
Ratio: integrator/ reference level knock control
|-
|
WKRDY
|
Ignition retard during dynamic-function of knock control
|-
|
WKRDYA
|
Adapted ignition timing for dynamic knock control
|-
|
ZALDY
|
Ignition counter for deactivation of load dynamics
|-
|
ZLDY
|
Ignition counter for load dynamic
|-
|
ZLDYKE
|
Ignition counter for load dynamics ®
knock detection
|-
|
ZNDY
|
Ignition counter for rpm-dynamics
|-
|
ZZWDYKR
|
Ignition counter for knock control with bit B_zwkra
= 1 set during dynamic knock control
|-
|
ZZWDYMD
|
Ignition counter for knock control with bit B.zwkra =
0 not set during dynamic knock control
|-
|
ZZYLKR
|
cylinder counter Knock Control
|}

KRDY 17.120 (Dynamic Knock Control)

2012-05-02T22:24:21Z

TTQS:

KRDY 17.120 Function Description

See the ''funktionsrahmen'' for the following diagrams:

krdy-krdy KRDY: Overview of Dynamic Knock Control
krdy-bb-dyn BB_DYN: Detection of Load- and Engine Speed Dynamic, Enable Adaptation
krdy-dlast DLAST: Determination of the Load Gradient
krdy-bb-dyna BB_DYNA: Detection of Load- and Engine Speed Dynamic for Steady-State Adaptation
krdy-dyn-adap DYN_ADAP: Adaptation of Dynamic Response Derivation

Function Description
Dynamic Load Response
The dynamic load response is characterized by two phenomena:
- Increased knock tendency (at the equivalent temperature)
- Rapid increase in noise level which are by the following measures:
- Additional ignition retard (dynamic response derivation wkrdy at B_krldya = 1)
- Faster tracking of the reference level and increased knock detection thresholds (at B_krldy = 1, see module KRKE)

Detection of the Dynamic Load Response and Enabling the Dynamic Response Adaptation (BB_DYN)
The load dynamic response is triggered by the positive load difference drlkrdy (load gradient, see DLAST).
If the difference between two successive samples (drlkrdy) during an acceleration of the load signal is greater than the 1st dynamic detection threshold KFDYES, the timer is set to the initial value zldy AZKRLDYN and bit B_krldyv = 1.
As soon as drlkrdy < KFDYES, zldy is decremented by 1 increment per cycle. When zldy = 0, B_krldyv is reset.
(For the set / reset with B_krldy, the procedure is basically the same but with AZKELDYN as a starting value for the counter zldyke.)

As long as zldy > 0 and TMKR < tmot £ TMDYNA, only the condition B_krldyv = 1 applies. Additionally, when tmot > TMDYNA, the condition B_krldya = 1 applies and thus a dynamic derivative wkrdy is output. The down-regulation of wkrdy
starts with resetting B_krldyv. If wkrdy is down-regulated to 0, B_krldya will
also be reset. At idle (B_ll), no dynamics are detected (e.g. LLR).

Set- and Reset Conditions for the Dynamic Load Response Bits
See the ''funktionsrahmen''for the diagrams

Determination of the Load Gradients drlkrdy (DLAST)
To determine the load gradient, a load signal
generated by the charge detection (rl or drl) or a predicted load signal (drlp
or rlp) is used. Bit 0 of the code word CWKR is used to switch between actual and
predicted load signal.
The dynamic load response must be detected in a 10 ms time
interval and triggered. The instantaneously available load signals are
calculated in real time.
The applicable speed threshold NKRUM describes the
bounding range in which the time interval is less than 10 ms. Below the speed
threshold NKRUM, drlkrdy comes from the real-time delta load signals from the
detected or predicted load (drl or drlp). Above NKRUM, drlkrdy comes from the
difference between the load signals rl or rlp sampled at 10 ms intervals.
Because of this switchover, oversampling of rlp and rl is avoided in the range
below NKRUM.
Influence of the Dynamic Load Response on Knock
Detection
During active load dynamics B_krldy, the following
functions take effect:
1. The cylinder-selective reference level calculations are carried out with the label KRFTP3 (see module KRKE) --> Faster tracking of the reference level.
2. The knock detection thresholds kew(i)w can be increased by a factor FKELDY. The result is corrected knock detection thresholds kek(i) (see module KRKE).

Influence of the Dynamic Load Response on Knock Control
3. For each detected knocking combustion, the ignition angle is retarded by the value KRFKN on a cylinder-specific basis (see module KRRA).
When steady-state knock control adaptation is enabled, the stored ignition angle retards are read from the current adaptation map range each time. In contrast however, write access to the stead-state adaptation map, is forbidden (see module KRRA).
As long as tmot =< TMDYNA, there is no additional dynamic retarding of the ignition angle!

Dynamic Load Adaptation (DYN_ADAP)
If dynamic load response is triggered when tmot > TMDYNA --> B_krldya, the following functions additionally take effect:
4. Adaptive dynamic retarding of the ignition angle for all cylinders (modules KRDY and KRRA). In addition to the steady-state cylinder-selective knock control retarding, the ignition angle for all cylinders is retarded when dynamic response is detected for the time zldy > 0, to wkrdya(stkrnx) + KLDYMNT(evtmod) = starting value of wkrdy. If zldy = 0, this additional dynamic retardation wkrdy is reduced by one increment per DYAVF combustion events.
5.1 If dynamic load response is triggered without exceeding the second dynamic response threshold (KFDYES < drlkrdy < KFDYES + KFDYESOF >= B_krldya), then the retard adaptation (BB_DYN) is enabled for the initial value (wkrdy) of the dynamic response retarding. I.e. by heavy knocking B_kldystk, a new adaptation of wkrdya is performed for the next dynamic procedure (wkrdya (new) = wkrdya (old) + DYADS limited to DYADMX). In the case of purely normal knock (B_kldynrm), and also if no knock occurs (DYN_ADAP) the adaptation value remains unchanged.
5.2 If the second dynamic response threshold is also exceeded (drlkrdy > KFDYES + KFDYESOF ³ B_krldya & B_krldyf), then in addition to the measures from 4 and
5.1, the adaptation of the dynamic response retarding is enabled to advance
(BB_DYN).
During the active dynamic phase (B_krldyf = 1), two counters zzwdykr and zzwdymd are started. For each set bit B_zwkraa = 1 (i.e. the ignition angle from knock control is output) zzwdykr is incremented. For each bit not set B_zwkraa = 0 (i.e. the ignition angle from the torque interface was output) zzwdymd is incremented. At the end of the dynamic phase (B_krldyf = 0) the ratio is zzwdykr / (zzwdykr + zzwdymd) is determined; the two counters zzwdykr and zzwdymd are then reset to zero (DYN_ADAP).
If no knocking combustion occurs during the active dynamic phase (B_krldyf = 1), which is detected by the knock detection threshold kek (see module KRKE, B_kl), and zzwdykr / (zzwdykr + zzwdymd) >= PZWKRA (adjustable constant), then the initial value of the adaptive dynamic response derivation wkrdya is adjusted towards advance by 1 increment but is limited to the value DYAMNV.
The RAM area wkrdya is divided into 5 speed ranges stkrnx.

{| border="1"
|-
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stkrnx =
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0
|
1
|
2
|
3
|
4
|
|-
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wkrdya
|
|
|
|
|
|-
|
Speed sample points
|
|
KRAN1
|
KRAN2
|
KRAN3
|
KRAN4
|
|-
|
|
<---------+
|
|
|
---------> nmot (rpm)
|-
|
|
Hysteresis KRANH
|
|
|-
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|}
The engine speed ranges are identical to those of the steady-state adaptation characteristic map (see module KRRA). The engine speed limits apply with increasing engine speed.
The engine speed hysteresis KRANH is deducted only with decreasing speed (same as module KRRA).
The dynamic response derivation is recalculated for each write to the RAM area wkrdya and then into the engine speed range which is valid at the time of triggering of the dynamic response trigger point (! B_krldya --> B_krldya). It is then available as wkrdy for the next dynamic procedure which starts in this engine speed range.
When the ignition is turned off, all retardings are stored in the RAM area wkrdya until the engine is restarted.
After a ‘power cut’ of the RAM area, DYAMNV is initialized with wkrdya.

Engine Speed Dynamic Response
If the engine temperature tmot > TMKR and the engine speed gradient ngas_w are larger than the engine speed dynamic response detection threshold DNKRDYSN then the timer zndy is set to the initial value AZKRNDYN.
If ngas_w < DNKRDYSN, zndy is decremented up to zero for each ignition event in cylinder 1. The condition B krndy=1 applies until zndy > 0.
As long as B krndy = 1 the following applies:
1. The cylinder-selective reference level calculations are performed with the label KRFTP2 (see module KRKE) --> faster tracking of the reference level.
2. The knock detection thresholds ke(i)w are increased by the factor FKENDY. Corrected knock detection thresholds kek(i) result (see module KRKE).
3. For each detected knocking combustion, the ignition angle is retarded by the value KRFKN cylinder-selectively (see module KRRA).
When steady-state adaptation is enabled, the stored retardings are read from the current adaptation map range each time in case of range changes. Write access to the characteristic map of the steady-state adaptation is, however, forbidden (see module KRRA).
The triggering of the dynamic load response may also take place during active engine speed dynamic response and vice versa. It is decided in modules KRKE and KRRA respectively which of the introduced measures takes priority.

Application Notes
The application aim of dynamic load response is adjustment that optimizes performance with no audible “dynamic knocking” in the vehicle.
The adjustment should be performed under “worst-case conditions” (summer temperatures and fuel with lowest enabled octane number).
The following values taken from experience can be used for a rough adjustment:
TMKR approx. 40°C
TMDYNA approx. 80°C
AZKELDYN should be chosen so that error labels via the load-dependent noise recording are avoided
AZKRLDYN should be chosen in such a way that the dynamic condition approx. 300-600 ms applies.
Guidance values are: 2-5 working cycles (AS) at 1000 rpm and 15-25 working cycles at 6000 rpm.
DYADMX approx. -8 ... -10 °crank
FKELDYA 1.2 - 1.3
DYAVF should be chosen such that during each working cycle adjustment to advance is performed by approx. 4 increments at most (so DYAVF must be equal to or exceed no. of cylinders / 4, DYAVF is an integer and DYAVF > 0 is demanded!)
The greater the DYAVF then the smaller the down-regulation of speed will be
CWKR bit 0 = 1 as long as load prediction is not available or not stable
NKRUM = 4000 rpm for SY_ZYLZA = 3
NKRUM = 3000 rpm for SY_ZYLZA = 4
NKRUM = 2400 rpm for SY_ZYLZA = 5
NKRUM = 2000 rpm for SY_ZYLZA = 6
NKRUM = 1500 rpm for SY_ZYLZA = 8
NKRUM = 1200 rpm for SY_ZYLZA = 10
NKRUM = 1000 rpm for
SY_ZYLZA = 12
The application aim of engine speed dynamic response is avoiding misdetections due to a very fast increase in engine speed resulting in abrupt noise increase (especially critical: gear shifting on powerful vehicles with automatic gearbox)
NGKRWN approx. 500 - 1000 rpm/s;
AZKRNDYN should be chosen such that the dynamic
response condition approx. 300-600 ms applies.
Guidance values are: 2-5 working cycles at 1000 rpm
and 15-25 working cycles at 6000 rpm.

Abbreviations

{| border="1"
|-
|
AZKELDYN
|
Ignition per cylinder for load dynamics ®
knock detection
|-
|
AZKRLDYN
|
Number of ignition per cylinder during knock control
load dynamic
|-
|
AZKRNDYN
|
Number of ignition for knock control engine speed
dynamic
|-
|
CWKR
|
Code word for knock control
|-
|
CWTIPIN
|
Codeword for tip-in function
|-
|
DRLKRAN
|
Detection threshold dynamic load response for steady-state
adaptation
|-
|
DYADMXN
|
Maximum value of dynamic response derivation
|-
|
DYADS
|
Additive retarding per cycle through adaptation
dynamics
|-
|
DYAFVS
|
Advance step for deactivation of dynamic response
|-
|
DYAMNV
|
Minimum value of dynamic response derivation
|-
|
DYAVF
|
Deactivation period for dynamics retardation
|-
|
DZWTIN
|
Delta ignition angle at tip-in
|-
|
FKELDYA
|
Correction factor for knock detection threshold for
adaptation of load dynamics
|-
|
KFDYES
|
Threshold for dynamic presetting values
|-
|
KFDYMNT
|
Pilot-controlled dynamic derivation
|-
|
KFDYRS
|
Dynamic derivation detection threshold
|-
|
KFDYRSOF
|
Offset threshold for dynamic presetting values
|-
|
NGKRAWN
|
Speed gradient threshold for dynamic
detection KRRA
|-
|
NGKRWN
|
Speed gradient threshold for dynamic
detection
|-
|
NKRUM
|
Revolution threshold for change of delta load signal
for load dynamics
|-
|
PZWKRA
|
Percentage frequency of ignition angle output by
knock control during dynamic adaptation
|-
|
TMDYNA
|
Engine temperature threshold to enable load dynamic
adaptation
|-
|
ZDRLKRA
|
Time constant for low-pass load gradient in knock
control
|-
|
ZNGKRA
|
Time constant for low-pass engine speed gradient
|-
|
'''Variable'''
|
'''Description'''
|-
|
B_DRLKRDY
|
Flag for n > NKRUM
|-
|
B_KL
|
Condition: knock detected
|-
|
B_KLDYNRM
|
Condition: normal knocking with adapted load dynamic
|-
|
B_KLDYSTK
|
Condition: heavy knocking with adapted load dynamic
|-
|
B_KRDWS
|
Condition: knock control safety ignition retarding
|-
|
B_KRLDY
|
Condition: load dynamics for knock detection active
|-
|
B_KRLDYA
|
Condition: load dynamics retard and dynamics
adaptation active
|-
|
B_KRLDYF
|
Condition: adaptation load dynamics retard towards
advance enabled
|-
|
B_KRLDYN
|
Condition: load dynamic for steady-state adaptation
active
|-
|
B_KRLDYV
|
Condition: threshold for additional load dynamics
retard exceeded
|-
|
B_KRNDY
|
Condition: speed dynamics for knock detection active
|-
|
B_KRNDYN
|
Condition: engine speed dynamics for steady-state
adaptation active
|-
|
B_KUPPL
|
EGAS Condition: clutch is disengaged
|-
|
B_LL
|
Condition: idle
|-
|
B_MF
|
Condition: measurement window
|-
|
B_TIPIN
|
Condition: tip-in detected
|-
|
B_TMKR
|
Condition: engine temperature (tmot) for knock
control reached
|-
|
B_VNULL
|
Condition: vehicle at standstill
|-
|
B_ZWKRAA
|
Condition: ignition angle is output from knock
control
|-
|
C_PWF
|
ECU condition: Power fail-initializing
|-
|
DRLKRAV
|
Actual value of DRLKRAN
|-
|
DRLKRDY
|
Load gradient for activating knock control load
dynamics
|-
|
DRLKRRA
|
Load gradient for selecting steady-state adaptation
|-
|
DRLP_W
|
Delta predicted load for injection time calculation
(word)
|-
|
DRL_W
|
Charge change (Word)
|-
|
DYESV
|
Current value of load dynamic response detection
threshold
|-
|
DYMNTV
|
Minimum additive dynamic derivation of KL
|-
|
DYRSOFV
|
Actual value of the offset for load dynamics
detection threshold
|-
|
DYRSV
|
Actual value of the load dynamics detection
threshold
|-
|
EVTMOD
|
Modelled inlet valve temperature (temperature model)
|-
|
GANGI
|
Engaged gear
|-
|
KEK
|
Knock detection threshold corrected
|-
|
LKRNEW
|
Value of load at time t
|-
|
LKROLD
|
Value of load at time t-dt
|-
|
NGAS_W
|
Engine speed gradient during one working cycle
|-
|
NGKRAF_W
|
Instantaneous value of threshold speed dynamics
|-
|
NGKRAV_W
|
Actual value of the engine speed dynamic threshold
|-
|
NGKRV_W
|
Actual value of the engine speed dynamic threshold
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
RLP_W
|
Relative cylinder charge predicted for injection
calculation (Word)
|-
|
RL_W
|
Relative air charge (Word)
|-
|
R_T10
|
10 ms time frame
|-
|
R_T100
|
100 ms time frame
|-
|
STKRNX
|
Speed range adaption map knock control
|-
|
STUETZ
|
Engine speed adaptation range during triggering of
the load dynamic
|-
|
TMOT
|
Engine temperature
|-
|
VIRKR
|
Ratio: integrator/ reference level knock control
|-
|
WKRDY
|
Ignition retard during dynamic-function of knock control
|-
|
WKRDYA
|
Adapted ignition timing for dynamic knock control
|-
|
ZALDY
|
Ignition counter for deactivation of load dynamics
|-
|
ZLDY
|
Ignition counter for load dynamic
|-
|
ZLDYKE
|
Ignition counter for load dynamics ®
knock detection
|-
|
ZNDY
|
Ignition counter for rpm-dynamics
|-
|
ZZWDYKR
|
Ignition counter for knock control with bit B_zwkra
= 1 set during dynamic knock control
|-
|
ZZWDYMD
|
Ignition counter for knock control with bit B.zwkra =
0 not set during dynamic knock control
|-
|
ZZYLKR
|
cylinder counter Knock Control
|}

KRDY 17.120 (Dynamic Knock Control)

2012-05-02T22:22:59Z

TTQS: Created page with "KRDY 17.120 Function Description See the ''funktionsrahmen'' for the following diagrams: krdy-krdy KRDY: Overview of Dynamic Knock Control krdy-bb-dyn BB_DYN: Detection of..."

KRDY 17.120 Function Description
See the ''funktionsrahmen'' for the following diagrams:
krdy-krdy KRDY: Overview of Dynamic Knock Control
krdy-bb-dyn BB_DYN: Detection of Load- and Engine Speed Dynamic, Enable Adaptation
krdy-dlast DLAST: Determination of the Load Gradient
krdy-bb-dyna BB_DYNA: Detection of Load- and Engine Speed Dynamic for Steady-State Adaptation
krdy-dyn-adap DYN_ADAP: Adaptation of Dynamic Response Derivation

Function Description
Dynamic Load Response
The dynamic load response is characterized by two phenomena:
- Increased knock tendency (at the equivalent temperature)
- Rapid increase in noise level which are by the following measures:
- Additional ignition retard (dynamic response derivation wkrdy at B_krldya = 1)
- Faster tracking of the reference level and increased knock detection thresholds (at B_krldy = 1, see module KRKE)

Detection of the Dynamic Load Response and Enabling the Dynamic Response Adaptation (BB_DYN)
The load dynamic response is triggered by the positive load difference drlkrdy (load gradient, see DLAST).
If the difference between two successive samples (drlkrdy) during an acceleration of the load signal is greater than the 1st dynamic detection threshold KFDYES, the timer is set to the initial value zldy AZKRLDYN and bit B_krldyv = 1.
As soon as drlkrdy < KFDYES, zldy is decremented by 1 increment per cycle. When zldy = 0, B_krldyv is reset.
(For the set / reset with B_krldy, the procedure is basically the same but with AZKELDYN as a starting value for the counter zldyke.)
As long as zldy > 0 and TMKR < tmot £ TMDYNA, only the condition B_krldyv = 1 applies. Additionally, when tmot > TMDYNA, the condition B_krldya = 1 applies and thus a dynamic derivative wkrdy is output. The down-regulation of wkrdy
starts with resetting B_krldyv. If wkrdy is down-regulated to 0, B_krldya will
also be reset. At idle (B_ll), no dynamics are detected (e.g. LLR).
Set- and Reset Conditions for the Dynamic Load
Response Bits
See the ''funktionsrahmen''
for the diagrams
Determination of the Load Gradients drlkrdy (DLAST)
To determine the load gradient, a load signal
generated by the charge detection (rl or drl) or a predicted load signal (drlp
or rlp) is used. Bit 0 of the code word CWKR is used to switch between actual and
predicted load signal.
The dynamic load response must be detected in a 10 ms time
interval and triggered. The instantaneously available load signals are
calculated in real time.
The applicable speed threshold NKRUM describes the
bounding range in which the time interval is less than 10 ms. Below the speed
threshold NKRUM, drlkrdy comes from the real-time delta load signals from the
detected or predicted load (drl or drlp). Above NKRUM, drlkrdy comes from the
difference between the load signals rl or rlp sampled at 10 ms intervals.
Because of this switchover, oversampling of rlp and rl is avoided in the range
below NKRUM.
Influence of the Dynamic Load Response on Knock
Detection
During active load dynamics B_krldy, the following
functions take effect:
1. The cylinder-selective reference level calculations are carried out with the label KRFTP3 (see module KRKE) --> Faster tracking of the reference level.
2. The knock detection thresholds kew(i)w can be increased by a factor FKELDY. The result is corrected knock detection thresholds kek(i) (see module KRKE).

Influence of the Dynamic Load Response on Knock Control
3. For each detected knocking combustion, the ignition angle is retarded by the value KRFKN on a cylinder-specific basis (see module KRRA).
When steady-state knock control adaptation is enabled, the stored ignition angle retards are read from the current adaptation map range each time. In contrast however, write access to the stead-state adaptation map, is forbidden (see module KRRA).
As long as tmot =< TMDYNA, there is no additional dynamic retarding of the ignition angle!

Dynamic Load Adaptation (DYN_ADAP)
If dynamic load response is triggered when tmot > TMDYNA --> B_krldya, the following functions additionally take effect:
4. Adaptive dynamic retarding of the ignition angle for all cylinders (modules KRDY and KRRA). In addition to the steady-state cylinder-selective knock control retarding, the ignition angle for all cylinders is retarded when dynamic response is detected for the time zldy > 0, to wkrdya(stkrnx) + KLDYMNT(evtmod) = starting value of wkrdy. If zldy = 0, this additional dynamic retardation wkrdy is reduced by one increment per DYAVF combustion events.
5.1 If dynamic load response is triggered without exceeding the second dynamic response threshold (KFDYES < drlkrdy < KFDYES + KFDYESOF >= B_krldya), then the retard adaptation (BB_DYN) is enabled for the initial value (wkrdy) of the dynamic response retarding. I.e. by heavy knocking B_kldystk, a new adaptation of wkrdya is performed for the next dynamic procedure (wkrdya (new) = wkrdya (old) + DYADS limited to DYADMX). In the case of purely normal knock (B_kldynrm), and also if no knock occurs (DYN_ADAP) the adaptation value remains unchanged.
5.2 If the second dynamic response threshold is also exceeded (drlkrdy > KFDYES + KFDYESOF ³ B_krldya & B_krldyf), then in addition to the measures from 4 and
5.1, the adaptation of the dynamic response retarding is enabled to advance
(BB_DYN).
During the active dynamic phase (B_krldyf = 1), two counters zzwdykr and zzwdymd are started. For each set bit B_zwkraa = 1 (i.e. the ignition angle from knock control is output) zzwdykr is incremented. For each bit not set B_zwkraa = 0 (i.e. the ignition angle from the torque interface was output) zzwdymd is incremented. At the end of the dynamic phase (B_krldyf = 0) the ratio is zzwdykr / (zzwdykr + zzwdymd) is determined; the two counters zzwdykr and zzwdymd are then reset to zero (DYN_ADAP).
If no knocking combustion occurs during the active dynamic phase (B_krldyf = 1), which is detected by the knock detection threshold kek (see module KRKE, B_kl), and zzwdykr / (zzwdykr + zzwdymd) >= PZWKRA (adjustable constant), then the initial value of the adaptive dynamic response derivation wkrdya is adjusted towards advance by 1 increment but is limited to the value DYAMNV.
The RAM area wkrdya is divided into 5 speed ranges stkrnx.

{| border="1"
|-
|
stkrnx =
|
0
|
1
|
2
|
3
|
4
|
|-
|
wkrdya
|
|
|
|
|
|-
|
Speed sample points
|
|
KRAN1
|
KRAN2
|
KRAN3
|
KRAN4
|
|-
|
|
<---------+
|
|
|
---------> nmot (rpm)
|-
|
|
Hysteresis KRANH
|
|
|-
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|}
The engine speed ranges are identical to those of the steady-state adaptation characteristic map (see module KRRA). The engine speed limits apply with increasing engine speed.
The engine speed hysteresis KRANH is deducted only with decreasing speed (same as module KRRA).
The dynamic response derivation is recalculated for each write to the RAM area wkrdya and then into the engine speed range which is valid at the time of triggering of the dynamic response trigger point (! B_krldya --> B_krldya). It is then available as wkrdy for the next dynamic procedure which starts in this engine speed range.
When the ignition is turned off, all retardings are stored in the RAM area wkrdya until the engine is restarted.
After a ‘power cut’ of the RAM area, DYAMNV is initialized with wkrdya.

Engine Speed Dynamic Response
If the engine temperature tmot > TMKR and the engine speed gradient ngas_w are larger than the engine speed dynamic response detection threshold DNKRDYSN then the timer zndy is set to the initial value AZKRNDYN.
If ngas_w < DNKRDYSN, zndy is decremented up to zero for each ignition event in cylinder 1. The condition B krndy=1 applies until zndy > 0.
As long as B krndy = 1 the following applies:
1. The cylinder-selective reference level calculations are performed with the label KRFTP2 (see module KRKE) --> faster tracking of the reference level.
2. The knock detection thresholds ke(i)w are increased by the factor FKENDY. Corrected knock detection thresholds kek(i) result (see module KRKE).
3. For each detected knocking combustion, the ignition angle is retarded by the value KRFKN cylinder-selectively (see module KRRA).
When steady-state adaptation is enabled, the stored retardings are read from the current adaptation map range each time in case of range changes. Write access to the characteristic map of the steady-state adaptation is, however, forbidden (see module KRRA).
The triggering of the dynamic load response may also take place during active engine speed dynamic response and vice versa. It is decided in modules KRKE and KRRA respectively which of the introduced measures takes priority.

Application Notes
The application aim of dynamic load response is adjustment that optimizes performance with no audible “dynamic knocking” in the vehicle.
The adjustment should be performed under “worst-case conditions” (summer temperatures and fuel with lowest enabled octane number).
The following values taken from experience can be used for a rough adjustment:
TMKR approx. 40°C
TMDYNA approx. 80°C
AZKELDYN should be chosen so that error labels via the load-dependent noise recording are avoided
AZKRLDYN should be chosen in such a way that the dynamic condition approx. 300-600 ms applies.
Guidance values are: 2-5 working cycles (AS) at 1000 rpm and 15-25 working cycles at 6000 rpm.
DYADMX approx. -8 ... -10 °crank
FKELDYA 1.2 - 1.3
DYAVF should be chosen such that during each working cycle adjustment to advance is performed by approx. 4 increments at most (so DYAVF must be equal to or exceed no. of cylinders / 4, DYAVF is an integer and DYAVF > 0 is demanded!)
The greater the DYAVF then the smaller the down-regulation of speed will be
CWKR bit 0 = 1 as long as load prediction is not available or not stable
NKRUM = 4000 rpm for SY_ZYLZA = 3
NKRUM = 3000 rpm for SY_ZYLZA = 4
NKRUM = 2400 rpm for SY_ZYLZA = 5
NKRUM = 2000 rpm for SY_ZYLZA = 6
NKRUM = 1500 rpm for SY_ZYLZA = 8
NKRUM = 1200 rpm for SY_ZYLZA = 10
NKRUM = 1000 rpm for
SY_ZYLZA = 12
The application aim of engine speed dynamic response is avoiding misdetections due to a very fast increase in engine speed resulting in abrupt noise increase (especially critical: gear shifting on powerful vehicles with automatic gearbox)
NGKRWN approx. 500 - 1000 rpm/s;
AZKRNDYN should be chosen such that the dynamic
response condition approx. 300-600 ms applies.
Guidance values are: 2-5 working cycles at 1000 rpm
and 15-25 working cycles at 6000 rpm.

Abbreviations

{| border="1"
|-
|
AZKELDYN
|
Ignition per cylinder for load dynamics ®
knock detection
|-
|
AZKRLDYN
|
Number of ignition per cylinder during knock control
load dynamic
|-
|
AZKRNDYN
|
Number of ignition for knock control engine speed
dynamic
|-
|
CWKR
|
Code word for knock control
|-
|
CWTIPIN
|
Codeword for tip-in function
|-
|
DRLKRAN
|
Detection threshold dynamic load response for steady-state
adaptation
|-
|
DYADMXN
|
Maximum value of dynamic response derivation
|-
|
DYADS
|
Additive retarding per cycle through adaptation
dynamics
|-
|
DYAFVS
|
Advance step for deactivation of dynamic response
|-
|
DYAMNV
|
Minimum value of dynamic response derivation
|-
|
DYAVF
|
Deactivation period for dynamics retardation
|-
|
DZWTIN
|
Delta ignition angle at tip-in
|-
|
FKELDYA
|
Correction factor for knock detection threshold for
adaptation of load dynamics
|-
|
KFDYES
|
Threshold for dynamic presetting values
|-
|
KFDYMNT
|
Pilot-controlled dynamic derivation
|-
|
KFDYRS
|
Dynamic derivation detection threshold
|-
|
KFDYRSOF
|
Offset threshold for dynamic presetting values
|-
|
NGKRAWN
|
Speed gradient threshold for dynamic
detection KRRA
|-
|
NGKRWN
|
Speed gradient threshold for dynamic
detection
|-
|
NKRUM
|
Revolution threshold for change of delta load signal
for load dynamics
|-
|
PZWKRA
|
Percentage frequency of ignition angle output by
knock control during dynamic adaptation
|-
|
TMDYNA
|
Engine temperature threshold to enable load dynamic
adaptation
|-
|
ZDRLKRA
|
Time constant for low-pass load gradient in knock
control
|-
|
ZNGKRA
|
Time constant for low-pass engine speed gradient
|-
|
'''Variable'''
|
'''Description'''
|-
|
B_DRLKRDY
|
Flag for n > NKRUM
|-
|
B_KL
|
Condition: knock detected
|-
|
B_KLDYNRM
|
Condition: normal knocking with adapted load dynamic
|-
|
B_KLDYSTK
|
Condition: heavy knocking with adapted load dynamic
|-
|
B_KRDWS
|
Condition: knock control safety ignition retarding
|-
|
B_KRLDY
|
Condition: load dynamics for knock detection active
|-
|
B_KRLDYA
|
Condition: load dynamics retard and dynamics
adaptation active
|-
|
B_KRLDYF
|
Condition: adaptation load dynamics retard towards
advance enabled
|-
|
B_KRLDYN
|
Condition: load dynamic for steady-state adaptation
active
|-
|
B_KRLDYV
|
Condition: threshold for additional load dynamics
retard exceeded
|-
|
B_KRNDY
|
Condition: speed dynamics for knock detection active
|-
|
B_KRNDYN
|
Condition: engine speed dynamics for steady-state
adaptation active
|-
|
B_KUPPL
|
EGAS Condition: clutch is disengaged
|-
|
B_LL
|
Condition: idle
|-
|
B_MF
|
Condition: measurement window
|-
|
B_TIPIN
|
Condition: tip-in detected
|-
|
B_TMKR
|
Condition: engine temperature (tmot) for knock
control reached
|-
|
B_VNULL
|
Condition: vehicle at standstill
|-
|
B_ZWKRAA
|
Condition: ignition angle is output from knock
control
|-
|
C_PWF
|
ECU condition: Power fail-initializing
|-
|
DRLKRAV
|
Actual value of DRLKRAN
|-
|
DRLKRDY
|
Load gradient for activating knock control load
dynamics
|-
|
DRLKRRA
|
Load gradient for selecting steady-state adaptation
|-
|
DRLP_W
|
Delta predicted load for injection time calculation
(word)
|-
|
DRL_W
|
Charge change (Word)
|-
|
DYESV
|
Current value of load dynamic response detection
threshold
|-
|
DYMNTV
|
Minimum additive dynamic derivation of KL
|-
|
DYRSOFV
|
Actual value of the offset for load dynamics
detection threshold
|-
|
DYRSV
|
Actual value of the load dynamics detection
threshold
|-
|
EVTMOD
|
Modelled inlet valve temperature (temperature model)
|-
|
GANGI
|
Engaged gear
|-
|
KEK
|
Knock detection threshold corrected
|-
|
LKRNEW
|
Value of load at time t
|-
|
LKROLD
|
Value of load at time t-dt
|-
|
NGAS_W
|
Engine speed gradient during one working cycle
|-
|
NGKRAF_W
|
Instantaneous value of threshold speed dynamics
|-
|
NGKRAV_W
|
Actual value of the engine speed dynamic threshold
|-
|
NGKRV_W
|
Actual value of the engine speed dynamic threshold
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
RLP_W
|
Relative cylinder charge predicted for injection
calculation (Word)
|-
|
RL_W
|
Relative air charge (Word)
|-
|
R_T10
|
10 ms time frame
|-
|
R_T100
|
100 ms time frame
|-
|
STKRNX
|
Speed range adaption map knock control
|-
|
STUETZ
|
Engine speed adaptation range during triggering of
the load dynamic
|-
|
TMOT
|
Engine temperature
|-
|
VIRKR
|
Ratio: integrator/ reference level knock control
|-
|
WKRDY
|
Ignition retard during dynamic-function of knock control
|-
|
WKRDYA
|
Adapted ignition timing for dynamic knock control
|-
|
ZALDY
|
Ignition counter for deactivation of load dynamics
|-
|
ZLDY
|
Ignition counter for load dynamic
|-
|
ZLDYKE
|
Ignition counter for load dynamics ®
knock detection
|-
|
ZNDY
|
Ignition counter for rpm-dynamics
|-
|
ZZWDYKR
|
Ignition counter for knock control with bit B_zwkra
= 1 set during dynamic knock control
|-
|
ZZWDYMD
|
Ignition counter for knock control with bit B.zwkra =
0 not set during dynamic knock control
|-
|
ZZYLKR
|
cylinder counter Knock Control
|}

Main Page

2012-05-02T22:22:23Z

TTQS: /* Motronic 7 (ME7.x) Breakdown */

=NefMoto Wiki - Welcome!=
The NefMoto site is a collective body of VW/Audi ME7 ECU tuning information.

==Overview==
*[[Getting Started]]

==Flashing==
*[[NefMoto ECU Flashing Software]] - Free, fast and reliable ECU flashing
*[[ECU Bench Flashing]]
*[[Galletto 1260 Flashing Cable]] - Recover a failed flash in [[ECU Boot Mode|boot mode]]

==Software Tools==
*[http://www.nefariousmotorsports.com/wiki/index.php/NefMoto_ECU_Flashing_Software NefMoto]
*[[Me7 Logger]]
**[[GUI for Me7 Logger]]
**[[Innovate LC1 / ME7 Logger]]
*[http://www.nefariousmotorsports.com/forum/index.php/topic,447.0title,.html ME7Check]
**[http://nefariousmotorsports.com/forum/index.php/topic,447.msg9477.html#msg9477 Gui for ME7Check]
*[[ECUxPlot]]
*[[ME7_95040 EEPROM programmer - Read over OBD / (Boot mode Write)]]
*[[Findmap v0.3b]]
*[http://nefariousmotorsports.com/forum/index.php?action=dlattach;topic=639.0;attach=720 Galletto 1260]

==Motronic 7 (ME7.x) Breakdown==
*[http://s4wiki.com/wiki/Tuning S4Wiki.org Tuning guide] <- A must read!
*[[Funktionsrahmen|Bosch ME7.x Funktionsrahmen]]
*[[Checksums]]
*[[ME7 Tuning Information]]
*[[ME7 Communication Protocol Information]]
Manually translated modules
*[[ATM 33.50 (Exhaust Gas Temperature Model)]]
*[[ATR 1.60 (Exhaust Gas Temperature Control)]]
*[[BGSRM 17.10 (Cylinder Charge Detection, Intake Manifold Model)]]
*[[FUEDK 21.90 (Cylinder Charge Control, Calculating Target Throttle Angle)]]
*[[GGHFM 57.60 (MAF Meter System Pulsations)]]
*[[KRDY 17.120 (Dynamic Knock Control)]]
*[[KRRA 15.130 (Knock Control with Individual Cylinder Retard)]]
*[[LAMBTS 2.120 (Lambda for Component Protection)]]
*[[LAMFAW 7.100 (Driver's Requested Lambda)]]
*[[LAMKO 9.80 (Lambda Coordination)]]
*[[LDRLMX 3.100 (Calculation of LDR Maximum Cylinder Charge rlmax)]]
*[[LDRPID 25.10 (Charge Pressure Regulation PID Control)]]
*[[LRSHK 9.20 (Continuous Post-Catalyst Lambda Control)]]
*[[MDBAS 8.30 (Calculation of the Basic Parameters for the Torque Interface)]]
*[[MDFAW 12.260 (Driver Requested Torque)]]
*[[MDFUE 8.50 (Setpoint for Air Mass from Load Torque)]]
*[[MDKOG 14.70 (Torque Coordination for Overall Interventions)]]
*[[MDZW 1.120 (Calculating Torque at the Desired Ignition Angle)]]
*[[RKTI 11.40 (Calculation of Injection Time ti from Relative Fuel Mass rk)]]
*[[SLS 88.150 (Secondary Air Control)]]
*[[ZUE 282.130 (Fundamental Function - Ignition)]]
*[[ZWGRU 23.110 (Fundamental Ignition Angle)]]

==Motronic MED9 Breakdown==

*[[MED9 Abbreviations in English (A-C)]]
*[[MED9 Abbreviations in English (D-F)]]
*[[MED9 Abbreviations in English (G-L)]]
*[[MED9 Abbreviations in English (M-Q)]]
*[[MED9 Abbreviations in English (R-S)]]
*[[MED9 Abbreviations in English (T)]]
*[[MED9 Abbreviations in English (U-Z)]]
*[http://nefariousmotorsports.com/forum/index.php?topic=1353.0 Download all as Excel workbook]

==Development==
*[[Reverse Engineering Generic Guide]]
*[[Camden's ME7.5 Reverse Engineering]]
*[[ECU pin outs]]

==Vehicle Information==
*[[Volkswagen]]
*[[Audi]]

LDRLMX 3.100 (Calculation of LDR Maximum Cylinder Charge rlmax)

2012-01-29T11:20:30Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

ldrlmx-main LDRLMX function definition

ldrlmx-fldrrx

ldrlmx-sstb

ldrlmx-set

ldrlmx-rlmx-w

ldrlmx-tsel

ldrlmx-frxta-w

ldrlmx-hierarchy

ldrlmx-initialise

LDRLMX 3.100 Function Description

The function LDRLMX calculates the allowed maximum cylinder charge.

In the main path, the maximum charge value dependent on engine speed is given by the characteristic LDRXN. This can be corrected, if necessary, through intervention of the workshop tester.

For this purpose, an additive overboost increase (drlmaxo, delta maximum cylinder charge during overboost) is applied via the knock-control intervention.

On the rlmx path, a multiplicative correction is applied via the characteristic field KFTARX as a function of engine speed and intake air temperature.

Subsequently, there is an intervention via the sub-function FLDRRX as a function of the average ignition angle retardation in knock control (wkrma). This function consists of two parts, a quasi-steady state long-term component (permanent RAM) which takes the fuel octane rating into account, and a dynamic short-term component to take all other perturbations into account. The low pass of the long-term component is active only above a speed-dependent load threshold RLKRLDA that is representative for fuel adaption. The characteristic field KFFLLDE sets the steady-state reduction.

The low pass of the short-term component works with the difference of the filtered long-term average value (wkrmstat) and the actual average value (wkrma). To avoid conflicting interventions from both the aforementioned components, the minimum difference is limited to zero.

The associated drawdown value is determined by KFFSLDE.

The overboost path is corrected separately, by a dependence on the sum of both low-pass outputs (wkrmsu) and the speed of the associated drawdown is determined via KFFLDEO.

The time constants of the two components are each separated into predetermined up-regulating and down-regulating speed dependencies.

Further on down the main pathway, the maximum cylinder charge is limited by an external pressure dependency to avoid overloading the turbocharger at high altitudes.

This limit (maximum compressor pressure ratio) which is engine speed and tsel (tans/tumc)-dependent is determined via KFLDHBN, by multiplying the external pressure by the maximum absolute pressure and then using pirg_w and fupsrl_w to convert to a cylinder charge level.

When an ambient temperature sensor is present, the map KFLDHBN is addressed with the ambient temperature through the system constant SY_TFUMG and CWRLMX = 1 and to the instrument cluster via CAN. If no ambient temperature sensor is available or CWRLMX = 0, the map KFLDHBN is addressed with tans.

Via the system constants SY_TFMO, SY_GGGTS the oil temperature (toel) or the cooling water temperature from the instrument cluster (tmki) are read by sensors, whose signal is evaluated in functions %GGTOL or %GGGTS. If the respective variables are available via the CAN (tolc or tmkic) then switching to the CAN-variables will occur or, in case of failure, to surrogate values.

If a system failure is detected, an additional engine speed dependent (pressure) limitation (LDPBN) comes into force, which is analogous to the altitude limitation on the cylinder charge level. Switching back only occurs when resetting the tripping fault and in idle mode (B_ll).

In the overboost condition (E_ldo) an engine speed dependent limit (LDORXN) is switched in so that both the engine and the turbocharger adequately protected. Switching back also occurs only when resetting the error (E_ldo) and in idle-mode (B_ll).

LDRLMX 3.100 Application Notes

LDRXN: It must be ensured that even at speeds below the turbocharger response speed meaningful rlmax-values (about 10% above the value of throttle plate at full open test bench) can be specified. Above the turbocharger response speed, the regular allowable and desired rlmax values are defined in this characteristic.

LDORXN: maximum allowable cylinder charge, such that there is sufficient protection by an appropriately strong throttling of the throttle and turbocharger. (Remove the wastegate pressure hose during application!)

LDPBN: pressure relief in case of diagnosis (sudden torque drop should be no larger than about 15%).

KFLDHBN: Firstly, in the compressor performance map, acquire the regular full load line at speed sample points of KFLDHBN as well as the maximum pressure ratio line (due to the surge limit, maximum turbocharger-speed or prohibited areas of poor efficiency) to define the operational limit.

Then one carries on the height gradients from the normal full load line starting, at any engine speed, up to an operating limit.

This increases with increasing altitude (decreasing ambient pressure) of the volume flow rate and the pressure ratio with 1013/ambient pressure.

This new intersection then defines the maximum pressure ratio for KFLDHBN at the respective engine speed.

Attention! It must be ensured through appropriate application of RLKRLDA and LDRXN that the operating range of the long-time filter (rl > RLKRLDA) can always be reached! Otherwise, it might happen that a very large decrease will be locked in the long-term component itself and no new adaptation can take place.

All other values are highly dependent on the project.

Basic data input

ATTENTION applicators, these data are extremely project-specific and must be verified in each project application! Please note carefully or risk engine damage! In order to achieve the same functionality as in LDRLMX 3.70 in the absence of CAN message from the instrument cluster, note the following.

{| border="1"
|-
|
SY_TFMO
|
SY_GGGTS
|
Remark
|-
|
0
|
0
|
FKRXTOL and KFFKRXTM set = 1 >= frxt = 1
|-
|
1
|
0
|
FKRXTOL
set to a maximum value >= frxt = output KFFKRXTM
|-
|
0
|
1
|
KFFKRXTM set to a maximum value >= frxt = output FKRXTOL
|}

LDRXN: 140%

LDORXN: 15%

LDPBN: 1500 mbar

KFLDHBN: from low engine speed 1.9 to medium engine speed (2500 rpm) constant 2.5

FKRXTOL: 1.0 (1.0 does not limit the boost pressure control)

KFFKRXTM: 1.0 (1.0 does not limit the boost pressure control)

KFFLDEO: 1.0 (1.0 does not limit the boost pressure control)

KFFSLDE: 1.0 (1.0 does not limit the boost pressure control)

KFFLLDE: 1.0 (1.0 does not limit the boost pressure control)

KFFWLLDE: 1.0 (1.0 does not limit the boost pressure control)

KFTARX: data values of 1.0 below IAT of 75°C. Data values linearly reduced from 1.0 to 0.8 between 75°C and 120°C)

KFTARXZK: about 10% less than KFTARX

LDRXNZK: about 15% less than LDRXN

RLKRLDA: ca. 0.6 x LDRXN (the greatest possible relative load reduction must be greater than the value from RLKRLDA otherwise there will be a risk of dead lock!)

TLKRLDAB: ca. 3-5 seconds

TLKRLDAU: ca. 5-7 seconds

TSKRLDAB: 1-2 seconds

TSKRLDAU: 2-4 seconds

CWRLMX: 1 (Addressing of KFLDHBN via ambient temperature in instrument cluster (tumc)).

CWRLMX: 0 (Addressing of KFLDHBN via intake air temperature (tans)).

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CWRLMX
|
Codeword for LDRLMX (boost pressure control)
|-
|
FKRXTOL
|
Factor for correction of rlmax at higher engine oil temperature
|-
|
KFFKRXTM
|
Factor for correction of rlmax at higher engine temperature
|-
|
KFFLDEO
|
Factor for boost pressure intervention at overboost value via knock
control
|-
|
KFFLLDE
|
Factor for slow boost pressure control intervention at rlmax via knock
control
|-
|
KFFSLDE
|
Factor for fast boost pressure control intervention (lowering)
|-
|
KFFWLLDE
|
Weighting factor for slow boost pressure intervention at rlmax via knock
control
|-
|
KFLDHBN
|
Boost pressure control upper limit (maximum compressor pressure ratio)
|-
|
KFTARX
|
Map for maximum cylinder charge IAT correction factor
|-
|
KFTARXZK
|
Map for maximum cylinder charge IAT correction factor during continuous
knock
|-
|
LDORXN
|
Maximum cylinder charge LDR during E_ldo (overboost error)
|-
|
LDPBN
|
Charge pressure control P-limit when engine temperature is too high
|-
|
LDRXN
|
Maximum cylinder charge (charge pressure control)
|-
|
LDRXNZK
|
Maximum cylinder charge during continuous knock (charge pressure control)
|-
|
RLKRLDA
|
RL-threshold for slow charge pressure control intervention (adaption)
|-
|
SNM08LDUB
|
Sample point distribution for charge pressure control
|-
|
SNM08LDUW
|
Sample point distribution for charge pressure control
|-
|
SNM12LDUW
|
Sample point distribution for charge pressure control
|-
|
STA08LDUB
|
Sample point distribution for charge pressure control
|-
|
SWK08LDUW
|
Sample point distribution for charge pressure control
|-
|
SWK108LDUW
|
Sample point distribution for charge pressure control
|-
|
SWK208LDUW
|
Sample point distribution for charge pressure control
|-
|
SY_ATR
|
System constant: exhaust gas temperature control available
|-
|
SY_GGGTS
|
System constant: temperature transducer signal accuracy
|-
|
SY_TFMO
|
System constant: TOEL-sensor present (Initial. GGTFM surrogate value)
|-
|
SY_TFUMG
|
System constant: ambient temperature sensor present
|-
|
SY TRLX
|
System constant: intervention for workshop tester for rlmax present
|-
|
TLKRLDAB
|
Time constant for slow LDR-reduction
|-
|
TLKRLDAU
|
Time constant for slow LDR-up regulation
|-
|
TMOTMX
|
Engine temperature threshold for initial filling of the fuel system
|-
|
TOELMX
|
Oil temperature threshold for engine protection during transmission
emergency
|-
|
TOLEWRLMX
|
Surrogate oil temperature value with faulty CAN-message
|-
|
TSKRLDAB
|
Time constant for fast charge pressure control lowering
|-
|
TSKRLDAU
|
Time constant for fast charge pressure control up-regulation
|-
|
Variable
|
Description
|-
|
B_ATRF
|
Condition: exhaust gas temperature control error
|-
|
B_ATSB
|
Condition: exhaust gas temperature sensor operational
|-
|
B_BRLMX
|
Condition: charge pressure control limit for maximum cylinder charge
|-
|
B_CKIEN
|
Condition: CAN-transmission from instrument cluster enable
|-
|
B_KFZK
|
Condition: map for knock protection
|-
|
B_LL
|
Condition: idle
|-
|
B_PWF
|
Condition: power fail
|-
|
B_TMKIB
|
Condition: engine temperature from the instrument cluster operational
|-
|
B_TOLCB
|
Condition: oil temperature from instrument cluster can be evaluated
|-
|
B_TUMCB
|
Condition: error in CAN-ambient temperature information
|-
|
DFP_ATS
|
ECU internal error path number: exhaust temperature sensor, cylinder bank
1
|-
|
DFP_ATS2
|
ECU internal error path number: exhaust temperature sensor, cylinder bank
2
|-
|
DFP_LDO
|
ECU internal error path number: overboost charge pressure control
|-
|
DFP_TA
|
ECU internal error path number: intake air temperature TANS (-charge air)
|-
|
DFP_TM
|
ECU internal error path number: engine temperature
|-
|
DFP_TMKI
|
ECU internal error path number: engine temperature from the instrument
cluster
|-
|
DFP_TOL
|
ECU internal error path number: oil temperature
|-
|
DRLMAXO
|
Delta maximum cylinder charge during overboost
|-
|
DWKRM_W
|
Difference: wkrm - wkrmstat
|-
|
E_ATS
|
Error flag: exhaust gas temperature sensor, cylinder bank 1
|-
|
E_ATS2
|
Error flag: exhaust gas temperatur sensor, cylinder bank 2
|-
|
E_LDO
|
Error flag: charge pressure characteristic; upper value exceeded
|-
|
E_TA
|
Error flag: intake air temperature
|-
|
E_TM
|
Error flag: engine temperature
|-
|
E_TMKI
|
Error flag: engine temperature from the instrument cluster
|-
|
E_TOL
|
Error flag: oil temperature
|-
|
FLDRRX_W
|
Correction factor for maximum cylinder charge from knock control
|-
|
FLDRXK_W
|
Factor for LDR rlmax-correction via the short-time part
|-
|
FLDRXL_W
|
Factor for LDR rlmax-correction via the long-time part
|-
|
FLDRXO_W
|
Factor for charge pressure lowering of the overboost values (drlmaxo)
|-
|
FRXT
|
Factor for correction of rlmx as a function of tmki and tol
|-
|
FRXTA_W
|
Factor for correction of rlmx as a function of intake air temperature
|-
|
FUPSRL_W
|
Factor for system-related conversion of pressure to cylinder charge (16-Bit)
|-
|
LDRLMS_W
|
Limiting value for maximum cylinder charge LDR for engine protection
|-
|
LDRLTS_W
|
Limting value for maximum cylinder charge LDR for turbocharger protection
|-
|
NMOT
|
Engine speed
|-
|
NMOT W
|
Engine speed (word)
|-
|
PIRG_W
|
Partial pressure of residual gas internal exhaust gas recirculation
(16-Bit)
|-
|
PU
|
Ambient pressure
|-
|
RL
|
Relative cylinder charge
|-
|
RLMAX_W
|
Maximum permitted charge at the turbo
|-
|
RLMXKO_W
|
Maximum corrected cylinder charge (without limitations)
|-
|
RLMX_W
|
Rohwert maximum cylinder charge
|-
|
TANS
|
Intake air temperature
|-
|
TMKI
|
Engine temperature from the instrument cluster
|-
|
TMOT
|
Engine temperature
|-
|
TMOTLDRLMX
|
Engine temperature in LDRLMX after selection (tmot/tmkic/tmki)
|-
|
TOEL
|
Oil temperature
|-
|
TOELLDRLMX
|
Oil temperature in LDRLMX after selection (tolc/toel/TOLEWRLMX)
|-
|
TOLC
|
Oil temperature from instrument cluster message
|-
|
TSEL
|
Selected temperature (tans/tumc)
|-
|
TUMC
|
Ambient temperature from CAN-cluster
|-
|
VFZG
|
Vehicle speed
|-
|
VSRLMX
|
Additive cylinder charge correction for rlmx from the adjustment system
|-
|
VSTRLX
|
Adjustable value of the maximum cylinder charge for the calibrator/tester
|-
|
WKRMA
|
Average value of the individual cylinder ignition angle retardation
(knock control), general (in emergency mode with safety margin)
|-
|
WKRMDY_W
|
Dynamic average value of the individual cylinder ignition angle
retardation
|-
|
WKRMSTAT_W
|
Quasi-steady state average value of the individual cylinder ignition
angle retardation
|-
|
WKRMSU_W
|
Total value of the dynamic and static average value of the individual
cylinder ignition angle retardation
|}

LDRLMX 3.100 (Calculation of LDR Maximum Cylinder Charge rlmax)

2012-01-29T11:18:16Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

ldrlmx-main LDRLMX function definition

ldrlmx-fldrrx

ldrlmx-sstb

ldrlmx-set

ldrlmx-rlmx-w

ldrlmx-tsel

ldrlmx-frxta-w

ldrlmx-hierarchy

ldrlmx-initialise

LDRLMX 3.100 Function Description

The function LDRLMX calculates the allowed maximum cylinder charge.

In the main path, the maximum charge value dependent on engine speed is given by the characteristic LDRXN. This can be corrected, if necessary, through intervention of the workshop tester.

For this purpose, an additive overboost increase (drlmaxo, delta maximum cylinder charge during overboost) is applied via the knock-control intervention.

On the rlmx path, a multiplicative correction is applied via the characteristic field KFTARX as a function of engine speed and intake air temperature.

Subsequently, there is an intervention via the sub-function FLDRRX as a function of the average ignition angle retardation in knock control (wkrma). This function consists of two parts, a quasi-steady state long-term component (permanent RAM) which takes the fuel octane rating into account, and a dynamic short-term component to take all other perturbations into account. The low pass of the long-term component is active only above a speed-dependent load threshold RLKRLDA that is representative for fuel adaption. The characteristic field KFFLLDE sets the steady-state reduction.

The low pass of the short-term component works with the difference of the filtered long-term average value (wkrmstat) and the actual average value (wkrma). To avoid conflicting interventions from both the aforementioned components, the minimum difference is limited to zero.

The associated drawdown value is determined by KFFSLDE.

The overboost path is corrected separately, by a dependence on the sum of both low-pass outputs (wkrmsu) and the speed of the associated drawdown is determined via KFFLDEO.

The time constants of the two components are each separated into predetermined up-regulating and down-regulating speed dependencies.

Further on down the main pathway, the maximum cylinder charge is limited by an external pressure dependency to avoid overloading the turbocharger at high altitudes.

This limit (maximum compressor pressure ratio) which is engine speed and tsel (tans/tumc)-dependent is determined via KFLDHBN, by multiplying the external pressure by the maximum absolute pressure and then using pirg_w and fupsrl_w to convert to a cylinder charge level.

When an ambient temperature sensor is present, the map KFLDHBN is addressed with the ambient temperature through the system constant SY_TFUMG and CWRLMX = 1 and to the instrument cluster via CAN. If no ambient temperature sensor is available or CWRLMX = 0, the map KFLDHBN is addressed with tans.

Via the system constants SY_TFMO, SY_GGGTS the oil temperature (toel) or the cooling water temperature from the instrument cluster (tmki) are read by sensors, whose signal is evaluated in functions %GGTOL or %GGGTS. If the respective variables are available via the CAN (tolc or tmkic) then switching to the CAN-variables will occur or, in case of failure, to surrogate values.

If a system failure is detected, an additional engine speed dependent (pressure) limitation (LDPBN) comes into force, which is analogous to the altitude limitation on the cylinder charge level. Switching back only occurs when resetting the tripping fault and in idle mode (B_ll).

In the overboost condition (E_ldo) an engine speed dependent limit (LDORXN) is switched in so that both the engine and the turbocharger adequately protected. Switching back also occurs only when resetting the error (E_ldo) and in idle-mode (B_ll).

LDRLMX 3.100 Application Notes

[B]LDRXN[/B]: It must be ensured that even at speeds below the turbocharger response speed meaningful rlmax-values (about 10% above the value of throttle plate at full open test bench) can be specified. Above the turbocharger response speed, the regular allowable and desired rlmax values are defined in this characteristic.

[B]LDORXN[/B]: maximum allowable cylinder charge, such that there is sufficient protection by an appropriately strong throttling of the throttle and turbocharger. (Remove the wastegate pressure hose during application!)

[B]LDPBN[/B]: pressure relief in case of diagnosis (sudden torque drop should be no larger than about 15%).

[B]KFLDHBN[/B]: Firstly, in the compressor performance map, acquire the regular full load line at speed sample points of KFLDHBN as well as the maximum pressure ratio line (due to the surge limit, maximum turbocharger-speed or prohibited areas of poor efficiency) to define the operational limit.

Then one carries on the height gradients from the normal full load line starting, at any engine speed, up to an operating limit.

This increases with increasing altitude (decreasing ambient pressure) of the volume flow rate and the pressure ratio with 1013/ambient pressure.

This new intersection then defines the maximum pressure ratio for KFLDHBN at the respective engine speed.

Attention! It must be ensured through appropriate application of RLKRLDA and LDRXN that the operating range of the long-time filter (rl > RLKRLDA) can always be reached! Otherwise, it might happen that a very large decrease will be locked in the long-term component itself and no new adaptation can take place.

All other values are highly dependent on the project.

Basic data input

ATTENTION applicators, these data are extremely project-specific and must be verified in each project application! Please note carefully or risk engine damage! In order to achieve the same functionality as in LDRLMX 3.70 in the absence of CAN message from the instrument cluster, note the following.

{| border="1"
|-
|
SY_TFMO
|
SY_GGGTS
|
Remark
|-
|
0
|
0
|
FKRXTOL and KFFKRXTM set = 1 >= frxt = 1
|-
|
1
|
0
|
FKRXTOL
set to a maximum value >= frxt = output KFFKRXTM
|-
|
0
|
1
|
KFFKRXTM set to a maximum value >= frxt = output FKRXTOL
|}

LDRXN: 140%

LDORXN: 15%

LDPBN: 1500 mbar

KFLDHBN: from low engine speed 1.9 to medium engine speed (2500 rpm) constant 2.5

FKRXTOL: 1.0 (1.0 does not limit the boost pressure control)

KFFKRXTM: 1.0 (1.0 does not limit the boost pressure control)

KFFLDEO: 1.0 (1.0 does not limit the boost pressure control)

KFFSLDE: 1.0 (1.0 does not limit the boost pressure control)

KFFLLDE: 1.0 (1.0 does not limit the boost pressure control)

KFFWLLDE: 1.0 (1.0 does not limit the boost pressure control)

KFTARX: data values of 1.0 below IAT of 75°C. Data values linearly reduced from 1.0 to 0.8 between 75°C and 120°C)

KFTARXZK: about 10% less than KFTARX

LDRXNZK: about 15% less than LDRXN

RLKRLDA: ca. 0.6 x LDRXN (the greatest possible relative load reduction must be greater than the value from RLKRLDA otherwise there will be a risk of dead lock!)

TLKRLDAB: ca. 3-5 seconds

TLKRLDAU: ca. 5-7 seconds

TSKRLDAB: 1-2 seconds

TSKRLDAU: 2-4 seconds

CWRLMX: 1 (Addressing of KFLDHBN via ambient temperature in instrument cluster (tumc)).

CWRLMX: 0 (Addressing of KFLDHBN via intake air temperature (tans)).

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CWRLMX
|
Codeword for LDRLMX (boost pressure control)
|-
|
FKRXTOL
|
Factor for correction of rlmax at higher engine oil temperature
|-
|
KFFKRXTM
|
Factor for correction of rlmax at higher engine temperature
|-
|
KFFLDEO
|
Factor for boost pressure intervention at overboost value via knock
control
|-
|
KFFLLDE
|
Factor for slow boost pressure control intervention at rlmax via knock
control
|-
|
KFFSLDE
|
Factor for fast boost pressure control intervention (lowering)
|-
|
KFFWLLDE
|
Weighting factor for slow boost pressure intervention at rlmax via knock
control
|-
|
KFLDHBN
|
Boost pressure control upper limit (maximum compressor pressure ratio)
|-
|
KFTARX
|
Map for maximum cylinder charge IAT correction factor
|-
|
KFTARXZK
|
Map for maximum cylinder charge IAT correction factor during continuous
knock
|-
|
LDORXN
|
Maximum cylinder charge LDR during E_ldo (overboost error)
|-
|
LDPBN
|
Charge pressure control P-limit when engine temperature is too high
|-
|
LDRXN
|
Maximum cylinder charge (charge pressure control)
|-
|
LDRXNZK
|
Maximum cylinder charge during continuous knock (charge pressure control)
|-
|
RLKRLDA
|
RL-threshold for slow charge pressure control intervention (adaption)
|-
|
SNM08LDUB
|
Sample point distribution for charge pressure control
|-
|
SNM08LDUW
|
Sample point distribution for charge pressure control
|-
|
SNM12LDUW
|
Sample point distribution for charge pressure control
|-
|
STA08LDUB
|
Sample point distribution for charge pressure control
|-
|
SWK08LDUW
|
Sample point distribution for charge pressure control
|-
|
SWK108LDUW
|
Sample point distribution for charge pressure control
|-
|
SWK208LDUW
|
Sample point distribution for charge pressure control
|-
|
SY_ATR
|
System constant: exhaust gas temperature control available
|-
|
SY_GGGTS
|
System constant: temperature transducer signal accuracy
|-
|
SY_TFMO
|
System constant: TOEL-sensor present (Initial. GGTFM surrogate value)
|-
|
SY_TFUMG
|
System constant: ambient temperature sensor present
|-
|
SY TRLX
|
System constant: intervention for workshop tester for rlmax present
|-
|
TLKRLDAB
|
Time constant for slow LDR-reduction
|-
|
TLKRLDAU
|
Time constant for slow LDR-up regulation
|-
|
TMOTMX
|
Engine temperature threshold for initial filling of the fuel system
|-
|
TOELMX
|
Oil temperature threshold for engine protection during transmission
emergency
|-
|
TOLEWRLMX
|
Surrogate oil temperature value with faulty CAN-message
|-
|
TSKRLDAB
|
Time constant for fast charge pressure control lowering
|-
|
TSKRLDAU
|
Time constant for fast charge pressure control up-regulation
|-
|
Variable
|
Description
|-
|
B_ATRF
|
Condition: exhaust gas temperature control error
|-
|
B_ATSB
|
Condition: exhaust gas temperature sensor operational
|-
|
B_BRLMX
|
Condition: charge pressure control limit for maximum cylinder charge
|-
|
B_CKIEN
|
Condition: CAN-transmission from instrument cluster enable
|-
|
B_KFZK
|
Condition: map for knock protection
|-
|
B_LL
|
Condition: idle
|-
|
B_PWF
|
Condition: power fail
|-
|
B_TMKIB
|
Condition: engine temperature from the instrument cluster operational
|-
|
B_TOLCB
|
Condition: oil temperature from instrument cluster can be evaluated
|-
|
B_TUMCB
|
Condition: error in CAN-ambient temperature information
|-
|
DFP_ATS
|
ECU internal error path number: exhaust temperature sensor, cylinder bank
1
|-
|
DFP_ATS2
|
ECU internal error path number: exhaust temperature sensor, cylinder bank
2
|-
|
DFP_LDO
|
ECU internal error path number: overboost charge pressure control
|-
|
DFP_TA
|
ECU internal error path number: intake air temperature TANS (-charge air)
|-
|
DFP_TM
|
ECU internal error path number: engine temperature
|-
|
DFP_TMKI
|
ECU internal error path number: engine temperature from the instrument
cluster
|-
|
DFP_TOL
|
ECU internal error path number: oil temperature
|-
|
DRLMAXO
|
Delta maximum cylinder charge during overboost
|-
|
DWKRM_W
|
Difference: wkrm - wkrmstat
|-
|
E_ATS
|
Error flag: exhaust gas temperature sensor, cylinder bank 1
|-
|
E_ATS2
|
Error flag: exhaust gas temperatur sensor, cylinder bank 2
|-
|
E_LDO
|
Error flag: charge pressure characteristic; upper value exceeded
|-
|
E_TA
|
Error flag: intake air temperature
|-
|
E_TM
|
Error flag: engine temperature
|-
|
E_TMKI
|
Error flag: engine temperature from the instrument cluster
|-
|
E_TOL
|
Error flag: oil temperature
|-
|
FLDRRX_W
|
Correction factor for maximum cylinder charge from knock control
|-
|
FLDRXK_W
|
Factor for LDR rlmax-correction via the short-time part
|-
|
FLDRXL_W
|
Factor for LDR rlmax-correction via the long-time part
|-
|
FLDRXO_W
|
Factor for charge pressure lowering of the overboost values (drlmaxo)
|-
|
FRXT
|
Factor for correction of rlmx as a function of tmki and tol
|-
|
FRXTA_W
|
Factor for correction of rlmx as a function of intake air temperature
|-
|
FUPSRL_W
|
Factor for system-related conversion of pressure to cylinder charge (16-Bit)
|-
|
LDRLMS_W
|
Limiting value for maximum cylinder charge LDR for engine protection
|-
|
LDRLTS_W
|
Limting value for maximum cylinder charge LDR for turbocharger protection
|-
|
NMOT
|
Engine speed
|-
|
NMOT W
|
Engine speed (word)
|-
|
PIRG_W
|
Partial pressure of residual gas internal exhaust gas recirculation
(16-Bit)
|-
|
PU
|
Ambient pressure
|-
|
RL
|
Relative cylinder charge
|-
|
RLMAX_W
|
Maximum permitted charge at the turbo
|-
|
RLMXKO_W
|
Maximum corrected cylinder charge (without limitations)
|-
|
RLMX_W
|
Rohwert maximum cylinder charge
|-
|
TANS
|
Intake air temperature
|-
|
TMKI
|
Engine temperature from the instrument cluster
|-
|
TMOT
|
Engine temperature
|-
|
TMOTLDRLMX
|
Engine temperature in LDRLMX after selection (tmot/tmkic/tmki)
|-
|
TOEL
|
Oil temperature
|-
|
TOELLDRLMX
|
Oil temperature in LDRLMX after selection (tolc/toel/TOLEWRLMX)
|-
|
TOLC
|
Oil temperature from instrument cluster message
|-
|
TSEL
|
Selected temperature (tans/tumc)
|-
|
TUMC
|
Ambient temperature from CAN-cluster
|-
|
VFZG
|
Vehicle speed
|-
|
VSRLMX
|
Additive cylinder charge correction for rlmx from the adjustment system
|-
|
VSTRLX
|
Adjustable value of the maximum cylinder charge for the calibrator/tester
|-
|
WKRMA
|
Average value of the individual cylinder ignition angle retardation
(knock control), general (in emergency mode with safety margin)
|-
|
WKRMDY_W
|
Dynamic average value of the individual cylinder ignition angle
retardation
|-
|
WKRMSTAT_W
|
Quasi-steady state average value of the individual cylinder ignition
angle retardation
|-
|
WKRMSU_W
|
Total value of the dynamic and static average value of the individual
cylinder ignition angle retardation
|}

LDRLMX 3.100 (Calculation of LDR Maximum Cylinder Charge rlmax)

2012-01-29T11:15:13Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

ldrlmx-main LDRLMX function definition

ldrlmx-fldrrx

ldrlmx-sstb

ldrlmx-set

ldrlmx-rlmx-w

ldrlmx-tsel

ldrlmx-frxta-w

ldrlmx-hierarchy

ldrlmx-initialise

LDRLMX 3.100 Function Description

The function LDRLMX calculates the allowed maximum cylinder charge.

In the main path, the maximum charge value dependent on engine speed is given by the characteristic LDRXN. This can be corrected, if necessary, through intervention of the workshop tester.

For this purpose, an additive overboost increase (drlmaxo, delta maximum cylinder charge during overboost) is applied via the knock-control intervention.

On the rlmx path, a multiplicative correction is applied via the characteristic field KFTARX as a function of engine speed and intake air temperature.

Subsequently, there is an intervention via the sub-function FLDRRX as a function of the average ignition angle retardation in knock control (wkrma). This function consists of two parts, a quasi-steady state long-term component (permanent RAM) which takes the fuel octane rating into account, and a dynamic short-term component to take all other perturbations into account.

The low pass of the long-term component is active only above a speed-dependent load threshold RLKRLDA that is representative for fuel adaption. The characteristic field KFFLLDE sets the steady-state reduction.

The low pass of the short-term component works with the difference of the filtered long-term average value (wkrmstat) and the actual average value (wkrma). To avoid conflicting interventions from both the aforementioned components, the minimum difference is limited to zero.

The associated drawdown value is determined by KFFSLDE.

The overboost path is corrected separately, by a dependence on the sum of both low-pass outputs (wkrmsu) and the speed of the associated drawdown is determined via KFFLDEO.

The time constants of the two components are each separated into predetermined up-regulating and down-regulating speed dependencies.

Further on down the main pathway, the maximum cylinder charge is limited by an external pressure dependency to avoid overloading the turbocharger at high altitudes.

This limit (maximum compressor pressure ratio) which is engine speed and tsel (tans/tumc)-dependent is determined via KFLDHBN, by multiplying the external pressure by the maximum absolute pressure and then using pirg_w and fupsrl_w to convert to a cylinder charge level.

When an ambient temperature sensor is present, the map KFLDHBN is addressed with the ambient temperature through the system constant SY_TFUMG and CWRLMX = 1 and to the instrument cluster via CAN. If no ambient temperature sensor is available or CWRLMX = 0, the map KFLDHBN is addressed with tans.

Via the system constants SY_TFMO, SY_GGGTS the oil temperature (toel) or the cooling water temperature from the instrument cluster (tmki) are read by sensors, whose signal is evaluated in functions %GGTOL or %GGGTS. If the respective variables are available via the CAN (tolc or tmkic) then switching to the CAN-variables will occur or, in case of failure, to surrogate values.

If a system failure is detected, an additional engine speed dependent (pressure) limitation (LDPBN) comes into force, which is analogous to the altitude limitation on the cylinder charge level. Switching back only occurs when resetting the tripping fault and in idle mode (B_ll).

In the overboost condition (E_ldo) an engine speed dependent limit (LDORXN) is switched in so that both the engine and the turbocharger adequately protected. Switching back also occurs only when resetting the error (E_ldo) and in idle-mode (B_ll).

LDRLMX 3.100 Application Notes

[B]LDRXN[/B]: It must be ensured that even at speeds below the turbocharger response speed meaningful rlmax-values (about 10% above the value of throttle plate at full open test bench) can be specified. Above the turbocharger response speed, the regular allowable and desired rlmax values are defined in this characteristic.

[B]LDORXN[/B]: maximum allowable cylinder charge, such that there is sufficient protection by an appropriately strong throttling of the throttle and turbocharger. (Remove the wastegate pressure hose during application!)

[B]LDPBN[/B]: pressure relief in case of diagnosis (sudden torque drop should be no larger than about 15%).

[B]KFLDHBN[/B]: Firstly, in the compressor performance map, acquire the regular full load line at speed sample points of KFLDHBN as well as the maximum pressure ratio line (due to the surge limit, maximum turbocharger-speed or prohibited areas of poor efficiency) to define the operational limit.

Then one carries on the height gradients from the normal full load line starting, at any engine speed, up to an operating limit.

This increases with increasing altitude (decreasing ambient pressure) of the volume flow rate and the pressure ratio with 1013/ambient pressure.

This new intersection then defines the maximum pressure ratio for KFLDHBN at the respective engine speed.

Attention! It must be ensured through appropriate application of RLKRLDA and LDRXN that the operating range of the long-time filter (rl > RLKRLDA) can always be reached! Otherwise, it might happen that a very large decrease will be locked in the long-term component itself and no new adaptation can take place.

All other values are highly dependent on the project.

Basic data input

ATTENTION applicators, these data are extremely project-specific and must be verified in each project application! Please note carefully or risk engine damage! In order to achieve the same functionality as in LDRLMX 3.70 in the absence of CAN message from the instrument cluster, note the following.

{| border="1"
|-
|
SY_TFMO
|
SY_GGGTS
|
Remark
|-
|
0
|
0
|
FKRXTOL and KFFKRXTM set = 1 >= frxt = 1
|-
|
1
|
0
|
FKRXTOL
set to a maximum value >= frxt = output KFFKRXTM
|-
|
0
|
1
|
KFFKRXTM set to a maximum value >= frxt = output FKRXTOL
|}

LDRXN: 140%

LDORXN: 15%

LDPBN: 1500 mbar

KFLDHBN: from low engine speed 1.9 to medium engine speed (2500 rpm) constant 2.5

FKRXTOL: 1.0 (1.0 does not limit the boost pressure control)

KFFKRXTM: 1.0 (1.0 does not limit the boost pressure control)

KFFLDEO: 1.0 (1.0 does not limit the boost pressure control)

KFFSLDE: 1.0 (1.0 does not limit the boost pressure control)

KFFLLDE: 1.0 (1.0 does not limit the boost pressure control)

KFFWLLDE: 1.0 (1.0 does not limit the boost pressure control)

KFTARX: data values of 1.0 below IAT of 75°C. Data values linearly reduced from 1.0 to 0.8 between 75°C and 120°C)

KFTARXZK: about 10% less than KFTARX

LDRXNZK: about 15% less than LDRXN

RLKRLDA: ca. 0.6 x LDRXN (the greatest possible relative load reduction must be greater than the value from RLKRLDA otherwise there will be a risk of dead lock!)

TLKRLDAB: ca. 3-5 seconds

TLKRLDAU: ca. 5-7 seconds

TSKRLDAB: 1-2 seconds

TSKRLDAU: 2-4 seconds

CWRLMX: 1 (Addressing of KFLDHBN via ambient temperature in instrument cluster (tumc)).

CWRLMX: 0 (Addressing of KFLDHBN via intake air temperature (tans)).

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CWRLMX
|
Codeword for LDRLMX (boost pressure control)
|-
|
FKRXTOL
|
Factor for correction of rlmax at higher engine oil temperature
|-
|
KFFKRXTM
|
Factor for correction of rlmax at higher engine temperature
|-
|
KFFLDEO
|
Factor for boost pressure intervention at overboost value via knock
control
|-
|
KFFLLDE
|
Factor for slow boost pressure control intervention at rlmax via knock
control
|-
|
KFFSLDE
|
Factor for fast boost pressure control intervention (lowering)
|-
|
KFFWLLDE
|
Weighting factor for slow boost pressure intervention at rlmax via knock
control
|-
|
KFLDHBN
|
Boost pressure control upper limit (maximum compressor pressure ratio)
|-
|
KFTARX
|
Map for maximum cylinder charge IAT correction factor
|-
|
KFTARXZK
|
Map for maximum cylinder charge IAT correction factor during continuous
knock
|-
|
LDORXN
|
Maximum cylinder charge LDR during E_ldo (overboost error)
|-
|
LDPBN
|
Charge pressure control P-limit when engine temperature is too high
|-
|
LDRXN
|
Maximum cylinder charge (charge pressure control)
|-
|
LDRXNZK
|
Maximum cylinder charge during continuous knock (charge pressure control)
|-
|
RLKRLDA
|
RL-threshold for slow charge pressure control intervention (adaption)
|-
|
SNM08LDUB
|
Sample point distribution for charge pressure control
|-
|
SNM08LDUW
|
Sample point distribution for charge pressure control
|-
|
SNM12LDUW
|
Sample point distribution for charge pressure control
|-
|
STA08LDUB
|
Sample point distribution for charge pressure control
|-
|
SWK08LDUW
|
Sample point distribution for charge pressure control
|-
|
SWK108LDUW
|
Sample point distribution for charge pressure control
|-
|
SWK208LDUW
|
Sample point distribution for charge pressure control
|-
|
SY_ATR
|
System constant: exhaust gas temperature control available
|-
|
SY_GGGTS
|
System constant: temperature transducer signal accuracy
|-
|
SY_TFMO
|
System constant: TOEL-sensor present (Initial. GGTFM surrogate value)
|-
|
SY_TFUMG
|
System constant: ambient temperature sensor present
|-
|
SY TRLX
|
System constant: intervention for workshop tester for rlmax present
|-
|
TLKRLDAB
|
Time constant for slow LDR-reduction
|-
|
TLKRLDAU
|
Time constant for slow LDR-up regulation
|-
|
TMOTMX
|
Engine temperature threshold for initial filling of the fuel system
|-
|
TOELMX
|
Oil temperature threshold for engine protection during transmission
emergency
|-
|
TOLEWRLMX
|
Surrogate oil temperature value with faulty CAN-message
|-
|
TSKRLDAB
|
Time constant for fast charge pressure control lowering
|-
|
TSKRLDAU
|
Time constant for fast charge pressure control up-regulation
|-
|
Variable
|
Description
|-
|
B_ATRF
|
Condition: exhaust gas temperature control error
|-
|
B_ATSB
|
Condition: exhaust gas temperature sensor operational
|-
|
B_BRLMX
|
Condition: charge pressure control limit for maximum cylinder charge
|-
|
B_CKIEN
|
Condition: CAN-transmission from instrument cluster enable
|-
|
B_KFZK
|
Condition: map for knock protection
|-
|
B_LL
|
Condition: idle
|-
|
B_PWF
|
Condition: power fail
|-
|
B_TMKIB
|
Condition: engine temperature from the instrument cluster operational
|-
|
B_TOLCB
|
Condition: oil temperature from instrument cluster can be evaluated
|-
|
B_TUMCB
|
Condition: error in CAN-ambient temperature information
|-
|
DFP_ATS
|
ECU internal error path number: exhaust temperature sensor, cylinder bank
1
|-
|
DFP_ATS2
|
ECU internal error path number: exhaust temperature sensor, cylinder bank
2
|-
|
DFP_LDO
|
ECU internal error path number: overboost charge pressure control
|-
|
DFP_TA
|
ECU internal error path number: intake air temperature TANS (-charge air)
|-
|
DFP_TM
|
ECU internal error path number: engine temperature
|-
|
DFP_TMKI
|
ECU internal error path number: engine temperature from the instrument
cluster
|-
|
DFP_TOL
|
ECU internal error path number: oil temperature
|-
|
DRLMAXO
|
Delta maximum cylinder charge during overboost
|-
|
DWKRM_W
|
Difference: wkrm - wkrmstat
|-
|
E_ATS
|
Error flag: exhaust gas temperature sensor, cylinder bank 1
|-
|
E_ATS2
|
Error flag: exhaust gas temperatur sensor, cylinder bank 2
|-
|
E_LDO
|
Error flag: charge pressure characteristic; upper value exceeded
|-
|
E_TA
|
Error flag: intake air temperature
|-
|
E_TM
|
Error flag: engine temperature
|-
|
E_TMKI
|
Error flag: engine temperature from the instrument cluster
|-
|
E_TOL
|
Error flag: oil temperature
|-
|
FLDRRX_W
|
Correction factor for maximum cylinder charge from knock control
|-
|
FLDRXK_W
|
Factor for LDR rlmax-correction via the short-time part
|-
|
FLDRXL_W
|
Factor for LDR rlmax-correction via the long-time part
|-
|
FLDRXO_W
|
Factor for charge pressure lowering of the overboost values (drlmaxo)
|-
|
FRXT
|
Factor for correction of rlmx as a function of tmki and tol
|-
|
FRXTA_W
|
Factor for correction of rlmx as a function of intake air temperature
|-
|
FUPSRL_W
|
Factor for system-related conversion of pressure to cylinder charge (16-Bit)
|-
|
LDRLMS_W
|
Limiting value for maximum cylinder charge LDR for engine protection
|-
|
LDRLTS_W
|
Limting value for maximum cylinder charge LDR for turbocharger protection
|-
|
NMOT
|
Engine speed
|-
|
NMOT W
|
Engine speed (word)
|-
|
PIRG_W
|
Partial pressure of residual gas internal exhaust gas recirculation
(16-Bit)
|-
|
PU
|
Ambient pressure
|-
|
RL
|
Relative cylinder charge
|-
|
RLMAX_W
|
Maximum permitted charge at the turbo
|-
|
RLMXKO_W
|
Maximum corrected cylinder charge (without limitations)
|-
|
RLMX_W
|
Rohwert maximum cylinder charge
|-
|
TANS
|
Intake air temperature
|-
|
TMKI
|
Engine temperature from the instrument cluster
|-
|
TMOT
|
Engine temperature
|-
|
TMOTLDRLMX
|
Engine temperature in LDRLMX after selection (tmot/tmkic/tmki)
|-
|
TOEL
|
Oil temperature
|-
|
TOELLDRLMX
|
Oil temperature in LDRLMX after selection (tolc/toel/TOLEWRLMX)
|-
|
TOLC
|
Oil temperature from instrument cluster message
|-
|
TSEL
|
Selected temperature (tans/tumc)
|-
|
TUMC
|
Ambient temperature from CAN-cluster
|-
|
VFZG
|
Vehicle speed
|-
|
VSRLMX
|
Additive cylinder charge correction for rlmx from the adjustment system
|-
|
VSTRLX
|
Adjustable value of the maximum cylinder charge for the calibrator/tester
|-
|
WKRMA
|
Average value of the individual cylinder ignition angle retardation
(knock control), general (in emergency mode with safety margin)
|-
|
WKRMDY_W
|
Dynamic average value of the individual cylinder ignition angle
retardation
|-
|
WKRMSTAT_W
|
Quasi-steady state average value of the individual cylinder ignition
angle retardation
|-
|
WKRMSU_W
|
Total value of the dynamic and static average value of the individual
cylinder ignition angle retardation
|}

LDRLMX 3.100 (Calculation of LDR Maximum Cylinder Charge rlmax)

2012-01-29T11:13:39Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

ldrlmx-main LDRLMX function definition

ldrlmx-fldrrx

ldrlmx-sstb

ldrlmx-set

ldrlmx-rlmx-w

ldrlmx-tsel

ldrlmx-frxta-w

ldrlmx-hierarchy

ldrlmx-initialise

LDRLMX 3.100 Function Description

The function LDRLMX calculates the allowed maximum cylinder charge.

In the main path, the maximum charge value dependent on engine speed is given by the characteristic LDRXN. This can be corrected, if necessary, through intervention of the workshop tester.

For this purpose, an additive overboost increase (drlmaxo, delta maximum cylinder charge during overboost) is applied via the knock-control intervention.

On the rlmx path, a multiplicative correction is applied via the characteristic field KFTARX as a function of engine speed and intake air temperature.

Subsequently, there is an intervention via the sub-function FLDRRX as a function of the average ignition angle retardation in knock control (wkrma). This function consists of two parts, a quasi-steady state long-term component (permanent RAM) which takes the fuel octane rating into account, and a dynamic short-term component to take all other perturbations into account.

The low pass of the long-term component is active only above a speed-dependent load threshold RLKRLDA that is representative for fuel adaption. The characteristic field KFFLLDE sets the steady-state reduction.

The low pass of the short-term component works with the difference of the filtered long-term average value (wkrmstat) and the actual average value (wkrma). To avoid interference of opposing interventions from both the aforementioned components, the minimum difference is limited to zero.

The associated drawdown value is determined by KFFSLDE.

The overboost path is corrected separately, by a dependence on the sum of both low-pass outputs (wkrmsu) and the speed of the associated drawdown is determined via KFFLDEO.

The time constants of the two components are each separated into predetermined up-regulating and down-regulating speed dependencies.

Further on down the main pathway, the maximum cylinder charge is limited by an external pressure dependency to avoid overloading the turbocharger at high altitudes.

This limit (maximum compressor pressure ratio) which is engine speed and tsel (tans/tumc)-dependent is determined via KFLDHBN, by multiplying the external pressure by the maximum absolute pressure and then using pirg_w and fupsrl_w to convert to a cylinder charge level.

When an ambient temperature sensor is present, the map KFLDHBN is addressed with the ambient temperature through the system constant SY_TFUMG and CWRLMX = 1 and to the instrument cluster via CAN. If no ambient temperature sensor is available or CWRLMX = 0, the map KFLDHBN is addressed with tans.

Via the system constants SY_TFMO, SY_GGGTS the oil temperature (toel) or the cooling water temperature from the instrument cluster (tmki) are read by sensors, whose signal is evaluated in functions %GGTOL or %GGGTS. If the respective variables are available via the CAN (tolc or tmkic) then switching to the CAN-variables will occur or, in case of failure, to surrogate values.

If a system failure is detected, an additional engine speed dependent (pressure) limitation (LDPBN) comes into force, which is analogous to the altitude limitation on the cylinder charge level. Switching back only occurs when resetting the tripping fault and in idle mode (B_ll).

In the overboost condition (E_ldo) an engine speed dependent limit (LDORXN) is switched in so that both the engine and the turbocharger adequately protected. Switching back also occurs only when resetting the error (E_ldo) and in idle-mode (B_ll).

LDRLMX 3.100 Application Notes

[B]LDRXN[/B]: It must be ensured that even at speeds below the turbocharger response speed meaningful rlmax-values (about 10% above the value of throttle plate at full open test bench) can be specified. Above the turbocharger response speed, the regular allowable and desired rlmax values are defined in this characteristic.

[B]LDORXN[/B]: maximum allowable cylinder charge, such that there is sufficient protection by an appropriately strong throttling of the throttle and turbocharger. (Remove the wastegate pressure hose during application!)

[B]LDPBN[/B]: pressure relief in case of diagnosis (sudden torque drop should be no larger than about 15%).

[B]KFLDHBN[/B]: Firstly, in the compressor performance map, acquire the regular full load line at speed sample points of KFLDHBN as well as the maximum pressure ratio line (due to the surge limit, maximum turbocharger-speed or prohibited areas of poor efficiency) to define the operational limit.

Then one carries on the height gradients from the normal full load line starting, at any engine speed, up to an operating limit.

This increases with increasing altitude (decreasing ambient pressure) of the volume flow rate and the pressure ratio with 1013/ambient pressure.

This new intersection then defines the maximum pressure ratio for KFLDHBN at the respective engine speed.

Attention! It must be ensured through appropriate application of RLKRLDA and LDRXN that the operating range of the long-time filter (rl > RLKRLDA) can always be reached! Otherwise, it might happen that a very large decrease will be locked in the long-term component itself and no new adaptation can take place.

All other values are highly dependent on the project.

Basic data input

ATTENTION applicators, these data are extremely project-specific and must be verified in each project application! Please note carefully or risk engine damage! In order to achieve the same functionality as in LDRLMX 3.70 in the absence of CAN message from the instrument cluster, note the following.

{| border="1"
|-
|
SY_TFMO
|
SY_GGGTS
|
Remark
|-
|
0
|
0
|
FKRXTOL and KFFKRXTM set = 1 >= frxt = 1
|-
|
1
|
0
|
FKRXTOL
set to a maximum value >= frxt = output KFFKRXTM
|-
|
0
|
1
|
KFFKRXTM set to a maximum value >= frxt = output FKRXTOL
|}

LDRXN: 140%

LDORXN: 15%

LDPBN: 1500 mbar

KFLDHBN: from low engine speed 1.9 to medium engine speed (2500 rpm) constant 2.5

FKRXTOL: 1.0 (1.0 does not limit the boost pressure control)

KFFKRXTM: 1.0 (1.0 does not limit the boost pressure control)

KFFLDEO: 1.0 (1.0 does not limit the boost pressure control)

KFFSLDE: 1.0 (1.0 does not limit the boost pressure control)

KFFLLDE: 1.0 (1.0 does not limit the boost pressure control)

KFFWLLDE: 1.0 (1.0 does not limit the boost pressure control)

KFTARX: data values of 1.0 below IAT of 75°C. Data values linearly reduced from 1.0 to 0.8 between 75°C and 120°C)

KFTARXZK: about 10% less than KFTARX

LDRXNZK: about 15% less than LDRXN

RLKRLDA: ca. 0.6 x LDRXN (the greatest possible relative load reduction must be greater than the value from RLKRLDA otherwise there will be a risk of dead lock!)

TLKRLDAB: ca. 3-5 seconds

TLKRLDAU: ca. 5-7 seconds

TSKRLDAB: 1-2 seconds

TSKRLDAU: 2-4 seconds

CWRLMX: 1 (Addressing of KFLDHBN via ambient temperature in instrument cluster (tumc)).

CWRLMX: 0 (Addressing of KFLDHBN via intake air temperature (tans)).

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CWRLMX
|
Codeword for LDRLMX (boost pressure control)
|-
|
FKRXTOL
|
Factor for correction of rlmax at higher engine oil temperature
|-
|
KFFKRXTM
|
Factor for correction of rlmax at higher engine temperature
|-
|
KFFLDEO
|
Factor for boost pressure intervention at overboost value via knock
control
|-
|
KFFLLDE
|
Factor for slow boost pressure control intervention at rlmax via knock
control
|-
|
KFFSLDE
|
Factor for fast boost pressure control intervention (lowering)
|-
|
KFFWLLDE
|
Weighting factor for slow boost pressure intervention at rlmax via knock
control
|-
|
KFLDHBN
|
Boost pressure control upper limit (maximum compressor pressure ratio)
|-
|
KFTARX
|
Map for maximum cylinder charge IAT correction factor
|-
|
KFTARXZK
|
Map for maximum cylinder charge IAT correction factor during continuous
knock
|-
|
LDORXN
|
Maximum cylinder charge LDR during E_ldo (overboost error)
|-
|
LDPBN
|
Charge pressure control P-limit when engine temperature is too high
|-
|
LDRXN
|
Maximum cylinder charge (charge pressure control)
|-
|
LDRXNZK
|
Maximum cylinder charge during continuous knock (charge pressure control)
|-
|
RLKRLDA
|
RL-threshold for slow charge pressure control intervention (adaption)
|-
|
SNM08LDUB
|
Sample point distribution for charge pressure control
|-
|
SNM08LDUW
|
Sample point distribution for charge pressure control
|-
|
SNM12LDUW
|
Sample point distribution for charge pressure control
|-
|
STA08LDUB
|
Sample point distribution for charge pressure control
|-
|
SWK08LDUW
|
Sample point distribution for charge pressure control
|-
|
SWK108LDUW
|
Sample point distribution for charge pressure control
|-
|
SWK208LDUW
|
Sample point distribution for charge pressure control
|-
|
SY_ATR
|
System constant: exhaust gas temperature control available
|-
|
SY_GGGTS
|
System constant: temperature transducer signal accuracy
|-
|
SY_TFMO
|
System constant: TOEL-sensor present (Initial. GGTFM surrogate value)
|-
|
SY_TFUMG
|
System constant: ambient temperature sensor present
|-
|
SY TRLX
|
System constant: intervention for workshop tester for rlmax present
|-
|
TLKRLDAB
|
Time constant for slow LDR-reduction
|-
|
TLKRLDAU
|
Time constant for slow LDR-up regulation
|-
|
TMOTMX
|
Engine temperature threshold for initial filling of the fuel system
|-
|
TOELMX
|
Oil temperature threshold for engine protection during transmission
emergency
|-
|
TOLEWRLMX
|
Surrogate oil temperature value with faulty CAN-message
|-
|
TSKRLDAB
|
Time constant for fast charge pressure control lowering
|-
|
TSKRLDAU
|
Time constant for fast charge pressure control up-regulation
|-
|
Variable
|
Description
|-
|
B_ATRF
|
Condition: exhaust gas temperature control error
|-
|
B_ATSB
|
Condition: exhaust gas temperature sensor operational
|-
|
B_BRLMX
|
Condition: charge pressure control limit for maximum cylinder charge
|-
|
B_CKIEN
|
Condition: CAN-transmission from instrument cluster enable
|-
|
B_KFZK
|
Condition: map for knock protection
|-
|
B_LL
|
Condition: idle
|-
|
B_PWF
|
Condition: power fail
|-
|
B_TMKIB
|
Condition: engine temperature from the instrument cluster operational
|-
|
B_TOLCB
|
Condition: oil temperature from instrument cluster can be evaluated
|-
|
B_TUMCB
|
Condition: error in CAN-ambient temperature information
|-
|
DFP_ATS
|
ECU internal error path number: exhaust temperature sensor, cylinder bank
1
|-
|
DFP_ATS2
|
ECU internal error path number: exhaust temperature sensor, cylinder bank
2
|-
|
DFP_LDO
|
ECU internal error path number: overboost charge pressure control
|-
|
DFP_TA
|
ECU internal error path number: intake air temperature TANS (-charge air)
|-
|
DFP_TM
|
ECU internal error path number: engine temperature
|-
|
DFP_TMKI
|
ECU internal error path number: engine temperature from the instrument
cluster
|-
|
DFP_TOL
|
ECU internal error path number: oil temperature
|-
|
DRLMAXO
|
Delta maximum cylinder charge during overboost
|-
|
DWKRM_W
|
Difference: wkrm - wkrmstat
|-
|
E_ATS
|
Error flag: exhaust gas temperature sensor, cylinder bank 1
|-
|
E_ATS2
|
Error flag: exhaust gas temperatur sensor, cylinder bank 2
|-
|
E_LDO
|
Error flag: charge pressure characteristic; upper value exceeded
|-
|
E_TA
|
Error flag: intake air temperature
|-
|
E_TM
|
Error flag: engine temperature
|-
|
E_TMKI
|
Error flag: engine temperature from the instrument cluster
|-
|
E_TOL
|
Error flag: oil temperature
|-
|
FLDRRX_W
|
Correction factor for maximum cylinder charge from knock control
|-
|
FLDRXK_W
|
Factor for LDR rlmax-correction via the short-time part
|-
|
FLDRXL_W
|
Factor for LDR rlmax-correction via the long-time part
|-
|
FLDRXO_W
|
Factor for charge pressure lowering of the overboost values (drlmaxo)
|-
|
FRXT
|
Factor for correction of rlmx as a function of tmki and tol
|-
|
FRXTA_W
|
Factor for correction of rlmx as a function of intake air temperature
|-
|
FUPSRL_W
|
Factor for system-related conversion of pressure to cylinder charge (16-Bit)
|-
|
LDRLMS_W
|
Limiting value for maximum cylinder charge LDR for engine protection
|-
|
LDRLTS_W
|
Limting value for maximum cylinder charge LDR for turbocharger protection
|-
|
NMOT
|
Engine speed
|-
|
NMOT W
|
Engine speed (word)
|-
|
PIRG_W
|
Partial pressure of residual gas internal exhaust gas recirculation
(16-Bit)
|-
|
PU
|
Ambient pressure
|-
|
RL
|
Relative cylinder charge
|-
|
RLMAX_W
|
Maximum permitted charge at the turbo
|-
|
RLMXKO_W
|
Maximum corrected cylinder charge (without limitations)
|-
|
RLMX_W
|
Rohwert maximum cylinder charge
|-
|
TANS
|
Intake air temperature
|-
|
TMKI
|
Engine temperature from the instrument cluster
|-
|
TMOT
|
Engine temperature
|-
|
TMOTLDRLMX
|
Engine temperature in LDRLMX after selection (tmot/tmkic/tmki)
|-
|
TOEL
|
Oil temperature
|-
|
TOELLDRLMX
|
Oil temperature in LDRLMX after selection (tolc/toel/TOLEWRLMX)
|-
|
TOLC
|
Oil temperature from instrument cluster message
|-
|
TSEL
|
Selected temperature (tans/tumc)
|-
|
TUMC
|
Ambient temperature from CAN-cluster
|-
|
VFZG
|
Vehicle speed
|-
|
VSRLMX
|
Additive cylinder charge correction for rlmx from the adjustment system
|-
|
VSTRLX
|
Adjustable value of the maximum cylinder charge for the calibrator/tester
|-
|
WKRMA
|
Average value of the individual cylinder ignition angle retardation
(knock control), general (in emergency mode with safety margin)
|-
|
WKRMDY_W
|
Dynamic average value of the individual cylinder ignition angle
retardation
|-
|
WKRMSTAT_W
|
Quasi-steady state average value of the individual cylinder ignition
angle retardation
|-
|
WKRMSU_W
|
Total value of the dynamic and static average value of the individual
cylinder ignition angle retardation
|}

LDRLMX 3.100 (Calculation of LDR Maximum Cylinder Charge rlmax)

2012-01-29T11:10:11Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

ldrlmx-main LDRLMX function definition

ldrlmx-fldrrx

ldrlmx-sstb

ldrlmx-set

ldrlmx-rlmx-w

ldrlmx-tsel

ldrlmx-frxta-w

ldrlmx-hierarchy

ldrlmx-initialise

LDRLMX 3.100 Function Description

The function LDRLMX calculates the allowed maximum cylinder charge.

In the main path, the maximum charge value dependent on engine speed is given by the characteristic LDRXN. This can be corrected, if necessary, through intervention of the workshop tester.

For this purpose, an additive overboost increase (drlmaxo, delta maximum cylinder charge during overboost) is applied via the knock-control intervention.

On the rlmx path, a multiplicative correction is applied via the characteristic field KFTARX as a function of engine speed and intake air temperature.

Subsequently, there is an intervention via the sub-function FLDRRX as a function of the average ignition angle retardation in knock control (wkrma). This function consists of two parts, a quasi-steady state long-term component (permanent RAM) which takes the fuel octane rating into account, and a dynamic short-term component to take all other perturbations into account.

The low pass of the long-time part is active only above a speed-dependent load threshold RLKRLDA that is representative for fuel adaption. The characteristic field KFFLLDE sets the steady-state reduction.

The low pass of the short-time part works with the difference of the filtered long-time average value (wkrmstat) and the actual average value (wkrma). To avoid interference of opposing interventions from both the aforementioned components, the minimum difference is limited to zero.

The associated drawdown value is determined by KFFSLDE.

The overboost path is corrected separately, by a dependence on the sum of both low-pass outputs (wkrmsu) and the speed of the associated drawdown is determined via KFFLDEO.

The time constants of the two components are each separated into predetermined up-regulating and down-regulating speed dependencies.

Further on down the main pathway, the maximum cylinder charge is limited by an external pressure dependency to avoid overloading the turbocharger at high altitudes.

This limit (maximum compressor pressure ratio) which is engine speed and tsel (tans/tumc)-dependent is determined via KFLDHBN, by multiplying the external pressure by the maximum absolute pressure and then using pirg_w and fupsrl_w to convert to a cylinder charge level.

When an ambient temperature sensor is present, the map KFLDHBN is addressed with the ambient temperature through the system constant SY_TFUMG and CWRLMX = 1 and to the instrument cluster via CAN. If no ambient temperature sensor is available or CWRLMX = 0, the map KFLDHBN is addressed with tans.

Via the system constants SY_TFMO, SY_GGGTS the oil temperature (toel) or the cooling water temperature from the instrument cluster (tmki) are read by sensors, whose signal is evaluated in functions %GGTOL or %GGGTS. If the respective variables are available via the CAN (tolc or tmkic) then switching to the CAN-variables will occur or, in case of failure, to surrogate values.

If a system failure is detected, an additional engine speed dependent (pressure) limitation (LDPBN) comes into force, which is analogous to the altitude limitation on the cylinder charge level. Switching back only occurs when resetting the tripping fault and in idle mode (B_ll).

In the overboost condition (E_ldo) an engine speed dependent limit (LDORXN) is switched in so that both the engine and the turbocharger adequately protected. Switching back also occurs only when resetting the error (E_ldo) and in idle-mode (B_ll).

LDRLMX 3.100 Application Notes

[B]LDRXN[/B]: It must be ensured that even at speeds below the turbocharger response speed meaningful rlmax-values (about 10% above the value of throttle plate at full open test bench) can be specified. Above the turbocharger response speed, the regular allowable and desired rlmax values are defined in this characteristic.

[B]LDORXN[/B]: maximum allowable cylinder charge, such that there is sufficient protection by an appropriately strong throttling of the throttle and turbocharger. (Remove the wastegate pressure hose during application!)

[B]LDPBN[/B]: pressure relief in case of diagnosis (sudden torque drop should be no larger than about 15%).

[B]KFLDHBN[/B]: Firstly, in the compressor performance map, acquire the regular full load line at speed sample points of KFLDHBN as well as the maximum pressure ratio line (due to the surge limit, maximum turbocharger-speed or prohibited areas of poor efficiency) to define the operational limit.

Then one carries on the height gradients from the normal full load line starting, at any engine speed, up to an operating limit.

This increases with increasing altitude (decreasing ambient pressure) of the volume flow rate and the pressure ratio with 1013/ambient pressure.

This new intersection then defines the maximum pressure ratio for KFLDHBN at the respective engine speed.

Attention!

It must be ensured through appropriate application of RLKRLDA and LDRXN that the operating range of the long-time filter (rl > RLKRLDA) can always be reached!

Otherwise, it might happen that a very large decrease will be locked in the long-term component itself and no new adaptation can take place.

All other values are highly dependent on the project.

Basic data input

ATTENTION applicators, these data are extremely project-specific and must be verified in each project application!

Please note carefully or risk engine damage!

In order to achieve the same functionality as in LDRLMX 3.70 in the absence of CAN message from the instrument cluster, note the following.

{| border="1"
|-
|
SY_TFMO
|
SY_GGGTS
|
Remark
|-
|
0
|
0
|
FKRXTOL and KFFKRXTM set = 1 >= frxt = 1
|-
|
1
|
0
|
FKRXTOL
set to a maximum value >= frxt = output KFFKRXTM
|-
|
0
|
1
|
KFFKRXTM set to a maximum value >= frxt = output FKRXTOL
|}

LDRXN: 140%

LDORXN: 15%

LDPBN: 1500 mbar

KFLDHBN: from low engine speed 1.9 to medium engine speed (2500 rpm) constant 2.5

FKRXTOL: 1.0 (1.0 does not limit the boost pressure control)

KFFKRXTM: 1.0 (1.0 does not limit the boost pressure control)

KFFLDEO: 1.0 (1.0 does not limit the boost pressure control)

KFFSLDE: 1.0 (1.0 does not limit the boost pressure control)

KFFLLDE: 1.0 (1.0 does not limit the boost pressure control)

KFFWLLDE: 1.0 (1.0 does not limit the boost pressure control)

KFTARX: data values of 1.0 below IAT of 75°C. Data values linearly reduced from 1.0 to 0.8 between 75°C and 120°C)

KFTARXZK: about 10% less than KFTARX

LDRXNZK: about 15% less than LDRXN

RLKRLDA: ca. 0.6 x LDRXN (the greatest possible relative load reduction must be greater than the value from RLKRLDA otherwise there will be a risk of dead lock!)

TLKRLDAB: ca. 3-5 seconds

TLKRLDAU: ca. 5-7 seconds

TSKRLDAB: 1-2 seconds

TSKRLDAU: 2-4 seconds

CWRLMX: 1 (Addressing of KFLDHBN via ambient temperature in instrument cluster (tumc)).

CWRLMX: 0 (Addressing of KFLDHBN via intake air temperature (tans)).

[u]Abbreviations[/u]

{| border="1"
|-
|
Parameter
|
Description
|-
|
CWRLMX
|
Codeword for LDRLMX (boost pressure control)
|-
|
FKRXTOL
|
Factor for correction of rlmax at higher engine oil temperature
|-
|
KFFKRXTM
|
Factor for correction of rlmax at higher engine temperature
|-
|
KFFLDEO
|
Factor for boost pressure intervention at overboost value via knock
control
|-
|
KFFLLDE
|
Factor for slow boost pressure control intervention at rlmax via knock
control
|-
|
KFFSLDE
|
Factor for fast boost pressure control intervention (lowering)
|-
|
KFFWLLDE
|
Weighting factor for slow boost pressure intervention at rlmax via knock
control
|-
|
KFLDHBN
|
Boost pressure control upper limit (maximum compressor pressure ratio)
|-
|
KFTARX
|
Map for maximum cylinder charge IAT correction factor
|-
|
KFTARXZK
|
Map for maximum cylinder charge IAT correction factor during continuous
knock
|-
|
LDORXN
|
Maximum cylinder charge LDR during E_ldo (overboost error)
|-
|
LDPBN
|
Charge pressure control P-limit when engine temperature is too high
|-
|
LDRXN
|
Maximum cylinder charge (charge pressure control)
|-
|
LDRXNZK
|
Maximum cylinder charge during continuous knock (charge pressure control)
|-
|
RLKRLDA
|
RL-threshold for slow charge pressure control intervention (adaption)
|-
|
SNM08LDUB
|
Sample point distribution for charge pressure control
|-
|
SNM08LDUW
|
Sample point distribution for charge pressure control
|-
|
SNM12LDUW
|
Sample point distribution for charge pressure control
|-
|
STA08LDUB
|
Sample point distribution for charge pressure control
|-
|
SWK08LDUW
|
Sample point distribution for charge pressure control
|-
|
SWK108LDUW
|
Sample point distribution for charge pressure control
|-
|
SWK208LDUW
|
Sample point distribution for charge pressure control
|-
|
SY_ATR
|
System constant: exhaust gas temperature control available
|-
|
SY_GGGTS
|
System constant: temperature transducer signal accuracy
|-
|
SY_TFMO
|
System constant: TOEL-sensor present (Initial. GGTFM surrogate value)
|-
|
SY_TFUMG
|
System constant: ambient temperature sensor present
|-
|
SY TRLX
|
System constant: intervention for workshop tester for rlmax present
|-
|
TLKRLDAB
|
Time constant for slow LDR-reduction
|-
|
TLKRLDAU
|
Time constant for slow LDR-up regulation
|-
|
TMOTMX
|
Engine temperature threshold for initial filling of the fuel system
|-
|
TOELMX
|
Oil temperature threshold for engine protection during transmission
emergency
|-
|
TOLEWRLMX
|
Surrogate oil temperature value with faulty CAN-message
|-
|
TSKRLDAB
|
Time constant for fast charge pressure control lowering
|-
|
TSKRLDAU
|
Time constant for fast charge pressure control up-regulation
|-
|
Variable
|
Description
|-
|
B_ATRF
|
Condition: exhaust gas temperature control error
|-
|
B_ATSB
|
Condition: exhaust gas temperature sensor operational
|-
|
B_BRLMX
|
Condition: charge pressure control limit for maximum cylinder charge
|-
|
B_CKIEN
|
Condition: CAN-transmission from instrument cluster enable
|-
|
B_KFZK
|
Condition: map for knock protection
|-
|
B_LL
|
Condition: idle
|-
|
B_PWF
|
Condition: power fail
|-
|
B_TMKIB
|
Condition: engine temperature from the instrument cluster operational
|-
|
B_TOLCB
|
Condition: oil temperature from instrument cluster can be evaluated
|-
|
B_TUMCB
|
Condition: error in CAN-ambient temperature information
|-
|
DFP_ATS
|
ECU internal error path number: exhaust temperature sensor, cylinder bank
1
|-
|
DFP_ATS2
|
ECU internal error path number: exhaust temperature sensor, cylinder bank
2
|-
|
DFP_LDO
|
ECU internal error path number: overboost charge pressure control
|-
|
DFP_TA
|
ECU internal error path number: intake air temperature TANS (-charge air)
|-
|
DFP_TM
|
ECU internal error path number: engine temperature
|-
|
DFP_TMKI
|
ECU internal error path number: engine temperature from the instrument
cluster
|-
|
DFP_TOL
|
ECU internal error path number: oil temperature
|-
|
DRLMAXO
|
Delta maximum cylinder charge during overboost
|-
|
DWKRM_W
|
Difference: wkrm - wkrmstat
|-
|
E_ATS
|
Error flag: exhaust gas temperature sensor, cylinder bank 1
|-
|
E_ATS2
|
Error flag: exhaust gas temperatur sensor, cylinder bank 2
|-
|
E_LDO
|
Error flag: charge pressure characteristic; upper value exceeded
|-
|
E_TA
|
Error flag: intake air temperature
|-
|
E_TM
|
Error flag: engine temperature
|-
|
E_TMKI
|
Error flag: engine temperature from the instrument cluster
|-
|
E_TOL
|
Error flag: oil temperature
|-
|
FLDRRX_W
|
Correction factor for maximum cylinder charge from knock control
|-
|
FLDRXK_W
|
Factor for LDR rlmax-correction via the short-time part
|-
|
FLDRXL_W
|
Factor for LDR rlmax-correction via the long-time part
|-
|
FLDRXO_W
|
Factor for charge pressure lowering of the overboost values (drlmaxo)
|-
|
FRXT
|
Factor for correction of rlmx as a function of tmki and tol
|-
|
FRXTA_W
|
Factor for correction of rlmx as a function of intake air temperature
|-
|
FUPSRL_W
|
Factor for system-related conversion of pressure to cylinder charge (16-Bit)
|-
|
LDRLMS_W
|
Limiting value for maximum cylinder charge LDR for engine protection
|-
|
LDRLTS_W
|
Limting value for maximum cylinder charge LDR for turbocharger protection
|-
|
NMOT
|
Engine speed
|-
|
NMOT W
|
Engine speed (word)
|-
|
PIRG_W
|
Partial pressure of residual gas internal exhaust gas recirculation
(16-Bit)
|-
|
PU
|
Ambient pressure
|-
|
RL
|
Relative cylinder charge
|-
|
RLMAX_W
|
Maximum permitted charge at the turbo
|-
|
RLMXKO_W
|
Maximum corrected cylinder charge (without limitations)
|-
|
RLMX_W
|
Rohwert maximum cylinder charge
|-
|
TANS
|
Intake air temperature
|-
|
TMKI
|
Engine temperature from the instrument cluster
|-
|
TMOT
|
Engine temperature
|-
|
TMOTLDRLMX
|
Engine temperature in LDRLMX after selection (tmot/tmkic/tmki)
|-
|
TOEL
|
Oil temperature
|-
|
TOELLDRLMX
|
Oil temperature in LDRLMX after selection (tolc/toel/TOLEWRLMX)
|-
|
TOLC
|
Oil temperature from instrument cluster message
|-
|
TSEL
|
Selected temperature (tans/tumc)
|-
|
TUMC
|
Ambient temperature from CAN-cluster
|-
|
VFZG
|
Vehicle speed
|-
|
VSRLMX
|
Additive cylinder charge correction for rlmx from the adjustment system
|-
|
VSTRLX
|
Adjustable value of the maximum cylinder charge for the calibrator/tester
|-
|
WKRMA
|
Average value of the individual cylinder ignition angle retardation
(knock control), general (in emergency mode with safety margin)
|-
|
WKRMDY_W
|
Dynamic average value of the individual cylinder ignition angle
retardation
|-
|
WKRMSTAT_W
|
Quasi-steady state average value of the individual cylinder ignition
angle retardation
|-
|
WKRMSU_W
|
Total value of the dynamic and static average value of the individual
cylinder ignition angle retardation
|}

LRSHK 9.20 (Continuous Post-Catalyst Lambda Control)

2012-01-16T10:03:12Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

lrshk-lrshk: function overview

lrshk-lrhkini: initialization of the post-catalyst lambda control

lrshk-lrhkebg: general switch conditions post-catalyst lambda control

lrshk-lrhkla: determination of the error signal to lambda level

lrshk-dlahksm: selection of fr-synchronous lambda averaging/filtering by average value/linearizing lrshk-lambda directly

lrshk-lrhkebp: cylinder bank-specific readiness switch

lrshk-lrhkb1: PI controller post-catalyst with activation condition, cylinder bank 1

lrshk-lrhkb2: PI controller post-catalyst with activation condition, cylinder bank 2

lrshk-lrhkeb: cylinder bank-specific enable of proportional and integral components, cylinder bank 1

lrshk-lrhkeb2: cylinder bank-specific enable of proportional and integral components, cylinder bank 2

lrshk-lrhkip: PI controller, cylinder bank 1

lrshk-lrhkip2: PI controller, cylinder bank 2

lrshk-lahkma: fr-synchronous averaging

Function Description

Control with the post-catalyst probe is superimposed on the pre-cat lambda control.

Control action on the pre-catalyst control is via the delta-lambda-correction variables dlahi_w and dlahp_w.

Post-catalyst Control:

This is switched off by setting bit 0 in word CLRSHK code to 1 (FALSE).

PI Control Action

Post-catalyst lambda control is achieved with a PI controller. Control action via the proportional component dlahp_w will be immediate because it has no "memory" of the correct sign with respect to the control position after a change of lambda probe voltage due to enrichment or enleanment by the delta-lambda intervention.

Via the integral component, post-catalyst control LRSHK is able to compensate, to a large extent, for exhaust gas deterioration, caused by a shift of the steady-state probe characteristic.

The LRSHK calculation is carried out continuously on the lambda level. This requires that the probe voltage ushk_w is linearized via the characteristic LALIUSH (lamsonh_w). A similar linearization is performed with the voltage target value USRHK (lamsolh_w). The pseudo-value lamsonh_w can continue to work via the project-specific codeword CLRSHK

(a) directly (--> default in continuous pre-catalyst control, intervention is possible every 10 ms)

(b) via a PT1 filter (--> project-specific)

(c) fr-synchronous averaged (--> default for two-point control, as the ratio can be added only before the fr-jump)

because lamhm_w will supply the control error dlashkm_w.

By assessing the characteristic curves KDLASHKP and KDLASHKI, the control error dlashkm_w can be corrected separately according to the catalyst properties before the calculation of the P and I components.

The resulting skewed control errors dlashkp_w or dlashki_w are now weighting with KPLRHML = f (ml) of the proportional component dlahp_w, or by weighting with KILRHML = f (ml) of the integral component
dlahi_w.

In the case of aged catalysts, control oscillation of the pre-catalyst control imprinting itself on the post-catalyst probe voltage behaviour which, if proportional intervention is left unchanged, can lead to post-catalyst control oscillations. Moreover, catalyst ageing, which is associated with a decrease in the oxygen storage capacity, the need for the proportional control action in post-catalyst control is less important. Therefore, in a further multiplication by the weighting factor from the characteristic PLRHAV = f(avkatf), the proportional component of the post-catalyst control is revoked for aged catalysts.

Effect on LRSHK of the Lambda Probe Diagnostics

Post-catalyst control takes over the additional delta Lambda offsets (dlahki_w --> pre-catalyst actual value offset, dlahkp_w --> pre-catalyst target value offset) from the former control in LRS 15.40. The magnitude of the intervention dlahi_w is a measure of probe ageing and is used in the diagnosis of lambda probe aging. A symmetric increase in the probe response time cannot be detected by dlahi_w.

Control Threshold from Map KFUSHK

If the post-catalyst probe reports that the mixture is, for example, too lean, dlahp_w will be negative according to the selected control direction and dlahi_w will become smaller. Thus, there is an enrichment until ushk goes back up to the control threshold usrhk. In contrast to the pre-cat control, a map is provided for the post-catalyst control threshold. Via the choice of threshold, a slight load or speed-dependent lambda offset can be achieved.

If catalyst diagnostics are required in the short test B_fakat = TRUE is switched to the threshold USRHKFA.

LRSHK Control Dynamics

The superimposed control is significantly slower than the control applied before the catalyst. Since at low air mass flow rates (low load or engine speed point), the post-catalyst probe voltage as a general rule can exhibit more erratic behaviour and oscillations, following low probe voltages it should not be evaluated so strongly here. The time constant of the post-catalyst control depends on the air mass flow rate ml (--> characteristic KILRHML). At high air mass flow rates, the integration rate should be selected higher as a general rule.

Activation Conditions

If post-catalyst control LRSHK is disabled, the learned integrator value dlahi_w up to that point is the output of the post-catalyst controller. Also, when stopping the engine over the value of the continuous RAM.

The activation conditions for the proportional and integral components are defined differently and are indicated by the bits B_lrhkp and B_lrhk.

The following conditions apply for the proportional component:

When pre-catalyst control readiness (B_lr = 1) is detected, LRSHK is enabled after the delay time TBLRH. This is only useful for lambda target values (lamsons_w = 1) of the pre-catalyst control.

Post-catalyst regulation is only activated above a certain catalyst temperature threshold (tkatm > TKATMLRH) and the operational readiness of the post-catalyst probe (B_sbbhk) is activated.

The following additional conditions apply for the integral component:

Thus, the integrator is only disabled when nmot or rl is in the ranges (NLRHU =< nmot =< NLRHO and RLRHUN(nmot) =< rL =< RLRHON(nmot)). The characteristic curves RLRHUN and RLRHON make it possible to select engine speed-dependent rL-limits on the control range. This allows the control range to be defined so that the operational ranges which give rise to incorrect adaptation of post-catalyst control are delineated. This can happen at operating points where, for example, air mass flow rates are too low.

After the overrun fuel cut-off, the catalyst is saturated with oxygen. The post-catalyst probe voltage will retain small, lean values for a certain time. In this phase, the system deactivates the section LRSKA of the post-catalyst control via bit B_lrka.

After the end of catalyst clear out, post-catalyst control is prohibited until the air mass MLNKAX has passed through the catalytic converter.

If the bit B_tehb corresponding to “tank venting high loading” is set, the integral component of LRSHK is deactivated because the integrator would learn wrong values in this case. The proportional component remains active in this case since it helps to reduce exhaust problems.

In addition, a series of diagnostic errors deactivates post-catalyst control.

Dynamic Overshoot of the Control Threshold after Catalyst Clear Out

After the end of catalyst clear out, the post-catalyst probe voltage oscillates significantly higher than the nominal value of 600 mV for typically 5 to 30 s. The probe voltage attains values of 750-800 mV. The overshoot depends on the catalytic properties. With catalyst types that do not exhibit this behavior, the excesscan be applied away.

SCHEMATIC

The probe voltage characteristic ushk and the status bits B_sa (boost cut-off) and B_lrka (catalyst clear out) are illustrated schematically in the diagram above.

Thus the "time" (air mass MLNKAX) during which the post-catalyst control is prohibited can be kept as short as possible, the probe voltage behaviour after catalyst clear over time is described by a dynamic increase in the target value. The input of a quick PT1 filter is populated with LASHKAB and governed by the time constant ZLASHKAB to 0. The time constant is derived from the adopted course of the probe voltage.

Through this function it is possible, in cases in which the catalyst clear out function has not been successful, or a situation in which the pre-catalyst control condition gives rise to a lean post-catalyst probe voltage, the probe voltage can be raised via LRSHK.

Application Notes

LRSHK Application Procedure:

Codeword CLRSHK

The codeword CLRSHK was introduced in order influence the treatment of the adaptation value dlahi_w within the application. The importance of the individual control bits in CLRSHK are described under the block comments.

Sensible combinations, in decimal, are listed below:

CLRSHK = odd: LRSHK is deactivated

CLRSHK = 16: dlahi_w will erase memory errors when reset with the value DLAHIINI, otherwise default status for LRSHK

CLRSHK = 24: dlahi_w is reset with the value DLAHIINI when the engine starts

Parameter LRSHK

The application of LRS must be completed.

4 x 4 grid points are provided for map KFLASOHK:

Suggestion nmot sample points: 1000, 1800, 2400 & 3000 rpm

rL: 14, 42, 56 & 70%

- Lower control limit e.g. NLRHU = 1200 rpm

Characteristic curve RLRHUN is dependent on n

- Upper control limit e.g. NLRHO = 3000 rpm

Characteristic curve RLRHON is dependent on n

The characteristic curves RLRHUN and RLRHON are strongly project-dependent. However, a characteristic with four sample points, which lie between NLRHU and NLRHO should be sufficient.

- TKATMLRH is chosen so as to control catalyst temperatures >300°C. There is a catalyst temperature model (module ATM) which yields catalyst temperatures, tkatm.

- TBLRH is dependent on the catalytic properties and should be at least 1 second to be selected. Via this label, the time that elapses after switching on the lambda control until the post-catalyst probe signal is correlated against the pre-catalyst control scheme is defined.

- KILRHML curve describes the rate of integration of the air mass in %/s.

Reference points for example engine with ml load: 450 kg/hr

ml: 8, 28, 88, 200, 400 kg/hr

KILRHML: 0.0015, 0.003, 0.0045, 0.006 and 0.0075 /s

Characteristic Curves KDLASHKI and KDLASHKP

The control error corresponding to project-specific lambda probes and catalytic converter properties can be defined via the characteristic curves KDLASHKI and KDLASHKP. So firstly, inaccuracies of the probe voltage linearization (LALIUSH) are corrected and secondly, the emissions characteristics of catalytic converters are considered.

Application of the Proportional Component in the LRSHK PI-Control Scheme:

The effective action of the proportional component of the post-catalyst control system is calculated as follows:

dlahp_w = dlashkl x KPLRHML (ml) x PLRHAV (avkatf)

The influence of catalyst ageing is included as a multiplier in the calculation (RAM cell dlahp_w) using a factor from the characteristic curve PLRHAV, as described above. For a new catalytic converter (avkatf at 0.0), PLRHAV is populated with the value 1.0. With increasing amplitude ratio (as the catalyst ages), PLRHAV is returned to 0.0.

The choice of parameters is determined mainly by the properties of the catalyst. When we ask questions in the application development function, please contact us.

Application of the Parameter MLNKAX:

The overshoot voltage of the lambda probe after the end of the catalyst clear out function is a project-specific phenomenon, which disrupts the LRSHK. Therefore, LRSHK should be blocked until the air mass MLNKAX has been enforced. Since there is no experience (especially with the new catalyst types), the definition of the parameters should be consulted in the responsible function for LRSKA.

Application of the Parameter KILRHML:

During application of the map KFLASO in module LRS, the post-catalyst control integration rate will be set by means of the curve KILRHML so that one sample point of the integrator control stroke dlahi_w of +/-0.03 to +/-0.04 is measured. During measurement, the air mass at the respective operating point is noted. After completion of the application of map KFLASO, the set values from KILRHML are plotted against air mass. The air mass is obtained from a scatter plot. The actual curve KILRHML in LRSHK is obtained by averaging the point cloud.

For more detailed information, please refer to the general application note in the module covering Continuous Lambda Control.

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CLRSHK
|
Codeword
to enable LRSHK and select initialization
|-
|
DLAHINI
|
Initial
value of the integrator dlahi in LRSHK, Bank 1
|-
|
DLAHINI2
|
Initial
value of the integrator dlahi in LRSHK, Bank 2
|-
|
KDLASHKI
|
Characteristic
curve of dlashkm, weighting factor for integral component in LRHK, Bank 1
|-
|
KDLASHKI2
|
Characteristic
curve of dlashkm, weighting factor for integral component in LRHK, Bank 2
|-
|
KDLASHKP
|
Characteristic
curve of dlashkm, weighting factor for proportional component in LRHK, Bank 1
|-
|
KDLASHKP2
|
Characteristic
curve of dlashkm, weighting factor for proportional component in LRHK, Bank 2
|-
|
KFUSHK
|
Probe
voltage target value for post-catalyst control (instead KFUSRHK for
Variantenk.)
|-
|
KILRHML
|
Integral
component for LRSHK
|-
|
KPLRHML
|
Proportional
component for LRSHK
|-
|
LALIUSH
|
Lambda
linearization, post-catalyst probe, Bank 1
|-
|
LALIUSH2
|
Lambda
linearization, post-catalyst probe, Bank 2
|-
|
LALIUSRH
|
Lambda
linearization, post-catalyst probe, target value, Bank 1
|-
|
LALIUSRH2
|
Lambda
linearization, post-catalyst probe, target value, Bank 2
|-
|
LASHKAB
|
Initial
value for dynamic target value increase (lamsolh) in LRHK
|-
|
LRHIMN
|
Minimum
limit of the integrator constant in LRHK
|-
|
LRHIMX
|
Maximum
limit of the integrator constant in LRHK
|-
|
MLNKAX
|
Mass
air threshold for activation readiness LRSHK integral component
|-
|
NLRHO
|
Upper
speed limit for post-catalyst control
|-
|
NLRHU
|
Lower
speed limit for post-catalyst control
|-
|
PLRHAV
|
Catalyst ageing
weighting factor for the proportional component in LRHK, Bank 1
|-
|
PLRHAV2
|
Catalyst ageing
weighting factor for the proportional component in LRHK, Bank 1
|-
|
RLLRHON
|
Characteristic
curve of nmot, rL upper control limit for the post-catalyst controller
|-
|
RLLRHUN
|
Characteristic
curve of nmot, rL lower control limit for the post-catalyst controller
|-
|
RLLRHUFA
|
rL
control limit for post-catalyst control functional requirement B_fakat
|-
|
TBLRH
|
Deactivation
time for post-catalyst control before it is enabled by pre-catalyst control
|-
|
TKATMLRH
|
Switch
threshold for model temperature for post-catalyst lambda control
|-
|
USRHKFA
|
Probe
voltage target value for control post-catalyst at function requirement,
B_fakat
|-
|
ZLASHKAB
|
Time
constant for the dynamic speed regulation. Target value increase (dlasohkab)
in LRHK
|-
|
ZLASOHML
|
PT1-filter
time constant for the pseudo post-catalyst lambda
|-
|
Variable
|
'''Description'''
|-
|
AVKATF
|
Filtered
amplitude ratio laafh/laafv, Bank 1
|-
|
AVKATF2
|
Filtered
amplitude ratio laafh/laafv, Bank 2
|-
|
B_DLAHINI
|
Condition
flag: initialization of the LRSHK integral component, Bank 1
|-
|
B_DLAHINI2
|
Condition
flag: initialization of the LRSHK integral component, Bank 2
|-
|
B_EDKVS
|
Condition
flag: actual adaptation error thresholds exceeded, Bank 1
|-
|
B EDKVS2
|
Condition
flag: actual adaptation error thresholds exceeded, Bank 2
|-
|
B_FAKAT
|
Condition
flag: monitoring function requirement catalyst
|-
|
B_FALSH
|
Functional
requirement condition post-catalyst lambda probe, Bank 1
|-
|
B_FALSH2
|
Functional
requirement condition post-catalyst lambda probe, Bank 2
|-
|
B_LR
|
LREB
Condition: pre-catalyst lambda control, Bank 1
|-
|
B_LR2
|
Condition:
pre-catalyst lambda control, Bank 2
|-
|
B_LRHK
|
Condition:
post-catalyst lambda control, Bank 1
|-
|
B_LRHK2
|
Condition:
post-catalyst lambda control, Bank 2
|-
|
B_LRHKB
|
Condition:
post-catalyst lambda control, bank specific parameters, Bank 1
|-
|
B_LRHKB2
|
Condition:
post-catalyst lambda control, bank specific parameters, Bank 2
|-
|
B_LRHKG
|
Condition:
bank independent condition post-catalyst lambda control
|-
|
B_LRHKP
|
Condition:
enable condition proportional component post-catalyst lambda control, Bank 1
|-
|
B_LRHKP2
|
Condition:
enable condition proportional component post-catalyst lambda control, Bank 2
|-
|
B_LRKA
|
Catalyst-clearing
condition for stereo lambda control, Bank 1
|-
|
B_LRKA2
|
Catalyst-clearing
condition for stereo lambda control, Bank 2
|-
|
B_LRSSP
|
Condition:
lambda-control bit set if additional amplitude sign change
|-
|
B MDARV
|
Condition:
critical dropout rate available
|-
|
B_PWF
|
Power
fail condition
|-
|
B_SBBHK
|
Condition
flag: post-catalyst lambda probe ready Bank 1
|-
|
B_SBBHK2
|
Condition
flag: post-catalyst lambda probe ready Bank 2
|-
|
B_ST
|
Start
condition
|-
|
B_TEHB
|
Tank
ventilation with high loading condition
|-
|
C_FCMCLR
|
System
status: error erasing memory
|-
|
C_INI
|
ECU
initialization condition
|-
|
DLAHI W
|
Integral
component of LRSHK, Bank 1
|-
|
DLAHI2_W
|
Integral
component of LRSHK, Bank 2
|-
|
DLAHINI2_W
|
Initialization
value for integral component LRSHK, Bank 2
|-
|
DLAHINI_W
|
Initialization
value for integral component LRSHK, Bank 1
|-
|
DLAHKAB_W
|
Dynamic
elevation of the pseudo post catalyst lambda target value, Bank 1
|-
|
DLAHKAB2_W
|
Dynamic
elevation of the pseudo post-catalyst lambda target value, Bank 2
|-
|
DLAHP_W
|
Proportional
component of LRSHK, Bank 1
|-
|
DLAHP2_W
|
Proportional
component of LRSHK, Bank 2
|-
|
DLASHKI_W
|
Delta
Lambda weighted for integral component LRSHK, Bank 1
|-
|
DLASHKI2_W
|
Delta
Lambda weighted for integral component LRSHK, Bank 2
|-
|
DLASHKM_W
|
Post-catalyst
delta lambda control (actual value fr-synchronously averaged), Bank 1
|-
|
DLASHKM2_W
|
Post-catalyst
delta lambda control (actual value fr-synchronously averaged), Bank 2
|-
|
DLASHKP_W
|
Delta-lambda
weighted for proportional component LRSHK 5.30, Bank 1
|-
|
DLASHKP2_W
|
Delta-lambda
weighted for proportional component LRSHK 5.30, Bank 2
|-
|
E_HSH
|
Error
flag: post-catalyst lambda probe heating, Bank 1
|-
|
E_HSH2
|
Error
flag: post-catalyst lambda probe heating, Bank 2
|-
|
E_HSV
|
Error
flag: pre-catalyst lambda probe heating, Bank 1
|-
|
E_HSV2
|
Error
flag: pre-catalyst lambda probe heating, Bank 2
|-
|
E_KAT
|
Error
flag: catalytic conversion, Bank 1
|-
|
E_KAT2
|
Error
flag: catalytic conversion, Bank 2
|-
|
E_LASH
|
Error
flag: post-catalyst lambda probe ageing, Bank 1
|-
|
E_LASH2
|
Error
flag: post-catalyst lambda probe ageing, Bank 2
|-
|
E_LM
|
Error
flag: main load sensor
|-
|
E_LSV
|
Error
flag: pre-catalyst lambda probe, Bank 1
|-
|
E_LSV2
|
Error
flag: pre-catalyst lambda probe, Bank 2
|-
|
E_SLS
|
Error
flag: secondary air system, Bank 1
|-
|
E_SLS2
|
Error
flag: secondary air system, Bank 2
|-
|
E_TES
|
Error
flag: fuel tank breather system
|-
|
E_TEVE
|
Error
flag: fuel tank breather valve end stage, Bank 1
|-
|
E_TEVE2
|
Error
flag: fuel tank breather valve end stage, Bank 1
|-
|
LAHKMZ
|
Status
byte of the machine: fr-synchronous averaging pseudo lambda post-catalyst,
Bank 1
|-
|
LAHKMZ2
|
Status
byte of the machine: fr-synchronous averaging pseudo lambda post-catalyst,
Bank 2
|-
|
LAMHF_W
|
Pseudo-linearized
lambda post-catalyst, PT1 filtered, Bank 1, Word
|-
|
LAMHF2_W
|
Pseudo-linearized
lambda post-catalyst, PT1-filtered, Bank 2, Word
|-
|
LAMHM_W
|
fr-synchronously
averaged pseudo post-catalyst lambda value measured by the Nernst probe, Bank
1
|-
|
LAMHM2_W
|
fr-synchronously
averaged pseudo post-catalyst lambda value measured by the Nernst probe, Bank
2
|-
|
LAMSOLH_W
|
Pseudo
post-catalyst lambda target value, Bank 1
|-
|
LAMSOLH2_W
|
Pseudo
post-catalyst lambda target value, Bank 2
|-
|
LAMSONH_W
|
Pseudo
post-catalyst lambda value measured with Nernst probe (word), Bank 2
|-
|
LAMSONH2_W
|
Pseudo
post-catalyst lambda value measured with Nernst probe (word), Bank 2
|-
|
LAMSONS_W
|
Lambda target value based on location of lambda sensor, Bank 1
|-
|
LAMSONS2_W
|
Lambda target value based on location of lambda sensor, Bank 2
|-
|
ML
|
Air
mass flow
|-
|
MLNKA_W
|
Catalyst
air mass after clear out, Bank 1
|-
|
MLNKA2_W
|
Catalyst
air mass after clear out, Bank 2
|-
|
ML_W
|
Filtered
air mass (Word)
|-
|
NMOT
|
Engine
speed
|-
|
PERCNT_W
|
Number
of 10 ms steps for fr-synchronous lamsolh averaging, Bank 1
|-
|
PERCNT2_W
|
Number
of 10 ms steps for fr-synchronous lamsolh averaging, Bank 2
|-
|
RL
|
Relative
air charge
|-
|
R_T10
|
10
ms time frame
|-
|
R_T100
|
100
ms time frame
|-
|
SY_STERHK
|
System
constant condition: stereo post-catalyst system
|-
|
SY_STERVK
|
System
constant condition: stereo pre-catalyst system
|-
|
TKATM
|
Catalyst
temperature from model Bank 1
|-
|
TKATM2
|
Catalyst
temperature from model Bank 2
|-
|
USHK_W
|
Lambda
probe voltage (4.88 mV/LSB) post-catalyst, Bank 1
|-
|
USHK2_W
|
Lambda
probe voltage (4.88 mV/LSB) post-catalyst, Bank 2
|-
|
USRHK
|
Actual
post-catalyst lambda signal control threshold, Bank 1
|-
|
USRHK2
|
Actual
post-catalyst lambda signal control threshold, Bank 2
|-
|
Z_LASH
|
Cycle
flag: post-catalyst lambda probe ageing, Bank 1
|-
|
Z_LASH2
|
Cycle
flag: post-catalyst lambda probe ageing, Bank 2
|}

GGHFM 57.60 (MAF Meter System Pulsations)

2012-01-14T17:10:00Z

TTQS:

GGHFM57.60 (MAF Meter System Pulsations) Function Description

The MAF sensor output is sampled at 1 millisecond intervals. The sampled voltage value is first linearized using the 512 value characteristic curve MLHFM (which contains only positive values) for further calculation of mass air flow. Therefore, when using a HFM5 sensor, an offset (defined by MLOFS) is required to take account of the reverse current region in the calculation of MLHFM values.

The calculated air mass values are then summed in a memory segment. Once a segment is nearly full, the simple arithmetic average of the cumulative value over the last segment is calculated, i.e. it is divided by the number of samples of the last segment and then the offset MLOFS is subtracted.

During idle conditions, a selection is made between the measured air mass flow and the maximum possible air mass flow at this operating point, mldmx_w (taken at a height of -500 m and a temperature of -40°C) weighted by the multiplication factor FKMSHFM. By this measure, short circuiting of Ubat output to the engine can be prevented. [See module DHFM 63.130 Diagnosis: MAF sensor signal plausibility check: ''“With the HFM5 sensor, if the battery voltage is less than 11 V , no more information about the plausibility of the HFM signal is possible (basis: voltage levels of 0.5-2.0 V cause a short circuit between Ubat and Uref)...”'']

Then, the value is corrected via fpuk for pulsations and return flow (i.e. pressurized air dumped back to the intake tract on the overrun) and via fkhfm in areas with no pulsation and surging. When the turbo is on, the system constant SY_TURBO sets fpuk to 1.0 since there will not be any pulsations or return flow. The value mshfm_w is corrected in this case by the map KFKHFM.

Since different displacement elements of the engine hardware, such as the camshaft, intake manifold or charge movement flap can influence pulsation in the MAF sensor, the code words CWHFMPUKL1 and CWHFMPUKL2 determine which influencing factors are taken into account.

The air mass flow output is supplied as the 16-bit value mshfm_w. The RAM-cell mshfm_w is limited to zero. To take into account return flow (based on 1-segment) for turbo engines, the RAM-cell mshfms_w is provided, which is administered by the limiting value FW MLMIN.

The pulsation-correcting curve PUKANS corrects for the engine speed nmot so that intake air temperature-dependent displacements of actual pulsation areas are managed.

GGHFM 57.60 Application Notes

Pre-assignment of the Parameters

CWHFMPUKL1 = 1

CWHFMPUKL2 = 1

FLBKPUHFM = 0.5

FNWUEPUHFM = 0.5

KFKHFM = 1.0

KFPU = 1.0

KFPUKLP1 = 1.0

KFPUKLP12 = 1.0

KFPUKLP2 = 1.0

MLHFM = MAF sensor curve

MLMIN = -200 kg/h

MLOFS = 200 kg/h

PUKANS = 1.0

Application Procedure

1. Determine, input and review the MAF sensor linearization curve

2. Linearization curves depend on size and type (hybrid/sensor) of the MAF metering system deployed

3. For the HFM5 sensor, the curve with return flow, i.e., positive and negative air masses and use additional offset (MLOFS = 200 kg/h)

4. When using an alternative plug-in sensor, check the linearization curve is appropriate for the mounting position used.

Requirements for the Application of the Pulsation Map

Mixture pre-input path:

1. Normalise all enrichment (input factors and input-lambda), i.e. feed forward control to
obtain lambda = 1;

2. In fuel systems where there is no constant differential pressure over the fuel injectors (e.g. returnless fuel systems, i.e. in which the pressure regulator is not working against the intake manifold pressure as a reference) this must especially be ensured for the application of pulsation maps (connection of a pressure regulator on the intake manifold).

3. If this is not technically possible, i.e. the differential pressure across the fuel injectors was previously considered in a correction curve (see note to returnless fuel systems), then carry out the following:

Pre-input charge detection:

1. Determine the MAF sensor characteristic curve

2. Normalise the pulsation corrections first (set KFPU, KFPUKLP1, KFPUKLP2, KFPUKLP12 to 1.0)

3. Set the MAF correction map values to 1.0

4. Limit rlmax by disabling or setting PSMXN to its maximum values

The pulsation correction depends on Tans in the characteristic PUKANS stored as a factor and is addressed with Tans/°C. This characteristic is used for engine speed correction to address the pulsation map KFPU.

PUKANS = (T0/TANS)0.5)
where T0 and TANS are absolute temperatures (i.e. in Kelvin)

The base temperature T0 is 0°C = 273 K i.e. ftans (0°C) = 1.0

To apply the curve with 8 data points for pulsation corrections:

{| border="1"
|-
|
TANS/°C
|
-40
|
-20
|
0
|
20
|
30
|
40
|
50
|
80
|-
|
TANS/K
|
233
|
253
|
273
|
293
|
303
|
313
|
323
|
353
|-
|
PUKANS
|
1.0824
|
1.0388
|
1.0000
|
0.9653
|
0.9492
|
0.9339
|
0.9194
|
0.8794
|}

Application of the Pulse Maps KFPU, KFPUKLP1, KFPUKLP2, KFPUKLP12

The pulsation maps compensate for pulsation and reverse flow errors in the MAF meter system. There are four pulsation maps:

KFPU: the basic map

KFPUKLP1: pulsation-influencing adjustment element 1

KFPUKLP2: pulsation-influencing adjustment element 2

KFPUKLP12: pulsation-influencing adjustment elements 1 and 2

Parameterization of the code words CWHFMPUKL1 and CWHFMPUKL2:

Definition of adjustment element 1 for taking pulsation into account

CWHFMKLPU1:

1. 1 Intake manifold flap

2. Camshaft

3. Charge movement flap

Definition of adjustment element 2 for taking pulsation into account

CWHFMKLPU2:

1. 2 Intake manifold flap

2. Camshaft

3. Charge movement flap

Definition of the pulsation range:

MAF sensor voltage fluctuations with an amplitude of 0.5 V

Definition of the return-flow (i.e. pressurized air dumped back to the intake tract on the overrun) range:

MAF sensor voltage <1 V

Pulsation Map Adaptation:

Determining the pulsation or reverse flow region; possibly changing the sample-point resolution of pulsation maps to better cover the pulsation region.

The air mass in the intake manifold (ml_w) is compared with the calculated air mass in the exhaust gas via the characteristic curves KFPU, KFPUKLP1, KFPUKLP2 and KFPUKLP12. As an alternative to the calculated air mass in the exhaust, the air mass flow through a pulsation-damping volume to the air filter housing (e.g. a Helmholtz resonator device) can be measured instead.

Application of the MAF Correction Map KFKHFM:

In regions of no pulsation, the air mass comparison is carried out via the map KFKHFM. In this way, MAF-sensor errors caused, for
example, by a problematic installation position can be corrected. For either, the balancing should maintain lambda of approximately 1.0, so the error in calculating the air mass in the exhaust gas is low. The residual errors (lambda deviation
around 1.0) are interpreted as a mixture error and are compensated for by the characteristic curve FKKVS in the RKTI 11.40 module.

Abbreviations

{| border="1"
|-
|
'''Parameter'''
|
'''Definition'''
|-
|
CWHFMPUKL1
|
Code
word 1 for selecting one of the adjustment elements for MAF sensor-pulsation
map
|-
|
CWHFMPUKL2
|
Code
word 2 for selecting one of the adjustment elements for MAF sensor-pulsation
map
|-
|
FLBKPUHFM
|
Switching
threshold for the charge movement flap adjustment factor for MAF sensor
pulsation
|-
|
FNWUEPUHFM
|
Switching
threshold for the camshaft adjustment factor in MAF sensor pulsation
|-
|
KFKHFM
|
Correction
map for MAF sensor
|-
|
KFPU
|
Pulsations
map
|-
|
KFPUKLP1
|
Pulsations
map with active adjustment element 1
|-
|
KFPUKLP12
|
Pulsations
map with active adjustment elements 1 and 2
|-
|
KFPUKLP2
|
Pulsations
map with active adjustment element 2
|-
|
MLHFM
|
Characteristic
curve for linearization of MAF voltage
|-
|
MLMIN
|
MAF
sensor minimum air mass
|-
|
MLOFS
|
Curve
offset for the HFM5 sensor
|-
|
PUKANS
|
Pulsations correction depending on intake air temperature
|-
|
SY_LBK
|
System
constant for the charge movement flap
|-
|
SY_NWS
|
System
constant for the camshaft control system: none, binary (on/off) or variable
|-
|
SY_SU
|
System
constant for alternative intake manifold
|-
|
SY_TURBO
|
System
constant for the turbocharger
|-
|
Variable
|
Definition
|-
|
ANZHFMA_W
|
Number of MAF sensor samples
in a synchronisation
|-
|
B_PUKLP1
|
Switching of pulsations map with active adjustment element 1
|-
|
B_PUKLP2
|
Switching of pulsations map with active adjustment element 2
|-
|
B_SU
|
Intake manifold condition
|-
|
B_SU2
|
Intake manifold condition, 2. Flap
|-
|
FKHFM
|
MAF sensor correction factor
|-
|
FLB_W
|
Charge flow factor
|-
|
FNWUE
|
Weighting factor for inlet valve camshaft overlap
|-
|
FPUK
|
MAF sensor correction factor in pulsation range
|-
|
MLHFMAS_W
|
Cumulative air mass in a synchronisation
|-
|
MLHFMA_W
|
Air masses sampled by the MAF sensor (16-Bit)
|-
|
MLHFMM_W
|
Average of sampled air masses (16 bit value)
|-
|
MSHFMS_W
|
Air
mass flow output value taking return flow into account (signed value)
|-
|
MSHFM_W
|
Air
mass flow output value (16-Bit)
|-
|
NMOT
|
Engine speed
|-
|
NMOTKOR
|
Engine speed intake air temperature correction (zur Pulsations correction)
|-
|
PUANS
|
Pulsations correction depending on intake air temperature (Tans)
|-
|
RL
|
Relative air charge
|-
|
TANS
|
Intake air temperature
|-
|
UHFM_W
|
MAF
sensor voltage
|-
|
WDKBA
|
Throttle plate angle relative to its lower end stop
|}

[[Category:ME7]]

BGSRM 17.10 (Cylinder Charge Detection, Intake Manifold Model)

2012-01-14T17:03:57Z

TTQS:

BGSRM 17.10 Function Description

See the ''funktionsrahmen'' for the following diagrams:

bgsrm-bgsrm Function overview

bgsrm-bps

bgsrm-brl Calculation of the fresh and residual gas filling of the cylinders

bgsrm-brfges Calculating total cylinder charge

bgsrm-bpirg

bgsrm-bpirg1

bgsrm-pirg

bgsrm-rlsu

Function Description

The aim of the function:

The intake manifold model calculates the fresh gas filling of the combustion chamber from the air mass flow into the intake manifold.

Description:

An integrator emulates the storage characteristic of the intake manifold. It integrates, with the integrator coefficient KISRM, the relative difference between the inlet relative air fill rlroh_w and the outlet relative air fill rl_w and supplies, after correction with the intake manifold temperature via ftsr and the standard pressure 1013 mbar, the fresh gas partial pressure in the intake manifold.

This integrator is calculated in real time. This makes it possible to describe the increase in pumping capacity with increasing engine speed without parameter change.

External exhaust gas recirculation is taken into account by adding the partial pressure of residual gas psagr_w in the intake manifold (see module BGAGR). As a result there is now a measurable quantity available, namely the intake manifold pressure ps_w, that can be used to compare with the model in the application phase.

The partial pressure of fresh gas in the intake manifold is now limited to a maximum value such that the overall pressure in the intake manifold ps_w does not increase beyond psmx_w, and also so that in the MAF meter reverse flow range, the intake manifold pressure never oscillates to large values; thus the fresh gas filling rl_w is indirectly limited by the intake manifold pressure model.

During load variations-UT, an approximate pressure balance exists between the intake manifold and cylinder which means that there is also a linear relationship between cylinder filling and the intake manifold. Additionally, there is still the residual gas in the cylinder which must be described, since exhaust gas remains in the cylinder after the end of the exhaust event and a part of this residual gas temporarily flows back into the intake manifold, but is then sucked in again.

The camshaft overlap angle wnwue is characteristic of the crank angle, during which both inlet and also exhaust valves are opened and is thus a (nonlinear) measure of the average cross-sectional area, which represents an available flow of exhaust gas from the exhaust tract into the intake manifold. Since the exhaust gas mass throughput also depends on the transit time, engine speed must also be used as an input variable to describe the effect.

Hence it follows that there is a linear rl_w - ps_w connection with offset KFPIRG (as a function of engine speed and camshaft overlap angle) and gradient KFPSURL (as a function of engine speed and camshaft overlap angle).

Since the residual gas component pirg and the gradient fupsrl are dependent on the intake manifold changeover, the intake manifold position switches over as required by the corresponding map. To obtain fupsrl no abrupt changes in the residual gas component pirg and the gradient fupsrl, they are filtered by a lowpass filter with time constant ZVTPRGSU.

Exhaust gas pressure decreases with decreasing ambient pressure and therefore the residual gas component in the cylinder, therefore the offset pirg_w corrected with the altitude factor fho_w. For the slope fupsrl_w, a correction takes place according to the combustion chamber temperature ftbr.

With external exhaust gas recirculation, the conversion of intake manifold pressure to cylinder filling supplies all of the air filling the cylinder rfges_w including the EGR component. The component part of residual gas filling of the cylinders rfagr_w is obtained from the ratio of residual gas partial pressures in the intake manifold psagr_w to intake manifold pressure ps_w. The remaining filling part describes the fresh gas filling of the cylinders rl_w.

rl_w is the key parameter for incorporating all the filling-dependent effects and is the basic variable for pilot control of the fuel injection.

The extracted fresh gas mass flow rate mlw is obtained from the product of rl_w, speed and the conversion factor umsrln_w.

In contrast to previous tl-filter applications, the time constant of the relative load-transient effect is no longer explicitly applied via a characteristic curve, but this is implicit in the equilibrium of the intake manifold pressure models and the (predictable) value of KISRM. The value for KISRM is also switched depending on the intake manifold setting.

Application Notes

Requirements:

"- Conversion for air mass flow rate applied in rl (see function BGMSZS)"

"- Applied temperature compensation (see function BGTEMPK)"

Application tools:

for intake manifold pressure model equilibrium conditions:

"- Slow manifold pressure measurement in the collector'

dynamic comparison of intake manifold pressure with the intake manifold pressure model for measurement:

"- Throttle plate actuator"

"- Fast-measurement in the intake manifold collector (sensor time constant <10 ms, sampling rate
<4 ms)"

Default values for the parameters:

"- Maximum allowable ratio manifold pressure/pressure before throttle”

FPVMXN = 1.20

"- In the cylinder internal residual gas partial pressure KFPRG"

50 mbar at the smallest wnwue, 300 mbar at largest wnwue small, with increasing engine speed is less

"- Gradient rl (ps) characteristic KFURL"

0.105%/mbar at the smallest wnwue, 0.142%/mbar at the largest wnwue, with increasing speed is less

"- Gradient of intake manifold pressure integrator KISRM"

KISRM = zkorr/[(Vs/VH) x z]

where

z is the number of cylinders (4 – 8)

VH is the total stroke volume of all the cylinders (i.e. engine displacement)

Vs is the intake volume from throttle plate through to the inlet valves, typically 1.5 to 3.0 x VH

zkorr is a correction factor for numerical stability: 0.90 when z = 4, 0.92 when z = 5, 0.95 when z = 6 or 1.00 when z > 6.

e.g. if z = 4 with Vs/VH = 2.2, KISRM = 0.1023

Switching off the Function:

"- From the intake manifold dynamics emulation: KISRM = 1.0"

Procedure:

"- Steady state for each engine speed nmot and camshaft overlap angle wnwue"

At about 4 to 5 points of relative load rl, determine measured intake manifold pressure, calculate a straight line through these points, then determine the intake manifold pressure offset KFPRG (at rl = 0) and KFURL from the gradient of the line.

"- After steady-state application of the intake manifold pressure model takes place, throttle plate jumps should be (e.g. rl = 26% to 60%)"

and comparing intake manifold pressures measured by the fast intake manifold pressure sensor with intake manifold pressures emulated in the ECU ps_w, the dynamic correctness of the air-filling model must be proven. Existing small deviations can possibly be corrected through minor changes in KISRM; but the intake manifold pressure dynamics and thus the rl-dynamics should be described satisfactorily with the calculated value of KISRM.

Affected functions:

All functions that use the charge signal rl, almost all!

Abbreviations
{| border="1"
|-
|
Parameter
|
Description
|-
|
CWBGSRM
|
Code word in BGSRM
|-
|
FPVMXN2
|
Maximum pressure ratio factor
with secondary load signal
|-
|
KFPBRK
|
Correction factor for the
combustion chamber pressure
|-
|
KFPBRKNW
|
Correction factor for the
combustion chamber pressure during active camshaft control
|-
|
KFPRG
|
Internal exhaust gas partial
pressure dependent on adjustable camshaft when sumode = 0
|-
|
KFPRGSU
|
Internal exhaust gas partial
pressure dependent on adjustable camshaft when sumode = 1
|-
|
KFPRG2SU
|
Internal exhaust gas partial
pressure dependent on adjustable camshaft when sumode = 2
|-
|
KFPRG3SU
|
Internal exhaust gas partial
pressure dependent on adjustable camshaft when sumode = 3
|-
|
KFURL
|
Conversion factor from ps to
rl dependent on adjustable camshaft when sumode = 0
|-
|
KFURLSU
|
Conversion factor from ps to
rl dependent on adjustable camshaft when sumode = 1
|-
|
KFURL2SU
|
Conversion factor from ps to
rl dependent on adjustable camshaft when sumode = 2
|-
|
KFURL3SU
|
Conversion factor from ps to
rl dependent on adjustable camshaft when sumode = 3
|-
|
KISRM
|
Integrator coefficient for
intake manifold model (dynamic)
|-
|
KISRMSU
|
Integrator coefficient for
intake manifold model when sumode = 1
|-
|
KISRM2SU
|
Integrator coefficient for
intake manifold model when sumode = 2
|-
|
KISRM3SU
|
Integrator coefficient for
intake manifold model when sumode = 3
|-
|
PRGNM
|
Internal exhaust gas partial
pressure dependent on engine speed
|-
|
PRGSUNM
|
Internal exhaust gas partial
pressure dependent on engine speed when there is intake manifold changeover
flap switching (1 flap)
|-
|
PRG2SUNM
|
Internal exhaust gas partial
pressure dependent on engine speed when there is intake manifold changeover
flap switching (2 flaps)
|-
|
PRG3SUNM
|
Internal exhaust gas partial
pressure dependent on engine speed when there is intake manifold changeover
flap switching (1+2 flaps)
|-
|
SY_NWS
|
System constant: camshaft
control: none, binary or continuously variable
|-
|
URLNM
|
Conversion factor from ps to
rl dependent on engine speed, nmot_w
|-
|
URLSUNM
|
Conversion factor from ps to
rl dependent on engine speed, nmot_w when there is intake manifold changeover
flap switching (1 flap)
|-
|
URL2SUNM
|
Conversion factor from ps to
rl dependent on engine speed, nmot_w when there is intake manifold changeover
flap switching (2 flaps)
|-
|
URL3SUNM
|
Conversion factor from ps to
rl dependent on engine speed, nmot_w when there is intake manifold changeover
flap switching (1+2 flaps)
|-
|
ZVTPRGSU
|
Low pass filter time constant
for intake manifold flap dynamic
|-
|
AGRR
|
Exhaust gas recirculation
rate
|-
|
AGRR W
|
Exhaust gas recirculation
rate (word)
|-
|
B_HFM
|
Condition flag: MAF sensor measurement
range
|-
|
B_MXRLROH
|
Condition flag: maximum range
for rlroh is fulfilled
|-
|
B_NWS
|
Condition flag: camshaft
control
|-
|
B_NWVS
|
Condition flag: camshaft
adjustment (binary or continuous) present
|-
|
B_SUMOD1
|
Condition flag: intake
manifold changeover sumode = 1
|-
|
B_SUMOD2
|
Condition flag: intake
manifold changeover sumode = 2
|-
|
B_SUMOD3
|
Condition flag: intake
manifold changeover sumode = 3
|-
|
DPSFG W
|
Delta-fresh gas partial
pressure in the intake manifold
|-
|
DRL_W
|
Delta cylinder charge (Word)
|-
|
FHO_W
|
Correction factor for
altitude (word)
|-
|
FNWUE
|
Weighting factor camshaft
overlap angle (inlet)
|-
|
FPBRKDS_W
|
Factor for determining the
combustion chamber pressure
|-
|
FTBR_W
|
Factor for correcting the
combustion chamber temperature
|-
|
FTSR
|
Correction factor for the
intake manifold air temperature
|-
|
FUPSRL_W
|
Conversion factor
system-related pressure on filling (16-bit)
|-
|
FVISRM_W
|
Intake manifold integrator gain factor
|-
|
ML
|
Air mass flow
|-
|
ML_W
|
Air mass flow, filtered
(Word)
|-
|
NMOT W
|
Engine speed
|-
|
PBR_W
|
Calculated combustion chamber
pressure
|-
|
PIRGRO_W
|
Raw value of residual gas partial
pressure for internal exhaust gas recirculation (16-Bit)
|-
|
PIRG_W
|
Residual gas partial pressure
for internal exhaust gas recirculation (16-Bit)
|-
|
PRG_W
|
Raw value of residual gas partial
pressure for internal exhaust gas recirculation when there is no intake
manifold changeover flap switching
|-
|
PRGSU_W
|
Raw value of residual gas partial
pressure for internal exhaust gas recirculation when there is intake manifold
changeover flap switching (1 flap)
|-
|
PRG2SU_W
|
Raw value of residual gas partial
pressure for internal exhaust gas recirculation when there is intake manifold
changeover flap switching (2 flaps)
|-
|
PRG3SU_W
|
Raw value of residual gas partial
pressure for internal exhaust gas recirculation when there is intake manifold
changeover flap switching (1+2 flaps)
|-
|
PSAGR_W
|
Partial pressure through
external residual gas (residual air + inert gas)
|-
|
PSFG_W
|
Fresh gas partial pressure in
the intake manifold (word)
|-
|
PSMX_W
|
Intake manifold maximum
pressure limit for modelling intake manifold pressure
|-
|
PSRLRO_W
|
Raw value for system-related
conversion factor pressure from cylinder charge
|-
|
PS_W
|
Manifold absolute pressure,
MAP (Word)
|-
|
PU_W
|
Ambient pressure
|-
|
PVDKDS_W
|
Pressure before the throttle
plate from the pressure sensor (word)
|-
|
RFAGR_W
|
Relative cylinder charge from
exhaust gas recirculation (word)
|-
|
RFGES_W
|
Total relative cylinder
charge (inclusive of exhaust gas recirculation) 16-Bit
|-
|
RL
|
Relative air charge
|-
|
RLROH W
|
Relative air charge: raw
value from the load sensor (word)
|-
|
RL_W
|
Relative air charge (word)
|-
|
SUMODE
|
Status of the intake manifold
switching
|-
|
UMSRLN_W
|
Conversion factor for
cylinder charge in mass flow
|-
|
URL_W
|
Factor for converting
pressure from cylinder charge at the default position of the intake manifold
flap
|-
|
URLSU_W
|
Factor for converting
pressure from cylinder charge when there is intake manifold changeover flap
switching (1 flap)
|-
|
URL2SU_W
|
Factor for converting
pressure from cylinder charge when there is intake manifold changeover flap
switching (2 flaps)
|-
|
URL3SU_W
|
Factor for converting
pressure from cylinder charge when there is intake manifold changeover flap
switching (1+2 flaps)
|-
|
WNWISA_W
|
Actual exhaust camshaft angle
|-
|
WNWSRM_W
|
Choice between wnwue and wnwisa
for addressing the map for PIRG and fupsrl
|-
|
WNWUE W
|
Camshaft overlap angle
|}

BGSRM 17.10 (Cylinder Charge Detection, Intake Manifold Model)

2012-01-14T17:02:31Z

TTQS:

BGSRM 17.10 Function Description

See the ''funktionsrahmen'' for the following diagrams:

bgsrm-bgsrm Function overview

bgsrm-bps

bgsrm-brl Calculation of the fresh and residual gas filling of the cylinders

bgsrm-brfges Calculating total cylinder charge

bgsrm-bpirg

bgsrm-bpirg1

bgsrm-pirg

bgsrm-rlsu

Function Description

The aim of the function:

The intake manifold model calculates the fresh gas filling of the combustion chamber from the air mass flow into the intake manifold.

Description:

An integrator emulates the storage characteristic of the intake manifold. It integrates, with the integrator coefficient KISRM, the relative difference between the inlet relative air fill rlroh_w and the outlet relative air fill rl_w and supplies, after correction with the intake manifold temperature via ftsr and the standard pressure 1013 mbar, the fresh gas partial pressure in the intake manifold.

This integrator is calculated in real time. This makes it possible to describe the increase in pumping capacity with increasing engine speed without parameter change.

External exhaust gas recirculation is taken into account by adding the partial pressure of residual gas psagr_w in the intake manifold (see module BGAGR). As a result there is now a measurable quantity available, namely the intake manifold pressure ps_w, that can be used to compare with the model in the application phase.

The partial pressure of fresh gas in the intake manifold is now limited to a maximum value such that the overall pressure in the intake manifold ps_w does not increase beyond psmx_w, and also so that in the MAF meter reverse flow range, the intake manifold pressure never oscillates to large values; thus the fresh gas filling rl_w is indirectly limited by the intake manifold pressure model.

During load variations-UT, an approximate pressure balance exists between the intake manifold and cylinder which means that there is also a linear relationship between cylinder filling and the intake manifold. Additionally, there is still the residual gas in the cylinder which must be described, since exhaust gas remains in the cylinder after the end of the exhaust event and a part of this residual gas temporarily flows back into the intake manifold, but is then sucked in again.

The camshaft overlap angle wnwue is characteristic of the crank angle, during which both inlet and also exhaust valves are opened and is thus a (nonlinear) measure of the average cross-sectional area, which represents an available flow of exhaust gas from the exhaust tract into the intake manifold. Since the exhaust gas mass throughput also depends on the transit time, engine speed must also be used as an input variable to describe the effect.

Hence it follows that there is a linear rl_w - ps_w connection with offset KFPIRG (as a function of engine speed and camshaft overlap angle) and gradient KFPSURL (as a function of engine speed and camshaft overlap angle).

Since the residual gas component pirg and the gradient fupsrl are dependent on the intake manifold changeover, the intake manifold position switches over as required by the corresponding map. To obtain fupsrl no abrupt changes in the residual gas component pirg and the gradient fupsrl, they are filtered by a lowpass filter with time constant ZVTPRGSU.

Exhaust gas pressure decreases with decreasing ambient pressure and therefore the residual gas component in the cylinder, therefore the offset pirg_w corrected with the altitude factor fho_w. For the slope fupsrl_w, a correction takes place according to the combustion chamber temperature ftbr.

With external exhaust gas recirculation, the conversion of intake manifold pressure to cylinder filling supplies all of the air filling the cylinder rfges_w including the EGR component. The component part of residual gas filling of the cylinders rfagr_w is obtained from the ratio of residual gas partial pressures in the intake manifold psagr_w to intake manifold pressure ps_w. The remaining filling part describes the fresh gas filling of the cylinders rl_w.

rl_w is the key parameter for incorporating all the filling-dependent effects and is the basic variable for pilot control of the fuel injection.

The extracted fresh gas mass flow rate mlw is obtained from the product of rl_w, speed and the conversion factor umsrln_w.

In contrast to previous tl-filter applications, the time constant of the relative load-transient effect is no longer explicitly applied via a characteristic curve, but this is implicit in the equilibrium of the intake manifold pressure models and the (predictable) value of KISRM. The value for KISRM is also switched depending on the intake manifold setting.

Application Notes

Requirements:

"- Conversion for air mass flow rate applied in rl (see function BGMSZS)"

"- Applied temperature compensation (see function BGTEMPK)"

Application tools:

for intake manifold pressure model equilibrium conditions:

"- Slow manifold pressure measurement in the collector'

dynamic comparison of intake manifold pressure with the intake manifold pressure model for measurement:

"- Throttle plate actuator"

"- Fast-measurement in the intake manifold collector (sensor time constant <10 ms, sampling rate
<4 ms)"

Default values for the parameters:

"- Maximum allowable ratio manifold pressure/pressure before throttle”

FPVMXN = 1.20

"- In the cylinder internal residual gas partial pressure KFPRG"

50 mbar at the smallest wnwue, 300 mbar at largest wnwue small, with increasing engine speed is less

"- Gradient rl (ps) characteristic KFURL"

0.105%/mbar at the smallest wnwue, 0.142%/mbar at the largest wnwue, with increasing speed is less

"- Gradient of intake manifold pressure integrator KISRM"

KISRM = zkorr/[(Vs/VH) x z]

where

z is the number of cylinders (4 – 8)

VH is the total stroke volume of all the cylinders (i.e. engine displacement)

Vs is the intake volume from throttle plate through to the inlet valves, typically 1.5 to 3.0 x VH

zkorr is a correction factor for numerical stability: 0.90 when z = 4, 0.92 when z = 5, 0.95 when z = 6 or 1.00 when z > 6.

e.g. if z = 4 with Vs/VH = 2.2, KISRM = 0.1023

Switching off the Function:

"- From the intake manifold dynamics emulation: KISRM = 1.0"

Procedure:

"- Steady state for each engine speed nmot and camshaft overlap angle wnwue"

At about 4 to 5 points of relative load rl, determine measured intake manifold pressure, calculate a straight line through these points, then determine the intake manifold pressure offset KFPRG (at rl = 0) and KFURL from the gradient of the line.

"- After steady-state application of the intake manifold pressure model takes place, throttle plate jumps should be (e.g. rl = 26% to 60%)"

and comparing intake manifold pressures measured by the fast intake manifold pressure sensor with intake manifold pressures emulated in the ECU ps_w, the dynamic correctness of the air-filling model must be proven. Existing small deviations can possibly be corrected through minor changes in KISRM; but the intake manifold pressure dynamics and thus the rl-dynamics should be described satisfactorily with the calculated value of KISRM.

Affected functions:

All functions that use the charge signal rl, almost all!

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CWBGSRM
|
Code word in BGSRM
|-
|
FPVMXN2
|
Maximum pressure ratio factor
with secondary load signal
|-
|
KFPBRK
|
Correction factor for the
combustion chamber pressure
|-
|
KFPBRKNW
|
Correction factor for the
combustion chamber pressure during active camshaft control
|-
|
KFPRG
|
Internal exhaust gas partial
pressure dependent on adjustable camshaft when sumode = 0
|-
|
KFPRGSU
|
Internal exhaust gas partial
pressure dependent on adjustable camshaft when sumode = 1
|-
|
KFPRG2SU
|
Internal exhaust gas partial
pressure dependent on adjustable camshaft when sumode = 2
|-
|
KFPRG3SU
|
Internal exhaust gas partial
pressure dependent on adjustable camshaft when sumode = 3
|-
|
KFURL
|
Conversion factor from ps to
rl dependent on adjustable camshaft when sumode = 0
|-
|
KFURLSU
|
Conversion factor from ps to
rl dependent on adjustable camshaft when sumode = 1
|-
|
KFURL2SU
|
Conversion factor from ps to
rl dependent on adjustable camshaft when sumode = 2
|-
|
KFURL3SU
|
Conversion factor from ps to
rl dependent on adjustable camshaft when sumode = 3
|-
|
KISRM
|
Integrator coefficient for
intake manifold model (dynamic)
|-
|
KISRMSU
|
Integrator coefficient for
intake manifold model when sumode = 1
|-
|
KISRM2SU
|
Integrator coefficient for
intake manifold model when sumode = 2
|-
|
KISRM3SU
|
Integrator coefficient for
intake manifold model when sumode = 3
|-
|
PRGNM
|
Internal exhaust gas partial
pressure dependent on engine speed
|-
|
PRGSUNM
|
Internal exhaust gas partial
pressure dependent on engine speed when there is intake manifold changeover
flap switching (1 flap)
|-
|
PRG2SUNM
|
Internal exhaust gas partial
pressure dependent on engine speed when there is intake manifold changeover
flap switching (2 flaps)
|-
|
PRG3SUNM
|
Internal exhaust gas partial
pressure dependent on engine speed when there is intake manifold changeover
flap switching (1+2 flaps)
|-
|
SY_NWS
|
System constant: camshaft
control: none, binary or continuously variable
|-
|
URLNM
|
Conversion factor from ps to
rl dependent on engine speed, nmot_w
|-
|
URLSUNM
|
Conversion factor from ps to
rl dependent on engine speed, nmot_w when there is intake manifold changeover
flap switching (1 flap)
|-
|
URL2SUNM
|
Conversion factor from ps to
rl dependent on engine speed, nmot_w when there is intake manifold changeover
flap switching (2 flaps)
|-
|
URL3SUNM
|
Conversion factor from ps to
rl dependent on engine speed, nmot_w when there is intake manifold changeover
flap switching (1+2 flaps)
|-
|
ZVTPRGSU
|
Low pass filter time constant
for intake manifold flap dynamic
|-
|
AGRR
|
Exhaust gas recirculation
rate
|-
|
AGRR W
|
Exhaust gas recirculation
rate (word)
|-
|
B_HFM
|
Condition flag: MAF sensor measurement
range
|-
|
B_MXRLROH
|
Condition flag: maximum range
for rlroh is fulfilled
|-
|
B_NWS
|
Condition flag: camshaft
control
|-
|
B_NWVS
|
Condition flag: camshaft
adjustment (binary or continuous) present
|-
|
B_SUMOD1
|
Condition flag: intake
manifold changeover sumode = 1
|-
|
B_SUMOD2
|
Condition flag: intake
manifold changeover sumode = 2
|-
|
B_SUMOD3
|
Condition flag: intake
manifold changeover sumode = 3
|-
|
DPSFG W
|
Delta-fresh gas partial
pressure in the intake manifold
|-
|
DRL_W
|
Delta cylinder charge (Word)
|-
|
FHO_W
|
Correction factor for
altitude (word)
|-
|
FNWUE
|
Weighting factor camshaft
overlap angle (inlet)
|-
|
FPBRKDS_W
|
Factor for determining the
combustion chamber pressure
|-
|
FTBR_W
|
Factor for correcting the
combustion chamber temperature
|-
|
FTSR
|
Correction factor for the
intake manifold air temperature
|-
|
FUPSRL_W
|
Conversion factor
system-related pressure on filling (16-bit)
|-
|
FVISRM_W
|
Intake manifold integrator gain factor
|-
|
ML
|
Air mass flow
|-
|
ML_W
|
Air mass flow, filtered
(Word)
|-
|
NMOT W
|
Engine speed
|-
|
PBR_W
|
Calculated combustion chamber
pressure
|-
|
PIRGRO_W
|
Raw value of residual gas partial
pressure for internal exhaust gas recirculation (16-Bit)
|-
|
PIRG_W
|
Residual gas partial pressure
for internal exhaust gas recirculation (16-Bit)
|-
|
PRG_W
|
Raw value of residual gas partial
pressure for internal exhaust gas recirculation when there is no intake
manifold changeover flap switching
|-
|
PRGSU_W
|
Raw value of residual gas partial
pressure for internal exhaust gas recirculation when there is intake manifold
changeover flap switching (1 flap)
|-
|
PRG2SU_W
|
Raw value of residual gas partial
pressure for internal exhaust gas recirculation when there is intake manifold
changeover flap switching (2 flaps)
|-
|
PRG3SU_W
|
Raw value of residual gas partial
pressure for internal exhaust gas recirculation when there is intake manifold
changeover flap switching (1+2 flaps)
|-
|
PSAGR_W
|
Partial pressure through
external residual gas (residual air + inert gas)
|-
|
PSFG_W
|
Fresh gas partial pressure in
the intake manifold (word)
|-
|
PSMX_W
|
Intake manifold maximum
pressure limit for modelling intake manifold pressure
|-
|
PSRLRO_W
|
Raw value for system-related
conversion factor pressure from cylinder charge
|-
|
PS_W
|
Manifold absolute pressure,
MAP (Word)
|-
|
PU_W
|
Ambient pressure
|-
|
PVDKDS_W
|
Pressure before the throttle
plate from the pressure sensor (word)
|-
|
RFAGR_W
|
Relative cylinder charge from
exhaust gas recirculation (word)
|-
|
RFGES_W
|
Total relative cylinder
charge (inclusive of exhaust gas recirculation) 16-Bit
|-
|
RL
|
Relative air charge
|-
|
RLROH W
|
Relative air charge: raw
value from the load sensor (word)
|-
|
RL_W
|
Relative air charge (word)
|-
|
SUMODE
|
Status of the intake manifold
switching
|-
|
UMSRLN_W
|
Conversion factor for
cylinder charge in mass flow
|-
|
URL_W
|
Factor for converting
pressure from cylinder charge at the default position of the intake manifold
flap
|-
|
URLSU_W
|
Factor for converting
pressure from cylinder charge when there is intake manifold changeover flap
switching (1 flap)
|-
|
URL2SU_W
|
Factor for converting
pressure from cylinder charge when there is intake manifold changeover flap
switching (2 flaps)
|-
|
URL3SU_W
|
Factor for converting
pressure from cylinder charge when there is intake manifold changeover flap
switching (1+2 flaps)
|-
|
WNWISA_W
|
Actual exhaust camshaft angle
|-
|
WNWSRM_W
|
Choice between wnwue and wnwisa
for addressing the map for PIRG and fupsrl
|-
|
WNWUE W
|
Camshaft overlap angle
|}

GGHFM 57.60 (MAF Meter System Pulsations)

2012-01-14T17:01:19Z

TTQS:

GGHFM 57.60 (MAF Meter System Pulsations)

2012-01-14T16:59:35Z

TTQS:

GGHFM57.60 (MAF Meter System Pulsations) Function Description

The MAF sensor output is sampled at 1 millisecond intervals. The sampled voltage value is first linearized using the 512 value characteristic curve MLHFM (which contains only positive values) for further calculation of mass air flow. Therefore, when using a HFM5 sensor, an offset (defined by MLOFS) is required to take account of the reverse current region in the calculation of MLHFM values.

The calculated air mass values are then summed in a memory segment. Once a segment is nearly full, the simple arithmetic average of the cumulative value over the last segment is calculated, i.e. it is divided by the number of samples of the last segment and then the offset MLOFS is subtracted.

During idle conditions, a selection is made between the measured air mass flow and the maximum possible air mass flow at this operating point, mldmx_w (taken at a height of -500 m and a temperature of -40°C) weighted by the multiplication factor FKMSHFM. By this measure, short circuiting of Ubat output to the engine can be prevented. [See module DHFM 63.130 Diagnosis: MAF sensor signal plausibility check: ''“With the HFM5 sensor, if the battery voltage is less than 11 V , no more information about the plausibility of the HFM signal is possible (basis: voltage levels of 0.5-2.0 V cause a short circuit between Ubat and Uref)...”'']

Then, the value is corrected via fpuk for pulsations and return flow (i.e. pressurized air dumped back to the intake tract on the overrun) and via fkhfm in areas with no pulsation and surging. When the turbo is on, the system constant SY_TURBO sets fpuk to 1.0 since there will not be any pulsations or return flow. The value mshfm_w is corrected in this case by the map KFKHFM.

Since different displacement elements of the engine hardware, such as the camshaft, intake manifold or charge movement flap can influence pulsation in the MAF sensor, the code words CWHFMPUKL1 and CWHFMPUKL2 determine which influencing factors are taken into account.

The air mass flow output is supplied as the 16-bit value mshfm_w. The RAM-cell mshfm_w is limited to zero. To take into account return flow (based on 1-segment) for turbo engines, the RAM-cell mshfms_w is provided, which is administered by the limiting value FW MLMIN.

The pulsation-correcting curve PUKANS corrects for the engine speed nmot so that intake air temperature-dependent displacements of actual pulsation areas are managed.

GGHFM 57.60 Application Notes

Pre-assignment of the Parameters

CWHFMPUKL1 = 1

CWHFMPUKL2 = 1

FLBKPUHFM = 0.5

FNWUEPUHFM = 0.5

KFKHFM = 1.0

KFPU = 1.0

KFPUKLP1 = 1.0

KFPUKLP12 = 1.0

KFPUKLP2 = 1.0

MLHFM = MAF sensor curve

MLMIN = -200 kg/h

MLOFS = 200 kg/h

PUKANS = 1.0

Application Procedure

1. Determine, input and review the MAF sensor linearization curve

2. Linearization curves depend on size and type (hybrid/sensor) of the MAF metering system deployed

3. For the HFM5 sensor, the curve with return flow, i.e., positive and negative air masses and use additional offset (MLOFS = 200 kg/h)

4. When using an alternative plug-in sensor, check the linearization curve is appropriate for the mounting position used.

Requirements for the Application of the Pulsation Map

Mixture pre-input path:

1. Normalise all enrichment (input factors and input-lambda), i.e. feed forward control to
obtain lambda = 1;

2. In fuel systems where there is no constant differential pressure over the fuel injectors (e.g. returnless fuel systems, i.e. in which the pressure regulator is not working against the intake manifold pressure as a reference) this must especially be ensured for the application of pulsation maps (connection of a pressure regulator on the intake manifold).

3. If this is not technically possible, i.e. the differential pressure across the fuel injectors was previously considered in a correction curve (see note to returnless fuel systems), then carry out the following:

Pre-input charge detection:

1. Determine the MAF sensor characteristic curve

2. Normalise the pulsation corrections first (set KFPU, KFPUKLP1, KFPUKLP2, KFPUKLP12 to 1.0)

3. Set the MAF correction map values to 1.0

4. Limit rlmax by disabling or setting PSMXN to its maximum values

The pulsation correction depends on Tans in the characteristic PUKANS stored as a factor and is addressed with Tans/°C. This characteristic is used for engine speed correction to address the pulsation map KFPU.

PUKANS = (T0/TANS)0.5)
where T0 and TANS are absolute temperatures (i.e. in Kelvin)

The base temperature T0 is 0°C = 273 K i.e. ftans (0°C) = 1.0

To apply the curve with 8 data points for pulsation corrections:

{| border="1"
|-
|
TANS/°C
|
-40
|
-20
|
0
|
20
|
30
|
40
|
50
|
80
|-
|
TANS/K
|
233
|
253
|
273
|
293
|
303
|
313
|
323
|
353
|-
|
PUKANS
|
1.0824
|
1.0388
|
1.0000
|
0.9653
|
0.9492
|
0.9339
|
0.9194
|
0.8794
|}
Application of the Pulse Maps KFPU, KFPUKLP1, KFPUKLP2, KFPUKLP12

The pulsation maps compensate for pulsation and reverse flow errors in the MAF meter system. There are four pulsation maps:

KFPU: the basic map

KFPUKLP1: pulsation-influencing adjustment element 1

KFPUKLP2: pulsation-influencing adjustment element 2

KFPUKLP12: pulsation-influencing adjustment elements 1 and 2

Parameterization of the code words CWHFMPUKL1 and CWHFMPUKL2:

Definition of adjustment element 1 for taking pulsation into account

CWHFMKLPU1:

1. 1 Intake manifold flap

2. Camshaft

3. Charge movement flap

Definition of adjustment element 2 for taking pulsation into account

CWHFMKLPU2:

1. 2 Intake manifold flap

2. Camshaft

3. Charge movement flap

Definition of the pulsation range:

MAF sensor voltage fluctuations with an amplitude of 0.5 V

Definition of the return-flow (i.e. pressurized air dumped back to the intake tract on the overrun) range:

MAF sensor voltage <1 V

Pulsation Map Adaptation:

Determining the pulsation or reverse flow region; possibly changing the sample-point resolution of pulsation maps to better cover the pulsation region.

The air mass in the intake manifold (ml_w) is compared with the calculated air mass in the exhaust gas via the characteristic curves KFPU, KFPUKLP1, KFPUKLP2 and KFPUKLP12. As an alternative to the calculated air mass in the exhaust, the air mass flow through a pulsation-damping volume to the air filter housing (e.g. a Helmholtz resonator device) can be measured instead.

Application of the MAF Correction Map KFKHFM:

In regions of no pulsation, the air mass comparison is carried out via the map KFKHFM. In this way, MAF-sensor errors caused, for
example, by a problematic installation position can be corrected. For either, the balancing should maintain lambda of approximately 1.0, so the error in calculating the air mass in the exhaust gas is low. The residual errors (lambda deviation
around 1.0) are interpreted as a mixture error and are compensated for by the characteristic curve FKKVS in the RKTI 11.40 module.

Abbreviations

{| border="1"
|-
|
'''Parameter'''
|
'''Definition'''
|-
|
CWHFMPUKL1
|
Code
word 1 for selecting one of the adjustment elements for MAF sensor-pulsation
map
|-
|
CWHFMPUKL2
|
Code
word 2 for selecting one of the adjustment elements for MAF sensor-pulsation
map
|-
|
FLBKPUHFM
|
Switching
threshold for the charge movement flap adjustment factor for MAF sensor
pulsation
|-
|
FNWUEPUHFM
|
Switching
threshold for the camshaft adjustment factor in MAF sensor pulsation
|-
|
KFKHFM
|
Correction
map for MAF sensor
|-
|
KFPU
|
Pulsations
map
|-
|
KFPUKLP1
|
Pulsations
map with active adjustment element 1
|-
|
KFPUKLP12
|
Pulsations
map with active adjustment elements 1 and 2
|-
|
KFPUKLP2
|
Pulsations
map with active adjustment element 2
|-
|
MLHFM
|
Characteristic
curve for linearization of MAF voltage
|-
|
MLMIN
|
MAF
sensor minimum air mass
|-
|
MLOFS
|
Curve
offset for the HFM5 sensor
|-
|
PUKANS
|
Pulsations correction depending on intake air temperature
|-
|
SY_LBK
|
System
constant for the charge movement flap
|-
|
SY_NWS
|
System
constant for the camshaft control system: none, binary (on/off) or variable
|-
|
SY_SU
|
System
constant for alternative intake manifold
|-
|
SY_TURBO
|
System
constant for the turbocharger
|-
|
Variable
|
Definition
|-
|
ANZHFMA_W
|
Number of MAF sensor samples
in a synchronisation
|-
|
B_PUKLP1
|
Switching of pulsations map with active adjustment element 1
|-
|
B_PUKLP2
|
Switching of pulsations map with active adjustment element 2
|-
|
B_SU
|
Intake manifold condition
|-
|
B_SU2
|
Intake manifold condition, 2. Flap
|-
|
FKHFM
|
MAF sensor correction factor
|-
|
FLB_W
|
Charge flow factor
|-
|
FNWUE
|
Weighting factor for inlet valve camshaft overlap
|-
|
FPUK
|
MAF sensor correction factor in pulsation range
|-
|
MLHFMAS_W
|
Cumulative air mass in a synchronisation
|-
|
MLHFMA_W
|
Air masses sampled by the MAF sensor (16-Bit)
|-
|
MLHFMM_W
|
Average of sampled air masses (16 bit value)
|-
|
MSHFMS_W
|
Air
mass flow output value taking return flow into account (signed value)
|-
|
MSHFM_W
|
Air
mass flow output value (16-Bit)
|-
|
NMOT
|
Engine speed
|-
|
NMOTKOR
|
Engine speed intake air temperature correction (zur Pulsations correction)
|-
|
PUANS
|
Pulsations correction depending on intake air temperature (Tans)
|-
|
RL
|
Relative air charge
|-
|
TANS
|
Intake air temperature
|-
|
UHFM_W
|
MAF
sensor voltage
|-
|
WDKBA
|
Throttle plate angle relative to its lower end stop
|}

[[Category:ME7]]

LRSHK 9.20 (Continuous Post-Catalyst Lambda Control)

2012-01-10T17:47:34Z

TTQS:

See the ''funktionsrahmen'' for the following diagrams:

lrshk-lrshk: function overview

lrshk-lrhkini: initialization of the post-catalyst lambda control

lrshk-lrhkebg: general switch conditions post-catalyst lambda control

lrshk-lrhkla: determination of the error signal to lambda level

lrshk-dlahksm: selection of fr-synchronous lambda averaging/filtering by average value/linearizing lrshk-lambda directly

lrshk-lrhkebp: cylinder bank-specific readiness switch

lrshk-lrhkb1: PI controller post-catalyst with activation condition, cylinder bank 1

lrshk-lrhkb2: PI controller post-catalyst with activation condition, cylinder bank 2

lrshk-lrhkeb: cylinder bank-specific enable of proportional and integral components, cylinder bank 1

lrshk-lrhkeb2: cylinder bank-specific enable of proportional and integral components, cylinder bank 2

lrshk-lrhkip: PI controller, cylinder bank 1

lrshk-lrhkip2: PI controller, cylinder bank 2

lrshk-lahkma: fr-synchronous averaging

Function Description

Control with the post-catalyst probe is superimposed on the pre-cat lambda control.

Control action on the pre-catalyst control is via the delta-lambda-correction variables dlahi_w and dlahp_w.

Post-catalyst Control:

This is switched off by setting bit 0 in word CLRSHK code to 1 (FALSE).

PI Control Action

Post-catalyst lambda control is achieved with a PI controller. Control action via the proportional component dlahp_w will be immediate because it has no "memory" of the correct sign with respect to the control position after a change of lambda probe voltage due to enrichment or enleanment by the delta-lambda intervention.

Via the integral component, post-catalyst control LRSHK is able to compensate, to a large extent, for exhaust gas deterioration, caused by a shift of the steady-state probe characteristic.

The LRSHK calculation is carried out continuously on the lambda level. This requires that the probe voltage ushk_w is linearized via the characteristic LALIUSH (lamsonh_w). A similar linearization is performed with the voltage target value USRHK (lamsolh_w). The pseudo-value lamsonh_w can continue to work via the project-specific codeword CLRSHK

(a) directly (--> default in continuous pre-catalyst control, intervention is possible every 10 ms)

(b) via a PT1 filter (--> project-specific)

(c) fr-synchronous averaged (--> default for two-point control, as the ratio can be added only before the fr-jump)

because lamhm_w will supply the control error dlashkm_w.

By assessing the characteristic curves KDLASHKP and KDLASHKI, the control error dlashkm_w can be corrected separately according to the catalyst properties before the calculation of the P and I components.

The resulting skewed control errors dlashkp_w or dlashki_w are now weighting with KPLRHML = f (ml) of the proportional component dlahp_w, or by weighting with KILRHML = f (ml) of the integral component
dlahi_w.

In the case of aged catalysts, control oscillation of the pre-catalyst control imprinting itself on the post-catalyst probe voltage behaviour which, if proportional intervention is left unchanged, can lead to post-catalyst control oscillations. Moreover, catalyst ageing, which is associated with a decrease in the oxygen storage capacity, the need for the proportional control action in post-catalyst control is less important. Therefore, in a further multiplication by the weighting factor from the characteristic PLRHAV = f(avkatf), the proportional component of the post-catalyst control is revoked for aged catalysts.

Effect on LRSHK of the Lambda Probe Diagnostics

Post-catalyst control takes over the additional delta Lambda offsets (dlahki_w --> pre-catalyst actual value offset, dlahkp_w --> pre-catalyst target value offset) from the former control in LRS 15.40. The magnitude of the intervention dlahi_w is a measure of probe ageing and is used in the diagnosis of lambda probe aging. A symmetric increase in the probe response time cannot be detected by dlahi_w.

Control Threshold from Map KFUSHK

If the post-catalyst probe reports that the mixture is, for example, too lean, dlahp_w will be negative according to the selected control direction and dlahi_w will become smaller. Thus, there is an enrichment until ushk goes back up to the control threshold usrhk. In contrast to the pre-cat control, a map is provided for the post-catalyst control threshold. Via the choice of threshold, a slight load or speed-dependent lambda offset can be achieved.

If catalyst diagnostics are required in the short test B_fakat = TRUE is switched to the threshold USRHKFA.

LRSHK Control Dynamics

The superimposed control is significantly slower than the control applied before the catalyst. Since at low air mass flow rates (low load or engine speed point), the post-catalyst probe voltage as a general rule can exhibit more erratic behaviour and oscillations, following low probe voltages it should not be evaluated so strongly here. The time constant of the post-catalyst control depends on the air mass flow rate ml (--> characteristic KILRHML). At high air mass flow rates, the integration rate should be selected higher as a general rule.

Activation Conditions

If post-catalyst control LRSHK is disabled, the learned integrator value dlahi_w up to that point is the output of the post-catalyst controller. Also, when stopping the engine over the value of the continuous RAM.

The activation conditions for the proportional and integral components are defined differently and are indicated by the bits B_lrhkp and B_lrhk.

The following conditions apply for the proportional component:

When pre-catalyst control readiness (B_lr = 1) is detected, LRSHK is enabled after the delay time TBLRH. This is only useful for lambda target values (lamsons_w = 1) of the pre-catalyst control.

Post-catalyst regulation is only activated above a certain catalyst temperature threshold (tkatm > TKATMLRH) and the operational readiness of the post-catalyst probe (B_sbbhk) is activated.

The following additional conditions apply for the integral component:

Thus, the integrator is only disabled when nmot or rl is in the ranges (NLRHU =< nmot =< NLRHO and RLRHUN(nmot) =< rL =< RLRHON(nmot)). The characteristic curves RLRHUN and RLRHON make it possible to select engine speed-dependent rL-limits on the control range. This allows the control range to be defined so that the operational ranges which give rise to incorrect adaptation of post-catalyst control are delineated. This can happen at operating points where, for example, air mass flow rates are too low.

After the overrun fuel cut-off, the catalyst is saturated with oxygen. The post-catalyst probe voltage will retain small, lean values for a certain time. In this phase, the system deactivates the section LRSKA of the post-catalyst control via bit B_lrka.

After the end of catalyst clear out, post-catalyst control is prohibited until the air mass MLNKAX has passed through the catalytic converter.

If the bit B_tehb corresponding to “tank venting high loading” is set, the integral component of LRSHK is deactivated because the integrator would learn wrong values in this case. The proportional component remains active in this case since it helps to reduce exhaust problems.

In addition, a series of diagnostic errors deactivates post-catalyst control.

Dynamic Overshoot of the Control Threshold after Catalyst Clear Out

After the end of catalyst clear out, the post-catalyst probe voltage oscillates significantly higher than the nominal value of 600 mV for typically 5 to 30 s. The probe voltage attains values of 750-800 mV. The overshoot depends on the catalytic properties. With catalyst types that do not exhibit this behavior, the excesscan be applied away.

SCHEMATIC

The probe voltage characteristic ushk and the status bits B_sa (boost cut-off) and B_lrka (catalyst clear out) are illustrated schematically in the diagram above.

Thus the "time" (air mass MLNKAX) during which the post-catalyst control is prohibited can be kept as short as possible, the probe voltage behaviour after catalyst clear over time is described by a dynamic increase in the target value. The input of a quick PT1 filter is populated with LASHKAB and governed by the time constant ZLASHKAB to 0. The time constant is derived from the adopted course of the probe voltage.

Through this function it is possible, in cases in which the catalyst clear out function has not been successful, or a situation in which the pre-catalyst control condition gives rise to a lean post-catalyst probe voltage, the probe voltage can be raised via LRSHK.

Application Notes

LRSHK Application Procedure:

Codeword CLRSHK

The codeword CLRSHK was introduced in order influence the treatment of the adaptation value dlahi_w within the application. The importance of the individual control bits in CLRSHK are described under the block comments.

Sensible combinations, in decimal, are listed below:

CLRSHK = odd: LRSHK is deactivated

CLRSHK = 16: dlahi_w will erase memory errors when reset with the value DLAHIINI, otherwise default status for LRSHK

CLRSHK = 24: dlahi_w is reset with the value DLAHIINI when the engine starts

Parameter LRSHK

The application of LRS must be completed.

4 x 4 grid points are provided for map KFLASOHK:

Suggestion nmot sample points: 1000, 1800, 2400 & 3000 rpm

rL: 14, 42, 56 & 70%

- Lower control limit e.g. NLRHU = 1200 rpm

Characteristic curve RLRHUN is dependent on n

- Upper control limit e.g. NLRHO = 3000 rpm

Characteristic curve RLRHON is dependent on n

The characteristic curves RLRHUN and RLRHON are strongly project-dependent. However, a characteristic with four sample points, which lie between NLRHU and NLRHO should be sufficient.

- TKATMLRH is chosen so as to control catalyst temperatures >300°C. There is a catalyst temperature model (module ATM) which yields catalyst temperatures, tkatm.

- TBLRH is dependent on the catalytic properties and should be at least 1 second to be selected. Via this label, the time that elapses after switching on the lambda control until the post-catalyst probe signal is correlated against the pre-catalyst control scheme is defined.

- KILRHML curve describes the rate of integration of the air mass in %/s.

Reference points for example engine with ml load: 450 kg/hr

ml: 8, 28, 88, 200, 400 kg/hr

KILRHML: 0.0015, 0.003, 0.0045, 0.006 and 0.0075 /s

Characteristic Curves KDLASHKI and KDLASHKP

The control error corresponding to project-specific lambda probes and catalytic converter properties can be defined via the characteristic curves KDLASHKI and KDLASHKP. So firstly, inaccuracies of the probe voltage linearization (LALIUSH) are corrected and secondly, the emissions characteristics of catalytic converters are considered.

Application of the Proportional Component in the LRSHK PI-Control Scheme:

The effective action of the proportional component of the post-catalyst control system is calculated as follows:

dlahp_w = dlashkl x KPLRHML (ml) x PLRHAV (avkatf)

The influence of catalyst ageing is included as a multiplier in the calculation (RAM cell dlahp_w) using a factor from the characteristic curve PLRHAV, as described above. For a new catalytic converter (avkatf at 0.0), PLRHAV is populated with the value 1.0. With increasing amplitude ratio (as the catalyst ages), PLRHAV is returned to 0.0.

The choice of parameters is determined mainly by the properties of the catalyst. When we ask questions in the application development function, please contact us.

Application of the Parameter MLNKAX:

The overshoot voltage of the lambda probe after the end of the catalyst clear out function is a project-specific phenomenon, which disrupts the LRSHK. Therefore, LRSHK should be blocked until the air mass MLNKAX has been enforced. Since there is no experience (especially with the new catalyst types), the definition of the parameters should be consulted in the responsible function for LRSKA.

Application of the Parameter KILRHML:

During application of the map KFLASO in module LRS, the post-catalyst control integration rate will be set by means of the curve KILRHML so that one sample point of the integrator control stroke dlahi_w of +/-0.03 to +/-0.04 is measured. During measurement, the air mass at the respective operating point is noted. After completion of the application of map KFLASO, the set values from KILRHML are plotted against air mass. The air mass is obtained from a scatter plot. The actual curve KILRHML in LRSHK is obtained by averaging the point cloud.

For more detailed information, please refer to the general application note in the module covering Continuous Lambda Control.

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CLRSHK
|
Codeword
to enable LRSHK and select initialization
|-
|
DLAHINI
|
Initial
value of the integrator dlahi in LRSHK, Bank 1
|-
|
DLAHINI2
|
Initial
value of the integrator dlahi in LRSHK, Bank 2
|-
|
KDLASHKI
|
Characteristic
curve of dlashkm, weighting factor for integral component in LRHK, Bank 1
|-
|
KDLASHKI2
|
Characteristic
curve of dlashkm, weighting factor for integral component in LRHK, Bank 2
|-
|
KDLASHKP
|
Characteristic
curve of dlashkm, weighting factor for proportional component in LRHK, Bank 1
|-
|
KDLASHKP2
|
Characteristic
curve of dlashkm, weighting factor for proportional component in LRHK, Bank 2
|-
|
KFUSHK
|
Probe
voltage target value for post-catalyst control (instead KFUSRHK for
Variantenk.)
|-
|
KILRHML
|
Integral
component for LRSHK
|-
|
KPLRHML
|
Proportional
component for LRSHK
|-
|
LALIUSH
|
Lambda
linearization, post-catalyst probe, Bank 1
|-
|
LALIUSH2
|
Lambda
linearization, post-catalyst probe, Bank 2
|-
|
LALIUSRH
|
Lambda
linearization, post-catalyst probe, target value, Bank 1
|-
|
LALIUSRH2
|
Lambda
linearization, post-catalyst probe, target value, Bank 2
|-
|
LASHKAB
|
Initial
value for dynamic target value increase (lamsolh) in LRHK
|-
|
LRHIMN
|
Minimum
limit of the integrator constant in LRHK
|-
|
LRHIMX
|
Maximum
limit of the integrator constant in LRHK
|-
|
MLNKAX
|
Mass
air threshold for activation readiness LRSHK integral component
|-
|
NLRHO
|
Upper
speed limit for post-catalyst control
|-
|
NLRHU
|
Lower
speed limit for post-catalyst control
|-
|
PLRHAV
|
Catalyst ageing
weighting factor for the proportional component in LRHK, Bank 1
|-
|
PLRHAV2
|
Catalyst ageing
weighting factor for the proportional component in LRHK, Bank 1
|-
|
RLLRHON
|
Characteristic
curve of nmot, rL upper control limit for the post-catalyst controller
|-
|
RLLRHUN
|
Characteristic
curve of nmot, rL lower control limit for the post-catalyst controller
|-
|
RLLRHUFA
|
rL
control limit for post-catalyst control functional requirement B_fakat
|-
|
TBLRH
|
Deactivation
time for post-catalyst control before it is enabled by pre-catalyst control
|-
|
TKATMLRH
|
Switch
threshold for model temperature for post-catalyst lambda control
|-
|
USRHKFA
|
Probe
voltage target value for control post-catalyst at function requirement,
B_fakat
|-
|
ZLASHKAB
|
Time
constant for the dynamic speed regulation. Target value increase (dlasohkab)
in LRHK
|-
|
ZLASOHML
|
PT1-filter
time constant for the pseudo post-catalyst lambda
|-
|
Variable
|
'''Description'''
|-
|
AVKATF
|
Filtered
amplitude ratio laafh/laafv, Bank 1
|-
|
AVKATF2
|
Filtered
amplitude ratio laafh/laafv, Bank 2
|-
|
B_DLAHINI
|
Condition
flag: initialization of the LRSHK integral component, Bank 1
|-
|
B_DLAHINI2
|
Condition
flag: initialization of the LRSHK integral component, Bank 2
|-
|
B_EDKVS
|
Condition
flag: actual adaptation error thresholds exceeded, Bank 1
|-
|
B EDKVS2
|
Condition
flag: actual adaptation error thresholds exceeded, Bank 2
|-
|
B_FAKAT
|
Condition
flag: monitoring function requirement catalyst
|-
|
B_FALSH
|
Functional
requirement condition post-catalyst lambda probe, Bank 1
|-
|
B_FALSH2
|
Functional
requirement condition post-catalyst lambda probe, Bank 2
|-
|
B_LR
|
LREB
Condition: pre-catalyst lambda control, Bank 1
|-
|
B_LR2
|
Condition:
pre-catalyst lambda control, Bank 2
|-
|
B_LRHK
|
Condition:
post-catalyst lambda control, Bank 1
|-
|
B_LRHK2
|
Condition:
post-catalyst lambda control, Bank 2
|-
|
B_LRHKB
|
Condition:
post-catalyst lambda control, bank specific parameters, Bank 1
|-
|
B_LRHKB2
|
Condition:
post-catalyst lambda control, bank specific parameters, Bank 2
|-
|
B_LRHKG
|
Condition:
bank independent condition post-catalyst lambda control
|-
|
B_LRHKP
|
Condition:
enable condition proportional component post-catalyst lambda control, Bank 1
|-
|
B_LRHKP2
|
Condition:
enable condition proportional component post-catalyst lambda control, Bank 2
|-
|
B_LRKA
|
Catalyst-clearing
condition for stereo lambda control, Bank 1
|-
|
B_LRKA2
|
Catalyst-clearing
condition for stereo lambda control, Bank 2
|-
|
B_LRSSP
|
Condition:
lambda-control bit set if additional amplitude sign change
|-
|
B MDARV
|
Condition:
critical dropout rate available
|-
|
B_PWF
|
Power
fail condition
|-
|
B_SBBHK
|
Condition
flag: post-catalyst lambda probe ready Bank 1
|-
|
B_SBBHK2
|
Condition
flag: post-catalyst lambda probe ready Bank 2
|-
|
B_ST
|
Start
condition
|-
|
B_TEHB
|
Tank
ventilation with high loading condition
|-
|
C_FCMCLR
|
System
status: error erasing memory
|-
|
C_INI
|
ECU
initialization condition
|-
|
DLAHI W
|
Integral
component of LRSHK, Bank 1
|-
|
DLAHI2_W
|
Integral
component of LRSHK, Bank 2
|-
|
DLAHINI2_W
|
Initialization
value for integral component LRSHK, Bank 2
|-
|
DLAHINI_W
|
Initialization
value for integral component LRSHK, Bank 1
|-
|
DLAHKAB_W
|
Dynamic
elevation of the pseudo post catalyst lambda target value, Bank 1
|-
|
DLAHKAB2_W
|
Dynamic
elevation of the pseudo post-catalyst lambda target value, Bank 2
|-
|
DLAHP_W
|
Proportional
component of LRSHK, Bank 1
|-
|
DLAHP2_W
|
Proportional
component of LRSHK, Bank 2
|-
|
DLASHKI_W
|
Delta
Lambda weighted for integral component LRSHK, Bank 1
|-
|
DLASHKI2_W
|
Delta
Lambda weighted for integral component LRSHK, Bank 2
|-
|
DLASHKM_W
|
Post-catalyst
delta lambda control (actual value fr-synchronously averaged), Bank 1
|-
|
DLASHKM2_W
|
Post-catalyst
delta lambda control (actual value fr-synchronously averaged), Bank 2
|-
|
DLASHKP_W
|
Delta-lambda
weighted for proportional component LRSHK 5.30, Bank 1
|-
|
DLASHKP2_W
|
Delta-lambda
weighted for proportional component LRSHK 5.30, Bank 2
|-
|
E_HSH
|
Error
flag: post-catalyst lambda probe heating, Bank 1
|-
|
E_HSH2
|
Error
flag: post-catalyst lambda probe heating, Bank 2
|-
|
E_HSV
|
Error
flag: pre-catalyst lambda probe heating, Bank 1
|-
|
E_HSV2
|
Error
flag: pre-catalyst lambda probe heating, Bank 2
|-
|
E_KAT
|
Error
flag: catalytic conversion, Bank 1
|-
|
E_KAT2
|
Error
flag: catalytic conversion, Bank 2
|-
|
E_LASH
|
Error
flag: post-catalyst lambda probe ageing, Bank 1
|-
|
E_LASH2
|
Error
flag: post-catalyst lambda probe ageing, Bank 2
|-
|
E_LM
|
Error
flag: main load sensor
|-
|
E_LSV
|
Error
flag: pre-catalyst lambda probe, Bank 1
|-
|
E_LSV2
|
Error
flag: pre-catalyst lambda probe, Bank 2
|-
|
E_SLS
|
Error
flag: secondary air system, Bank 1
|-
|
E_SLS2
|
Error
flag: secondary air system, Bank 2
|-
|
E_TES
|
Error
flag: fuel tank breather system
|-
|
E_TEVE
|
Error
flag: fuel tank breather valve end stage, Bank 1
|-
|
E_TEVE2
|
Error
flag: fuel tank breather valve end stage, Bank 1
|-
|
LAHKMZ
|
Status
byte of the machine: fr-synchronous averaging pseudo lambda post-catalyst,
Bank 1
|-
|
LAHKMZ2
|
Status
byte of the machine: fr-synchronous averaging pseudo lambda post-catalyst,
Bank 2
|-
|
LAMHF_W
|
Pseudo-linearized
lambda post-catalyst, PT1 filtered, Bank 1, Word
|-
|
LAMHF2_W
|
Pseudo-linearized
lambda post-catalyst, PT1-filtered, Bank 2, Word
|-
|
LAMHM_W
|
fr-synchronously
averaged pseudo post-catalyst lambda value measured by the Nernst probe, Bank
1
|-
|
LAMHM2_W
|
fr-synchronously
averaged pseudo post-catalyst lambda value measured by the Nernst probe, Bank
2
|-
|
LAMSOLH_W
|
Pseudo
post-catalyst lambda target value, Bank 1
|-
|
LAMSOLH2_W
|
Pseudo
post-catalyst lambda target value, Bank 2
|-
|
LAMSONH_W
|
Pseudo
post-catalyst lambda value measured with Nernst probe (word), Bank 2
|-
|
LAMSONH2_W
|
Pseudo
post-catalyst lambda value measured with Nernst probe (word), Bank 2
|-
|
LAMSONS_W
|
Lambda
target value based on location of lambda sensor
|-
|
LAMSONS2_W
|
Lambda
nominal value based on location lambda sensor Bank2
|-
|
ML
|
Air
mass flow
|-
|
MLNKA_W
|
Catalyst
air mass after clear out, Bank 1
|-
|
MLNKA2_W
|
Catalyst
air mass after clear out, Bank 2
|-
|
ML_W
|
Filtered
air mass (Word)
|-
|
NMOT
|
Engine
speed
|-
|
PERCNT_W
|
Number
of 10 ms steps for fr-synchronous lamsolh averaging, Bank 1
|-
|
PERCNT2_W
|
Number
of 10 ms steps for fr-synchronous lamsolh averaging, Bank 2
|-
|
RL
|
Relative
air charge
|-
|
R_T10
|
10
ms time frame
|-
|
R_T100
|
100
ms time frame
|-
|
SY_STERHK
|
System
constant condition: stereo post-catalyst system
|-
|
SY_STERVK
|
System
constant condition: stereo pre-catalyst system
|-
|
TKATM
|
Catalyst
temperature from model Bank 1
|-
|
TKATM2
|
Catalyst
temperature from model Bank 2
|-
|
USHK_W
|
Lambda
probe voltage (4.88 mV/LSB) post-catalyst, Bank 1
|-
|
USHK2_W
|
Lambda
probe voltage (4.88 mV/LSB) post-catalyst, Bank 2
|-
|
USRHK
|
Actual
post-catalyst lambda signal control threshold, Bank 1
|-
|
USRHK2
|
Actual
post-catalyst lambda signal control threshold, Bank 2
|-
|
Z_LASH
|
Cycle
flag: post-catalyst lambda probe ageing, Bank 1
|-
|
Z_LASH2
|
Cycle
flag: post-catalyst lambda probe ageing, Bank 2
|}

LRSHK 9.20 (Continuous Post-Catalyst Lambda Control)

2012-01-10T17:43:30Z

TTQS: Created page with "See the ''funktionsrahmen'' for the following diagrams: lrshk-lrshk: function overview lrshk-lrhkini: initialization of the post-catalyst lambda control lrshk-lrhkebg: gener..."

See the ''funktionsrahmen'' for the following diagrams:

lrshk-lrshk: function overview

lrshk-lrhkini: initialization of the post-catalyst lambda control

lrshk-lrhkebg: general switch conditions post-catalyst lambda control

lrshk-lrhkla: determination of the error signal to lambda level

lrshk-dlahksm: selection of fr-synchronous lambda averaging/filtering by average value/linearizing lrshk-lambda directly

lrshk-lrhkebp: cylinder bank-specific readiness switch

lrshk-lrhkb1: PI controller post-catalyst with activation condition, cylinder bank 1

lrshk-lrhkb2: PI controller post-catalyst with activation condition, cylinder bank 2

lrshk-lrhkeb: cylinder bank-specific enable of proportional and integral components, cylinder bank 1

lrshk-lrhkeb2: cylinder bank-specific enable of proportional and integral components, cylinder bank 2

lrshk-lrhkip: PI controller, cylinder bank 1

lrshk-lrhkip2: PI controller, cylinder bank 2

lrshk-lahkma: fr-synchronous averaging

Function Description

Control with the post-catalyst probe is superimposed on the pre-cat lambda control.

Control action on the pre-catalyst control is via the delta-lambda-correction variables dlahi_w and dlahp_w.

Post-catalyst Control:

This is switched off by setting bit 0 in word CLRSHK code to 1 (FALSE).

PI Control Action

Post-catalyst lambda control is achieved with a PI controller. Control action via the proportional component dlahp_w will be immediate because it has no "memory" of the correct sign with respect
to the control position after a change of lambda probe voltage due to enrichment or enleanment by the delta-lambda intervention.

Via the integral component, post-catalyst control LRSHK is able to compensate, to a large extent, for exhaust gas deterioration, caused by a shift of the steady-state probe characteristic.

The LRSHK calculation is carried out continuously on the lambda level. This requires that the probe voltage ushk_w is linearized via the characteristic LALIUSH (lamsonh_w). A similar linearization is performed
with the voltage target value USRHK (lamsolh_w). The pseudo-value lamsonh_w can continue to work via the project-specific codeword CLRSHK

(a) directly (--> default in continuous pre-catalyst control, intervention is possible every 10 ms)

(b) via a PT1 filter (--> project-specific)

(c) fr-synchronous averaged (--> default for two-point control, as the ratio can be added only before the fr-jump)

because lamhm_w will supply the control error dlashkm_w.

By assessing the characteristic curves KDLASHKP and KDLASHKI, the control error dlashkm_w can be corrected separately according to the catalyst properties before the calculation of the P and I components.

The resulting skewed control errors dlashkp_w or dlashki_w are now weighting with KPLRHML = f (ml) of the proportional component dlahp_w, or by weighting with KILRHML = f (ml) of the integral component
dlahi_w.

In the case of aged catalysts, control oscillation of the pre-catalyst control imprinting itself on the post-catalyst probe voltage behaviour which, if proportional intervention is left unchanged, can lead to
post-catalyst control oscillations. Moreover, catalyst ageing, which is associated with a decrease in the oxygen storage capacity, the need for the proportional control action in post-catalyst control is less important. Therefore, in a further multiplication by the weighting factor from the characteristic PLRHAV = f(avkatf), the proportional component of the post-catalyst control is revoked for aged catalysts.

Effect on LRSHK of the Lambda Probe Diagnostics

Post-catalyst control takes over the additional delta Lambda offsets (dlahki_w --> pre-catalyst actual value offset, dlahkp_w --> pre-catalyst target value offset) from the former control in LRS 15.40. The magnitude of the intervention dlahi_w is a measure of probe ageing and is used in the diagnosis of lambda probe aging. A symmetric increase in the probe response time cannot be detected by dlahi_w.

Control Threshold from Map KFUSHK

If the post-catalyst probe reports that the mixture is, for example, too lean, dlahp_w will be negative according to the selected control direction and dlahi_w will become smaller. Thus, there is an enrichment until
ushk goes back up to the control threshold usrhk. In contrast to the pre-cat control, a map is provided for the post-catalyst control threshold. Via the choice of threshold, a slight load or speed-dependent lambda offset can be achieved.

If catalyst diagnostics are required in the short test B_fakat = TRUE is switched to the threshold USRHKFA.

LRSHK Control Dynamics

The superimposed control is significantly slower than the control applied before the catalyst. Since at low air mass flow rates (low load or engine speed point), the post-catalyst probe voltage as a general rule can exhibit more erratic behaviour and oscillations, following low probe voltages it should not be evaluated so strongly here. The time constant of the post-catalyst control depends on the air mass flow rate ml (--> characteristic KILRHML). At high air mass flow rates, the integration rate should be selected higher as a general rule.

Activation Conditions

If post-catalyst control LRSHK is disabled, the learned integrator value dlahi_w up to that point is the output of the post-catalyst controller. Also, when stopping the engine over the value of the continuous RAM.

The activation conditions for the proportional and integral components are defined differently and are indicated by the bits B_lrhkp and B_lrhk.

The following conditions apply for the proportional component:

When pre-catalyst control readiness (B_lr = 1) is detected, LRSHK is enabled after the delay time TBLRH. This is only useful for lambda target values (lamsons_w = 1) of the pre-catalyst control.

Post-catalyst regulation is only activated above a certain catalyst temperature threshold (tkatm > TKATMLRH) and the operational readiness of the post-catalyst probe (B_sbbhk) is activated.

The following additional conditions apply for the integral component:

Thus, the integrator is only disabled when nmot or rl is in the ranges (NLRHU =< nmot =< NLRHO and RLRHUN(nmot) =< rL =< RLRHON(nmot)). The characteristic curves RLRHUN and RLRHON make it possible to
select engine speed-dependent rL-limits on the control range. This allows the control range to be defined so that the operational ranges which give rise to incorrect adaptation of post-catalyst control are delineated. This can happen at operating points where, for example, air mass flow rates are too low.

After the overrun fuel cut-off, the catalyst is saturated with oxygen. The post-catalyst probe voltage will retain small, lean values for a certain time. In this phase, the system deactivates the section LRSKA of the post-catalyst control via bit B_lrka.

After the end of catalyst clear out, post-catalyst control is prohibited until the air mass MLNKAX has passed through the catalytic converter.

If the bit B_tehb corresponding to “tank venting high loading” is set, the integral component of LRSHK is deactivated because the integrator would learn wrong values in this case. The proportional component
remains active in this case since it helps to reduce exhaust problems.

In addition, a series of diagnostic errors deactivates post-catalyst control.

Dynamic Overshoot of the Control Threshold after Catalyst Clear Out

After the end of catalyst clear out, the post-catalyst probe voltage oscillates significantly higher than the nominal value of 600 mV for typically 5 to 30 s. The probe voltage attains values of 750-800 mV. The overshoot depends on the catalytic properties. With catalyst types that do not exhibit this behavior, the excesscan be applied away.

SCHEMATIC

The probe voltage characteristic ushk and the status bits B_sa (boost cut-off) and B_lrka (catalyst clear out) are illustrated schematically in the diagram above.

Thus the "time" (air mass MLNKAX) during which the post-catalyst control is prohibited can be kept as short as possible, the probe voltage behaviour after catalyst clear over time is described by a
dynamic increase in the target value. The input of a quick PT1 filter is populated with LASHKAB and governed by the time constant ZLASHKAB to 0. The time constant is derived from the adopted course of the probe voltage.

Through this function it is possible, in cases in which the catalyst clear out function has not been successful, or a situation in which the pre-catalyst control condition gives rise to a lean post-catalyst probe voltage, the probe voltage can be raised via LRSHK.

Application Notes

LRSHK Application Procedure:

Codeword CLRSHK

The codeword CLRSHK was introduced in order influence the treatment of the adaptation value dlahi_w within the application. The importance of the individual control bits in CLRSHK are described under the block comments.

Sensible combinations, in decimal, are listed below:

CLRSHK = odd: LRSHK is deactivated

CLRSHK = 16: dlahi_w will erase memory errors when reset with the value DLAHIINI, otherwise default status for LRSHK

CLRSHK = 24: dlahi_w is reset with the value DLAHIINI when the engine starts

Parameter LRSHK

The application of LRS must be completed.

4 x 4 grid points are provided for map KFLASOHK:

Suggestion nmot sample points: 1000, 1800, 2400 & 3000 rpm

rL: 14, 42, 56 & 70%

- Lower control limit e.g. NLRHU = 1200 rpm

Characteristic curve RLRHUN is dependent on n

- Upper control limit e.g. NLRHO = 3000 rpm

Characteristic curve RLRHON is dependent on n

The characteristic curves RLRHUN and RLRHON are strongly project-dependent. However, a characteristic with four sample points, which lie between NLRHU and NLRHO should be sufficient.

- TKATMLRH is chosen so as to control catalyst temperatures >300°C. There is a catalyst temperature model (module ATM) which yields catalyst temperatures, tkatm.

- TBLRH is dependent on the catalytic properties and should be at least 1 second to be selected. Via this label, the time that elapses after switching on the lambda control until the post-catalyst probe signal is correlated against the pre-catalyst control scheme is defined.

- KILRHML curve describes the rate of integration of the air mass in %/s.

Reference points for example engine with ml load: 450 kg/hr

ml: 8, 28, 88, 200, 400 kg/hr

KILRHML: 0.0015, 0.003, 0.0045, 0.006 and 0.0075 /s

Characteristic Curves KDLASHKI and KDLASHKP

The control error corresponding to project-specific lambda probes and catalytic converter properties can be defined via the characteristic curves KDLASHKI and KDLASHKP. So firstly, inaccuracies of the probe voltage
linearization (LALIUSH) are corrected and secondly, the emissions characteristics of catalytic converters are considered.

Application of the Proportional Component in the LRSHK PI-Control Scheme:

The effective action of the proportional component of the post-catalyst control system is calculated as follows:

dlahp_w = dlashkl x KPLRHML (ml) x PLRHAV (avkatf)

The influence of catalyst ageing is included as a multiplier in the calculation (RAM cell dlahp_w) using a factor from the characteristic curve PLRHAV, as described above. For a new catalytic converter (avkatf at 0.0), PLRHAV is populated with the value 1.0. With increasing amplitude ratio (as the catalyst ages), PLRHAV is returned to 0.0.

The choice of parameters is determined mainly by the properties of the catalyst. When we ask questions in the application development function, please contact us.

Application of the Parameter MLNKAX:

The overshoot voltage of the lambda probe after the end of the catalyst clear out function is a project-specific phenomenon, which disrupts the LRSHK. Therefore, LRSHK should be blocked until the air mass
MLNKAX has been enforced. Since there is no experience (especially with the new catalyst types), the definition of the parameters should be consulted in the responsible function for LRSKA.

Application of the Parameter KILRHML:

During application of the map KFLASO in module LRS, the post-catalyst control integration rate will be set by means of the curve KILRHML so that one sample point of the integrator control stroke dlahi_w of +/-0.03 to +/-0.04 is measured. During measurement, the air mass at the respective operating point is noted. After completion of the application of map KFLASO, the set values from KILRHML are plotted against air mass. The air mass is obtained from a scatter plot. The actual curve KILRHML in LRSHK is obtained by averaging the point cloud.

For more detailed information, please refer to the general application note in the module covering Continuous Lambda Control.

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CLRSHK
|
Codeword
to enable LRSHK and select initialization
|-
|
DLAHINI
|
Initial
value of the integrator dlahi in LRSHK, Bank 1
|-
|
DLAHINI2
|
Initial
value of the integrator dlahi in LRSHK, Bank 2
|-
|
KDLASHKI
|
Characteristic
curve of dlashkm, weighting factor for integral component in LRHK, Bank 1
|-
|
KDLASHKI2
|
Characteristic
curve of dlashkm, weighting factor for integral component in LRHK, Bank 2
|-
|
KDLASHKP
|
Characteristic
curve of dlashkm, weighting factor for proportional component in LRHK, Bank 1
|-
|
KDLASHKP2
|
Characteristic
curve of dlashkm, weighting factor for proportional component in LRHK, Bank 2
|-
|
KFUSHK
|
Probe
voltage target value for post-catalyst control (instead KFUSRHK for
Variantenk.)
|-
|
KILRHML
|
Integral
component for LRSHK
|-
|
KPLRHML
|
Proportional
component for LRSHK
|-
|
LALIUSH
|
Lambda
linearization, post-catalyst probe, Bank 1
|-
|
LALIUSH2
|
Lambda
linearization, post-catalyst probe, Bank 2
|-
|
LALIUSRH
|
Lambda
linearization, post-catalyst probe, target value, Bank 1
|-
|
LALIUSRH2
|
Lambda
linearization, post-catalyst probe, target value, Bank 2
|-
|
LASHKAB
|
Initial
value for dynamic target value increase (lamsolh) in LRHK
|-
|
LRHIMN
|
Minimum
limit of the integrator constant in LRHK
|-
|
LRHIMX
|
Maximum
limit of the integrator constant in LRHK
|-
|
MLNKAX
|
Mass
air threshold for activation readiness LRSHK integral component
|-
|
NLRHO
|
Upper
speed limit for post-catalyst control
|-
|
NLRHU
|
Lower
speed limit for post-catalyst control
|-
|
PLRHAV
|
Catalyst ageing
weighting factor for the proportional component in LRHK, Bank 1
|-
|
PLRHAV2
|
Catalyst ageing
weighting factor for the proportional component in LRHK, Bank 1
|-
|
RLLRHON
|
Characteristic
curve of nmot, rL upper control limit for the post-catalyst controller
|-
|
RLLRHUN
|
Characteristic
curve of nmot, rL lower control limit for the post-catalyst controller
|-
|
RLLRHUFA
|
rL
control limit for post-catalyst control functional requirement B_fakat
|-
|
TBLRH
|
Deactivation
time for post-catalyst control before it is enabled by pre-catalyst control
|-
|
TKATMLRH
|
Switch
threshold for model temperature for post-catalyst lambda control
|-
|
USRHKFA
|
Probe
voltage target value for control post-catalyst at function requirement,
B_fakat
|-
|
ZLASHKAB
|
Time
constant for the dynamic speed regulation. Target value increase (dlasohkab)
in LRHK
|-
|
ZLASOHML
|
PT1-filter
time constant for the pseudo post-catalyst lambda
|-
|
Variable
|
'''Description'''
|-
|
AVKATF
|
Filtered
amplitude ratio laafh/laafv, Bank 1
|-
|
AVKATF2
|
Filtered
amplitude ratio laafh/laafv, Bank 2
|-
|
B_DLAHINI
|
Condition
flag: initialization of the LRSHK integral component, Bank 1
|-
|
B_DLAHINI2
|
Condition
flag: initialization of the LRSHK integral component, Bank 2
|-
|
B_EDKVS
|
Condition
flag: actual adaptation error thresholds exceeded, Bank 1
|-
|
B EDKVS2
|
Condition
flag: actual adaptation error thresholds exceeded, Bank 2
|-
|
B_FAKAT
|
Condition
flag: monitoring function requirement catalyst
|-
|
B_FALSH
|
Functional
requirement condition post-catalyst lambda probe, Bank 1
|-
|
B_FALSH2
|
Functional
requirement condition post-catalyst lambda probe, Bank 2
|-
|
B_LR
|
LREB
Condition: pre-catalyst lambda control, Bank 1
|-
|
B_LR2
|
Condition:
pre-catalyst lambda control, Bank 2
|-
|
B_LRHK
|
Condition:
post-catalyst lambda control, Bank 1
|-
|
B_LRHK2
|
Condition:
post-catalyst lambda control, Bank 2
|-
|
B_LRHKB
|
Condition:
post-catalyst lambda control, bank specific parameters, Bank 1
|-
|
B_LRHKB2
|
Condition:
post-catalyst lambda control, bank specific parameters, Bank 2
|-
|
B_LRHKG
|
Condition:
bank independent condition post-catalyst lambda control
|-
|
B_LRHKP
|
Condition:
enable condition proportional component post-catalyst lambda control, Bank 1
|-
|
B_LRHKP2
|
Condition:
enable condition proportional component post-catalyst lambda control, Bank 2
|-
|
B_LRKA
|
Catalyst-clearing
condition for stereo lambda control, Bank 1
|-
|
B_LRKA2
|
Catalyst-clearing
condition for stereo lambda control, Bank 2
|-
|
B_LRSSP
|
Condition:
lambda-control bit set if additional amplitude sign change
|-
|
B MDARV
|
Condition:
critical dropout rate available
|-
|
B_PWF
|
Power
fail condition
|-
|
B_SBBHK
|
Condition
flag: post-catalyst lambda probe ready Bank 1
|-
|
B_SBBHK2
|
Condition
flag: post-catalyst lambda probe ready Bank 2
|-
|
B_ST
|
Start
condition
|-
|
B_TEHB
|
Tank
ventilation with high loading condition
|-
|
C_FCMCLR
|
System
status: error erasing memory
|-
|
C_INI
|
ECU
initialization condition
|-
|
DLAHI W
|
Integral
component of LRSHK, Bank 1
|-
|
DLAHI2_W
|
Integral
component of LRSHK, Bank 2
|-
|
DLAHINI2_W
|
Initialization
value for integral component LRSHK, Bank 2
|-
|
DLAHINI_W
|
Initialization
value for integral component LRSHK, Bank 1
|-
|
DLAHKAB_W
|
Dynamic
elevation of the pseudo post catalyst lambda target value, Bank 1
|-
|
DLAHKAB2_W
|
Dynamic
elevation of the pseudo post-catalyst lambda target value, Bank 2
|-
|
DLAHP_W
|
Proportional
component of LRSHK, Bank 1
|-
|
DLAHP2_W
|
Proportional
component of LRSHK, Bank 2
|-
|
DLASHKI_W
|
Delta
Lambda weighted for integral component LRSHK, Bank 1
|-
|
DLASHKI2_W
|
Delta
Lambda weighted for integral component LRSHK, Bank 2
|-
|
DLASHKM_W
|
Post-catalyst
delta lambda control (actual value fr-synchronously averaged), Bank 1
|-
|
DLASHKM2_W
|
Post-catalyst
delta lambda control (actual value fr-synchronously averaged), Bank 2
|-
|
DLASHKP_W
|
Delta-lambda
weighted for proportional component LRSHK 5.30, Bank 1
|-
|
DLASHKP2_W
|
Delta-lambda
weighted for proportional component LRSHK 5.30, Bank 2
|-
|
E_HSH
|
Error
flag: post-catalyst lambda probe heating, Bank 1
|-
|
E_HSH2
|
Error
flag: post-catalyst lambda probe heating, Bank 2
|-
|
E_HSV
|
Error
flag: pre-catalyst lambda probe heating, Bank 1
|-
|
E_HSV2
|
Error
flag: pre-catalyst lambda probe heating, Bank 2
|-
|
E_KAT
|
Error
flag: catalytic conversion, Bank 1
|-
|
E_KAT2
|
Error
flag: catalytic conversion, Bank 2
|-
|
E_LASH
|
Error
flag: post-catalyst lambda probe ageing, Bank 1
|-
|
E_LASH2
|
Error
flag: post-catalyst lambda probe ageing, Bank 2
|-
|
E_LM
|
Error
flag: main load sensor
|-
|
E_LSV
|
Error
flag: pre-catalyst lambda probe, Bank 1
|-
|
E_LSV2
|
Error
flag: pre-catalyst lambda probe, Bank 2
|-
|
E_SLS
|
Error
flag: secondary air system, Bank 1
|-
|
E_SLS2
|
Error
flag: secondary air system, Bank 2
|-
|
E_TES
|
Error
flag: fuel tank breather system
|-
|
E_TEVE
|
Error
flag: fuel tank breather valve end stage, Bank 1
|-
|
E_TEVE2
|
Error
flag: fuel tank breather valve end stage, Bank 1
|-
|
LAHKMZ
|
Status
byte of the machine: fr-synchronous averaging pseudo lambda post-catalyst,
Bank 1
|-
|
LAHKMZ2
|
Status
byte of the machine: fr-synchronous averaging pseudo lambda post-catalyst,
Bank 2
|-
|
LAMHF_W
|
Pseudo-linearized
lambda post-catalyst, PT1 filtered, Bank 1, Word
|-
|
LAMHF2_W
|
Pseudo-linearized
lambda post-catalyst, PT1-filtered, Bank 2, Word
|-
|
LAMHM_W
|
fr-synchronously
averaged pseudo post-catalyst lambda value measured by the Nernst probe, Bank
1
|-
|
LAMHM2_W
|
fr-synchronously
averaged pseudo post-catalyst lambda value measured by the Nernst probe, Bank
2
|-
|
LAMSOLH_W
|
Pseudo
post-catalyst lambda target value, Bank 1
|-
|
LAMSOLH2_W
|
Pseudo
post-catalyst lambda target value, Bank 2
|-
|
LAMSONH_W
|
Pseudo
post-catalyst lambda value measured with Nernst probe (word), Bank 2
|-
|
LAMSONH2_W
|
Pseudo
post-catalyst lambda value measured with Nernst probe (word), Bank 2
|-
|
LAMSONS_W
|
Lambda
target value based on location of lambda sensor
|-
|
LAMSONS2_W
|
Lambda
nominal value based on location lambda sensor Bank2
|-
|
ML
|
Air
mass flow
|-
|
MLNKA_W
|
Catalyst
air mass after clear out, Bank 1
|-
|
MLNKA2_W
|
Catalyst
air mass after clear out, Bank 2
|-
|
ML_W
|
Filtered
air mass (Word)
|-
|
NMOT
|
Engine
speed
|-
|
PERCNT_W
|
Number
of 10 ms steps for fr-synchronous lamsolh averaging, Bank 1
|-
|
PERCNT2_W
|
Number
of 10 ms steps for fr-synchronous lamsolh averaging, Bank 2
|-
|
RL
|
Relative
air charge
|-
|
R_T10
|
10
ms time frame
|-
|
R_T100
|
100
ms time frame
|-
|
SY_STERHK
|
System
constant condition: stereo post-catalyst system
|-
|
SY_STERVK
|
System
constant condition: stereo pre-catalyst system
|-
|
TKATM
|
Catalyst
temperature from model Bank 1
|-
|
TKATM2
|
Catalyst
temperature from model Bank 2
|-
|
USHK_W
|
Lambda
probe voltage (4.88 mV/LSB) post-catalyst, Bank 1
|-
|
USHK2_W
|
Lambda
probe voltage (4.88 mV/LSB) post-catalyst, Bank 2
|-
|
USRHK
|
Actual
post-catalyst lambda signal control threshold, Bank 1
|-
|
USRHK2
|
Actual
post-catalyst lambda signal control threshold, Bank 2
|-
|
Z_LASH
|
Cycle
flag: post-catalyst lambda probe ageing, Bank 1
|-
|
Z_LASH2
|
Cycle
flag: post-catalyst lambda probe ageing, Bank 2
|}

Main Page

2012-01-10T17:30:20Z

TTQS: /* Motronic 7 (ME7.x) Breakdown */

=NefMoto Wiki - Welcome!=
The NefMoto site is a collective body of VW/Audi ME7 ECU tuning information.

==Overview==
*[[Getting Started]]

==Flashing==
*[[NefMoto ECU Flashing Software]] - Free, fast and reliable ECU flashing
*[[ECU Bench Flashing]]
*[[Galletto 1260 Flashing Cable]] - Recover a failed flash in [[ECU Boot Mode|boot mode]]

==Software Tools==
*[http://www.nefariousmotorsports.com/wiki/index.php/NefMoto_ECU_Flashing_Software NefMoto]
*[[Me7 Logger]]
**[[GUI for Me7 Logger]]
**[[Innovate LC1 / ME7 Logger]]
*[http://www.nefariousmotorsports.com/forum/index.php/topic,447.0title,.html ME7Check]
**[http://nefariousmotorsports.com/forum/index.php/topic,447.msg9477.html#msg9477 Gui for ME7Check]
*[[ECUxPlot]]
*[[ME7_95040 EEPROM programmer - Read over OBD / (Boot mode Write)]]
*[[Findmap v0.3b]]
*[http://nefariousmotorsports.com/forum/index.php?action=dlattach;topic=639.0;attach=720 Galletto 1260]

==Motronic 7 (ME7.x) Breakdown==
*[http://s4wiki.com/wiki/Tuning S4Wiki.org Tuning guide] <- A must read!
*[[Funktionsrahmen|Bosch ME7.x Funktionsrahmen]]
*[[Checksums]]
*[[ME7 Tuning Information]]
*[[ME7 Communication Protocol Information]]
Manually translated modules
*[[ATM 33.50 (Exhaust Gas Temperature Model)]]
*[[ATR 1.60 (Exhaust Gas Temperature Control)]]
*[[BGSRM 17.10 (Cylinder Charge Detection, Intake Manifold Model)]]
*[[FUEDK 21.90 (Cylinder Charge Control, Calculating Target Throttle Angle)]]
*[[GGHFM 57.60 (MAF Meter System Pulsations)]]
*[[LAMBTS 2.120 (Lambda for Component Protection)]]
*[[LAMFAW 7.100 (Driver's Requested Lambda)]]
*[[LAMKO 9.80 (Lambda Coordination)]]
*[[LDRLMX 3.100 (Calculation of LDR Maximum Cylinder Charge rlmax)]]
*[[LDRPID 25.10 (Charge Pressure Regulation PID Control)]]
*[[LRSHK 9.20 (Continuous Post-Catalyst Lambda Control)]]
*[[MDBAS 8.30 (Calculation of the Basic Parameters for the Torque Interface)]]
*[[MDFAW 12.260 (Driver Requested Torque)]]
*[[MDFUE 8.50 (Setpoint for Air Mass from Load Torque)]]
*[[MDKOG 14.70 (Torque Coordination for Overall Interventions)]]
*[[MDZW 1.120 (Calculating Torque at the Desired Ignition Angle)]]
*[[RKTI 11.40 (Calculation of Injection Time ti from Relative Fuel Mass rk)]]
*[[SLS 88.150 (Secondary Air Control)]]
*[[ZUE 282.130 (Fundamental Function - Ignition)]]
*[[ZWGRU 23.110 (Fundamental Ignition Angle)]]

==Motronic MED9 Breakdown==

*[[MED9 Abbreviations in English (A-C)]]
*[[MED9 Abbreviations in English (D-F)]]
*[[MED9 Abbreviations in English (G-L)]]
*[[MED9 Abbreviations in English (M-Q)]]
*[[MED9 Abbreviations in English (R-S)]]
*[[MED9 Abbreviations in English (T)]]
*[[MED9 Abbreviations in English (U-Z)]]
*[http://nefariousmotorsports.com/forum/index.php?topic=1353.0 Download all as Excel workbook]

==Development==
*[[Reverse Engineering Generic Guide]]
*[[Camden's ME7.5 Reverse Engineering]]
*[[ECU pin outs]]

==Vehicle Information==
*[[Volkswagen]]
*[[Audi]]

ATM 33.50 (Exhaust Gas Temperature Model)

2012-01-08T18:15:40Z

TTQS:

Refer to the ''funktionsrahmen'' for the following diagrams:

atm-main

atm-atm-b1 Exhaust gas temperature model (cylinder bank 1) overview

atm-tmp-stat TMP_STAT engine speed & relative cylinder charge map and corrected for temperature for acceleration, intake air temp., catalyst heating, catalyst warming, ignition angle, lambda and cold engine

atm-dynamik Temperature dynamic for exhaust gas and catalytic converter temperature (in and near the catalytic
converter)

atm-tabgm Temperature dynamic: exhaust gas, exhaust pipe wall effect, from the exhaust gas temperature tabgm

atm-tkatm Temperature dynamic for the temperature near the catalytic converter

atm-exotherme Exothermic temperature increase near the catalyst from measurement sites tabgm to tikatm

atm-tikatm Temperature dynamic for the temperature in the catalytic converter

atm-exoikat Exothermic temperature increase in the catalyst from measurement sites tabgm to tikatm

atm-kr-stat Exhaust gas temperature in the exhaust manifold under steady-state conditions

atm-kr-dyn Exhaust gas temperature in the exhaust manifold under dynamic conditions

atm-tmp-start Calculation of the exhaust gas or exhaust pipe wall temperature at engine start

atm-tpe-logik Calculation of the dew point at the pre-cat and post-cat lambda probes

atm-sp-nachl Storage of the dew point conditions at engine switch off

atm-mean Calculation of etazwist average values

atm-tmp-umgm If no ambient temperature sensor is available, calculate a substitute from ambient temperature (tans)

atm-mst If tabst_w is not correct tabstatm = maximum value, request for delay B_nlatm as a function of engine speed and tatu-threshold)

ATM 33.50 (Exhaust Gas Temperature Model) Function Description

The simulated exhaust gas temperatures tabgm and tabgkrm (for SY_TURBO = 1) and catalytic converter
temperatures tkatm and tikatm are used for the following purposes:

1. Monitoring the catalyst. If the catalytic converter falls below its starting temperature, then a fault can be detected.

2. For lambda control on the probe after the catalytic converter. This control is only activated after engine start, when the catalyst has exceeded its start-up temperature.

3. For the probe heater control after engine start. If the simulated dew point is exceeded, the probe heater is turned on.

4. Monitoring the heated exhaust gas oxygen (HEGO) sensor (i.e. lambda probe) heating system. If the exhaust gas temperature exceeds 800°C for example, then the lambda probe heater will be switched off, so that the probe is not too hot.

5. For fan motor control.

6. For switching on component protection.

This function provides only a rough approximation of the exhaust gas and catalytic converter temperature profiles, whereas throughout the application especially the four monitoring areas (dew point profiles in the exhaust gas, catalytic converter monitoring, enabling and shutting off lambda probe heating and high temperatures for component protection) should be considered to be critical.

1. Basic function

Steady-state temperature (tatmsta): the same applies for takrstc

With the engine speed/relative cylinder charge map KFTATM the steady-state exhaust gas temperature before the catalyst is set. This temperature is corrected for ambient temperature or simulated ambient temperature from the characteristic ATMTANS:

during boost with the constant TATMSA,

during catalyst heating with the constant TATMKH; catalyst warming with the constant TATMKW

with the ignition-angle efficiency map KFATMZW temperature as a function of ML and ETAZWIST

with the desired lambda map KFATMLA temperature as a function of ML and LAMSBG_W

for a cold engine block (TMOT - TATMTMOT) with TATMTMOT = 90°C.

The catalyst temperature (exothermic) is corrected for:

Temperature increase with the characteristic KATMEXML or KATMIEXML as a function of air mass

Temperature reduction with KLATMZWE or KLATMIZWE as a function of etazwimt (ignition angle influence)

Lambda influence with KLATMLAE or KLATMILAE as a function of lambsbg_w

Temperature set at TKATMOE or TIKATMOE at tabgm <TABGMEX or B_sa = 1

Different temperature increases are applied for the temperature in the catalytic converter tikatm and the temperature after the catalytic converter tkatm due to exothermic reaction and cooling and different ignition angles and lambda-corrections.

The time-based influence of the exhaust gas temperature before the catalytic converter:

Using a PT1 filter (filter time constant ZATMAML) the dynamics of the exhaust gas temperature are simulated and with a PT1 filter (time constant ZATMRML) the dynamics of the inlet manifold wall temperature are simulated.

The exhaust gas temperature and inlet manifold wall temperature are weighted by the division factor FATMRML.

The catalytic converter temperature tkatm is calculated from the exhaust gas temperature tabgm along with the PT1 filter (filter time constant ZATMKML).

The temperature in the catalyst tikatm is modelled from the exhaust gas temperature tabgm via three filters (time constant ZATMIKML) using the heat transfer principle. Due to a thrust caused by the small air mass flow in the catalytic converter, there is a possible exhaust gas temperature increase due to the greater influence on the matrix temperature by the exhaust gas throughput. This thrust-based temperature increase can be modelled by the positive B_sa side with a temperature, which is composed of the catalyst temperature tikatm and an offset TATMSAE, will be initialised. The time constants of the PT1-filter ZATMIKML are represented by air-mass-dependent characteristic curves.

The initial values for the exhaust and catalyst temperature at engine start can be calculated from the temperatures at switch-off and delay times. The starting values for the exhaust gas and catalyst temperatures should approximate to the manifold wall temperatures at the probe insertion points a few minutes after switch-off.
The filter for the exhaust gas temperature is stopped by setting B_stend = 0.
The filter for the manifold wall temperature is stopped when B_atmtpa = 1. The
filter for the catalyst temperature will be enabled only when B_atmtpk = 1.

2. Dew Point Detection

Initial values for the exhaust gas temperature tabgmst and catalyst temperature tkatmst

When stopping the engine (C_nachl 0 ® 1) the temperatures tabgm and tkatm are stored.

When starting the engine, the initial temperatures tabgmst and tkatmst are calculated from the switch-off temperature (corrected for ambient temperature) and a factor obtained from maps KFATMABKA or KFATMABKK as a function of tabstatm and tatu.

During power fail the switch-off temperature will be determined from the constant TATMSTI.

For test condition (B_faatm = 1), the initial temperatures are given by the constants TASTBFA and TKSTBFA.

Integrated Heat Quantity iwmatm_w

The dew point end time is approximately proportional to the heat quantity after engine start. The heat quantity = Integral (temp. x air mass x Cp) is calculated from the steady-state exhaust gas temperature tatmsta plus TATMWMK multiplied by the air mass. The result of the integration multiplied by the heat capacity at constant pressure Cp (approximately 1 kJ/kgK) gives the heat quantity.

Dew point end for the pre-cat lambda probe B_atmtpa and post-cat lambda probe B_atmtpk

The calculated exhaust gas temperature at engine start tabgmst approximates to the exhaust pipe wall temperature. If the exhaust pipe wall temperature is greater than 60°C for example then no condensation occurs.
The values in the map KFWMABG for these temperatures are less than 14 kJ, so the dew point end is detected immediately, or after only a few seconds.

For catalytic converter heating with thermal reaction (B_trkh = 1) the values in maps KFWMABG or KFWMKAT are multiplied by the factor WMKATKH or WMABGKH respectively. Thus, the dew point end-times are very short for this mode of operation.

Repeated starts (extension of the dew point-end-times)

If the engine had not reached the dew point end (B_atmtpa = 0 and B_atmtpf = 0) then when the engine restarts, the counter zwmatmf is increased by 1. After several periods of very short engine running (e.g. 3), the counter zwmatmf value would be set equal to 3. With a constant FWMABGW = 0.25 for example, the values in the map KFWMABG increase by a factor equal to (zwmatmf x KFWMABG + 1) = 1.75. When the engine starts, the dew point end time from the last engine run is detected and the
counter zwmatmf is reset.

Storage of the dew point end condition in the delay

For the determination of repeat start dew point end the conditions B_atmtpa in the flag B_atmtpf and B_atmtpk in the flag B_atmtpl are saved at engine switch-off due to a regular switch-off using the ignition or stall (B_stndnl). The function of dew point end for the post-cat lambda probe B_atmtpk
is analogous to the function for B_atmtpa.

3. Calculation of a simulated ambient temperature from the intake air temperature (tans) if no ambient temperature sensor is available.

The simulated temperature tatu will be used for calculating the temperature correction via the characteristic ATMTANS and for determining the starting temperatures tabgmst and tkatmst. The intake air temperature (tans) is corrected with the constant DTUMTAT and under certain conditions stored in continuous RAM. If for example at engine start, the temperature tatu > tans, then the temperature value tatu is set on the lower tans value.

With the constant TATMWMK (negative value) the difference in dew point end between catalyst heating and no catalyst heating can be increased.

When catalytic converter heating is active B_khtr = 1 and the bit B_atmtpa can be set equal to 1 immediately after engine start. This is possible only when no problematic condensation is formed during catalyst heating.

With the system constants SY_STERVK = 1 cylinder bank 2 can be applied separately for stereo systems.

For SY_TURBO = 1 the exhaust gas temperature tabgm is essentially identical in addition to the modeled temperature in the manifold tabgkrm.

ATM 33.50 Application Notes

1. Installation locations for temperature sensors in this application, running in
the direction of flow:

- In probe installation position before catalytic converter-

1. Exhaust gas temperature (pipe centre) for the high temperatures at high loads for probe heater switch off

2. Manifold wall temperature for the determination of the dew-end times. (Condensation protection)

- Before the catalytic converter

3. Exhaust gas temperature (pipe centre) for the catalyst start-up temperature

- In the catalytic converter

4. Ceramic temperature in and after catalytic converter (in the last third of the catalytic converter or behind the adjoining matrix) to determine the air-mass-dependent time constants.

- After the catalytic converter

5. Pipe wall temperature at probe installation site for the determination of the dew-end times (condensation protection).

Temperature measuring point 3 can be omitted if the distance from probe to catalytic converter is smaller than about 30 cm. The temperature drop from probe installation site to catalytic converter can then be neglected.

For the application of the functional data the modelled temperatures will always be compared with the measured temperatures and the functional data amended until a sufficiently high accuracy is achieved. In so doing, it will be the actual catalyst temperature, the temperature increase due to the exothermic reaction is not considered in the model.

2. Map KFTATM

For the determination of the steady-state temperature for example, before the catalytic converter the temperature corrections should not function. The cooling capacity of the wind on the dynamometer or on the measuring wheel can be simulated only very roughly at the higher engine load range. The map values can be determined on the rolling road dynamometer, but should be corrected on an
appropriate test drive.

3. Temperature Corrections

- TATMSA

Boost can cause low exhaust temperatures that fall below the starting temperature of the catalyst. The longer the time period for the thrust condition, the lower the exhaust and catalyst temperatures. For catalyst diagnosis during boost, the exhaust gas temperature model is more likely to calculate a lower value than the measured temperature.

- ATMTANS

At low ambient temperatures, exhaust gas temperature can fall below the catalyst start-up temperature. Therefore, the model temperature is only corrected at the low temperature range.

- TATMKH

As long as the catalyst-heating measures are effective, higher exhaust temperatures will result.

- TATMKW

The catalyst operating temperature will not be not reached during prolonged idling, so the exhaust gas temperature can be raised by the catalyst warming function.

- KFATMZW

The temperature increase as a result of ignition angle retardation can be determined on a rolling road dynamometer. First, on the dynamometer, the characteristic field values KFTATM are applied without ignition angle correction. Ignition angles are then modified so that allowed etazwist values will result in the map. Through the corresponding air mass, the temperature increase will then be displayed in the map KFATMZW.

- KFATMLA

The exhaust temperature is reduced by enrichment. The application is similar to KFATMZW, except that the ignition angle efficiency is changed instead of the enrichment factor.

- TATMTMOT

The map KFTATM is applied with a warm engine. Thus, the model exhaust gas temperature has smaller deviations during cold start. For this operating mode, the temperature is corrected with the difference of the cold engine temperature and the warm engine temperature. TATMTMOT should be about 90 to 100°C.

4. Maps ZATMAML, ZATMRML, FATMRML, ZATMKML, ZATMKKML, ZATMIKML und ZATMIKKML

The air-mass-dependent time constants ZATMAML, ZATMRML (temperature measuring points 1 or 3), and ZATMKML, ZATMKKML, ZATMIKML, ZATMIKKML (temperature measuring point 4), can help to more accurately determine “spikes in the air mass” during sudden load variations. Thereby "air mass jumps" at full load and in particular during boost can be avoided. For example, for an air mass jump from 30 kg/hr to 80 kg/hr, the measured time constant is applied to the air mass flow of 80 kg/hr. For large air mass jumps during idle, the time constants ZATMKKML and ZATMIKKML can be input instead of ZATMKML or ZATMIKML if required.

5. Block EXOTHERME:

- KATMEXML

The exothermic temperature is a function of air mass flow (warming by realizing emissions, reducing warming via a larger air mass). First KATMEXML applies, then KLATMZWE, KLATMLAE.

- KLATMZWE

When ignition angle retardation increases the temperature before the catalyst, the catalyst temperature drops.

- KLATMLAE

For lambda < 1 (richer), the air mass is lacking to improve emissions so the catalyst temperature decreases.

- TABGMEX

If the temperature before the catalyst tabgm < TABGMEX (catalyst switch-off temperature) then the temperature correction = TKATMOE.

- TKATMOE

Temperature correction during boost or through tabgm> TABGMEX

- TATMSAE

Temperature increase in the boost in the catalyst in terms of tkatm

Block EXOIKAT:

- KATMIEXML, KLATMIZWE, KLATMILAE, TIKATMOE

Application depends on the application for Block EXOTHERME

- TATMSAE

Temperature increase in the thrust in the catalyst in terms of tikatm

6. Dew point end times for exhaust gas temperatures vary greatly between the centre of the exhaust pipe and the pipe wall. Dew point end times for the tube wall temperatures before the catalyst (temperature measuring points 2) or after the catalyst (temperature measuring points 5) should be used. These times are usually due to delaying control readiness for too long, in which case the temperature gradients at the probe mounting location must be examined more closely. To avoid probe damage by “water hammer”, the sensor heater must be fully turned on until the dew point temperature is exceeded or the dew point end time is detected thus condensation will no longer occur.

When the switch-off time in the ECU delay is calculated, then the switch-off time tabst_w after ECU delay will be incorrect. At engine start after ECU delay, the switch-off time tabstatm therefore, will be set to the maximum value of 65,535 (i.e. 216-1). The ECU delay requirement for the time TNLATM when engine speed > TNLATMTM & tumg (tatu) > TNLATMTU.

8. For blocks KR_STAT and KR_DYN as appropriate, the descriptions in points 3 and
4 shall apply.

Typical Values:

KFTATM: x: engine speed/RPM, y: relative cylinder charge/%, z: temperature/°C

{| border="1"
|-
|
|
800
|
1200
|
1800
|
2400
|
3000
|
4000
|
5000
|
6000
|-
|
15
|
380
|
400
|
420
|
450
|
480
|
520
|
550
|
580
|-
|
22
|
400
|
420
|
450
|
480
|
520
|
550
|
580
|
610
|-
|
30
|
420
|
450
|
480
|
520
|
550
|
580
|
610
|
650
|-
|
50
|
450
|
480
|
520
|
550
|
580
|
610
|
650
|
700
|-
|
70
|
470
|
520
|
550
|
580
|
610
|
660
|
700
|
750
|-
|
100
|
490
|
550
|
580
|
610
|
650
|
700
|
750
|
790
|-
|
120
|
510
|
560
|
610
|
650
|
700
|
750
|
790
|
840
|-
|
140
|
530
|
580
|
650
|
700
|
750
|
790
|
840
|
900
|}

KFATMZW: x: temperature/°C, y: ml_w/kg/hr, z: etazwimt

{| border="1"
|-
|
|
20
|
40
|
80
|
150
|
250
|
400
|-
|
1.00
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|-
|
0.95
|
15
|
40
|
50
|
60
|
70
|
75
|-
|
0.90
|
15
|
60
|
80
|
100
|
125
|
140
|-
|
0.80
|
20
|
80
|
120
|
150
|
180
|
200
|-
|
0.70
|
25
|
100
|
150
|
190
|
210
|
220
|-
|
0.60
|
30
|
115
|
175
|
210
|
230
|
245
|}

KFATMLA: x: temperature/°C, y: ml_w/kg/hr, z: lamsbg_w

{| border="1"
|-
|
|
20
|
40
|
80
|
150
|
250
|
400
|-
|
1.15
|
5
|
10
|
30
|
50
|
60
|
70
|-
|
1.00
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|-
|
0.95
|
5
|
10
|
20
|
30
|
40
|
45
|-
|
0.90
|
15
|
25
|
40
|
50
|
60
|
75
|-
|
0.80
|
30
|
40
|
60
|
70
|
85
|
100
|-
|
0.70
|
40
|
60
|
80
|
90
|
100
|
120
|}

KFWMABG: x: energy/kJ, y: tabgmst/°C, z: tmst/°C

{| border="1"
|-
|
|
-40
|
0
|
15
|
25
|
30
|
55
|
60
|-
|
-40
|
200
|
160
|
150
|
140
|
100
|
60
|
30
|-
|
0
|
180
|
150
|
120
|
110
|
80
|
50
|
20
|-
|
15
|
160
|
140
|
60
|
55
|
30
|
40
|
0.45
|-
|
25
|
140
|
120
|
30
|
30
|
15
|
10
|
0.45
|-
|
60
|
120
|
30
|
20
|
15
|
10
|
5
|
0.45
|}

KFWMKAT values correspond to KFWMABG x 5

In the heat quantity maps KFWMABG and KFWMKAT a value of 0.0 is never required! It should always have at least the value to be entered; the 2 sec corresponds to idle after cold start. Only then does the repeat-start counter operate after several starts where the dew point was not reached.

ZATMAML

ml_w/kg/hr, Time constant/sec 10, 30 ; 20, 20 ; 40, 13 ; 80, 5 ; 180, 4 ; 400, 3 ; 600, 2 ;

ZATMKML

ml_w/kg/hr, Time constant/sec 10, 150 ; 20, 60 ; 40, 35 ; 80, 20 ; 180, 10 ;
400, 7 ; 600, 4 ;

ZATMIKML

value represents approximately ZATMKML x 0.3

ZATMKKML

for neutral input, the data must correlate to ZATMKML

ZATMIKKML

for neutral input, the data must correlate to ZATMIKML

ZATMRML

ml_w/kg/hr, Time constant/sec 10, 300 ; 20, 80 ; 40, 55 ; 80, 30 ; 180, 20 ; 400, 10 ; 600, 7 ;

FATMRML

ml_w/kg/hr, Time constant/sec 10, 0.5 ; 20, 0.6 ; 40, 0.7 ; 80, 0.8 ; 180, 0.95 ; 400,0.95 ; 600, 0.96;

KATMEXML

ml_w/kg/hr, Time constant/sec 10, 0 ; 20, 0 ; 40, 0 ; 80, 0 ; 180, 0 ; 400, 0 ;

KLATMZWE

etazwimt, Factor 1, 0 ; 0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ; 0.6, 0 ;

KLATMLAE

lamsbg_w, Factor 1.15, 0 ; 1 , 0 ;0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ;

TATMTP: 52°C

TKATMOE: 0°C

TATMSAE: 0°C

KATMIEXML

ml_w/kg/hr, Time constant/sec 10, 0 ; 20, 0 ; 40, 0 ; 80, 0 ; 180, 0 ; 400, 0 ;

KLATMIZWE

etazwimt, Factor 1, 0 ; 0.95, 0 ; 0.9, 0; 0.8, 0 ; 0.7, 0 ; 0.6, 0 ;

KLATMILAE

lamsbg_w, Factor 1.15, 0 ; 1 , 0 ;0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ;

TIKATMOE: 0°C

KFATMABKA: x: tatu/°C, y: tabstatm_w/seconds, z: no units

{| border="1"
|-
|
|
10
|
50
|
180
|
360
|
600
|
1000
|-
|
-40
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
-15
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
0
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
15
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
40
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|}

KFATMABKK: x: tatu/°C, y: tabstatm_w [s], z: no units

{| border="1"
|-
|
|
10
|
50
|
180
|
360
|
600
|
1000
|-
|
-40
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
-15
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
0
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
15
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
40
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|}

ATMTANS tatu/°C, Temp./°C -40, 60 ; -10, 20 ; 20, 0 ;

TATMSA: 100°C

TATMKH: 80°C

TATMTRKH: 200°C

TATMKW: 100°C

TATMTMOT: 90°C

TATMSTI: 20°C

TASTBFA: 40°C

TKSTBFA: 40°C

TATMWMK: -80°C

WMABGKH: Factor of 1.0

WMKATKH: Factor of 1.0

FWMABGW: Factor of 0.25

FWMKATW: Factor of 0.25

DTUMTAT: 20°C

VTUMTAT: 40 km/h

NTUMTAT: 1800 rpm

IMTUMTAT: 1 kg

TUMTAIT: 20°C

TNLATMTM: 80°C

TNLATMTU: 5°C

TNLATM: 660 seconds

Only when SY_TURBO = 1:

For neutral input (tabgkrm_w = tabgm_w)

KFATMKR = KFTATM

KFATZWK = KFATMZW

KFATLAK = KFATMLA

TATMKRSA = TATMSA

ZATRKRML = ZATMRML

ZATAKRML = ZATMAML

FATRKRML = FATMRML

ATMTANS
tans/°C, Temp./°C -40, 40 ; -20, 25 ; 0, 12 ; 20, 0 ; 60, -30

The functional data for cylinder bank 2 correspond to the functional data from cylinder bank 1 Note:

In order that ATM 22:20 for the application is backward compatible the default values should be entered thus: KATMEXML, KLATMZWE, KLATMLAE, TKATMOE = 0 and TABGMEX = 1220°C.

In order that ATM 33.10 remains application-neutral with ATM 22.50, TATMTRKH must be set equal to TATMKH and WMKATKH should be set equal to 1. Tikatm is not used in a function because the input can be used in the path in the exhaust gas temperature model without impact on safety, however, the default values for KATMIEXML, KLATMIZWE, KLATMILAE and TIKATMOE should be set equal to 0 and TABGMEX = 1220°C.

In DKATSP areas TMINKATS and TMAXKATS, a high accuracy is required for tikatm!

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
ATMTAKR
|
Correction
for the manifold temperature
|-
|
ATMTANS
|
Temperature
correction for the exhaust gas temperature model
|-
|
DTUMTAT
|
Offset:
intake air temperature ® ambient temperature
|-
|
FATMRML
|
Factor
for the difference between exhaust gas & exhaust pipe wall temperature
|-
|
FATMRML2
|
Factor
for the difference between exhaust gas & exhaust pipe wall temperature, cylinder
bank 2
|-
|
FATRKRML
|
Factor
for the difference between exhaust gas & wall temperature in the manifold
|-
|
FATRKRML2
|
Factor
for the difference between exhaust gas & wall temperature in the manifold,
cylinder bank 2
|-
|
FWMABGW
|
Factor
for heat quantity during repeated starts for pre-cat exhaust gas dew points
|-
|
FWMABGW2
|
Factor
for heat quantity during repeated starts for pre-cat exhaust gas dew points,
cylinder bank 2
|-
|
FWMKATW
|
Factor
for heat quantities during repeated starts for dew points after main catalyst
|-
|
FWMKATW2
|
Factor
for heat quantities during repeated starts for dew points after main catalyst,
cylinder bank 2
|-
|
IMTUMTAT
|
Integration
threshold air mass for determining ambient temperature from TANS
|-
|
KATMEXML
|
Exothermic
reaction temperature in catalyst, tkatm
|-
|
KATMEXML2
|
Exothermic
reaction temperature in catalyst, cylinder bank 2
|-
|
KATMIEXML
|
Exothermic
reaction temperature in catalyst, tikatm
|-
|
KATMIEXML2
|
Exothermic
reaction temperature in catalyst, tikatm, cylinder bank 2
|-
|
KFATLAK
|
Map for
lambda correction for manifold exhaust gas temperature
|-
|
KFATLAK2
|
Map for
lambda correction for manifold exhaust gas temperature, cylinder bank 2
|-
|
KFATMABKA
|
Factor
for exhaust gas temperature decrease as a function of stop time and ambient
temperature
|-
|
KFATMABKA2
|
Factor
for exhaust gas temperature decrease as a function of stop time and ambient
temperature, cylinder bank 2
|-
|
KFATMABKK
|
Factor
for reducing the catalyst temperature as a function of stop time and ambient
temperature
|-
|
KFATMABKK2
|
Factor
for reducing the catalyst temperature as a function of stop time and ambient
temperature, cylinder bank 2
|-
|
KFATMKR
|
Map for
steady-state manifold exhaust gas temperature as a function of engine speed
and relative cylinder charge
|-
|
KFATMKR2
|
Map for
steady-state manifold exhaust gas temperature, cylinder bank 2
|-
|
KFATMLA
|
Map for
exhaust gas temperature correction as a function of lambda
|-
|
KFATMLA2
|
Map for
exhaust gas temperature correction as a function of lambda, cylinder bank 2
|-
|
KFATMZW
|
Map for
exhaust gas temperature correction as a function of igntion angle correction
|-
|
KFATMZW2
|
Map for
exhaust gas temperature correction as a function of ignition angle, cylinder
bank 2
|-
|
KFATZWK
|
Map for
ignition angle correction for manifold gas temperature
|-
|
KFATZWK2
|
Map for
ignition angle correction for manifold gas temperature, cylinder bank 2
|-
|
KFTATM
|
Map for
exhaust gas temperature as a function of engine speed and relative cylinder
charge
|-
|
KFTATM2
|
Map for
exhaust gas temperature as a function of engine speed and relative cylinder
charge for cylinder bank 2
|-
|
KFWMABG
|
Map for
heat quantity threshold exhaust gas dew points
|-
|
KFWMABG2
|
Map for
heat quantity threshold exhaust gas dew points, cylinder bank 2
|-
|
KFWMKAT
|
Map for
heat quantity threshold dew points after catalyst
|-
|
KFWMKAT2
|
Map for
heat quantity threshold dew points after catalyst, cylinder bank 2
|-
|
KLATMILAE
|
Exothermic
temperature decrease through enrichment, tikatm
|-
|
KLATMILAE2
|
Exothermic
temperature decrease through enrichment, tikatm, Bank 2
|-
|
KLATMIZWE
|
Exothermic
temperature decrease in catalyst at later ignition angles, tikatm
|-
|
KLATMIZWE2
|
Exothermic
temperature decrease in catalyst at later ignition angles, tikatm, Bank 2
|-
|
KLATMLAE
|
Exothermic
temperature decrease through enrichment
|-
|
KLATMLAE2
|
Exothermic
temperature decrease through enrichment, cylinder bank 2
|-
|
KLATMZWE
|
Exothermic
temperature decrease in catalyst at later ignition angles, tkatm
|-
|
KLATMZWE2
|
Exothermic
temperature decrease in catalyst at later ignition angles, cylinder bank 2
|-
|
NTUMTAT
|
Speed
threshold for determining ambient temperature from TANS
|-
|
SEZ06TMUB
|
Sample
point distribution, ignition angle efficiency
|-
|
SLX06TMUW
|
Sample
point distribution, desired lambda
|-
|
SLY06TMUW
|
Sample
point distribution, desired lambda, cylinder bank 2
|-
|
SML06TMUW
|
Sample
point distribution, air mass, 6 sample points
|-
|
SML07TMUW
|
Sample
point distribution, air mass, 7 sample points
|-
|
SMT06TMUW
|
Sample
point distribution, air mass, 6 sample points
|-
|
ST107TMUB
|
Sample
point distribution, start temperature at front probe
|-
|
ST207TMUB
|
Sample
point distribution, start temperature at front probe, cylinder bank 2
|-
|
ST307TMUB
|
Sample point
distribution, start temperature at rear probe
|-
|
ST407TMUB
|
Sample
point distribution, start temperature at rear probe, cylinder bank 2
|-
|
STM05TMUB
|
Sample
point distribution, engine start temperature
|-
|
STS06TMUW
|
Sample
point distribution, exhaust gas mass flow
|-
|
STU05TMUB
|
Sample
point distribution, simulated ambient temperature
|-
|
SY_STERVK
|
System
constant condition: stereo before catalyst
|-
|
SY_TURBO
|
System
constant: turbocharger
|-
|
TABGMEX
|
Exhaust
gas temperature below the catalyst switch-off temperature
|-
|
TASTBFA
|
Model temperature
before pre-cat initial value via B_faatm requirement
|-
|
TATMKH
|
Exhaust
gas temperature correction via catalyst heating active
|-
|
TATMKH2
|
Exhaust
gas temperature correction via catalyst heating active, cylinder bank 2
|-
|
TATMKRSA
|
Exhaust
gas temperature correction in manifold via boost switch-off
|-
|
TATMKW
|
Exhaust
gas temperature correction with catalyst warming active
|-
|
TATMSA
|
Exhaust
gas temperature correction via boost cut-off
|-
|
TATMSAE
|
Exothermic
temperature increase in boost
|-
|
TATMSAE2
|
Exothermic
temperature increase in boost, cylinder bank 2
|-
|
TATMSTI
|
Initial
value for tabgm, tkatm intial value through power fail
|-
|
TATMTMOT
|
Engine temperature
warmer Motor, for temperature correction during cold start conditions
|-
|
TATMTP
|
Exhaust
gas dew point temperature
|-
|
TATMTRKH
|
Exhaust
gas temperature correction via thermal reaction catalyst heating
|-
|
TATMTRKH2
|
Exhaust
gas temperature correction via thermal reaction catalyst heating, cylinder bank
2
|-
|
TATMWMK
|
Temperature
offset for calculating heat quantities
|-
|
TIKATMOE
|
Temperature
correction in catalyst without exothermic reaction, tikatm
|-
|
TKATMOE
|
Temperature
correction near catalyst without exothermic reaction, tkatm
|-
|
TKSTBFA
|
Model temperature
post-cat initial value via B_faatm requirement
|-
|
TNLATM
|
Minimum
ECU delay time for exhaust gas temperature model – Abstellzeit
|-
|
TNLATMTM
|
When
tmot > threshold ECU delay requirement B_nlatm = 1
|-
|
TNLATMTU
|
When
tumg (tatu – ATM) > threshold ECU delay requirement
|-
|
TUMTAIT
|
Initialising
value for ambient temperature from TANS
|-
|
VTUMTAT
|
Vehicle
speed threshold for TANS ® ambient temperature
|-
|
WMABGKH
|
Factor
for heat quantity correction via catalyst heating for dew points
|-
|
WMABGKH2
|
Factor
for heat quantity correction via catalyst heating for dew points, cylinder bank
2
|-
|
WMKATKH
|
Factor
for heat quantity correction via catalyst heating for dew points after
catalyst
|-
|
WMKATKH2
|
Factor
for heat quantity correction via catalyst heating for dew points after
catalyst, cylinder bank 2
|-
|
ZATAKRML
|
Time
constant for exhaust gas temperature model (manifold)
|-
|
ZATAKRML2
|
Time
constant for exhaust gas temperature model (manifold), cylinder bank 2
|-
|
ZATMAML
|
Time
constant for exhaust gas temperature model
|-
|
ZATMAML2
|
Time
constant for exhaust gas temperature model, cylinder bank 2
|-
|
ZATMIKKML
|
Time
constant for catalyst temperature model – Temperature in catalyst tikatm during
cooling
|-
|
ZATMIKKML2
|
Time
constant for catalyst temperature model – Temperature in catalyst tikatm
during cooling, bank 2
|-
|
ZATMIKML
|
Time
constant for catalyst temperature model – Temperature in catalyst, tikatm
|-
|
ZATMIKML2
|
Time
constant for catalyst temperature model – Temperature in catalyst, cylinder bank
2
|-
|
ZATMKKML
|
Time
constant for catalyst temperature model – catalyst temperature tkatm during
cooling
|-
|
ZATMKKML2
|
Time
constant for catalyst temperature model – catalyst temperature tkatm during
cooling, bank 2
|-
|
ZATMKML
|
Time
constant for catalyst temperature model – catalyst temperature tkatm
|-
|
ZATMKML2
|
Time
constant for catalyst temperature model – catalyst temperature, cylinder bank
2
|-
|
ZATMRML
|
Time
constant for exhaust gas temperature model – exhaust pipe wall temperature
|-
|
ZATMRML2
|
Time
constant for exhaust gas temperature model – exhaust pipe wall temperature Bank
2
|-
|
ZATRKRML
|
Time
constant for exhaust gas temperature model – manifold wall temperature
|-
|
ZATRKRML2
|
Time
constant for exhaust gas temperature model – manifold wall temperature, cylinder
bank 2
|-
|
Variable
|
Description
|-
|
B_ATMLL
|
Condition
for time constant during cooling at idle
|-
|
B_ATMLL2
|
Condition
for time constant during cooling at idle
|-
|
B_ATMST
|
Condition
for tabgmst, tkatmst initial value calculation
|-
|
B_ATMST2
|
Condition
for tabgmst, tkatmst calculation, cylinder bank 2
|-
|
B_ATMTPA
|
Condition:
dew point before catalyst exceeded
|-
|
B_ATMTPA2
|
Condition:
dew point 2 before catalyst exceeded
|-
|
B_ATMTPF
|
Condition:
dew point before catalyst exceeded (last trip)
|-
|
B_ATMTPF2
|
Condition:
dew point before catalyst exceeded (last trip) cylinder bank 2
|-
|
B_ATMTPK
|
Condition:
dew point after catalyst exceeded
|-
|
B_ATMTPK2
|
Condition:
dew point 2 after catalyst exceeded
|-
|
B_ATMTPL
|
Condition: dew point after catalyst exceeded (last trip)
|-
|
B_ATMTPL2
|
Condition: dew point after catalyst exceeded (last trip) cylinder bank 2
|-
|
B_FAATM
|
Condition: functional requirements for dew
point end times
|-
|
B_KH
|
Condition: catalyst heating
|-
|
B_KW
|
Condition: catalyst warming
|-
|
B_LL
|
Condition: idle
|-
|
B_NACHL
|
Condition: ECU delay
|-
|
B_NACHLEND
|
Condition: ECU delay ended
|-
|
B_NLATM
|
Condition: ECU delay exhaust gas temperature
model probe protection
|-
|
B_PWF
|
Condition: Power fail
|-
|
B_SA
|
Condition: Overrun cut-off
|-
|
B_ST
|
Condition: Start
|-
|
B_STEND
|
Condition: End of start conditions achieved
|-
|
B_STNDNL
|
Condition: Beginning of ECU delay or end of
start conditions (1 ® 0)
|-
|
B_TFU
|
Condition: Ambient temperature sensor
available
|-
|
B_TRKH
|
Condition: Catalyst heating, thermal reaction
effective
|-
|
B_UHRRMIN
|
Condition: timer with a relative number of
minutes
|-
|
B_UHRRSEC
|
Condition: timer with a relative number of
minutes
|-
|
DFP_TA
|
ECU internal error path number: intake air
temperature TANS (charge air)
|-
|
DFP_TUM
|
ECU Internal error path number: ambient
temperature
|-
|
ETAZWIMT
|
Actual ignition angle efficiency average for exhaust
gas temperature model (200 ms)
|-
|
ETAZWIST
|
Actual ignition angle efficiency
|-
|
E_TA
|
Error flag: TANS
|-
|
E_TUM
|
Error flag: ambient temperature tumg
|-
|
IMLATM
|
Integral of air mass flows from engine start
bis Max.wert
|-
|
IMLATM_W
|
Integral of air mass flows from end of start
conditions up to the maximum value, (Word)
|-
|
IWMATM2_W
|
Heat quantity for Condensation - dew points
exhaust gas/catalyst (word), cylinder bank 2
|-
|
IWMATM_W
|
Heat quantity for Condensation - dew points
exhaust gas/catalyst (word)
|-
|
LAMSBG2_W
|
Desired lambda limit (word), cylinder bank 2
|-
|
LAMSBG_W
|
Desired lambda limit (word)
|-
|
ML_W
|
Filtered air mass flow (word)
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
TABGKRM2_W
|
Exhaust gas temperature in manifold from the
model, cylinder bank 2
|-
|
TABGKRM_W
|
Exhaust gas temperature in manifold from the
model
|-
|
TABGM
|
Exhaust gas temperature before catalyst from
the model
|-
|
TABGM2
|
Exhaust gas temperature before catalyst from
the model, cylinder bank 2
|-
|
TABGM2_W
|
Exhaust gas temperature before catalyst from
the model (word) cylinder bank 2
|-
|
TABGMAB
|
Exhaust gas temperature during engine
switch-off
|-
|
TABGMAB2
|
Exhaust gas temperature during engine
switch-off (model) cylinder bank 2
|-
|
TABGMST
|
Exhaust gas temperature at engine start
|-
|
TABGMST2
|
Exhaust gas temperature at engine start,
cylinder bank 2
|-
|
TABGM_W
|
Exhaust gas temperature before catalyst from
the model (word)
|-
|
TABSTATM_W
|
Stop time in ECU delay for exhaust gas
temperature model
|-
|
TABSTMX_W
|
Stop time maximum query for exhaust gas
temperature model
|-
|
TABST_W
|
Stop time
|-
|
TAKRKF
|
Steady-state manifold exhaust gas temperature without
correction
|-
|
TAKRKF2
|
Steady-state manifold exhaust gas temperature
without correction, cylinder bank 2
|-
|
TAKRSTC
|
Steady-state exhaust gas temperature in
manifold in °C
|-
|
TAKRSTC2
|
Steady-state exhaust gas temperature in
manifold, cylinder bank 2
|-
|
TANS
|
Intake air temperature
|-
|
TATAKRML
|
Output from PT1 element: exhaust gas
temperature influence on tabgkrm
|-
|
TATAKRML2
|
Output from PT1 element: exhaust gas
temperature influence on tabgkrm, cylinder bank 2
|-
|
TATMAML
|
Output from PT1 element: exhaust gas
temperature influence on tabgm
|-
|
TATMAML2
|
Output from PT1 element: exhaust gas
temperature influence on tabgm, cylinder bank 2
|-
|
TATMKF
|
Exhaust gas temperature before catalyst from map
KFTATM
|-
|
TATMKF2
|
Exhaust gas temperature before catalyst from map
KFTATM, cylinder bank 2
|-
|
TATMRML
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgm
|-
|
TATMRML2
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgm, cylinder bank 2
|-
|
TATMSTA
|
Exhaust gas temperature before catalyst from
the steady-state model
|-
|
TATMSTA2
|
Exhaust gas temperature before catalyst from
the steady-state model, cylinder bank 2
|-
|
TATRKRML
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgkrm
|-
|
TATRKRML2
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgkrm, cylinder bank 2
|-
|
TATU
|
Intake air temperature or ambient temperature
|-
|
TEXOIKM2_W
|
Exotherme temperature increase in catalyst for
tikatm, cylinder bank 2
|-
|
TEXOIKM_W
|
Exotherme temperature increase in catalyst for
tikatm
|-
|
TEXOM2_W
|
Exotherme temperature increase in catalyst for
tkatm2, cylinder bank 2
|-
|
TEXOM_W
|
Exotherme temperature increase in catalyst for
tkatm
|-
|
TIKATM
|
Exhaust gas temperature in catalyst from the
model
|-
|
TIKATM2
|
Exhaust gas temperature in catalyst from the
model, cylinder bank 2
|-
|
TIKATM2_W
|
Exhaust gas temperature in catalyst from the
model, cylinder bank 2
|-
|
TIKATM W
|
Exhaust gas temperature in catalyst from the
model
|-
|
TKATM
|
Catalyst temperature from the model
|-
|
TKATM2
|
Catalyst temperature from the model, cylinder
bank 2
|-
|
TKATM2_W
|
Catalyst temperature from the model (word),
cylinder bank 2
|-
|
TKATMAB
|
Exhaust gas temperature after catalyst through
engine switch-off (model)
|-
|
TKATMAB2
|
Exhaust gas temperature after catalyst through
engine switch-off (model), cylinder bank 2
|-
|
TKATMST
|
Catalyst temperature model initial value as a
function of switch-off value, switch-off time
|-
|
TKATMST2
|
Catalyst temperature model initial value as a
function of switch-off value, switch-off time, bank 2
|-
|
TKATM_W
|
Catalyst temperature from the model (word)
|-
|
TMOT
|
Engine temperature
|-
|
TMST
|
Engine start temperature
|-
|
TUMG
|
Ambient
temperature
|-
|
VFZG
|
Vehicle
speed
|-
|
ZWMATM
|
Counter
for repeated starts and factor for heat quantity threshold
|-
|
ZWMATM2
|
Counter
for repeated starts and factor for heat quantity threshold, cylinder bank 2
|-
|
ZWMATMF
|
Counter
for repeated starts and factor for heat quantity threshold upstream
|-
|
ZWMATMF2
|
Counter
for repeated starts and factor for heat quantity threshold upstream, cylinder
bank 2
|}

[[Category:ME7]]

ATM 33.50 (Exhaust Gas Temperature Model)

2012-01-08T18:09:46Z

TTQS:

Refer to the ''funktionsrahmen'' for the following diagrams:

atm-main

atm-atm-b1 Exhaust gas temperature model (cylinder
bank 1) overview

atm-tmp-stat TMP_STAT engine speed & relative cylinder charge map and corrected for temperature for acceleration, intake air temp., catalyst heating, catalyst warming, ignition angle, lambda and cold engine

atm-dynamik Temperature dynamic for exhaust gas and catalytic converter temperature (in and near the catalytic
converter)

atm-tabgm Temperature dynamic: exhaust gas, exhaust pipe wall effect, from the exhaust gas temperature tabgm

atm-tkatm Temperature dynamic for the temperature near the catalytic converter

atm-exotherme Exothermic temperature increase near the catalyst from measurement sites tabgm to tikatm

atm-tikatm Temperature dynamic for the temperature in the catalytic converter

atm-exoikat Exothermic temperature increase in the catalyst from measurement sites tabgm to tikatm

atm-kr-stat Exhaust gas temperature in the exhaust manifold under steady-state conditions

atm-kr-dyn Exhaust gas temperature in the exhaust manifold under dynamic conditions

atm-tmp-start Calculation of the exhaust gas or exhaust pipe wall temperature at engine start

atm-tpe-logik Calculation of the dew point at the pre-cat and post-cat lambda probes

atm-sp-nachl Storage of the dew point conditions at engine switch off

atm-mean Calculation of etazwist average values

atm-tmp-umgm If no ambient temperature sensor is available, calculate a substitute from ambient temperature (tans)

atm-mst If tabst_w is not correct tabstatm = maximum value, request for delay B_nlatm as a function of engine speed and tatu-threshold)

ATM 33.50 (Exhaust Gas Temperature Model) Function Description

The simulated exhaust gas temperatures tabgm and tabgkrm (for SY_TURBO = 1) and catalytic converter
temperatures tkatm and tikatm are used for the following purposes:

1. Monitoring the catalyst. If the catalytic converter falls below its starting temperature, then a fault can be detected.

2. For lambda control on the probe after the catalytic converter. This control is only activated after engine start, when the catalyst has exceeded its start-up temperature.

3. For the probe heater control after engine start. If the simulated dew point is exceeded, the probe heater is turned on.

4. Monitoring the heated exhaust gas oxygen (HEGO) sensor (i.e. lambda probe) heating system. If the exhaust gas temperature exceeds 800°C for example, then the lambda probe heater will be switched off, so that the probe is not too hot.

5. For fan motor control.

6. For switching on component protection.

This function provides only a rough approximation of the exhaust gas and catalytic converter temperature profiles, whereas throughout the application especially the four monitoring areas (dew point profiles in the exhaust gas, catalytic converter monitoring, enabling and shutting off lambda probe heating and high temperatures for component protection) should be considered to be critical.

1. Basic function

Steady-state temperature (tatmsta): the same applies for takrstc

With the engine speed/relative cylinder charge map KFTATM the steady-state exhaust gas temperature before the catalyst is set. This temperature is corrected for ambient temperature or simulated ambient temperature from the characteristic ATMTANS:

during boost with the constant TATMSA,

during catalyst heating with the constant TATMKH; catalyst warming with the constant TATMKW

with the ignition-angle efficiency map KFATMZW temperature as a function of ML and ETAZWIST

with the desired lambda map KFATMLA temperature as a function of ML and LAMSBG_W

for a cold engine block (TMOT - TATMTMOT) with TATMTMOT = 90°C.

The catalyst temperature (exothermic) is corrected for:

Temperature increase with the characteristic KATMEXML or KATMIEXML as a function of air mass

Temperature reduction with KLATMZWE or KLATMIZWE as a function of etazwimt (ignition angle influence)

Lambda influence with KLATMLAE or KLATMILAE as a function of lambsbg_w

Temperature set at TKATMOE or TIKATMOE at tabgm <TABGMEX or B_sa = 1

Different temperature increases are applied for the temperature in the catalytic converter tikatm and the temperature after the catalytic converter tkatm due to exothermic reaction and cooling and different ignition angles and lambda-corrections.

The time-based influence of the exhaust gas temperature before the catalytic converter:

Using a PT1 filter (filter time constant ZATMAML) the dynamics of the exhaust gas temperature are simulated and with a PT1 filter (time constant ZATMRML) the dynamics of the inlet manifold wall temperature are simulated.

The exhaust gas temperature and inlet manifold wall temperature are weighted by the division factor FATMRML.

The catalytic converter temperature tkatm is calculated from the exhaust gas temperature tabgm along with the PT1 filter (filter time constant ZATMKML).

The temperature in the catalyst tikatm is modelled from the exhaust gas temperature tabgm via three filters (time constant ZATMIKML) using the heat transfer principle. Due to a thrust caused by the small air mass flow in the catalytic converter, there is a possible exhaust gas temperature increase due to the greater influence on the matrix temperature by the exhaust gas throughput. This thrust-based temperature increase can be modelled by the positive B_sa side with a temperature, which is composed of the catalyst temperature tikatm and an offset TATMSAE, will be initialised. The time constants of the PT1-filter ZATMIKML are represented by air-mass-dependent characteristic curves.

The initial values for the exhaust and catalyst temperature at engine start can be calculated from the temperatures at switch-off and delay times. The starting values for the exhaust gas and catalyst temperatures should approximate to the manifold wall temperatures at the probe insertion points a few minutes after switch-off.
The filter for the exhaust gas temperature is stopped by setting B_stend = 0.
The filter for the manifold wall temperature is stopped when B_atmtpa = 1. The
filter for the catalyst temperature will be enabled only when B_atmtpk = 1.

2. Dew Point Detection

Initial values for the exhaust gas temperature tabgmst and catalyst temperature tkatmst

When stopping the engine (C_nachl 0 ® 1) the temperatures tabgm and tkatm are stored.

When starting the engine, the initial temperatures tabgmst and tkatmst are calculated from the switch-off temperature (corrected for ambient temperature) and a factor obtained from maps KFATMABKA or KFATMABKK as a function of tabstatm and tatu.

During power fail the switch-off temperature will be determined from the constant TATMSTI.

For test condition (B_faatm = 1), the initial temperatures are given by the constants TASTBFA and TKSTBFA.

Integrated Heat Quantity iwmatm_w

The dew point end time is approximately proportional to the heat quantity after engine start. The heat quantity = Integral (temp. x air mass x Cp) is calculated from the steady-state exhaust gas temperature tatmsta plus TATMWMK multiplied by the air mass. The result of the integration multiplied by the heat capacity at constant pressure Cp (approximately 1 kJ/kgK) gives the heat quantity.

Dew point end for the pre-cat lambda probe B_atmtpa and post-cat lambda probe B_atmtpk

The calculated exhaust gas temperature at engine start tabgmst approximates to the exhaust pipe wall temperature. If the exhaust pipe wall temperature is greater than 60°C for example then no condensation occurs.
The values in the map KFWMABG for these temperatures are less than 14 kJ, so the dew point end is detected immediately, or after only a few seconds.

For catalytic converter heating with thermal reaction (B_trkh = 1) the values in maps KFWMABG or KFWMKAT are multiplied by the factor WMKATKH or WMABGKH respectively. Thus, the dew point end-times are very short for this mode of operation.

Repeated starts (extension of the dew point-end-times)

If the engine had not reached the dew point end (B_atmtpa = 0 and B_atmtpf = 0) then when the engine restarts, the counter zwmatmf is increased by 1. After several periods of very short engine running (e.g. 3), the counter zwmatmf value would be set equal to 3. With a constant FWMABGW = 0.25 for example, the values in the map KFWMABG increase by a factor equal to (zwmatmf x KFWMABG + 1) = 1.75. When the engine starts, the dew point end time from the last engine run is detected and the
counter zwmatmf is reset.

Storage of the dew point end condition in the delay

For the determination of repeat start dew point end the conditions B_atmtpa in the flag B_atmtpf and B_atmtpk in the flag B_atmtpl are saved at engine switch-off due to a regular switch-off using the ignition or stall (B_stndnl). The function of dew point end for the post-cat lambda probe B_atmtpk
is analogous to the function for B_atmtpa.

3. Calculation of a simulated ambient temperature from the intake air temperature (tans) if no ambient temperature sensor is available.

The simulated temperature tatu will be used for calculating the temperature correction via the characteristic ATMTANS and for determining the starting temperatures tabgmst and tkatmst. The intake air temperature (tans) is corrected with the constant DTUMTAT and under certain conditions stored in continuous RAM. If for example at engine start, the temperature tatu > tans, then the temperature value tatu is set on the lower tans value.

With the constant TATMWMK (negative value) the difference in dew point end between catalyst heating and no catalyst heating can be increased.

When catalytic converter heating is active B_khtr = 1 and the bit B_atmtpa can be set equal to 1 immediately after engine start. This is possible only when no problematic condensation is formed during catalyst heating.

With the system constants SY_STERVK = 1 cylinder bank 2 can be applied separately for stereo systems.

For SY_TURBO = 1 the exhaust gas temperature tabgm is essentially identical in addition to the modeled temperature in the manifold tabgkrm.

ATM 33.50 Application Notes

1. Installation locations for temperature sensors in this application, running in
the direction of flow:

- In probe installation position before catalytic converter-

1. Exhaust gas temperature (pipe centre) for the high temperatures at high loads for probe heater switch off

2. Manifold wall temperature for the determination of the dew-end times. (Condensation protection)

- Before the catalytic converter

3. Exhaust gas temperature (pipe centre) for the catalyst start-up temperature

- In the catalytic converter

4. Ceramic temperature in and after catalytic converter (in the last third of the catalytic converter or behind the adjoining matrix) to determine the air-mass-dependent time constants.

- After the catalytic converter

5. Pipe wall temperature at probe installation site for the determination of the dew-end times (condensation protection).

Temperature measuring point 3 can be omitted if the distance from probe to catalytic converter is smaller than about 30 cm. The temperature drop from probe installation site to catalytic converter can then be neglected.

For the application of the functional data the modelled temperatures will always be compared with the measured temperatures and the functional data amended until a sufficiently high accuracy is achieved. In so doing, it will be the actual catalyst temperature, the temperature increase due to the exothermic reaction is not considered in the model.

2. Map KFTATM

For the determination of the steady-state temperature for example, before the catalytic converter the temperature corrections should not function. The cooling capacity of the wind on the dynamometer or on the measuring wheel can be simulated only very roughly at the higher engine load range. The map values can be determined on the rolling road dynamometer, but should be corrected on an
appropriate test drive.

3. Temperature Corrections

- TATMSA

Boost can cause low exhaust temperatures that fall below the starting temperature of the catalyst. The longer the time period for the thrust condition, the lower the exhaust and catalyst temperatures. For catalyst diagnosis during boost, the exhaust gas temperature model is more likely to calculate a lower value than the measured temperature.

- ATMTANS

At low ambient temperatures, exhaust gas temperature can fall below the catalyst start-up temperature. Therefore, the model temperature is only corrected at the low temperature range.

- TATMKH

As long as the catalyst-heating measures are effective, higher exhaust temperatures will result.

- TATMKW

The catalyst operating temperature will not be not reached during prolonged idling, so the exhaust gas temperature can be raised by the catalyst warming function.

- KFATMZW

The temperature increase as a result of ignition angle retardation can be determined on a rolling road dynamometer. First, on the dynamometer, the characteristic field values KFTATM are applied without ignition angle correction. Ignition angles are then modified so that allowed etazwist values will result in the map. Through the corresponding air mass, the temperature increase will then be displayed in the map KFATMZW.

- KFATMLA

The exhaust temperature is reduced by enrichment. The application is similar to KFATMZW, except that the ignition angle efficiency is changed instead of the enrichment factor.

- TATMTMOT

The map KFTATM is applied with a warm engine. Thus, the model exhaust gas temperature has smaller deviations during cold start. For this operating mode, the temperature is corrected with the difference of the cold engine temperature and the warm engine temperature. TATMTMOT should be about 90 to 100°C.

4. Maps ZATMAML, ZATMRML, FATMRML, ZATMKML, ZATMKKML, ZATMIKML und ZATMIKKML

The air-mass-dependent time constants ZATMAML, ZATMRML (temperature measuring points 1 or 3), and ZATMKML, ZATMKKML, ZATMIKML, ZATMIKKML (temperature measuring point 4), can help to more accurately determine “spikes in the air mass” during sudden load variations. Thereby "air mass jumps" at full load and in particular during boost can be avoided. For example, for an air mass jump from 30 kg/hr to 80 kg/hr, the measured time constant is applied to the air mass flow of 80 kg/hr. For large air mass jumps during idle, the time constants ZATMKKML and ZATMIKKML can be input instead of ZATMKML or ZATMIKML if required.

5. Block EXOTHERME:

- KATMEXML

The exothermic temperature is a function of air mass flow (warming by realizing emissions, reducing warming via a larger air mass). First KATMEXML applies, then KLATMZWE, KLATMLAE.

- KLATMZWE

When ignition angle retardation increases the temperature before the catalyst, the catalyst temperature drops.

- KLATMLAE

For lambda < 1 (richer), the air mass is lacking to improve emissions so the catalyst temperature decreases.

- TABGMEX

If the temperature before the catalyst tabgm < TABGMEX (catalyst switch-off temperature) then the temperature correction = TKATMOE.

- TKATMOE

Temperature correction during boost or through tabgm> TABGMEX

- TATMSAE

Temperature increase in the boost in the catalyst in terms of tkatm

Block EXOIKAT:

- KATMIEXML, KLATMIZWE, KLATMILAE, TIKATMOE

Application depends on the application for Block EXOTHERME

- TATMSAE

Temperature increase in the thrust in the catalyst in terms of tikatm

6. Dew point end times for exhaust gas temperatures vary greatly between the centre of the exhaust pipe and the pipe wall. Dew point end times for the tube wall temperatures before the catalyst (temperature measuring points 2) or after the catalyst (temperature measuring points 5) should be used. These times are usually due to delaying control readiness for too long, in which case the temperature gradients at the probe mounting location must be examined more closely. To avoid probe damage by “water hammer”, the sensor heater must be fully turned on until the dew point temperature is exceeded or the dew point end time is detected thus condensation will no longer occur.

When the switch-off time in the ECU delay is calculated, then the switch-off time tabst_w after ECU delay will be incorrect. At engine start after ECU delay, the switch-off time tabstatm therefore, will be set to the maximum value of 65,535 (i.e. 216-1). The ECU delay requirement for the time TNLATM when engine speed > TNLATMTM & tumg (tatu) > TNLATMTU.

8. For blocks KR_STAT and KR_DYN as appropriate, the descriptions in points 3 and
4 shall apply.

Typical Values:

KFTATM: x: engine speed/RPM, y: relative cylinder charge/%, z: temperature/°C

{| border="1"
|-
|
|
800
|
1200
|
1800
|
2400
|
3000
|
4000
|
5000
|
6000
|-
|
15
|
380
|
400
|
420
|
450
|
480
|
520
|
550
|
580
|-
|
22
|
400
|
420
|
450
|
480
|
520
|
550
|
580
|
610
|-
|
30
|
420
|
450
|
480
|
520
|
550
|
580
|
610
|
650
|-
|
50
|
450
|
480
|
520
|
550
|
580
|
610
|
650
|
700
|-
|
70
|
470
|
520
|
550
|
580
|
610
|
660
|
700
|
750
|-
|
100
|
490
|
550
|
580
|
610
|
650
|
700
|
750
|
790
|-
|
120
|
510
|
560
|
610
|
650
|
700
|
750
|
790
|
840
|-
|
140
|
530
|
580
|
650
|
700
|
750
|
790
|
840
|
900
|}

KFATMZW: x: temperature/°C, y: ml_w/kg/hr, z: etazwimt

{| border="1"
|-
|
|
20
|
40
|
80
|
150
|
250
|
400
|-
|
1.00
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|-
|
0.95
|
15
|
40
|
50
|
60
|
70
|
75
|-
|
0.90
|
15
|
60
|
80
|
100
|
125
|
140
|-
|
0.80
|
20
|
80
|
120
|
150
|
180
|
200
|-
|
0.70
|
25
|
100
|
150
|
190
|
210
|
220
|-
|
0.60
|
30
|
115
|
175
|
210
|
230
|
245
|}

KFATMLA: x: temperature/°C, y: ml_w/kg/hr, z: lamsbg_w

{| border="1"
|-
|
|
20
|
40
|
80
|
150
|
250
|
400
|-
|
1.15
|
5
|
10
|
30
|
50
|
60
|
70
|-
|
1.00
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|-
|
0.95
|
5
|
10
|
20
|
30
|
40
|
45
|-
|
0.90
|
15
|
25
|
40
|
50
|
60
|
75
|-
|
0.80
|
30
|
40
|
60
|
70
|
85
|
100
|-
|
0.70
|
40
|
60
|
80
|
90
|
100
|
120
|}

KFWMABG: x: energy/kJ, y: tabgmst/°C, z: tmst/°C

{| border="1"
|-
|
|
-40
|
0
|
15
|
25
|
30
|
55
|
60
|-
|
-40
|
200
|
160
|
150
|
140
|
100
|
60
|
30
|-
|
0
|
180
|
150
|
120
|
110
|
80
|
50
|
20
|-
|
15
|
160
|
140
|
60
|
55
|
30
|
40
|
0.45
|-
|
25
|
140
|
120
|
30
|
30
|
15
|
10
|
0.45
|-
|
60
|
120
|
30
|
20
|
15
|
10
|
5
|
0.45
|}

KFWMKAT values correspond to KFWMABG x 5

In the heat quantity maps KFWMABG and KFWMKAT a value of 0.0 is never required! It should always have at least the value to be entered; the 2 sec corresponds to idle after cold start. Only then does the repeat-start counter operate after several starts where the dew point was not reached.

ZATMAML

ml_w/kg/hr, Time constant/sec 10, 30 ; 20, 20 ; 40, 13 ; 80, 5 ; 180, 4 ; 400, 3 ; 600, 2 ;

ZATMKML

ml_w/kg/hr, Time constant/sec 10, 150 ; 20, 60 ; 40, 35 ; 80, 20 ; 180, 10 ;
400, 7 ; 600, 4 ;

ZATMIKML

value represents approximately ZATMKML x 0.3

ZATMKKML

for neutral input, the data must correlate to ZATMKML

ZATMIKKML

for neutral input, the data must correlate to ZATMIKML

ZATMRML

ml_w/kg/hr, Time constant/sec 10, 300 ; 20, 80 ; 40, 55 ; 80, 30 ; 180, 20 ; 400, 10 ; 600, 7 ;

FATMRML

ml_w/kg/hr, Time constant/sec 10, 0.5 ; 20, 0.6 ; 40, 0.7 ; 80, 0.8 ; 180, 0.95 ; 400,0.95 ; 600, 0.96;

KATMEXML

ml_w/kg/hr, Time constant/sec 10, 0 ; 20, 0 ; 40, 0 ; 80, 0 ; 180, 0 ; 400, 0 ;

KLATMZWE

etazwimt, Factor 1, 0 ; 0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ; 0.6, 0 ;

KLATMLAE

lamsbg_w, Factor 1.15, 0 ; 1 , 0 ;0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ;

TATMTP: 52°C

TKATMOE: 0°C

TATMSAE: 0°C

KATMIEXML

ml_w/kg/hr, Time constant/sec 10, 0 ; 20, 0 ; 40, 0 ; 80, 0 ; 180, 0 ; 400, 0 ;

KLATMIZWE

etazwimt, Factor 1, 0 ; 0.95, 0 ; 0.9, 0; 0.8, 0 ; 0.7, 0 ; 0.6, 0 ;

KLATMILAE

lamsbg_w, Factor 1.15, 0 ; 1 , 0 ;0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ;

TIKATMOE: 0°C

KFATMABKA: x: tatu/°C, y: tabstatm_w/seconds, z: no units

{| border="1"
|-
|
|
10
|
50
|
180
|
360
|
600
|
1000
|-
|
-40
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
-15
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
0
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
15
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
40
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|}

KFATMABKK: x: tatu/°C, y: tabstatm_w [s], z: no units

{| border="1"
|-
|
|
10
|
50
|
180
|
360
|
600
|
1000
|-
|
-40
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
-15
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
0
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
15
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
40
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|}

ATMTANS tatu/°C, Temp./°C -40, 60 ; -10, 20 ; 20, 0 ;

TATMSA: 100°C

TATMKH: 80°C

TATMTRKH: 200°C

TATMKW: 100°C

TATMTMOT: 90°C

TATMSTI: 20°C

TASTBFA: 40°C

TKSTBFA: 40°C

TATMWMK: -80°C

WMABGKH: Factor of 1.0

WMKATKH: Factor of 1.0

FWMABGW: Factor of 0.25

FWMKATW: Factor of 0.25

DTUMTAT: 20°C

VTUMTAT: 40 km/h

NTUMTAT: 1800 rpm

IMTUMTAT: 1 kg

TUMTAIT: 20°C

TNLATMTM: 80°C

TNLATMTU: 5°C

TNLATM: 660 seconds

Only when SY_TURBO = 1:

For neutral input (tabgkrm_w = tabgm_w)

KFATMKR = KFTATM

KFATZWK = KFATMZW

KFATLAK = KFATMLA

TATMKRSA = TATMSA

ZATRKRML = ZATMRML

ZATAKRML = ZATMAML

FATRKRML = FATMRML

ATMTANS
tans/°C, Temp./°C -40, 40 ; -20, 25 ; 0, 12 ; 20, 0 ; 60, -30

The functional data for cylinder bank 2 correspond to the functional data from cylinder bank 1 Note:

In order that ATM 22:20 for the application is backward compatible the default values should be entered thus: KATMEXML, KLATMZWE, KLATMLAE, TKATMOE = 0 and TABGMEX = 1220°C.

In order that ATM 33.10 remains application-neutral with ATM 22.50, TATMTRKH must be set equal to TATMKH and WMKATKH should be set equal to 1. Tikatm is not used in a function because the input can be used in the path in the exhaust gas temperature model without impact on safety, however, the default values for KATMIEXML, KLATMIZWE, KLATMILAE and TIKATMOE should be set equal to 0 and TABGMEX = 1220°C.

In DKATSP areas TMINKATS and TMAXKATS, a high accuracy is required for tikatm!

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
ATMTAKR
|
Correction
for the manifold temperature
|-
|
ATMTANS
|
Temperature
correction for the exhaust gas temperature model
|-
|
DTUMTAT
|
Offset:
intake air temperature ® ambient temperature
|-
|
FATMRML
|
Factor
for the difference between exhaust gas & exhaust pipe wall temperature
|-
|
FATMRML2
|
Factor
for the difference between exhaust gas & exhaust pipe wall temperature, cylinder
bank 2
|-
|
FATRKRML
|
Factor
for the difference between exhaust gas & wall temperature in the manifold
|-
|
FATRKRML2
|
Factor
for the difference between exhaust gas & wall temperature in the manifold,
cylinder bank 2
|-
|
FWMABGW
|
Factor
for heat quantity during repeated starts for pre-cat exhaust gas dew points
|-
|
FWMABGW2
|
Factor
for heat quantity during repeated starts for pre-cat exhaust gas dew points,
cylinder bank 2
|-
|
FWMKATW
|
Factor
for heat quantities during repeated starts for dew points after main catalyst
|-
|
FWMKATW2
|
Factor
for heat quantities during repeated starts for dew points after main catalyst,
cylinder bank 2
|-
|
IMTUMTAT
|
Integration
threshold air mass for determining ambient temperature from TANS
|-
|
KATMEXML
|
Exothermic
reaction temperature in catalyst, tkatm
|-
|
KATMEXML2
|
Exothermic
reaction temperature in catalyst, cylinder bank 2
|-
|
KATMIEXML
|
Exothermic
reaction temperature in catalyst, tikatm
|-
|
KATMIEXML2
|
Exothermic
reaction temperature in catalyst, tikatm, cylinder bank 2
|-
|
KFATLAK
|
Map for
lambda correction for manifold exhaust gas temperature
|-
|
KFATLAK2
|
Map for
lambda correction for manifold exhaust gas temperature, cylinder bank 2
|-
|
KFATMABKA
|
Factor
for exhaust gas temperature decrease as a function of stop time and ambient
temperature
|-
|
KFATMABKA2
|
Factor
for exhaust gas temperature decrease as a function of stop time and ambient
temperature, cylinder bank 2
|-
|
KFATMABKK
|
Factor
for reducing the catalyst temperature as a function of stop time and ambient
temperature
|-
|
KFATMABKK2
|
Factor
for reducing the catalyst temperature as a function of stop time and ambient
temperature, cylinder bank 2
|-
|
KFATMKR
|
Map for
steady-state manifold exhaust gas temperature as a function of engine speed
and relative cylinder charge
|-
|
KFATMKR2
|
Map for
steady-state manifold exhaust gas temperature, cylinder bank 2
|-
|
KFATMLA
|
Map for
exhaust gas temperature correction as a function of lambda
|-
|
KFATMLA2
|
Map for
exhaust gas temperature correction as a function of lambda, cylinder bank 2
|-
|
KFATMZW
|
Map for
exhaust gas temperature correction as a function of igntion angle correction
|-
|
KFATMZW2
|
Map for
exhaust gas temperature correction as a function of ignition angle, cylinder
bank 2
|-
|
KFATZWK
|
Map for
ignition angle correction for manifold gas temperature
|-
|
KFATZWK2
|
Map for
ignition angle correction for manifold gas temperature, cylinder bank 2
|-
|
KFTATM
|
Map for
exhaust gas temperature as a function of engine speed and relative cylinder
charge
|-
|
KFTATM2
|
Map for
exhaust gas temperature as a function of engine speed and relative cylinder
charge for cylinder bank 2
|-
|
KFWMABG
|
Map for
heat quantity threshold exhaust gas dew points
|-
|
KFWMABG2
|
Map for
heat quantity threshold exhaust gas dew points, cylinder bank 2
|-
|
KFWMKAT
|
Map for
heat quantity threshold dew points after catalyst
|-
|
KFWMKAT2
|
Map for
heat quantity threshold dew points after catalyst, cylinder bank 2
|-
|
KLATMILAE
|
Exothermic
temperature decrease through enrichment, tikatm
|-
|
KLATMILAE2
|
Exothermic
temperature decrease through enrichment, tikatm, Bank 2
|-
|
KLATMIZWE
|
Exothermic
temperature decrease in catalyst at later ignition angles, tikatm
|-
|
KLATMIZWE2
|
Exothermic
temperature decrease in catalyst at later ignition angles, tikatm, Bank 2
|-
|
KLATMLAE
|
Exothermic
temperature decrease through enrichment
|-
|
KLATMLAE2
|
Exothermic
temperature decrease through enrichment, cylinder bank 2
|-
|
KLATMZWE
|
Exothermic
temperature decrease in catalyst at later ignition angles, tkatm
|-
|
KLATMZWE2
|
Exothermic
temperature decrease in catalyst at later ignition angles, cylinder bank 2
|-
|
NTUMTAT
|
Speed
threshold for determining ambient temperature from TANS
|-
|
SEZ06TMUB
|
Sample
point distribution, ignition angle efficiency
|-
|
SLX06TMUW
|
Sample
point distribution, desired lambda
|-
|
SLY06TMUW
|
Sample
point distribution, desired lambda, cylinder bank 2
|-
|
SML06TMUW
|
Sample
point distribution, air mass, 6 sample points
|-
|
SML07TMUW
|
Sample
point distribution, air mass, 7 sample points
|-
|
SMT06TMUW
|
Sample
point distribution, air mass, 6 sample points
|-
|
ST107TMUB
|
Sample
point distribution, start temperature at front probe
|-
|
ST207TMUB
|
Sample
point distribution, start temperature at front probe, cylinder bank 2
|-
|
ST307TMUB
|
Sample point
distribution, start temperature at rear probe
|-
|
ST407TMUB
|
Sample
point distribution, start temperature at rear probe, cylinder bank 2
|-
|
STM05TMUB
|
Sample
point distribution, engine start temperature
|-
|
STS06TMUW
|
Sample
point distribution, exhaust gas mass flow
|-
|
STU05TMUB
|
Sample
point distribution, simulated ambient temperature
|-
|
SY_STERVK
|
System
constant condition: stereo before catalyst
|-
|
SY_TURBO
|
System
constant: turbocharger
|-
|
TABGMEX
|
Exhaust
gas temperature below the catalyst switch-off temperature
|-
|
TASTBFA
|
Model temperature
before pre-cat initial value via B_faatm requirement
|-
|
TATMKH
|
Exhaust
gas temperature correction via catalyst heating active
|-
|
TATMKH2
|
Exhaust
gas temperature correction via catalyst heating active, cylinder bank 2
|-
|
TATMKRSA
|
Exhaust
gas temperature correction in manifold via boost switch-off
|-
|
TATMKW
|
Exhaust
gas temperature correction with catalyst warming active
|-
|
TATMSA
|
Exhaust
gas temperature correction via boost cut-off
|-
|
TATMSAE
|
Exothermic
temperature increase in boost
|-
|
TATMSAE2
|
Exothermic
temperature increase in boost, cylinder bank 2
|-
|
TATMSTI
|
Initial
value for tabgm, tkatm intial value through power fail
|-
|
TATMTMOT
|
Engine temperature
warmer Motor, for temperature correction during cold start conditions
|-
|
TATMTP
|
Exhaust
gas dew point temperature
|-
|
TATMTRKH
|
Exhaust
gas temperature correction via thermal reaction catalyst heating
|-
|
TATMTRKH2
|
Exhaust
gas temperature correction via thermal reaction catalyst heating, cylinder bank
2
|-
|
TATMWMK
|
Temperature
offset for calculating heat quantities
|-
|
TIKATMOE
|
Temperature
correction in catalyst without exothermic reaction, tikatm
|-
|
TKATMOE
|
Temperature
correction near catalyst without exothermic reaction, tkatm
|-
|
TKSTBFA
|
Model temperature
post-cat initial value via B_faatm requirement
|-
|
TNLATM
|
Minimum
ECU delay time for exhaust gas temperature model – Abstellzeit
|-
|
TNLATMTM
|
When
tmot > threshold ECU delay requirement B_nlatm = 1
|-
|
TNLATMTU
|
When
tumg (tatu – ATM) > threshold ECU delay requirement
|-
|
TUMTAIT
|
Initialising
value for ambient temperature from TANS
|-
|
VTUMTAT
|
Vehicle
speed threshold for TANS ® ambient temperature
|-
|
WMABGKH
|
Factor
for heat quantity correction via catalyst heating for dew points
|-
|
WMABGKH2
|
Factor
for heat quantity correction via catalyst heating for dew points, cylinder bank
2
|-
|
WMKATKH
|
Factor
for heat quantity correction via catalyst heating for dew points after
catalyst
|-
|
WMKATKH2
|
Factor
for heat quantity correction via catalyst heating for dew points after
catalyst, cylinder bank 2
|-
|
ZATAKRML
|
Time
constant for exhaust gas temperature model (manifold)
|-
|
ZATAKRML2
|
Time
constant for exhaust gas temperature model (manifold), cylinder bank 2
|-
|
ZATMAML
|
Time
constant for exhaust gas temperature model
|-
|
ZATMAML2
|
Time
constant for exhaust gas temperature model, cylinder bank 2
|-
|
ZATMIKKML
|
Time
constant for catalyst temperature model – Temperature in catalyst tikatm during
cooling
|-
|
ZATMIKKML2
|
Time
constant for catalyst temperature model – Temperature in catalyst tikatm
during cooling, bank 2
|-
|
ZATMIKML
|
Time
constant for catalyst temperature model – Temperature in catalyst, tikatm
|-
|
ZATMIKML2
|
Time
constant for catalyst temperature model – Temperature in catalyst, cylinder bank
2
|-
|
ZATMKKML
|
Time
constant for catalyst temperature model – catalyst temperature tkatm during
cooling
|-
|
ZATMKKML2
|
Time
constant for catalyst temperature model – catalyst temperature tkatm during
cooling, bank 2
|-
|
ZATMKML
|
Time
constant for catalyst temperature model – catalyst temperature tkatm
|-
|
ZATMKML2
|
Time
constant for catalyst temperature model – catalyst temperature, cylinder bank
2
|-
|
ZATMRML
|
Time
constant for exhaust gas temperature model – exhaust pipe wall temperature
|-
|
ZATMRML2
|
Time
constant for exhaust gas temperature model – exhaust pipe wall temperature Bank
2
|-
|
ZATRKRML
|
Time
constant for exhaust gas temperature model – manifold wall temperature
|-
|
ZATRKRML2
|
Time
constant for exhaust gas temperature model – manifold wall temperature, cylinder
bank 2
|-
|
Variable
|
Description
|-
|
B_ATMLL
|
Condition
for time constant during cooling at idle
|-
|
B_ATMLL2
|
Condition
for time constant during cooling at idle
|-
|
B_ATMST
|
Condition
for tabgmst, tkatmst initial value calculation
|-
|
B_ATMST2
|
Condition
for tabgmst, tkatmst calculation, cylinder bank 2
|-
|
B_ATMTPA
|
Condition:
dew point before catalyst exceeded
|-
|
B_ATMTPA2
|
Condition:
dew point 2 before catalyst exceeded
|-
|
B_ATMTPF
|
Condition:
dew point before catalyst exceeded (last trip)
|-
|
B_ATMTPF2
|
Condition:
dew point before catalyst exceeded (last trip) cylinder bank 2
|-
|
B_ATMTPK
|
Condition:
dew point after catalyst exceeded
|-
|
B_ATMTPK2
|
Condition:
dew point 2 after catalyst exceeded
|-
|
B_ATMTPL
|
Condition: dew point after catalyst exceeded (last trip)
|-
|
B_ATMTPL2
|
Condition: dew point after catalyst exceeded (last trip) cylinder bank 2
|-
|
B_FAATM
|
Condition: functional requirements for dew
point end times
|-
|
B_KH
|
Condition: catalyst heating
|-
|
B_KW
|
Condition: catalyst warming
|-
|
B_LL
|
Condition: idle
|-
|
B_NACHL
|
Condition: ECU delay
|-
|
B_NACHLEND
|
Condition: ECU delay ended
|-
|
B_NLATM
|
Condition: ECU delay exhaust gas temperature
model probe protection
|-
|
B_PWF
|
Condition: Power fail
|-
|
B_SA
|
Condition: Overrun cut-off
|-
|
B_ST
|
Condition: Start
|-
|
B_STEND
|
Condition: End of start conditions achieved
|-
|
B_STNDNL
|
Condition: Beginning of ECU delay or end of
start conditions (1 ® 0)
|-
|
B_TFU
|
Condition: Ambient temperature sensor
available
|-
|
B_TRKH
|
Condition: Catalyst heating, thermal reaction
effective
|-
|
B_UHRRMIN
|
Condition: timer with a relative number of
minutes
|-
|
B_UHRRSEC
|
Condition: timer with a relative number of
minutes
|-
|
DFP_TA
|
ECU internal error path number: intake air
temperature TANS (charge air)
|-
|
DFP_TUM
|
ECU Internal error path number: ambient
temperature
|-
|
ETAZWIMT
|
Actual ignition angle efficiency average for exhaust
gas temperature model (200 ms)
|-
|
ETAZWIST
|
Actual ignition angle efficiency
|-
|
E_TA
|
Error flag: TANS
|-
|
E_TUM
|
Error flag: ambient temperature tumg
|-
|
IMLATM
|
Integral of air mass flows from engine start
bis Max.wert
|-
|
IMLATM_W
|
Integral of air mass flows from end of start
conditions up to the maximum value, (Word)
|-
|
IWMATM2_W
|
Heat quantity for Condensation - dew points
exhaust gas/catalyst (word), cylinder bank 2
|-
|
IWMATM_W
|
Heat quantity for Condensation - dew points
exhaust gas/catalyst (word)
|-
|
LAMSBG2_W
|
Desired lambda limit (word), cylinder bank 2
|-
|
LAMSBG_W
|
Desired lambda limit (word)
|-
|
ML_W
|
Filtered air mass flow (word)
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
TABGKRM2_W
|
Exhaust gas temperature in manifold from the
model, cylinder bank 2
|-
|
TABGKRM_W
|
Exhaust gas temperature in manifold from the
model
|-
|
TABGM
|
Exhaust gas temperature before catalyst from
the model
|-
|
TABGM2
|
Exhaust gas temperature before catalyst from
the model, cylinder bank 2
|-
|
TABGM2_W
|
Exhaust gas temperature before catalyst from
the model (word) cylinder bank 2
|-
|
TABGMAB
|
Exhaust gas temperature during engine
switch-off
|-
|
TABGMAB2
|
Exhaust gas temperature during engine
switch-off (model) cylinder bank 2
|-
|
TABGMST
|
Exhaust gas temperature at engine start
|-
|
TABGMST2
|
Exhaust gas temperature at engine start,
cylinder bank 2
|-
|
TABGM_W
|
Exhaust gas temperature before catalyst from
the model (word)
|-
|
TABSTATM_W
|
Stop time in ECU delay for exhaust gas
temperature model
|-
|
TABSTMX_W
|
Stop time maximum query for exhaust gas
temperature model
|-
|
TABST_W
|
Stop time
|-
|
TAKRKF
|
Steady-state manifold exhaust gas temperature without
correction
|-
|
TAKRKF2
|
Steady-state manifold exhaust gas temperature
without correction, cylinder bank 2
|-
|
TAKRSTC
|
Steady-state exhaust gas temperature in
manifold in °C
|-
|
TAKRSTC2
|
Steady-state exhaust gas temperature in
manifold, cylinder bank 2
|-
|
TANS
|
Intake air temperature
|-
|
TATAKRML
|
Output from PT1 element: exhaust gas
temperature influence on tabgkrm
|-
|
TATAKRML2
|
Output from PT1 element: exhaust gas
temperature influence on tabgkrm, cylinder bank 2
|-
|
TATMAML
|
Output from PT1 element: exhaust gas
temperature influence on tabgm
|-
|
TATMAML2
|
Output from PT1 element: exhaust gas
temperature influence on tabgm, cylinder bank 2
|-
|
TATMKF
|
Exhaust gas temperature before catalyst from map
KFTATM
|-
|
TATMKF2
|
Exhaust gas temperature before catalyst from map
KFTATM, cylinder bank 2
|-
|
TATMRML
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgm
|-
|
TATMRML2
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgm, cylinder bank 2
|-
|
TATMSTA
|
Exhaust gas temperature before catalyst from
the steady-state model
|-
|
TATMSTA2
|
Exhaust gas temperature before catalyst from
the steady-state model, cylinder bank 2
|-
|
TATRKRML
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgkrm
|-
|
TATRKRML2
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgkrm, cylinder bank 2
|-
|
TATU
|
Intake air temperature or ambient temperature
|-
|
TEXOIKM2_W
|
Exotherme temperature increase in catalyst for
tikatm, cylinder bank 2
|-
|
TEXOIKM_W
|
Exotherme temperature increase in catalyst for
tikatm
|-
|
TEXOM2_W
|
Exotherme temperature increase in catalyst for
tkatm2, cylinder bank 2
|-
|
TEXOM_W
|
Exotherme temperature increase in catalyst for
tkatm
|-
|
TIKATM
|
Exhaust gas temperature in catalyst from the
model
|-
|
TIKATM2
|
Exhaust gas temperature in catalyst from the
model, cylinder bank 2
|-
|
TIKATM2_W
|
Exhaust gas temperature in catalyst from the
model, cylinder bank 2
|-
|
TIKATM W
|
Exhaust gas temperature in catalyst from the
model
|-
|
TKATM
|
Catalyst temperature from the model
|-
|
TKATM2
|
Catalyst temperature from the model, cylinder
bank 2
|-
|
TKATM2_W
|
Catalyst temperature from the model (word),
cylinder bank 2
|-
|
TKATMAB
|
Exhaust gas temperature after catalyst through
engine switch-off (model)
|-
|
TKATMAB2
|
Exhaust gas temperature after catalyst through
engine switch-off (model), cylinder bank 2
|-
|
TKATMST
|
Catalyst temperature model initial value as a
function of switch-off value, switch-off time
|-
|
TKATMST2
|
Catalyst temperature model initial value as a
function of switch-off value, switch-off time, bank 2
|-
|
TKATM_W
|
Catalyst temperature from the model (word)
|-
|
TMOT
|
Engine temperature
|-
|
TMST
|
Engine start temperature
|-
|
TUMG
|
Ambient
temperature
|-
|
VFZG
|
Vehicle
speed
|-
|
ZWMATM
|
Counter
for repeated starts and factor for heat quantity threshold
|-
|
ZWMATM2
|
Counter
for repeated starts and factor for heat quantity threshold, cylinder bank 2
|-
|
ZWMATMF
|
Counter
for repeated starts and factor for heat quantity threshold upstream
|-
|
ZWMATMF2
|
Counter
for repeated starts and factor for heat quantity threshold upstream, cylinder
bank 2
|}

[[Category:ME7]]

ATM 33.50 (Exhaust Gas Temperature Model)

2012-01-08T18:08:27Z

TTQS:

Refer to the ''funktionsrahmen'' for the following diagrams:

atm-main

atm-atm-b1 Exhaust gas temperature model (cylinder
bank 1) overview

atm-tmp-stat TMP_STAT engine speed & relative cylinder charge map and corrected for temperature for acceleration, intake air temp., catalyst heating, catalyst warming, ignition angle, lambda and cold engine

atm-dynamik Temperature dynamic for exhaust gas and catalytic converter temperature (in and near the catalytic
converter)

atm-tabgm Temperature dynamic: exhaust gas, exhaust pipe wall effect, from the exhaust gas temperature tabgm

atm-tkatm Temperature dynamic for the temperature near the catalytic converter

atm-exotherme Exothermic temperature increase near the catalyst from measurement sites tabgm to tikatm

atm-tikatm Temperature dynamic for the temperature in the catalytic converter

atm-exoikat Exothermic temperature increase in the catalyst from measurement sites tabgm to tikatm

atm-kr-stat Exhaust gas temperature in the exhaust manifold under steady-state conditions

atm-kr-dyn Exhaust gas temperature in the exhaust manifold under dynamic conditions

atm-tmp-start Calculation of the exhaust gas or exhaust pipe wall temperature at engine start

atm-tpe-logik Calculation of the dew point at the pre-cat and post-cat lambda probes

atm-sp-nachl Storage of the dew point conditions at engine switch off

atm-mean Calculation of etazwist average values

atm-tmp-umgm If no ambient temperature sensor is available, calculate a substitute from ambient temperature (tans)

atm-mst If tabst_w is not correct tabstatm = maximum value, request for delay B_nlatm as a function of engine speed and tatu-threshold)

ATM 33.50 (Exhaust Gas Temperature Model) Function Description

The simulated exhaust gas temperatures tabgm and tabgkrm (for SY_TURBO = 1) and catalytic converter
temperatures tkatm and tikatm are used for the following purposes:

1. Monitoring the catalyst. If the catalytic converter falls below its starting temperature, then a fault can be detected.

2. For lambda control on the probe after the catalytic converter. This control is only activated after engine start, when the catalyst has exceeded its start-up temperature.

3. For the probe heater control after engine start. If the simulated dew point is exceeded, the probe heater is turned on.

4. Monitoring the heated exhaust gas oxygen (HEGO) sensor (i.e. lambda probe) heating system. If the exhaust gas temperature exceeds 800°C for example, then the lambda probe heater will be switched off, so that the probe is not too hot.

5. For fan motor control.

6. For switching on component protection.

This function provides only a rough approximation of the exhaust gas and catalytic converter temperature profiles, whereas throughout the application especially the four monitoring areas (dew point profiles in the exhaust gas, catalytic converter monitoring, enabling and shutting off lambda probe heating and high temperatures for component protection) should be considered to be critical.

1. Basic function

Steady-state temperature (tatmsta): the same applies for takrstc

With the engine speed/relative cylinder charge map KFTATM the steady-state exhaust gas temperature before the catalyst is set. This temperature is corrected for ambient temperature or simulated ambient temperature from the characteristic ATMTANS:

during boost with the constant TATMSA,

during catalyst heating with the constant TATMKH; catalyst warming with the constant TATMKW

with the ignition-angle efficiency map KFATMZW temperature as a function of ML and ETAZWIST

with the desired lambda map KFATMLA temperature as a function of ML and LAMSBG_W

for a cold engine block (TMOT - TATMTMOT) with TATMTMOT = 90°C.

The catalyst temperature (exothermic) is corrected for:

Temperature increase with the characteristic KATMEXML or KATMIEXML as a function of air mass

Temperature reduction with KLATMZWE or KLATMIZWE as a function of etazwimt (ignition angle influence)

Lambda influence with KLATMLAE or KLATMILAE as a function of lambsbg_w

Temperature set at TKATMOE or TIKATMOE at tabgm <TABGMEX or B_sa = 1

Different temperature increases are applied for the temperature in the catalytic converter tikatm and the temperature after the catalytic converter tkatm due to exothermic reaction and cooling and different ignition angles and lambda-corrections.

The time-based influence of the exhaust gas temperature before the catalytic converter:

Using a PT1 filter (filter time constant ZATMAML) the dynamics of the exhaust gas temperature are simulated and with a PT1 filter (time constant ZATMRML) the dynamics of the inlet manifold wall temperature are simulated.

The exhaust gas temperature and inlet manifold wall temperature are weighted by the division factor FATMRML.

The catalytic converter temperature tkatm is calculated from the exhaust gas temperature tabgm along with the PT1 filter (filter time constant ZATMKML).

The temperature in the catalyst tikatm is modelled from the exhaust gas temperature tabgm via three filters (time constant ZATMIKML) using the heat transfer principle. Due to a thrust caused by the small air mass flow in the catalytic converter, there is a possible exhaust gas temperature increase due to the greater influence on the matrix temperature by the exhaust gas throughput. This thrust-based temperature increase can be modelled by the positive B_sa side with a temperature, which is composed of the catalyst temperature tikatm and an offset TATMSAE, will be initialised. The time constants of the PT1-filter ZATMIKML are represented by air-mass-dependent characteristic curves.

The initial values for the exhaust and catalyst temperature at engine start can be calculated from the temperatures at switch-off and delay times. The starting values for the exhaust gas and catalyst temperatures should approximate to the manifold wall temperatures at the probe insertion points a few minutes after switch-off.
The filter for the exhaust gas temperature is stopped by setting B_stend = 0.
The filter for the manifold wall temperature is stopped when B_atmtpa = 1. The
filter for the catalyst temperature will be enabled only when B_atmtpk = 1.

2. Dew Point Detection

Initial values for the exhaust gas temperature tabgmst and catalyst temperature tkatmst

When stopping the engine (C_nachl 0 ® 1) the temperatures tabgm and tkatm are stored.

When starting the engine, the initial temperatures tabgmst and tkatmst are calculated from the switch-off temperature (corrected for ambient temperature) and a factor obtained from maps KFATMABKA or KFATMABKK as a function of tabstatm and tatu.

During power fail the switch-off temperature will be determined from the constant TATMSTI.

For test condition (B_faatm = 1), the initial temperatures are given by the constants TASTBFA and TKSTBFA.

Integrated Heat Quantity iwmatm_w

The dew point end time is approximately proportional to the heat quantity after engine start. The heat quantity = Integral (temp. x air mass x Cp) is calculated from the steady-state exhaust gas temperature tatmsta plus TATMWMK multiplied by the air mass. The result of the integration multiplied by the heat capacity at constant pressure Cp (approximately 1 kJ/kgK) gives the heat quantity.

Dew point end for the pre-cat lambda probe B_atmtpa and post-cat lambda probe B_atmtpk

The calculated exhaust gas temperature at engine start tabgmst approximates to the exhaust pipe wall temperature. If the exhaust pipe wall temperature is greater than 60°C for example then no condensation occurs.
The values in the map KFWMABG for these temperatures are less than 14 kJ, so the dew point end is detected immediately, or after only a few seconds.

For catalytic converter heating with thermal reaction (B_trkh = 1) the values in maps KFWMABG or KFWMKAT are multiplied by the factor WMKATKH or WMABGKH respectively. Thus, the dew point end-times are very short for this mode of operation.

Repeated starts (extension of the dew point-end-times)

If the engine had not reached the dew point end (B_atmtpa = 0 and B_atmtpf = 0) then when the engine restarts, the counter zwmatmf is increased by 1. After several periods of very short engine running (e.g. 3), the counter zwmatmf value would be set equal to 3. With a constant FWMABGW = 0.25 for example, the values in the map KFWMABG increase by a factor equal to (zwmatmf x KFWMABG + 1) = 1.75. When the engine starts, the dew point end time from the last engine run is detected and the
counter zwmatmf is reset.

Storage of the dew point end condition in the delay

For the determination of repeat start dew point end the conditions B_atmtpa in the flag B_atmtpf and B_atmtpk in the flag B_atmtpl are saved at engine switch-off due to a regular switch-off using the ignition or stall (B_stndnl). The function of dew point end for the post-cat lambda probe B_atmtpk
is analogous to the function for B_atmtpa.

3. Calculation of a simulated ambient temperature from the intake air temperature (tans) if no ambient temperature sensor is available.

The simulated temperature tatu will be used for calculating the temperature correction via the characteristic ATMTANS and for determining the starting temperatures tabgmst and tkatmst. The intake air temperature (tans) is corrected with the constant DTUMTAT and under certain conditions stored in continuous RAM. If for example at engine start, the temperature tatu > tans, then the temperature value tatu is set on the lower tans value.

With the constant TATMWMK (negative value) the difference in dew point end between catalyst heating and no catalyst heating can be increased.

When catalytic converter heating is active B_khtr = 1 and the bit B_atmtpa can be set equal to 1 immediately after engine start. This is possible only when no problematic condensation is formed during catalyst heating.

With the system constants SY_STERVK = 1 cylinder bank 2 can be applied separately for stereo systems.

For SY_TURBO = 1 the exhaust gas temperature tabgm is essentially identical in addition to the modeled temperature in the manifold tabgkrm.

ATM 33.50 Application Notes

1. Installation locations for temperature sensors in this application, running in
the direction of flow:

- In probe installation position before catalytic converter-

1. Exhaust gas temperature (pipe centre) for the high temperatures at high loads for probe heater switch off

2. Manifold wall temperature for the determination of the dew-end times. (Condensation protection)

- Before the catalytic converter

3. Exhaust gas temperature (pipe centre) for the catalyst start-up temperature

- In the catalytic converter

4. Ceramic temperature in and after catalytic converter (in the last third of the catalytic converter or behind the adjoining matrix) to determine the air-mass-dependent time constants.

- After the catalytic converter

5. Pipe wall temperature at probe installation site for the determination of the dew-end times (condensation protection).

Temperature measuring point 3 can be omitted if the distance from probe to catalytic converter is smaller than about 30 cm. The temperature drop from probe installation site to catalytic converter can then be neglected.

For the application of the functional data the modelled temperatures will always be compared with the measured temperatures and the functional data amended until a sufficiently high accuracy is achieved. In so doing, it will be the actual catalyst temperature, the temperature increase due to the exothermic reaction is not considered in the model.

2. Map KFTATM

For the determination of the steady-state temperature for example, before the catalytic converter the temperature corrections should not function. The cooling capacity of the wind on the dynamometer or on the measuring wheel can be simulated only very roughly at the higher engine load range. The map values can be determined on the rolling road dynamometer, but should be corrected on an
appropriate test drive.

3. Temperature Corrections

- TATMSA

Boost can cause low exhaust temperatures that fall below the starting temperature of the catalyst. The longer the time period for the thrust condition, the lower the exhaust and catalyst temperatures. For catalyst diagnosis during boost, the exhaust gas temperature model is more likely to calculate a lower value than the measured temperature.

- ATMTANS

At low ambient temperatures, exhaust gas temperature can fall below the catalyst start-up temperature. Therefore, the model temperature is only corrected at the low temperature range.

- TATMKH

As long as the catalyst-heating measures are effective, higher exhaust temperatures will result.

- TATMKW

The catalyst operating temperature will not be not reached during prolonged idling, so the exhaust gas temperature can be raised by the catalyst warming function.

- KFATMZW

The temperature increase as a result of ignition angle retardation can be determined on a rolling road dynamometer. First, on the dynamometer, the characteristic field values KFTATM are applied without ignition angle correction. Ignition angles are then modified so that allowed etazwist values will result in the map. Through the corresponding air mass, the temperature increase will then be displayed in the map KFATMZW.

- KFATMLA

The exhaust temperature is reduced by enrichment. The application is similar to KFATMZW, except that the ignition angle efficiency is changed instead of the enrichment factor.

- TATMTMOT

The map KFTATM is applied with a warm engine. Thus, the model exhaust gas temperature has smaller deviations during cold start. For this operating mode, the temperature is corrected with the difference of the cold engine temperature and the warm engine temperature. TATMTMOT should be about 90 to 100°C.

4. Maps ZATMAML, ZATMRML, FATMRML, ZATMKML, ZATMKKML, ZATMIKML und ZATMIKKML

The air-mass-dependent time constants ZATMAML, ZATMRML (temperature measuring points 1 or 3), and ZATMKML, ZATMKKML, ZATMIKML, ZATMIKKML (temperature measuring point 4), can help to more accurately determine “spikes in the air mass” during sudden load variations. Thereby "air mass jumps" at full load and in particular during boost can be avoided. For example, for an air mass jump from 30 kg/hr to 80 kg/hr, the measured time constant is applied to the air mass flow of 80 kg/hr. For large air mass jumps during idle, the time constants ZATMKKML and ZATMIKKML can be input instead of ZATMKML or ZATMIKML if required.

5. Block EXOTHERME:

- KATMEXML

The exothermic temperature is a function of air mass flow (warming by realizing emissions, reducing warming via a larger air mass). First KATMEXML applies, then KLATMZWE, KLATMLAE.

- KLATMZWE

When ignition angle retardation increases the temperature before the catalyst, the catalyst temperature drops.

- KLATMLAE

For lambda < 1 (richer), the air mass is lacking to improve emissions so the catalyst temperature decreases.

- TABGMEX

If the temperature before the catalyst tabgm < TABGMEX (catalyst switch-off temperature) then the temperature correction = TKATMOE.

- TKATMOE

Temperature correction during boost or through tabgm> TABGMEX

- TATMSAE

Temperature increase in the boost in the catalyst in terms of tkatm

Block EXOIKAT:

- KATMIEXML, KLATMIZWE, KLATMILAE, TIKATMOE

Application depends on the application for Block EXOTHERME

- TATMSAE

Temperature increase in the thrust in the catalyst in terms of tikatm

6. Dew point end times for exhaust gas temperatures vary greatly between the centre of the exhaust pipe and the pipe wall. Dew point end times for the tube wall temperatures before the catalyst (temperature measuring points 2) or after the catalyst (temperature measuring points 5) should be used. These times are usually due to delaying control readiness for too long, in which case the temperature gradients at the probe mounting location must be examined more closely. To avoid probe damage by “water hammer”, the sensor heater must be fully turned on until the dew point temperature is exceeded or the dew point end time is detected thus condensation will no longer occur.

When the switch-off time in the ECU delay is calculated, then the switch-off time tabst_w after ECU delay will be incorrect. At engine start after ECU delay, the switch-off time tabstatm therefore, will be set to the maximum value of 65,535 (i.e. 216-1). The ECU delay requirement for the time TNLATM when engine speed > TNLATMTM & tumg (tatu) > TNLATMTU.

8. For blocks KR_STAT and KR_DYN as appropriate, the descriptions in points 3 and
4 shall apply.

Typical Values:

KFTATM: x: engine speed/RPM, y: relative cylinder charge/%, z: temperature/°C

{| border="1"
|-
|
|
800
|
1200
|
1800
|
2400
|
3000
|
4000
|
5000
|
6000
|-
|
15
|
380
|
400
|
420
|
450
|
480
|
520
|
550
|
580
|-
|
22
|
400
|
420
|
450
|
480
|
520
|
550
|
580
|
610
|-
|
30
|
420
|
450
|
480
|
520
|
550
|
580
|
610
|
650
|-
|
50
|
450
|
480
|
520
|
550
|
580
|
610
|
650
|
700
|-
|
70
|
470
|
520
|
550
|
580
|
610
|
660
|
700
|
750
|-
|
100
|
490
|
550
|
580
|
610
|
650
|
700
|
750
|
790
|-
|
120
|
510
|
560
|
610
|
650
|
700
|
750
|
790
|
840
|-
|
140
|
530
|
580
|
650
|
700
|
750
|
790
|
840
|
900
|}

KFATMZW: x: temperature/°C, y: ml_w/kg/hr, z: etazwimt

{| border="1"
|-
|
|
20
|
40
|
80
|
150
|
250
|
400
|-
|
1.00
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|-
|
0.95
|
15
|
40
|
50
|
60
|
70
|
75
|-
|
0.90
|
15
|
60
|
80
|
100
|
125
|
140
|-
|
0.80
|
20
|
80
|
120
|
150
|
180
|
200
|-
|
0.70
|
25
|
100
|
150
|
190
|
210
|
220
|-
|
0.60
|
30
|
115
|
175
|
210
|
230
|
245
|}

KFATMLA: x: temperature/°C, y: ml_w/kg/hr, z: lamsbg_w

{| border="1"
|-
|
|
20
|
40
|
80
|
150
|
250
|
400
|-
|
1.15
|
5
|
10
|
30
|
50
|
60
|
70
|-
|
1.00
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|-
|
0.95
|
5
|
10
|
20
|
30
|
40
|
45
|-
|
0.90
|
15
|
25
|
40
|
50
|
60
|
75
|-
|
0.80
|
30
|
40
|
60
|
70
|
85
|
100
|-
|
0.70
|
40
|
60
|
80
|
90
|
100
|
120
|}

KFWMABG: x: energy/kJ, y: tabgmst/°C, z: tmst/°C

{| border="1"
|-
|
|
-40
|
0
|
15
|
25
|
30
|
55
|
60
|-
|
-40
|
200
|
160
|
150
|
140
|
100
|
60
|
30
|-
|
0
|
180
|
150
|
120
|
110
|
80
|
50
|
20
|-
|
15
|
160
|
140
|
60
|
55
|
30
|
40
|
0.45
|-
|
25
|
140
|
120
|
30
|
30
|
15
|
10
|
0.45
|-
|
60
|
120
|
30
|
20
|
15
|
10
|
5
|
0.45
|}

KFWMKAT values correspond to KFWMABG x 5

In the heat quantity maps KFWMABG and KFWMKAT a value of 0.0 is never required! It should always have at least the value to be entered; the 2 sec corresponds to idle after cold start. Only then does the repeat-start counter operate after several starts where the dew point was not reached.

ZATMAML
ml_w/kg/hr, Time constant/sec 10, 30 ; 20, 20 ; 40, 13 ; 80, 5 ; 180, 4 ; 400, 3 ; 600, 2 ;

ZATMKML
ml_w/kg/hr, Time constant/sec 10, 150 ; 20, 60 ; 40, 35 ; 80, 20 ; 180, 10 ;
400, 7 ; 600, 4 ;

ZATMIKML
value represents approximately ZATMKML x 0.3

ZATMKKML
for neutral input, the data must correlate to ZATMKML

ZATMIKKML
for neutral input, the data must correlate to ZATMIKML

ZATMRML
ml_w/kg/hr, Time constant/sec 10, 300 ; 20, 80 ; 40, 55 ; 80, 30 ; 180, 20 ; 400, 10 ; 600, 7 ;

FATMRML
ml_w/kg/hr, Time constant/sec 10, 0.5 ; 20, 0.6 ; 40, 0.7 ; 80, 0.8 ; 180, 0.95 ; 400,0.95 ; 600, 0.96;

KATMEXML
ml_w/kg/hr, Time constant/sec 10, 0 ; 20, 0 ; 40, 0 ; 80, 0 ; 180, 0 ; 400, 0 ;

KLATMZWE
etazwimt, Factor 1, 0 ; 0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ; 0.6, 0 ;

KLATMLAE
lamsbg_w, Factor 1.15, 0 ; 1 , 0 ;0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ;

TATMTP: 52°C

TKATMOE: 0°C

TATMSAE: 0°C

KATMIEXML
ml_w/kg/hr, Time constant/sec 10, 0 ; 20, 0 ; 40, 0 ; 80, 0 ; 180, 0 ; 400, 0 ;

KLATMIZWE
etazwimt, Factor 1, 0 ; 0.95, 0 ; 0.9, 0; 0.8, 0 ; 0.7, 0 ; 0.6, 0 ;

KLATMILAE
lamsbg_w, Factor 1.15, 0 ; 1 , 0 ;0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ;

TIKATMOE: 0°C

KFATMABKA: x: tatu/°C, y: tabstatm_w/seconds, z: no units

{| border="1"
|-
|
|
10
|
50
|
180
|
360
|
600
|
1000
|-
|
-40
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
-15
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
0
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
15
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
40
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|}

KFATMABKK: x: tatu/°C, y: tabstatm_w [s], z: no units

{| border="1"
|-
|
|
10
|
50
|
180
|
360
|
600
|
1000
|-
|
-40
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
-15
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
0
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
15
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
40
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|}

ATMTANS tatu/°C, Temp./°C -40, 60 ; -10, 20 ; 20, 0 ;

TATMSA: 100°C

TATMKH: 80°C

TATMTRKH: 200°C

TATMKW: 100°C

TATMTMOT: 90°C

TATMSTI: 20°C

TASTBFA: 40°C

TKSTBFA: 40°C

TATMWMK: -80°C

WMABGKH: Factor of 1.0

WMKATKH: Factor of 1.0

FWMABGW: Factor of 0.25

FWMKATW: Factor of 0.25

DTUMTAT: 20°C

VTUMTAT: 40 km/h

NTUMTAT: 1800 rpm

IMTUMTAT: 1 kg

TUMTAIT: 20°C

TNLATMTM: 80°C

TNLATMTU: 5°C

TNLATM: 660 seconds

Only when SY_TURBO = 1:

For neutral input (tabgkrm_w = tabgm_w)

KFATMKR = KFTATM

KFATZWK = KFATMZW

KFATLAK = KFATMLA

TATMKRSA = TATMSA

ZATRKRML = ZATMRML

ZATAKRML = ZATMAML

FATRKRML = FATMRML

ATMTANS
tans/°C, Temp./°C -40, 40 ; -20, 25 ; 0, 12 ; 20, 0 ; 60, -30

The functional data for cylinder bank 2 correspond to the functional data from cylinder bank 1 Note:

In order that ATM 22:20 for the application is backward compatible the default values should be entered thus: KATMEXML, KLATMZWE, KLATMLAE, TKATMOE = 0 and TABGMEX = 1220°C.

In order that ATM 33.10 remains application-neutral with ATM 22.50, TATMTRKH must be set equal to TATMKH and WMKATKH should be set equal to 1. Tikatm is not used in a function because the input can be used in the path in the exhaust gas temperature model without impact on safety, however, the default values for KATMIEXML, KLATMIZWE, KLATMILAE and TIKATMOE should be set equal to 0 and TABGMEX = 1220°C.

In DKATSP areas TMINKATS and TMAXKATS, a high accuracy is required for tikatm!

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
ATMTAKR
|
Correction
for the manifold temperature
|-
|
ATMTANS
|
Temperature
correction for the exhaust gas temperature model
|-
|
DTUMTAT
|
Offset:
intake air temperature ® ambient temperature
|-
|
FATMRML
|
Factor
for the difference between exhaust gas & exhaust pipe wall temperature
|-
|
FATMRML2
|
Factor
for the difference between exhaust gas & exhaust pipe wall temperature, cylinder
bank 2
|-
|
FATRKRML
|
Factor
for the difference between exhaust gas & wall temperature in the manifold
|-
|
FATRKRML2
|
Factor
for the difference between exhaust gas & wall temperature in the manifold,
cylinder bank 2
|-
|
FWMABGW
|
Factor
for heat quantity during repeated starts for pre-cat exhaust gas dew points
|-
|
FWMABGW2
|
Factor
for heat quantity during repeated starts for pre-cat exhaust gas dew points,
cylinder bank 2
|-
|
FWMKATW
|
Factor
for heat quantities during repeated starts for dew points after main catalyst
|-
|
FWMKATW2
|
Factor
for heat quantities during repeated starts for dew points after main catalyst,
cylinder bank 2
|-
|
IMTUMTAT
|
Integration
threshold air mass for determining ambient temperature from TANS
|-
|
KATMEXML
|
Exothermic
reaction temperature in catalyst, tkatm
|-
|
KATMEXML2
|
Exothermic
reaction temperature in catalyst, cylinder bank 2
|-
|
KATMIEXML
|
Exothermic
reaction temperature in catalyst, tikatm
|-
|
KATMIEXML2
|
Exothermic
reaction temperature in catalyst, tikatm, cylinder bank 2
|-
|
KFATLAK
|
Map for
lambda correction for manifold exhaust gas temperature
|-
|
KFATLAK2
|
Map for
lambda correction for manifold exhaust gas temperature, cylinder bank 2
|-
|
KFATMABKA
|
Factor
for exhaust gas temperature decrease as a function of stop time and ambient
temperature
|-
|
KFATMABKA2
|
Factor
for exhaust gas temperature decrease as a function of stop time and ambient
temperature, cylinder bank 2
|-
|
KFATMABKK
|
Factor
for reducing the catalyst temperature as a function of stop time and ambient
temperature
|-
|
KFATMABKK2
|
Factor
for reducing the catalyst temperature as a function of stop time and ambient
temperature, cylinder bank 2
|-
|
KFATMKR
|
Map for
steady-state manifold exhaust gas temperature as a function of engine speed
and relative cylinder charge
|-
|
KFATMKR2
|
Map for
steady-state manifold exhaust gas temperature, cylinder bank 2
|-
|
KFATMLA
|
Map for
exhaust gas temperature correction as a function of lambda
|-
|
KFATMLA2
|
Map for
exhaust gas temperature correction as a function of lambda, cylinder bank 2
|-
|
KFATMZW
|
Map for
exhaust gas temperature correction as a function of igntion angle correction
|-
|
KFATMZW2
|
Map for
exhaust gas temperature correction as a function of ignition angle, cylinder
bank 2
|-
|
KFATZWK
|
Map for
ignition angle correction for manifold gas temperature
|-
|
KFATZWK2
|
Map for
ignition angle correction for manifold gas temperature, cylinder bank 2
|-
|
KFTATM
|
Map for
exhaust gas temperature as a function of engine speed and relative cylinder
charge
|-
|
KFTATM2
|
Map for
exhaust gas temperature as a function of engine speed and relative cylinder
charge for cylinder bank 2
|-
|
KFWMABG
|
Map for
heat quantity threshold exhaust gas dew points
|-
|
KFWMABG2
|
Map for
heat quantity threshold exhaust gas dew points, cylinder bank 2
|-
|
KFWMKAT
|
Map for
heat quantity threshold dew points after catalyst
|-
|
KFWMKAT2
|
Map for
heat quantity threshold dew points after catalyst, cylinder bank 2
|-
|
KLATMILAE
|
Exothermic
temperature decrease through enrichment, tikatm
|-
|
KLATMILAE2
|
Exothermic
temperature decrease through enrichment, tikatm, Bank 2
|-
|
KLATMIZWE
|
Exothermic
temperature decrease in catalyst at later ignition angles, tikatm
|-
|
KLATMIZWE2
|
Exothermic
temperature decrease in catalyst at later ignition angles, tikatm, Bank 2
|-
|
KLATMLAE
|
Exothermic
temperature decrease through enrichment
|-
|
KLATMLAE2
|
Exothermic
temperature decrease through enrichment, cylinder bank 2
|-
|
KLATMZWE
|
Exothermic
temperature decrease in catalyst at later ignition angles, tkatm
|-
|
KLATMZWE2
|
Exothermic
temperature decrease in catalyst at later ignition angles, cylinder bank 2
|-
|
NTUMTAT
|
Speed
threshold for determining ambient temperature from TANS
|-
|
SEZ06TMUB
|
Sample
point distribution, ignition angle efficiency
|-
|
SLX06TMUW
|
Sample
point distribution, desired lambda
|-
|
SLY06TMUW
|
Sample
point distribution, desired lambda, cylinder bank 2
|-
|
SML06TMUW
|
Sample
point distribution, air mass, 6 sample points
|-
|
SML07TMUW
|
Sample
point distribution, air mass, 7 sample points
|-
|
SMT06TMUW
|
Sample
point distribution, air mass, 6 sample points
|-
|
ST107TMUB
|
Sample
point distribution, start temperature at front probe
|-
|
ST207TMUB
|
Sample
point distribution, start temperature at front probe, cylinder bank 2
|-
|
ST307TMUB
|
Sample point
distribution, start temperature at rear probe
|-
|
ST407TMUB
|
Sample
point distribution, start temperature at rear probe, cylinder bank 2
|-
|
STM05TMUB
|
Sample
point distribution, engine start temperature
|-
|
STS06TMUW
|
Sample
point distribution, exhaust gas mass flow
|-
|
STU05TMUB
|
Sample
point distribution, simulated ambient temperature
|-
|
SY_STERVK
|
System
constant condition: stereo before catalyst
|-
|
SY_TURBO
|
System
constant: turbocharger
|-
|
TABGMEX
|
Exhaust
gas temperature below the catalyst switch-off temperature
|-
|
TASTBFA
|
Model temperature
before pre-cat initial value via B_faatm requirement
|-
|
TATMKH
|
Exhaust
gas temperature correction via catalyst heating active
|-
|
TATMKH2
|
Exhaust
gas temperature correction via catalyst heating active, cylinder bank 2
|-
|
TATMKRSA
|
Exhaust
gas temperature correction in manifold via boost switch-off
|-
|
TATMKW
|
Exhaust
gas temperature correction with catalyst warming active
|-
|
TATMSA
|
Exhaust
gas temperature correction via boost cut-off
|-
|
TATMSAE
|
Exothermic
temperature increase in boost
|-
|
TATMSAE2
|
Exothermic
temperature increase in boost, cylinder bank 2
|-
|
TATMSTI
|
Initial
value for tabgm, tkatm intial value through power fail
|-
|
TATMTMOT
|
Engine temperature
warmer Motor, for temperature correction during cold start conditions
|-
|
TATMTP
|
Exhaust
gas dew point temperature
|-
|
TATMTRKH
|
Exhaust
gas temperature correction via thermal reaction catalyst heating
|-
|
TATMTRKH2
|
Exhaust
gas temperature correction via thermal reaction catalyst heating, cylinder bank
2
|-
|
TATMWMK
|
Temperature
offset for calculating heat quantities
|-
|
TIKATMOE
|
Temperature
correction in catalyst without exothermic reaction, tikatm
|-
|
TKATMOE
|
Temperature
correction near catalyst without exothermic reaction, tkatm
|-
|
TKSTBFA
|
Model temperature
post-cat initial value via B_faatm requirement
|-
|
TNLATM
|
Minimum
ECU delay time for exhaust gas temperature model – Abstellzeit
|-
|
TNLATMTM
|
When
tmot > threshold ECU delay requirement B_nlatm = 1
|-
|
TNLATMTU
|
When
tumg (tatu – ATM) > threshold ECU delay requirement
|-
|
TUMTAIT
|
Initialising
value for ambient temperature from TANS
|-
|
VTUMTAT
|
Vehicle
speed threshold for TANS ® ambient temperature
|-
|
WMABGKH
|
Factor
for heat quantity correction via catalyst heating for dew points
|-
|
WMABGKH2
|
Factor
for heat quantity correction via catalyst heating for dew points, cylinder bank
2
|-
|
WMKATKH
|
Factor
for heat quantity correction via catalyst heating for dew points after
catalyst
|-
|
WMKATKH2
|
Factor
for heat quantity correction via catalyst heating for dew points after
catalyst, cylinder bank 2
|-
|
ZATAKRML
|
Time
constant for exhaust gas temperature model (manifold)
|-
|
ZATAKRML2
|
Time
constant for exhaust gas temperature model (manifold), cylinder bank 2
|-
|
ZATMAML
|
Time
constant for exhaust gas temperature model
|-
|
ZATMAML2
|
Time
constant for exhaust gas temperature model, cylinder bank 2
|-
|
ZATMIKKML
|
Time
constant for catalyst temperature model – Temperature in catalyst tikatm during
cooling
|-
|
ZATMIKKML2
|
Time
constant for catalyst temperature model – Temperature in catalyst tikatm
during cooling, bank 2
|-
|
ZATMIKML
|
Time
constant for catalyst temperature model – Temperature in catalyst, tikatm
|-
|
ZATMIKML2
|
Time
constant for catalyst temperature model – Temperature in catalyst, cylinder bank
2
|-
|
ZATMKKML
|
Time
constant for catalyst temperature model – catalyst temperature tkatm during
cooling
|-
|
ZATMKKML2
|
Time
constant for catalyst temperature model – catalyst temperature tkatm during
cooling, bank 2
|-
|
ZATMKML
|
Time
constant for catalyst temperature model – catalyst temperature tkatm
|-
|
ZATMKML2
|
Time
constant for catalyst temperature model – catalyst temperature, cylinder bank
2
|-
|
ZATMRML
|
Time
constant for exhaust gas temperature model – exhaust pipe wall temperature
|-
|
ZATMRML2
|
Time
constant for exhaust gas temperature model – exhaust pipe wall temperature Bank
2
|-
|
ZATRKRML
|
Time
constant for exhaust gas temperature model – manifold wall temperature
|-
|
ZATRKRML2
|
Time
constant for exhaust gas temperature model – manifold wall temperature, cylinder
bank 2
|-
|
Variable
|
Description
|-
|
B_ATMLL
|
Condition
for time constant during cooling at idle
|-
|
B_ATMLL2
|
Condition
for time constant during cooling at idle
|-
|
B_ATMST
|
Condition
for tabgmst, tkatmst initial value calculation
|-
|
B_ATMST2
|
Condition
for tabgmst, tkatmst calculation, cylinder bank 2
|-
|
B_ATMTPA
|
Condition:
dew point before catalyst exceeded
|-
|
B_ATMTPA2
|
Condition:
dew point 2 before catalyst exceeded
|-
|
B_ATMTPF
|
Condition:
dew point before catalyst exceeded (last trip)
|-
|
B_ATMTPF2
|
Condition:
dew point before catalyst exceeded (last trip) cylinder bank 2
|-
|
B_ATMTPK
|
Condition:
dew point after catalyst exceeded
|-
|
B_ATMTPK2
|
Condition:
dew point 2 after catalyst exceeded
|-
|
B_ATMTPL
|
Condition: dew point after catalyst exceeded (last trip)
|-
|
B_ATMTPL2
|
Condition: dew point after catalyst exceeded (last trip) cylinder bank 2
|-
|
B_FAATM
|
Condition: functional requirements for dew
point end times
|-
|
B_KH
|
Condition: catalyst heating
|-
|
B_KW
|
Condition: catalyst warming
|-
|
B_LL
|
Condition: idle
|-
|
B_NACHL
|
Condition: ECU delay
|-
|
B_NACHLEND
|
Condition: ECU delay ended
|-
|
B_NLATM
|
Condition: ECU delay exhaust gas temperature
model probe protection
|-
|
B_PWF
|
Condition: Power fail
|-
|
B_SA
|
Condition: Overrun cut-off
|-
|
B_ST
|
Condition: Start
|-
|
B_STEND
|
Condition: End of start conditions achieved
|-
|
B_STNDNL
|
Condition: Beginning of ECU delay or end of
start conditions (1 ® 0)
|-
|
B_TFU
|
Condition: Ambient temperature sensor
available
|-
|
B_TRKH
|
Condition: Catalyst heating, thermal reaction
effective
|-
|
B_UHRRMIN
|
Condition: timer with a relative number of
minutes
|-
|
B_UHRRSEC
|
Condition: timer with a relative number of
minutes
|-
|
DFP_TA
|
ECU internal error path number: intake air
temperature TANS (charge air)
|-
|
DFP_TUM
|
ECU Internal error path number: ambient
temperature
|-
|
ETAZWIMT
|
Actual ignition angle efficiency average for exhaust
gas temperature model (200 ms)
|-
|
ETAZWIST
|
Actual ignition angle efficiency
|-
|
E_TA
|
Error flag: TANS
|-
|
E_TUM
|
Error flag: ambient temperature tumg
|-
|
IMLATM
|
Integral of air mass flows from engine start
bis Max.wert
|-
|
IMLATM_W
|
Integral of air mass flows from end of start
conditions up to the maximum value, (Word)
|-
|
IWMATM2_W
|
Heat quantity for Condensation - dew points
exhaust gas/catalyst (word), cylinder bank 2
|-
|
IWMATM_W
|
Heat quantity for Condensation - dew points
exhaust gas/catalyst (word)
|-
|
LAMSBG2_W
|
Desired lambda limit (word), cylinder bank 2
|-
|
LAMSBG_W
|
Desired lambda limit (word)
|-
|
ML_W
|
Filtered air mass flow (word)
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
TABGKRM2_W
|
Exhaust gas temperature in manifold from the
model, cylinder bank 2
|-
|
TABGKRM_W
|
Exhaust gas temperature in manifold from the
model
|-
|
TABGM
|
Exhaust gas temperature before catalyst from
the model
|-
|
TABGM2
|
Exhaust gas temperature before catalyst from
the model, cylinder bank 2
|-
|
TABGM2_W
|
Exhaust gas temperature before catalyst from
the model (word) cylinder bank 2
|-
|
TABGMAB
|
Exhaust gas temperature during engine
switch-off
|-
|
TABGMAB2
|
Exhaust gas temperature during engine
switch-off (model) cylinder bank 2
|-
|
TABGMST
|
Exhaust gas temperature at engine start
|-
|
TABGMST2
|
Exhaust gas temperature at engine start,
cylinder bank 2
|-
|
TABGM_W
|
Exhaust gas temperature before catalyst from
the model (word)
|-
|
TABSTATM_W
|
Stop time in ECU delay for exhaust gas
temperature model
|-
|
TABSTMX_W
|
Stop time maximum query for exhaust gas
temperature model
|-
|
TABST_W
|
Stop time
|-
|
TAKRKF
|
Steady-state manifold exhaust gas temperature without
correction
|-
|
TAKRKF2
|
Steady-state manifold exhaust gas temperature
without correction, cylinder bank 2
|-
|
TAKRSTC
|
Steady-state exhaust gas temperature in
manifold in °C
|-
|
TAKRSTC2
|
Steady-state exhaust gas temperature in
manifold, cylinder bank 2
|-
|
TANS
|
Intake air temperature
|-
|
TATAKRML
|
Output from PT1 element: exhaust gas
temperature influence on tabgkrm
|-
|
TATAKRML2
|
Output from PT1 element: exhaust gas
temperature influence on tabgkrm, cylinder bank 2
|-
|
TATMAML
|
Output from PT1 element: exhaust gas
temperature influence on tabgm
|-
|
TATMAML2
|
Output from PT1 element: exhaust gas
temperature influence on tabgm, cylinder bank 2
|-
|
TATMKF
|
Exhaust gas temperature before catalyst from map
KFTATM
|-
|
TATMKF2
|
Exhaust gas temperature before catalyst from map
KFTATM, cylinder bank 2
|-
|
TATMRML
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgm
|-
|
TATMRML2
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgm, cylinder bank 2
|-
|
TATMSTA
|
Exhaust gas temperature before catalyst from
the steady-state model
|-
|
TATMSTA2
|
Exhaust gas temperature before catalyst from
the steady-state model, cylinder bank 2
|-
|
TATRKRML
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgkrm
|-
|
TATRKRML2
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgkrm, cylinder bank 2
|-
|
TATU
|
Intake air temperature or ambient temperature
|-
|
TEXOIKM2_W
|
Exotherme temperature increase in catalyst for
tikatm, cylinder bank 2
|-
|
TEXOIKM_W
|
Exotherme temperature increase in catalyst for
tikatm
|-
|
TEXOM2_W
|
Exotherme temperature increase in catalyst for
tkatm2, cylinder bank 2
|-
|
TEXOM_W
|
Exotherme temperature increase in catalyst for
tkatm
|-
|
TIKATM
|
Exhaust gas temperature in catalyst from the
model
|-
|
TIKATM2
|
Exhaust gas temperature in catalyst from the
model, cylinder bank 2
|-
|
TIKATM2_W
|
Exhaust gas temperature in catalyst from the
model, cylinder bank 2
|-
|
TIKATM W
|
Exhaust gas temperature in catalyst from the
model
|-
|
TKATM
|
Catalyst temperature from the model
|-
|
TKATM2
|
Catalyst temperature from the model, cylinder
bank 2
|-
|
TKATM2_W
|
Catalyst temperature from the model (word),
cylinder bank 2
|-
|
TKATMAB
|
Exhaust gas temperature after catalyst through
engine switch-off (model)
|-
|
TKATMAB2
|
Exhaust gas temperature after catalyst through
engine switch-off (model), cylinder bank 2
|-
|
TKATMST
|
Catalyst temperature model initial value as a
function of switch-off value, switch-off time
|-
|
TKATMST2
|
Catalyst temperature model initial value as a
function of switch-off value, switch-off time, bank 2
|-
|
TKATM_W
|
Catalyst temperature from the model (word)
|-
|
TMOT
|
Engine temperature
|-
|
TMST
|
Engine start temperature
|-
|
TUMG
|
Ambient
temperature
|-
|
VFZG
|
Vehicle
speed
|-
|
ZWMATM
|
Counter
for repeated starts and factor for heat quantity threshold
|-
|
ZWMATM2
|
Counter
for repeated starts and factor for heat quantity threshold, cylinder bank 2
|-
|
ZWMATMF
|
Counter
for repeated starts and factor for heat quantity threshold upstream
|-
|
ZWMATMF2
|
Counter
for repeated starts and factor for heat quantity threshold upstream, cylinder
bank 2
|}

[[Category:ME7]]

ATM 33.50 (Exhaust Gas Temperature Model)

2012-01-08T18:01:54Z

TTQS:

Refer to the ''funktionsrahmen'' for the following diagrams:

atm-main

atm-atm-b1 Exhaust gas temperature model (cylinder
bank 1) overview

atm-tmp-stat TMP_STAT engine speed & relative cylinder charge map and corrected for temperature for acceleration, intake air temp., catalyst heating, catalyst warming, ignition angle, lambda and cold engine

atm-dynamik Temperature dynamic for exhaust gas and catalytic converter temperature (in and near the catalytic
converter)

atm-tabgm Temperature dynamic: exhaust gas, exhaust pipe wall effect, from the exhaust gas temperature tabgm

atm-tkatm Temperature dynamic for the temperature near the catalytic converter

atm-exotherme Exothermic temperature increase near the catalyst from measurement sites tabgm to tikatm

atm-tikatm Temperature dynamic for the temperature in the catalytic converter

atm-exoikat Exothermic temperature increase in the catalyst from measurement sites tabgm to tikatm

atm-kr-stat Exhaust gas temperature in the exhaust manifold under steady-state conditions

atm-kr-dyn Exhaust gas temperature in the exhaust manifold under dynamic conditions

atm-tmp-start Calculation of the exhaust gas or exhaust pipe wall temperature at engine start

atm-tpe-logik Calculation of the dew point at the pre-cat and post-cat lambda probes

atm-sp-nachl Storage of the dew point conditions at engine switch off

atm-mean Calculation of etazwist average values

atm-tmp-umgm If no ambient temperature sensor is available, calculate a substitute from ambient temperature (tans)

atm-mst If tabst_w is not correct tabstatm = maximum value, request for delay B_nlatm as a function of engine speed and tatu-threshold)

ATM 33.50 (Exhaust Gas
Temperature Model) Function Description

The simulated exhaust gas
temperatures tabgm and tabgkrm (for SY_TURBO = 1) and catalytic converter
temperatures tkatm and tikatm are used for the following purposes:

1. Monitoring the catalyst. If the catalytic converter falls below its starting temperature, then
a fault can be detected.

2. For lambda control on the probe after the catalytic converter. This control is only activated after
engine start, when the catalyst has exceeded its start-up temperature.

3. For the probe heater control after engine start. If the simulated dew point is exceeded, the probe
heater is turned on.

4. Monitoring the heated exhaust gas oxygen (HEGO) sensor (i.e. lambda probe) heating system. If the
exhaust gas temperature exceeds 800°C for example, then the lambda probe heater
will be switched off, so that the probe is not too hot.

5. For fan motor control.

6. For switching on component protection.

This function provides only a rough approximation of the exhaust gas and catalytic converter temperature profiles, whereas throughout the application especially the four monitoring areas (dew point profiles in the exhaust gas, catalytic converter monitoring, enabling and shutting off lambda probe heating and high temperatures for component protection) should be considered to be critical.

1. Basic function

Steady-state temperature (tatmsta): the same applies for takrstc

With the engine speed/relative cylinder charge map KFTATM the steady-state exhaust
gas temperature before the catalyst is set. This temperature is corrected for
ambient temperature or simulated ambient temperature from the characteristic
ATMTANS:

during boost with the constant TATMSA,

during catalyst heating with the constant TATMKH; catalyst warming with the constant TATMKW

with the ignition-angle efficiency map KFATMZW temperature as a function of ML and ETAZWIST

with the desired lambda map KFATMLA temperature as a function of ML and LAMSBG_W

for a cold engine block (TMOT - TATMTMOT) with TATMTMOT = 90°C.

The catalyst temperature (exothermic) is corrected for:

Temperature increase with the characteristic KATMEXML or KATMIEXML as a function of air mass

Temperature reduction with KLATMZWE or KLATMIZWE as a function of etazwimt (ignition angle influence)

Lambda influence with KLATMLAE or KLATMILAE as a function of lambsbg_w

Temperature set at TKATMOE or TIKATMOE at tabgm <TABGMEX or B_sa = 1

Different temperature increases are applied for the temperature in the catalytic converter tikatm and the temperature after the catalytic converter tkatm due to exothermic reaction and cooling and different ignition angles and lambda-corrections.

The time-based influence of the exhaust gas temperature before the catalytic
converter:

Using a PT1 filter (filter time constant ZATMAML) the dynamics of the exhaust gas temperature are simulated and with a PT1 filter (time constant ZATMRML) the dynamics of the inlet manifold wall temperature are simulated.

The exhaust gas temperature and inlet manifold wall temperature are weighted by the division factor FATMRML.

The catalytic converter temperature tkatm is calculated from the exhaust gas temperature tabgm along with the PT1 filter (filter time constant ZATMKML).

The temperature in the catalyst tikatm is modelled from the exhaust gas temperature tabgm via three filters (time constant ZATMIKML) using the heat transfer principle. Due to a thrust caused by the small air mass flow in the catalytic converter, there is a possible exhaust gas temperature increase due to the greater influence on the matrix temperature by the exhaust gas throughput. This thrust-based temperature increase can be modelled by the positive B_sa side with a temperature, which is composed of the catalyst temperature tikatm and an offset TATMSAE, will be initialised. The time constants of the PT1-filter ZATMIKML are represented by air-mass-dependent characteristic curves.

The initial values for the exhaust and catalyst temperature at engine start can be calculated from the temperatures at switch-off and delay times. The starting values for the exhaust gas and catalyst temperatures should approximate to the manifold wall temperatures at the
probe insertion points a few minutes after switch-off.
The filter for the exhaust gas temperature is stopped by setting B_stend = 0.
The filter for the manifold wall temperature is stopped when B_atmtpa = 1. The
filter for the catalyst temperature will be enabled only when B_atmtpk = 1.

2. Dew Point Detection

Initial values for the exhaust gas temperature tabgmst and catalyst temperature tkatmst

When stopping the engine (C_nachl 0 ® 1) the temperatures tabgm and tkatm are stored.

When starting the engine, the initial temperatures tabgmst and tkatmst are calculated from the switch-off temperature (corrected for ambient temperature) and a factor obtained from maps KFATMABKA or KFATMABKK as a function of tabstatm and tatu.

During power fail the switch-off temperature will be determined from the constant TATMSTI.

For test condition (B_faatm = 1), the initial temperatures are given by the constants TASTBFA and TKSTBFA.

Integrated Heat Quantity iwmatm_w

The dew point end time is approximately proportional to the heat quantity after engine start. The heat quantity = Integral (temp. x air mass x Cp) is calculated from the steady-state exhaust gas temperature tatmsta plus TATMWMK multiplied by the air mass. The result of the integration multiplied by the heat capacity at constant pressure Cp (approximately 1 kJ/kgK) gives the heat quantity.

Dew point end for the pre-cat lambda probe B_atmtpa and post-cat lambda probe B_atmtpk

The calculated exhaust gas temperature at engine start tabgmst approximates to the exhaust pipe wall temperature. If the exhaust pipe wall temperature is greater than 60°C for example then no condensation occurs.
The values in the map KFWMABG for these temperatures are less than 14 kJ, so the dew point end is detected immediately, or after only a few seconds.

For catalytic converter heating with thermal reaction (B_trkh = 1) the values in maps KFWMABG or KFWMKAT are multiplied by the factor WMKATKH or WMABGKH respectively. Thus, the dew point end-times are very short for this mode of operation.

Repeated starts (extension of the dew point-end-times)

If the engine had not reached the dew point end (B_atmtpa = 0 and B_atmtpf = 0) then when the engine restarts, the counter zwmatmf is increased by 1. After several periods of very short engine running (e.g. 3), the counter zwmatmf value would be set equal to 3. With a constant FWMABGW = 0.25 for example, the values in the map KFWMABG increase by a factor equal to (zwmatmf x KFWMABG + 1) = 1.75. When the engine starts, the dew point end time from the last engine run is detected and the
counter zwmatmf is reset.

Storage of the dew point end condition in the delay

For the determination of repeat start dew point end the conditions B_atmtpa in the flag B_atmtpf and B_atmtpk in the flag B_atmtpl are saved at engine switch-off due to a regular switch-off using the ignition or stall (B_stndnl). The function of dew point end for the post-cat lambda probe B_atmtpk
is analogous to the function for B_atmtpa.

3. Calculation of a simulated ambient temperature from the intake air temperature (tans) if no ambient temperature sensor is available.

The simulated temperature tatu will be used for calculating the temperature correction via the characteristic ATMTANS and for determining the starting temperatures tabgmst and tkatmst. The intake air temperature (tans) is corrected with the constant DTUMTAT and under certain conditions stored in continuous RAM. If for example at engine start, the temperature tatu > tans, then the temperature value tatu is set on the lower tans value.

With the constant TATMWMK (negative value) the difference in dew point end between catalyst heating and no catalyst heating can be increased.

When catalytic converter heating is active B_khtr = 1 and the bit B_atmtpa can be set equal to 1 immediately after engine start. This is possible only when no problematic condensation is formed during catalyst heating.

With the system constants SY_STERVK = 1 cylinder bank 2 can be applied separately for stereo systems.

For SY_TURBO = 1 the exhaust gas temperature tabgm is essentially identical in addition to the modeled temperature in the manifold tabgkrm.

ATM 33.50 Application Notes

1. Installation locations for temperature sensors in this application, running in
the direction of flow:

- In probe installation position before catalytic converter-

1. Exhaust gas temperature (pipe centre) for the high temperatures at high loads for probe heater switch off

2. Manifold wall temperature for the determination of the dew-end times. (Condensation protection)

- Before the catalytic converter

3. Exhaust gas temperature (pipe centre) for the catalyst start-up temperature

- In the catalytic converter

4. Ceramic temperature in and after catalytic converter (in the last third of the catalytic converter or behind the adjoining matrix) to determine the air-mass-dependent time constants.

- After the catalytic converter

5. Pipe wall temperature at probe installation site for the determination of the dew-end times (condensation protection).

Temperature measuring point 3 can be omitted if the distance from probe to catalytic converter is smaller than about 30 cm. The temperature drop from probe installation site to catalytic converter can then be neglected.

For the application of the functional data the modelled temperatures will always be compared with the measured temperatures and the functional data amended until a sufficiently high accuracy is achieved. In so doing, it will be the actual catalyst temperature, the temperature increase due to the exothermic reaction is not considered in the model.

2. Map KFTATM

For the determination of the steady-state temperature for example, before the catalytic converter the temperature corrections should not function. The cooling capacity of the wind on the dynamometer or on the measuring wheel can be simulated only very roughly at the higher engine load range. The map values can be determined on the rolling road dynamometer, but should be corrected on an
appropriate test drive.

3. Temperature Corrections

- TATMSA

Boost can cause low exhaust temperatures that fall below the starting temperature of the catalyst. The longer the time period for the thrust condition, the lower the exhaust and catalyst temperatures. For catalyst diagnosis during boost, the exhaust gas temperature model is more likely to calculate a lower value than the measured temperature.

- ATMTANS

At low ambient temperatures, exhaust gas temperature can fall below the catalyst start-up temperature. Therefore, the model temperature is only corrected at the low temperature range.

- TATMKH

As long as the catalyst-heating measures are effective, higher exhaust temperatures will result.

- TATMKW

The catalyst operating temperature will not be not reached during prolonged idling, so the exhaust gas temperature can be raised by the catalyst warming function.

- KFATMZW

The temperature increase as a result of ignition angle retardation can be determined on a rolling road dynamometer. First, on the dynamometer, the characteristic field values KFTATM are applied without ignition angle correction. Ignition angles are then modified so that allowed etazwist values will result in the map. Through the corresponding air mass, the temperature increase will then be displayed in the map KFATMZW.

- KFATMLA

The exhaust temperature is reduced by enrichment. The application is similar to KFATMZW, except that the ignition angle efficiency is changed instead of the enrichment factor.

- TATMTMOT

The map KFTATM is applied with a warm engine. Thus, the model exhaust gas temperature has smaller deviations during cold start. For this operating mode, the temperature is corrected with the difference of the cold engine temperature and the warm engine temperature.

TATMTMOT
should be about 90 to 100°C.

4. Maps ZATMAML, ZATMRML, FATMRML, ZATMKML, ZATMKKML, ZATMIKML und ZATMIKKML

The air-mass-dependent time constants ZATMAML, ZATMRML (temperature measuring points 1 or 3), and ZATMKML, ZATMKKML, ZATMIKML, ZATMIKKML (temperature measuring point 4), can help to more accurately determine “spikes in the air mass” during sudden load variations. Thereby "air mass jumps" at full load and in particular during boost can be avoided. For example, for an air mass jump from 30 kg/hr to 80 kg/hr, the measured time constant is applied to the air mass flow of 80 kg/hr. For large air mass jumps during idle, the time constants ZATMKKML and ZATMIKKML can be input instead of ZATMKML or ZATMIKML if required.

5. Block EXOTHERME:

- KATMEXML

The exothermic temperature is a function of air mass flow (warming by realizing emissions, reducing warming via a larger air mass). First KATMEXML applies, then KLATMZWE, KLATMLAE.

- KLATMZWE

When ignition angle retardation increases the temperature before the catalyst, the catalyst temperature drops.

- KLATMLAE

For lambda < 1 (richer), the air mass is lacking to improve emissions so the catalyst temperature decreases.

- TABGMEX

If the temperature before the catalyst tabgm < TABGMEX (catalyst switch-off temperature) then the temperature correction = TKATMOE.

- TKATMOE

Temperature
correction during boost or through tabgm> TABGMEX

- TATMSAE

Temperature increase in the boost in the catalyst in terms of tkatm

Block EXOIKAT:

- KATMIEXML, KLATMIZWE, KLATMILAE, TIKATMOE

Application depends on the application for Block EXOTHERME

- TATMSAE

Temperature increase in the thrust in the catalyst in terms of tikatm

6. Dew point end times for exhaust gas temperatures vary greatly between the centre of the exhaust pipe and the pipe wall. Dew point end times for the tube wall temperatures before the catalyst (temperature measuring points 2) or after the catalyst (temperature measuring points 5) should be used. These times are usually due to delaying control readiness for too long, in which case the temperature gradients at the probe mounting location must be examined more closely. To avoid probe damage by “water hammer”, the sensor heater must be fully turned on until the dew point temperature is exceeded or the dew point end time is detected thus condensation will no longer occur.

When the switch-off time in the ECU delay is calculated, then the switch-off time tabst_w after ECU delay will be incorrect. At engine start after ECU delay, the switch-off time tabstatm therefore, will be set to the maximum value of 65,535 (i.e. 216-1). The ECU delay requirement for the time TNLATM when engine speed > TNLATMTM & tumg (tatu) > TNLATMTU.

8.
For blocks KR_STAT and KR_DYN as appropriate, the descriptions in points 3 and
4 shall apply.

Typical
Values:

KFTATM: x: engine speed/RPM, y: relative cylinder charge/%, z: temperature/°C

{| border="1"
|-
|
|
800
|
1200
|
1800
|
2400
|
3000
|
4000
|
5000
|
6000
|-
|
15
|
380
|
400
|
420
|
450
|
480
|
520
|
550
|
580
|-
|
22
|
400
|
420
|
450
|
480
|
520
|
550
|
580
|
610
|-
|
30
|
420
|
450
|
480
|
520
|
550
|
580
|
610
|
650
|-
|
50
|
450
|
480
|
520
|
550
|
580
|
610
|
650
|
700
|-
|
70
|
470
|
520
|
550
|
580
|
610
|
660
|
700
|
750
|-
|
100
|
490
|
550
|
580
|
610
|
650
|
700
|
750
|
790
|-
|
120
|
510
|
560
|
610
|
650
|
700
|
750
|
790
|
840
|-
|
140
|
530
|
580
|
650
|
700
|
750
|
790
|
840
|
900
|}

KFATMZW: x: temperature/°C, y: ml_w/kg/hr, z: etazwimt

{| border="1"
|-
|
|
20
|
40
|
80
|
150
|
250
|
400
|-
|
1.00
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|-
|
0.95
|
15
|
40
|
50
|
60
|
70
|
75
|-
|
0.90
|
15
|
60
|
80
|
100
|
125
|
140
|-
|
0.80
|
20
|
80
|
120
|
150
|
180
|
200
|-
|
0.70
|
25
|
100
|
150
|
190
|
210
|
220
|-
|
0.60
|
30
|
115
|
175
|
210
|
230
|
245
|}

KFATMLA: x: temperature/°C, y: ml_w/kg/hr, z: lamsbg_w

{| border="1"
|-
|
|
20
|
40
|
80
|
150
|
250
|
400
|-
|
1.15
|
5
|
10
|
30
|
50
|
60
|
70
|-
|
1.00
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|-
|
0.95
|
5
|
10
|
20
|
30
|
40
|
45
|-
|
0.90
|
15
|
25
|
40
|
50
|
60
|
75
|-
|
0.80
|
30
|
40
|
60
|
70
|
85
|
100
|-
|
0.70
|
40
|
60
|
80
|
90
|
100
|
120
|}

KFWMABG: x: energy/kJ, y: tabgmst/°C, z: tmst/°C

{| border="1"
|-
|
|
-40
|
0
|
15
|
25
|
30
|
55
|
60
|-
|
-40
|
200
|
160
|
150
|
140
|
100
|
60
|
30
|-
|
0
|
180
|
150
|
120
|
110
|
80
|
50
|
20
|-
|
15
|
160
|
140
|
60
|
55
|
30
|
40
|
0.45
|-
|
25
|
140
|
120
|
30
|
30
|
15
|
10
|
0.45
|-
|
60
|
120
|
30
|
20
|
15
|
10
|
5
|
0.45
|}

KFWMKAT values correspond to KFWMABG x 5

In the heat quantity maps KFWMABG and KFWMKAT a value of 0.0 is never required! It should always have at least the value to be entered; the 2 sec corresponds to idle after cold start. Only then does the repeat-start counter operate after several starts where the dew point was not reached.

ZATMAML
ml_w/kg/hr, Time constant/sec 10, 30 ; 20, 20 ; 40, 13 ; 80, 5 ; 180, 4 ; 400, 3 ; 600, 2 ;

ZATMKML
ml_w/kg/hr, Time constant/sec 10, 150 ; 20, 60 ; 40, 35 ; 80, 20 ; 180, 10 ;
400, 7 ; 600, 4 ;

ZATMIKML
value represents approximately ZATMKML x 0.3

ZATMKKML
for neutral input, the data must correlate to ZATMKML

ZATMIKKML
for neutral input, the data must correlate to ZATMIKML

ZATMRML
ml_w/kg/hr, Time constant/sec 10, 300 ; 20, 80 ; 40, 55 ; 80, 30 ; 180, 20 ; 400, 10 ; 600, 7 ;

FATMRML
ml_w/kg/hr, Time constant/sec 10, 0.5 ; 20, 0.6 ; 40, 0.7 ; 80, 0.8 ; 180, 0.95 ; 400,0.95 ; 600, 0.96;

KATMEXML
ml_w/kg/hr, Time constant/sec 10, 0 ; 20, 0 ; 40, 0 ; 80, 0 ; 180, 0 ; 400, 0 ;

KLATMZWE
etazwimt, Factor 1, 0 ; 0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ; 0.6, 0 ;

KLATMLAE
lamsbg_w, Factor 1.15, 0 ; 1 , 0 ;0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ;

TATMTP: 52°C

TKATMOE: 0°C

TATMSAE: 0°C

KATMIEXML
ml_w/kg/hr, Time constant/sec 10, 0 ; 20, 0 ; 40, 0 ; 80, 0 ; 180, 0 ; 400, 0 ;

KLATMIZWE
etazwimt, Factor 1, 0 ; 0.95, 0 ; 0.9, 0; 0.8, 0 ; 0.7, 0 ; 0.6, 0 ;

KLATMILAE
lamsbg_w, Factor 1.15, 0 ; 1 , 0 ;0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ;

TIKATMOE: 0°C

KFATMABKA: x: tatu/°C, y: tabstatm_w/seconds, z: no units

{| border="1"
|-
|
|
10
|
50
|
180
|
360
|
600
|
1000
|-
|
-40
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
-15
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
0
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
15
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
40
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|}

KFATMABKK: x: tatu/°C, y: tabstatm_w [s], z: no units

{| border="1"
|-
|
|
10
|
50
|
180
|
360
|
600
|
1000
|-
|
-40
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
-15
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
0
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
15
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
40
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|}

ATMTANS tatu/°C, Temp./°C -40, 60 ; -10, 20 ; 20, 0 ;

TATMSA: 100°C

TATMKH: 80°C

TATMTRKH: 200°C

TATMKW: 100°C

TATMTMOT: 90°C

TATMSTI: 20°C

TASTBFA: 40°C

TKSTBFA: 40°C

TATMWMK: -80°C

WMABGKH: Factor of 1.0

WMKATKH: Factor of 1.0

FWMABGW: Factor of 0.25

FWMKATW: Factor of 0.25

DTUMTAT: 20°C

VTUMTAT: 40 km/h

NTUMTAT: 1800 rpm

IMTUMTAT: 1 kg

TUMTAIT: 20°C

TNLATMTM: 80°C

TNLATMTU: 5°C

TNLATM: 660 seconds

Only when SY_TURBO = 1:

For neutral input (tabgkrm_w = tabgm_w)

KFATMKR = KFTATM

KFATZWK = KFATMZW

KFATLAK = KFATMLA

TATMKRSA = TATMSA

ZATRKRML = ZATMRML

ZATAKRML = ZATMAML

FATRKRML = FATMRML

ATMTANS
tans/°C, Temp./°C -40, 40 ; -20, 25 ; 0, 12 ; 20, 0 ; 60, -30

The functional data for cylinder bank 2 correspond to the functional data from cylinder bank 1 Note:

In order that ATM 22:20 for the application is backward compatible the default values should be entered thus: KATMEXML, KLATMZWE, KLATMLAE, TKATMOE = 0 and TABGMEX = 1220°C.

In order that ATM 33.10 remains application-neutral with ATM 22.50, TATMTRKH must be set equal to TATMKH and WMKATKH should be set equal to 1. Tikatm is not used in a function because the input can be used in the path in the exhaust gas temperature model without impact on safety, however, the default values for KATMIEXML, KLATMIZWE, KLATMILAE and TIKATMOE should be set equal to 0 and TABGMEX = 1220°C.

In DKATSP areas TMINKATS and TMAXKATS, a high accuracy is required for tikatm!

[u]Abbreviations[/u]

{| border="1"
|-
|
Parameter
|
Description
|-
|
ATMTAKR
|
Correction
for the manifold temperature
|-
|
ATMTANS
|
Temperature
correction for the exhaust gas temperature model
|-
|
DTUMTAT
|
Offset:
intake air temperature ® ambient temperature
|-
|
FATMRML
|
Factor
for the difference between exhaust gas & exhaust pipe wall temperature
|-
|
FATMRML2
|
Factor
for the difference between exhaust gas & exhaust pipe wall temperature, cylinder
bank 2
|-
|
FATRKRML
|
Factor
for the difference between exhaust gas & wall temperature in the manifold
|-
|
FATRKRML2
|
Factor
for the difference between exhaust gas & wall temperature in the manifold,
cylinder bank 2
|-
|
FWMABGW
|
Factor
for heat quantity during repeated starts for pre-cat exhaust gas dew points
|-
|
FWMABGW2
|
Factor
for heat quantity during repeated starts for pre-cat exhaust gas dew points,
cylinder bank 2
|-
|
FWMKATW
|
Factor
for heat quantities during repeated starts for dew points after main catalyst
|-
|
FWMKATW2
|
Factor
for heat quantities during repeated starts for dew points after main catalyst,
cylinder bank 2
|-
|
IMTUMTAT
|
Integration
threshold air mass for determining ambient temperature from TANS
|-
|
KATMEXML
|
Exothermic
reaction temperature in catalyst, tkatm
|-
|
KATMEXML2
|
Exothermic
reaction temperature in catalyst, cylinder bank 2
|-
|
KATMIEXML
|
Exothermic
reaction temperature in catalyst, tikatm
|-
|
KATMIEXML2
|
Exothermic
reaction temperature in catalyst, tikatm, cylinder bank 2
|-
|
KFATLAK
|
Map for
lambda correction for manifold exhaust gas temperature
|-
|
KFATLAK2
|
Map for
lambda correction for manifold exhaust gas temperature, cylinder bank 2
|-
|
KFATMABKA
|
Factor
for exhaust gas temperature decrease as a function of stop time and ambient
temperature
|-
|
KFATMABKA2
|
Factor
for exhaust gas temperature decrease as a function of stop time and ambient
temperature, cylinder bank 2
|-
|
KFATMABKK
|
Factor
for reducing the catalyst temperature as a function of stop time and ambient
temperature
|-
|
KFATMABKK2
|
Factor
for reducing the catalyst temperature as a function of stop time and ambient
temperature, cylinder bank 2
|-
|
KFATMKR
|
Map for
steady-state manifold exhaust gas temperature as a function of engine speed
and relative cylinder charge
|-
|
KFATMKR2
|
Map for
steady-state manifold exhaust gas temperature, cylinder bank 2
|-
|
KFATMLA
|
Map for
exhaust gas temperature correction as a function of lambda
|-
|
KFATMLA2
|
Map for
exhaust gas temperature correction as a function of lambda, cylinder bank 2
|-
|
KFATMZW
|
Map for
exhaust gas temperature correction as a function of igntion angle correction
|-
|
KFATMZW2
|
Map for
exhaust gas temperature correction as a function of ignition angle, cylinder
bank 2
|-
|
KFATZWK
|
Map for
ignition angle correction for manifold gas temperature
|-
|
KFATZWK2
|
Map for
ignition angle correction for manifold gas temperature, cylinder bank 2
|-
|
KFTATM
|
Map for
exhaust gas temperature as a function of engine speed and relative cylinder
charge
|-
|
KFTATM2
|
Map for
exhaust gas temperature as a function of engine speed and relative cylinder
charge for cylinder bank 2
|-
|
KFWMABG
|
Map for
heat quantity threshold exhaust gas dew points
|-
|
KFWMABG2
|
Map for
heat quantity threshold exhaust gas dew points, cylinder bank 2
|-
|
KFWMKAT
|
Map for
heat quantity threshold dew points after catalyst
|-
|
KFWMKAT2
|
Map for
heat quantity threshold dew points after catalyst, cylinder bank 2
|-
|
KLATMILAE
|
Exothermic
temperature decrease through enrichment, tikatm
|-
|
KLATMILAE2
|
Exothermic
temperature decrease through enrichment, tikatm, Bank 2
|-
|
KLATMIZWE
|
Exothermic
temperature decrease in catalyst at later ignition angles, tikatm
|-
|
KLATMIZWE2
|
Exothermic
temperature decrease in catalyst at later ignition angles, tikatm, Bank 2
|-
|
KLATMLAE
|
Exothermic
temperature decrease through enrichment
|-
|
KLATMLAE2
|
Exothermic
temperature decrease through enrichment, cylinder bank 2
|-
|
KLATMZWE
|
Exothermic
temperature decrease in catalyst at later ignition angles, tkatm
|-
|
KLATMZWE2
|
Exothermic
temperature decrease in catalyst at later ignition angles, cylinder bank 2
|-
|
NTUMTAT
|
Speed
threshold for determining ambient temperature from TANS
|-
|
SEZ06TMUB
|
Sample
point distribution, ignition angle efficiency
|-
|
SLX06TMUW
|
Sample
point distribution, desired lambda
|-
|
SLY06TMUW
|
Sample
point distribution, desired lambda, cylinder bank 2
|-
|
SML06TMUW
|
Sample
point distribution, air mass, 6 sample points
|-
|
SML07TMUW
|
Sample
point distribution, air mass, 7 sample points
|-
|
SMT06TMUW
|
Sample
point distribution, air mass, 6 sample points
|-
|
ST107TMUB
|
Sample
point distribution, start temperature at front probe
|-
|
ST207TMUB
|
Sample
point distribution, start temperature at front probe, cylinder bank 2
|-
|
ST307TMUB
|
Sample point
distribution, start temperature at rear probe
|-
|
ST407TMUB
|
Sample
point distribution, start temperature at rear probe, cylinder bank 2
|-
|
STM05TMUB
|
Sample
point distribution, engine start temperature
|-
|
STS06TMUW
|
Sample
point distribution, exhaust gas mass flow
|-
|
STU05TMUB
|
Sample
point distribution, simulated ambient temperature
|-
|
SY_STERVK
|
System
constant condition: stereo before catalyst
|-
|
SY_TURBO
|
System
constant: turbocharger
|-
|
TABGMEX
|
Exhaust
gas temperature below the catalyst switch-off temperature
|-
|
TASTBFA
|
Model temperature
before pre-cat initial value via B_faatm requirement
|-
|
TATMKH
|
Exhaust
gas temperature correction via catalyst heating active
|-
|
TATMKH2
|
Exhaust
gas temperature correction via catalyst heating active, cylinder bank 2
|-
|
TATMKRSA
|
Exhaust
gas temperature correction in manifold via boost switch-off
|-
|
TATMKW
|
Exhaust
gas temperature correction with catalyst warming active
|-
|
TATMSA
|
Exhaust
gas temperature correction via boost cut-off
|-
|
TATMSAE
|
Exothermic
temperature increase in boost
|-
|
TATMSAE2
|
Exothermic
temperature increase in boost, cylinder bank 2
|-
|
TATMSTI
|
Initial
value for tabgm, tkatm intial value through power fail
|-
|
TATMTMOT
|
Engine temperature
warmer Motor, for temperature correction during cold start conditions
|-
|
TATMTP
|
Exhaust
gas dew point temperature
|-
|
TATMTRKH
|
Exhaust
gas temperature correction via thermal reaction catalyst heating
|-
|
TATMTRKH2
|
Exhaust
gas temperature correction via thermal reaction catalyst heating, cylinder bank
2
|-
|
TATMWMK
|
Temperature
offset for calculating heat quantities
|-
|
TIKATMOE
|
Temperature
correction in catalyst without exothermic reaction, tikatm
|-
|
TKATMOE
|
Temperature
correction near catalyst without exothermic reaction, tkatm
|-
|
TKSTBFA
|
Model temperature
post-cat initial value via B_faatm requirement
|-
|
TNLATM
|
Minimum
ECU delay time for exhaust gas temperature model – Abstellzeit
|-
|
TNLATMTM
|
When
tmot > threshold ECU delay requirement B_nlatm = 1
|-
|
TNLATMTU
|
When
tumg (tatu – ATM) > threshold ECU delay requirement
|-
|
TUMTAIT
|
Initialising
value for ambient temperature from TANS
|-
|
VTUMTAT
|
Vehicle
speed threshold for TANS ® ambient temperature
|-
|
WMABGKH
|
Factor
for heat quantity correction via catalyst heating for dew points
|-
|
WMABGKH2
|
Factor
for heat quantity correction via catalyst heating for dew points, cylinder bank
2
|-
|
WMKATKH
|
Factor
for heat quantity correction via catalyst heating for dew points after
catalyst
|-
|
WMKATKH2
|
Factor
for heat quantity correction via catalyst heating for dew points after
catalyst, cylinder bank 2
|-
|
ZATAKRML
|
Time
constant for exhaust gas temperature model (manifold)
|-
|
ZATAKRML2
|
Time
constant for exhaust gas temperature model (manifold), cylinder bank 2
|-
|
ZATMAML
|
Time
constant for exhaust gas temperature model
|-
|
ZATMAML2
|
Time
constant for exhaust gas temperature model, cylinder bank 2
|-
|
ZATMIKKML
|
Time
constant for catalyst temperature model – Temperature in catalyst tikatm during
cooling
|-
|
ZATMIKKML2
|
Time
constant for catalyst temperature model – Temperature in catalyst tikatm
during cooling, bank 2
|-
|
ZATMIKML
|
Time
constant for catalyst temperature model – Temperature in catalyst, tikatm
|-
|
ZATMIKML2
|
Time
constant for catalyst temperature model – Temperature in catalyst, cylinder bank
2
|-
|
ZATMKKML
|
Time
constant for catalyst temperature model – catalyst temperature tkatm during
cooling
|-
|
ZATMKKML2
|
Time
constant for catalyst temperature model – catalyst temperature tkatm during
cooling, bank 2
|-
|
ZATMKML
|
Time
constant for catalyst temperature model – catalyst temperature tkatm
|-
|
ZATMKML2
|
Time
constant for catalyst temperature model – catalyst temperature, cylinder bank
2
|-
|
ZATMRML
|
Time
constant for exhaust gas temperature model – exhaust pipe wall temperature
|-
|
ZATMRML2
|
Time
constant for exhaust gas temperature model – exhaust pipe wall temperature Bank
2
|-
|
ZATRKRML
|
Time
constant for exhaust gas temperature model – manifold wall temperature
|-
|
ZATRKRML2
|
Time
constant for exhaust gas temperature model – manifold wall temperature, cylinder
bank 2
|-
|
Variable
|
Description
|-
|
B_ATMLL
|
Condition
for time constant during cooling at idle
|-
|
B_ATMLL2
|
Condition
for time constant during cooling at idle
|-
|
B_ATMST
|
Condition
for tabgmst, tkatmst initial value calculation
|-
|
B_ATMST2
|
Condition
for tabgmst, tkatmst calculation, cylinder bank 2
|-
|
B_ATMTPA
|
Condition:
dew point before catalyst exceeded
|-
|
B_ATMTPA2
|
Condition:
dew point 2 before catalyst exceeded
|-
|
B_ATMTPF
|
Condition:
dew point before catalyst exceeded (last trip)
|-
|
B_ATMTPF2
|
Condition:
dew point before catalyst exceeded (last trip) cylinder bank 2
|-
|
B_ATMTPK
|
Condition:
dew point after catalyst exceeded
|-
|
B_ATMTPK2
|
Condition:
dew point 2 after catalyst exceeded
|-
|
B_ATMTPL
|
Condition: dew point after catalyst exceeded (last trip)
|-
|
B_ATMTPL2
|
Condition: dew point after catalyst exceeded (last trip) cylinder bank 2
|-
|
B_FAATM
|
Condition: functional requirements for dew
point end times
|-
|
B_KH
|
Condition: catalyst heating
|-
|
B_KW
|
Condition: catalyst warming
|-
|
B_LL
|
Condition: idle
|-
|
B_NACHL
|
Condition: ECU delay
|-
|
B_NACHLEND
|
Condition: ECU delay ended
|-
|
B_NLATM
|
Condition: ECU delay exhaust gas temperature
model probe protection
|-
|
B_PWF
|
Condition: Power fail
|-
|
B_SA
|
Condition: Overrun cut-off
|-
|
B_ST
|
Condition: Start
|-
|
B_STEND
|
Condition: End of start conditions achieved
|-
|
B_STNDNL
|
Condition: Beginning of ECU delay or end of
start conditions (1 ® 0)
|-
|
B_TFU
|
Condition: Ambient temperature sensor
available
|-
|
B_TRKH
|
Condition: Catalyst heating, thermal reaction
effective
|-
|
B_UHRRMIN
|
Condition: timer with a relative number of
minutes
|-
|
B_UHRRSEC
|
Condition: timer with a relative number of
minutes
|-
|
DFP_TA
|
ECU internal error path number: intake air
temperature TANS (charge air)
|-
|
DFP_TUM
|
ECU Internal error path number: ambient
temperature
|-
|
ETAZWIMT
|
Actual ignition angle efficiency average for exhaust
gas temperature model (200 ms)
|-
|
ETAZWIST
|
Actual ignition angle efficiency
|-
|
E_TA
|
Error flag: TANS
|-
|
E_TUM
|
Error flag: ambient temperature tumg
|-
|
IMLATM
|
Integral of air mass flows from engine start
bis Max.wert
|-
|
IMLATM_W
|
Integral of air mass flows from end of start
conditions up to the maximum value, (Word)
|-
|
IWMATM2_W
|
Heat quantity for Condensation - dew points
exhaust gas/catalyst (word), cylinder bank 2
|-
|
IWMATM_W
|
Heat quantity for Condensation - dew points
exhaust gas/catalyst (word)
|-
|
LAMSBG2_W
|
Desired lambda limit (word), cylinder bank 2
|-
|
LAMSBG_W
|
Desired lambda limit (word)
|-
|
ML_W
|
Filtered air mass flow (word)
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
TABGKRM2_W
|
Exhaust gas temperature in manifold from the
model, cylinder bank 2
|-
|
TABGKRM_W
|
Exhaust gas temperature in manifold from the
model
|-
|
TABGM
|
Exhaust gas temperature before catalyst from
the model
|-
|
TABGM2
|
Exhaust gas temperature before catalyst from
the model, cylinder bank 2
|-
|
TABGM2_W
|
Exhaust gas temperature before catalyst from
the model (word) cylinder bank 2
|-
|
TABGMAB
|
Exhaust gas temperature during engine
switch-off
|-
|
TABGMAB2
|
Exhaust gas temperature during engine
switch-off (model) cylinder bank 2
|-
|
TABGMST
|
Exhaust gas temperature at engine start
|-
|
TABGMST2
|
Exhaust gas temperature at engine start,
cylinder bank 2
|-
|
TABGM_W
|
Exhaust gas temperature before catalyst from
the model (word)
|-
|
TABSTATM_W
|
Stop time in ECU delay for exhaust gas
temperature model
|-
|
TABSTMX_W
|
Stop time maximum query for exhaust gas
temperature model
|-
|
TABST_W
|
Stop time
|-
|
TAKRKF
|
Steady-state manifold exhaust gas temperature without
correction
|-
|
TAKRKF2
|
Steady-state manifold exhaust gas temperature
without correction, cylinder bank 2
|-
|
TAKRSTC
|
Steady-state exhaust gas temperature in
manifold in °C
|-
|
TAKRSTC2
|
Steady-state exhaust gas temperature in
manifold, cylinder bank 2
|-
|
TANS
|
Intake air temperature
|-
|
TATAKRML
|
Output from PT1 element: exhaust gas
temperature influence on tabgkrm
|-
|
TATAKRML2
|
Output from PT1 element: exhaust gas
temperature influence on tabgkrm, cylinder bank 2
|-
|
TATMAML
|
Output from PT1 element: exhaust gas
temperature influence on tabgm
|-
|
TATMAML2
|
Output from PT1 element: exhaust gas
temperature influence on tabgm, cylinder bank 2
|-
|
TATMKF
|
Exhaust gas temperature before catalyst from map
KFTATM
|-
|
TATMKF2
|
Exhaust gas temperature before catalyst from map
KFTATM, cylinder bank 2
|-
|
TATMRML
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgm
|-
|
TATMRML2
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgm, cylinder bank 2
|-
|
TATMSTA
|
Exhaust gas temperature before catalyst from
the steady-state model
|-
|
TATMSTA2
|
Exhaust gas temperature before catalyst from
the steady-state model, cylinder bank 2
|-
|
TATRKRML
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgkrm
|-
|
TATRKRML2
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgkrm, cylinder bank 2
|-
|
TATU
|
Intake air temperature or ambient temperature
|-
|
TEXOIKM2_W
|
Exotherme temperature increase in catalyst for
tikatm, cylinder bank 2
|-
|
TEXOIKM_W
|
Exotherme temperature increase in catalyst for
tikatm
|-
|
TEXOM2_W
|
Exotherme temperature increase in catalyst for
tkatm2, cylinder bank 2
|-
|
TEXOM_W
|
Exotherme temperature increase in catalyst for
tkatm
|-
|
TIKATM
|
Exhaust gas temperature in catalyst from the
model
|-
|
TIKATM2
|
Exhaust gas temperature in catalyst from the
model, cylinder bank 2
|-
|
TIKATM2_W
|
Exhaust gas temperature in catalyst from the
model, cylinder bank 2
|-
|
TIKATM W
|
Exhaust gas temperature in catalyst from the
model
|-
|
TKATM
|
Catalyst temperature from the model
|-
|
TKATM2
|
Catalyst temperature from the model, cylinder
bank 2
|-
|
TKATM2_W
|
Catalyst temperature from the model (word),
cylinder bank 2
|-
|
TKATMAB
|
Exhaust gas temperature after catalyst through
engine switch-off (model)
|-
|
TKATMAB2
|
Exhaust gas temperature after catalyst through
engine switch-off (model), cylinder bank 2
|-
|
TKATMST
|
Catalyst temperature model initial value as a
function of switch-off value, switch-off time
|-
|
TKATMST2
|
Catalyst temperature model initial value as a
function of switch-off value, switch-off time, bank 2
|-
|
TKATM_W
|
Catalyst temperature from the model (word)
|-
|
TMOT
|
Engine temperature
|-
|
TMST
|
Engine start temperature
|-
|
TUMG
|
Ambient
temperature
|-
|
VFZG
|
Vehicle
speed
|-
|
ZWMATM
|
Counter
for repeated starts and factor for heat quantity threshold
|-
|
ZWMATM2
|
Counter
for repeated starts and factor for heat quantity threshold, cylinder bank 2
|-
|
ZWMATMF
|
Counter
for repeated starts and factor for heat quantity threshold upstream
|-
|
ZWMATMF2
|
Counter
for repeated starts and factor for heat quantity threshold upstream, cylinder
bank 2
|}

[[Category:ME7]]

ATM 33.50 (Exhaust Gas Temperature Model)

2012-01-08T17:50:11Z

TTQS:

Refer to the ''funktionsrahmen'' for the following diagrams:

atm-main

atm-atm-b1 Exhaust gas temperature model (cylinder
bank 1) overview

atm-tmp-stat TMP_STAT engine speed & relative cylinder charge map and corrected for temperature for acceleration, intake air temp., catalyst heating, catalyst warming, ignition angle, lambda and cold engine

atm-dynamik Temperature dynamic for exhaust gas and catalytic converter temperature (in and near the catalytic
converter)

atm-tabgm Temperature dynamic: exhaust gas, exhaust pipe wall effect, from the exhaust gas temperature tabgm

atm-tkatm Temperature dynamic for the temperature near the catalytic converter

atm-exotherme Exothermic temperature increase near the catalyst from measurement sites tabgm to tikatm

atm-tikatm Temperature dynamic for the temperature in the catalytic converter

atm-exoikat Exothermic temperature increase in the catalyst from measurement sites tabgm to tikatm

atm-kr-stat Exhaust gas temperature in the exhaust manifold under steady-state conditions

atm-kr-dyn Exhaust gas temperature in the exhaust manifold under dynamic conditions

atm-tmp-start Calculation of the exhaust gas or exhaust pipe wall temperature at engine start

atm-tpe-logik Calculation of the dew point at the pre-cat and post-cat lambda probes

atm-sp-nachl Storage of the dew point conditions at engine switch off

atm-mean Calculation of etazwist average values

atm-tmp-umgm If no ambient temperature sensor is available, calculate a substitute from ambient temperature (tans)

atm-mst If tabst_w is not correct tabstatm = maximum value, request for delay B_nlatm as a function of engine speed and tatu-threshold)

ATM 33.50 (Exhaust Gas
Temperature Model) Function Description

The simulated exhaust gas
temperatures tabgm and tabgkrm (for SY_TURBO = 1) and catalytic converter
temperatures tkatm and tikatm are used for the following purposes:

1. Monitoring the catalyst. If the catalytic converter falls below its starting temperature, then
a fault can be detected.

2. For lambda control on the probe after the catalytic converter. This control is only activated after
engine start, when the catalyst has exceeded its start-up temperature.

3. For the probe heater control after engine start. If the simulated dew point is exceeded, the probe
heater is turned on.

4. Monitoring the heated exhaust gas oxygen (HEGO) sensor (i.e. lambda probe) heating system. If the
exhaust gas temperature exceeds 800°C for example, then the lambda probe heater
will be switched off, so that the probe is not too hot.

5. For fan motor control.

6. For switching on component protection.

This function provides only a rough approximation of the exhaust gas and catalytic converter temperature profiles, whereas throughout the application especially the four monitoring areas (dew point profiles in the exhaust gas, catalytic converter monitoring, enabling and shutting off lambda probe heating and high temperatures for component protection) should be considered to be critical.

1. Basic function

Steady-state temperature (tatmsta): the same applies for takrstc

With the engine speed/relative cylinder charge map KFTATM the steady-state exhaust
gas temperature before the catalyst is set. This temperature is corrected for
ambient temperature or simulated ambient temperature from the characteristic
ATMTANS:

during boost with the constant TATMSA,

during catalyst heating with the constant TATMKH; catalyst warming with the constant TATMKW

with the ignition-angle efficiency map KFATMZW temperature as a function of ML and ETAZWIST

with the desired lambda map KFATMLA temperature as a function of ML and LAMSBG_W

for a cold engine block (TMOT - TATMTMOT) with TATMTMOT = 90°C.

The catalyst temperature (exothermic) is corrected for:

Temperature increase with the characteristic KATMEXML or KATMIEXML as a function of air mass

Temperature reduction with KLATMZWE or KLATMIZWE as a function of etazwimt (ignition angle influence)

Lambda influence with KLATMLAE or KLATMILAE as a function of lambsbg_w

Temperature set at TKATMOE or TIKATMOE at tabgm <TABGMEX or B_sa = 1

Different temperature increases are applied for the temperature in the catalytic converter tikatm and the temperature after the catalytic converter tkatm due to exothermic reaction and cooling and different ignition angles and lambda-corrections.

The time-based influence of the exhaust gas temperature before the catalytic
converter:

Using a PT1 filter (filter time constant ZATMAML) the dynamics of the exhaust gas temperature are simulated and with a PT1 filter (time constant ZATMRML) the dynamics of the inlet manifold wall temperature are simulated.

The exhaust gas temperature and inlet manifold wall temperature are weighted by the division factor FATMRML.

The catalytic converter temperature tkatm is calculated from the exhaust gas temperature tabgm along with the PT1 filter (filter time constant ZATMKML).

The temperature in the catalyst tikatm is modelled from the exhaust gas temperature tabgm via three filters (time constant ZATMIKML) using the heat transfer principle. Due to a thrust caused by the small air mass flow in the catalytic converter, there is a possible exhaust gas temperature increase due to the greater influence on the matrix temperature by the exhaust gas throughput. This thrust-based temperature increase can be modelled by the positive B_sa side with a temperature, which is composed of the catalyst temperature tikatm and an offset TATMSAE, will be initialised. The time constants of the PT1-filter ZATMIKML are represented by air-mass-dependent characteristic curves.

The initial values for the exhaust and catalyst temperature at engine start can be calculated from the temperatures at switch-off and delay times. The starting values for the exhaust gas and catalyst temperatures should approximate to the manifold wall temperatures at the
probe insertion points a few minutes after switch-off.
The filter for the exhaust gas temperature is stopped by setting B_stend = 0.
The filter for the manifold wall temperature is stopped when B_atmtpa = 1. The
filter for the catalyst temperature will be enabled only when B_atmtpk = 1.

2. Dew Point Detection

Initial values for the exhaust gas temperature tabgmst and catalyst temperature tkatmst

When stopping the engine (C_nachl 0 ® 1) the temperatures tabgm and tkatm are stored.

When starting the engine, the initial temperatures tabgmst and tkatmst are calculated from the switch-off temperature (corrected for ambient temperature) and a factor obtained from maps KFATMABKA or KFATMABKK as a function of tabstatm and tatu.

During power fail the switch-off temperature will be determined from the constant TATMSTI.

For test condition (B_faatm = 1), the initial temperatures are given by the constants TASTBFA and TKSTBFA.

Integrated Heat Quantity iwmatm_w

The dew point end time is approximately proportional to the heat quantity after engine start. The heat quantity = Integral (temp. x air mass x Cp) is calculated from the steady-state exhaust gas temperature tatmsta plus TATMWMK multiplied by the air mass. The result of the integration multiplied by the heat capacity at constant pressure Cp (approximately 1 kJ/kgK) gives the heat quantity.

Dew point end for the pre-cat lambda probe B_atmtpa and post-cat lambda probe B_atmtpk

The calculated exhaust gas temperature at engine start tabgmst approximates to the exhaust pipe wall temperature. If the exhaust pipe wall temperature is greater than 60°C for example then no condensation occurs.
The values in the map KFWMABG for these temperatures are less than 14 kJ, so the dew point end is detected immediately, or after only a few seconds.

For catalytic converter heating with thermal reaction (B_trkh = 1) the values in maps KFWMABG or KFWMKAT are multiplied by the factor WMKATKH or WMABGKH respectively. Thus, the dew point end-times are very short for this mode of operation.

Repeated starts (extension of the dew point-end-times)

If the engine had not reached the dew point end (B_atmtpa = 0 and B_atmtpf = 0) then when the engine restarts, the counter zwmatmf is increased by 1. After several periods of very short engine running (e.g. 3), the counter zwmatmf value would be set equal to 3. With a constant FWMABGW = 0.25 for example, the values in the map KFWMABG increase by a factor equal to (zwmatmf x KFWMABG + 1) = 1.75. When the engine starts, the dew point end time from the last engine run is detected and the
counter zwmatmf is reset.

Storage of the dew point end condition in the delay

For the determination of repeat start dew point end the conditions B_atmtpa in the flag B_atmtpf and B_atmtpk in the flag B_atmtpl are saved at engine switch-off due to a regular switch-off using the ignition or stall (B_stndnl). The function of dew point end for the post-cat lambda probe B_atmtpk
is analogous to the function for B_atmtpa.

3. Calculation of a simulated ambient temperature from the intake air temperature (tans) if no ambient temperature sensor is available.

The simulated temperature tatu will be used for calculating the temperature correction via the characteristic ATMTANS and for determining the starting temperatures tabgmst and tkatmst. The intake air temperature (tans) is corrected with the constant DTUMTAT and under certain conditions stored in continuous RAM. If for example at engine start, the temperature tatu > tans, then the temperature value tatu is set on the lower tans value.

With the constant TATMWMK (negative value) the difference in dew point end between catalyst heating and no catalyst heating can be increased.

When catalytic converter heating is active B_khtr = 1 and the bit B_atmtpa can be set equal to 1 immediately after engine start. This is possible only when no problematic condensation is formed during catalyst heating.

With the system constants SY_STERVK = 1 cylinder bank 2 can be applied separately for stereo systems.

For SY_TURBO = 1 the exhaust gas temperature tabgm is essentially identical in addition to the modeled temperature in the manifold tabgkrm.

ATM 33.50 Application Notes

1. Installation locations for temperature sensors in this application, running in
the direction of flow:

- In probe installation position before catalytic converter-

1. Exhaust gas temperature (pipe centre) for the high temperatures at high loads for probe heater switch off

2. Manifold wall temperature for the determination of the dew-end times. (Condensation protection)

- Before the catalytic converter

3. Exhaust gas temperature (pipe centre) for the catalyst start-up temperature

- In the catalytic converter

4. Ceramic temperature in and after catalytic converter (in the last third of the catalytic converter or behind the adjoining matrix) to determine the air-mass-dependent time constants.

- After the catalytic converter

5. Pipe wall temperature at probe installation site for the determination of the dew-end times (condensation protection).

Temperature measuring point 3 can be omitted if the distance from probe to catalytic converter is smaller than about 30 cm. The temperature drop from probe installation site to catalytic converter can then be neglected.

For the application of the functional data the modelled temperatures will always be compared with the measured temperatures and the functional data amended until a sufficiently high accuracy is achieved. In so doing, it will be the actual catalyst temperature, the temperature increase due to the exothermic reaction is not considered in the model.

2. Map KFTATM

For the determination of the steady-state temperature for example, before the catalytic converter the temperature corrections should not function. The cooling capacity of the wind on the dynamometer or on the measuring wheel can be simulated only very roughly at the higher engine load range. The map values can be determined on the rolling road dynamometer, but should be corrected on an
appropriate test drive.

3. Temperature Corrections

- TATMSA

Boost can cause low exhaust temperatures that fall below the starting temperature of the catalyst. The longer the time period for the thrust condition, the lower the exhaust and catalyst temperatures. For catalyst diagnosis during boost, the exhaust gas temperature model is more likely to calculate a lower value than the measured temperature.

- ATMTANS

At low ambient temperatures, exhaust gas temperature can fall below the catalyst start-up temperature. Therefore, the model temperature is only corrected at the low temperature range.

- TATMKH

As long as the catalyst-heating measures are effective, higher exhaust temperatures will result.

- TATMKW

The catalyst operating temperature will not be not reached during prolonged idling, so the exhaust gas temperature can be raised by the catalyst warming function.

- KFATMZW

The temperature increase as a result of ignition angle retardation can be determined on a rolling road dynamometer. First, on the dynamometer, the characteristic field values KFTATM are applied without ignition angle correction. Ignition angles are then modified so that allowed etazwist values will result in the map. Through the corresponding air mass, the temperature increase will then be displayed in the map KFATMZW.

- KFATMLA

The exhaust temperature is reduced by enrichment. The application is similar to KFATMZW, except that the ignition angle efficiency is changed instead of the enrichment factor.

- TATMTMOT

The map KFTATM is applied with a warm engine. Thus, the model exhaust gas temperature has smaller deviations during cold start. For this operating mode, the temperature is corrected with the difference of the cold engine temperature and the warm engine temperature.

TATMTMOT
should be about 90 to 100°C.

4. Maps ZATMAML, ZATMRML, FATMRML, ZATMKML, ZATMKKML, ZATMIKML und ZATMIKKML

The air-mass-dependent time constants ZATMAML, ZATMRML (temperature measuring points 1 or 3), and ZATMKML, ZATMKKML, ZATMIKML, ZATMIKKML (temperature measuring point 4), can help to more accurately
determine “spikes in the air mass” during sudden load variations. Thereby "air mass jumps" at full load and in particular during boost can be avoided. For example, for an air mass jump from 30 kg/hr to 80 kg/hr, the measured time constant is applied to the air mass flow of 80 kg/hr. For large
air mass jumps during idle, the time constants ZATMKKML and ZATMIKKML can be input instead of ZATMKML or ZATMIKML if required.

5. Block EXOTHERME:

- KATMEXML

The exothermic temperature is a function of air mass flow (warming by realizing emissions, reducing warming via a larger air mass). First KATMEXML applies, then KLATMZWE, KLATMLAE.

- KLATMZWE

When ignition angle retardation increases the temperature before the catalyst, the catalyst temperature drops.

- KLATMLAE

For
lambda < 1 (richer), the air mass is lacking to improve emissions so the
catalyst temperature decreases.

- TABGMEX

If
the temperature before the catalyst tabgm < TABGMEX (catalyst switch-off
temperature) then the temperature correction = TKATMOE.

- TKATMOE

Temperature
correction during boost or through tabgm> TABGMEX

- TATMSAE

Temperature
increase in the boost in the catalyst in terms of tkatm

Block EXOIKAT:

-
KATMIEXML, KLATMIZWE, KLATMILAE, TIKATMOE

Application
depends on the application for Block EXOTHERME

- TATMSAE

Temperature
increase in the thrust in the catalyst in terms of tikatm

6.
Dew point end times for exhaust gas temperatures vary greatly between the
centre of the exhaust pipe and the pipe wall. Dew point end times for the tube
wall temperatures before the catalyst (temperature measuring points 2) or after
the catalyst (temperature measuring points 5) should be used. These times are
usually due to delaying control readiness for too long, in which case the
temperature gradients at the probe mounting location must be examined more
closely. To avoid probe damage by “water hammer”, the sensor heater must be fully
turned on until the dew point temperature is exceeded or the dew point end time
is detected thus condensation will no longer occur.

When
the switch-off time in the ECU delay is calculated, then the switch-off time
tabst_w after ECU delay will be incorrect. At engine start after ECU delay, the
switch-off time tabstatm therefore, will be set to the maximum value of 65,535
(i.e. 216-1). The ECU delay
requirement for the time TNLATM when engine speed > TNLATMTM & tumg (tatu)
> TNLATMTU.

8.
For blocks KR_STAT and KR_DYN as appropriate, the descriptions in points 3 and
4 shall apply.

Typical
Values:

KFTATM:
x: engine speed/RPM, y: relative cylinder charge/%, z: temperature/°C

{| border="1"
|-
|
|
800
|
1200
|
1800
|
2400
|
3000
|
4000
|
5000
|
6000
|-
|
15
|
380
|
400
|
420
|
450
|
480
|
520
|
550
|
580
|-
|
22
|
400
|
420
|
450
|
480
|
520
|
550
|
580
|
610
|-
|
30
|
420
|
450
|
480
|
520
|
550
|
580
|
610
|
650
|-
|
50
|
450
|
480
|
520
|
550
|
580
|
610
|
650
|
700
|-
|
70
|
470
|
520
|
550
|
580
|
610
|
660
|
700
|
750
|-
|
100
|
490
|
550
|
580
|
610
|
650
|
700
|
750
|
790
|-
|
120
|
510
|
560
|
610
|
650
|
700
|
750
|
790
|
840
|-
|
140
|
530
|
580
|
650
|
700
|
750
|
790
|
840
|
900
|}
KFATMZW: x: temperature/°C, y: ml_w/kg/hr, z: etazwimt

{| border="1"
|-
|
|
20
|
40
|
80
|
150
|
250
|
400
|-
|
1.00
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|-
|
0.95
|
15
|
40
|
50
|
60
|
70
|
75
|-
|
0.90
|
15
|
60
|
80
|
100
|
125
|
140
|-
|
0.80
|
20
|
80
|
120
|
150
|
180
|
200
|-
|
0.70
|
25
|
100
|
150
|
190
|
210
|
220
|-
|
0.60
|
30
|
115
|
175
|
210
|
230
|
245
|}
KFATMLA:
x: temperature/°C, y: ml_w/kg/hr, z: lamsbg_w

{| border="1"
|-
|
|
20
|
40
|
80
|
150
|
250
|
400
|-
|
1.15
|
5
|
10
|
30
|
50
|
60
|
70
|-
|
1.00
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|-
|
0.95
|
5
|
10
|
20
|
30
|
40
|
45
|-
|
0.90
|
15
|
25
|
40
|
50
|
60
|
75
|-
|
0.80
|
30
|
40
|
60
|
70
|
85
|
100
|-
|
0.70
|
40
|
60
|
80
|
90
|
100
|
120
|}
KFWMABG: x: energy/kJ, y: tabgmst/°C, z:
tmst/°C

{| border="1"
|-
|
|
-40
|
0
|
15
|
25
|
30
|
55
|
60
|-
|
-40
|
200
|
160
|
150
|
140
|
100
|
60
|
30
|-
|
0
|
180
|
150
|
120
|
110
|
80
|
50
|
20
|-
|
15
|
160
|
140
|
60
|
55
|
30
|
40
|
0.45
|-
|
25
|
140
|
120
|
30
|
30
|
15
|
10
|
0.45
|-
|
60
|
120
|
30
|
20
|
15
|
10
|
5
|
0.45
|}

KFWMKAT values correspond to KFWMABG ´ 5

In the heat quantity maps KFWMABG and KFWMKAT a value of 0.0 is never required! It should always have at least the value to be entered; the 2 sec corresponds to idle after cold start. Only then does the repeat-start counter operate after several starts where the dew point was not reached.

ZATMAML
ml_w/kg/hr, Time constant/sec 10, 30 ; 20, 20 ; 40, 13 ; 80, 5 ; 180, 4 ; 400, 3 ; 600, 2 ;

ZATMKML
ml_w/kg/hr, Time constant/sec 10, 150 ; 20, 60 ; 40, 35 ; 80, 20 ; 180, 10 ;
400, 7 ; 600, 4 ;

ZATMIKML
value represents approximately ZATMKML ´ 0.3

ZATMKKML
for neutral input, the data must correlate to ZATMKML

ZATMIKKML
for neutral input, the data must correlate to ZATMIKML

ZATMRML
ml_w/kg/hr, Time constant/sec 10, 300 ; 20, 80 ; 40, 55 ; 80, 30 ; 180, 20 ;
400, 10 ; 600, 7 ;

FATMRML
ml_w/kg/hr, Time constant/sec 10, 0.5 ; 20, 0.6 ; 40, 0.7 ; 80, 0.8 ; 180, 0.95; 400,0.95 ; 600, 0.96;

KATMEXML
ml_w/kg/hr, Time constant/sec 10, 0 ; 20, 0 ; 40, 0 ; 80, 0 ; 180, 0 ; 400, 0 ;

KLATMZWE
etazwimt, Factor 1, 0 ; 0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ; 0.6, 0 ;

KLATMLAE
lamsbg_w, Factor 1.15, 0 ; 1 , 0 ;0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ;

TATMTP: 52°C

TKATMOE: 0°C

TATMSAE: 0°C

KATMIEXML
ml_w/kg/hr, Time constant/sec 10, 0 ; 20, 0 ; 40, 0 ; 80, 0 ; 180, 0 ; 400, 0 ;

KLATMIZWE etazwimt, Factor 1, 0 ; 0.95, 0 ; 0.9, 0; 0.8, 0 ; 0.7, 0 ; 0.6, 0 ;

KLATMILAE lamsbg_w, Factor 1.15, 0 ; 1 , 0 ;0.95, 0 ; 0.9, 0 ; 0.8, 0 ; 0.7, 0 ;

TIKATMOE: 0°C

KFATMABKA: x: tatu/°C, y: tabstatm_w/seconds, z: no units

{| border="1"
|-
|
|
10
|
50
|
180
|
360
|
600
|
1000
|-
|
-40
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
-15
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
0
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
15
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|-
|
40
|
0.95
|
0.70
|
0.50
|
0.30
|
0.15
|
0.00
|}
KFATMABKK:
x: tatu/°C, y: tabstatm_w [s], z: no units

{| border="1"
|-
|
|
10
|
50
|
180
|
360
|
600
|
1000
|-
|
-40
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
-15
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
0
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
15
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|-
|
40
|
0.90
|
0.60
|
0.40
|
0.25
|
0.15
|
0.00
|}

ATMTANS tatu/°C, Temp./°C -40, 60 ; -10, 20 ; 20, 0 ;

TATMSA: 100°C

TATMKH: 80°C

TATMTRKH: 200°C

TATMKW: 100°C

TATMTMOT: 90°C

TATMSTI: 20°C

TASTBFA: 40°C

TKSTBFA: 40°C

TATMWMK: -80°C

WMABGKH: Factor of 1.0

WMKATKH: Factor of 1.0

FWMABGW: Factor of 0.25

FWMKATW: Factor of 0.25

DTUMTAT: 20°C

VTUMTAT: 40 km/h

NTUMTAT: 1800 rpm

IMTUMTAT: 1 kg

TUMTAIT: 20°C

TNLATMTM: 80°C

TNLATMTU: 5°C

TNLATM: 660 seconds

Only when SY_TURBO = 1:

For neutral input (tabgkrm_w = tabgm_w)

KFATMKR = KFTATM

KFATZWK = KFATMZW

KFATLAK = KFATMLA

TATMKRSA = TATMSA

ZATRKRML = ZATMRML

ZATAKRML = ZATMAML

FATRKRML = FATMRML

ATMTANS
tans/°C, Temp./°C -40, 40 ; -20, 25 ; 0, 12 ; 20, 0 ; 60, -30

The functional data for cylinder bank 2 correspond to the functional data from cylinder bank 1 Note:

In order that ATM 22:20 for the application is backward compatible the default values should be entered thus: KATMEXML, KLATMZWE, KLATMLAE, TKATMOE = 0 and TABGMEX = 1220°C.

In order that ATM 33.10 remains application-neutral with ATM 22.50, TATMTRKH must be set equal to TATMKH and WMKATKH should be set equal to 1. Tikatm is not used in a function because the input can be used in the path in the exhaust gas temperature model without impact on safety, however, the default values for KATMIEXML, KLATMIZWE, KLATMILAE and TIKATMOE should be set equal to 0 and TABGMEX = 1220°C.

In DKATSP areas TMINKATS and TMAXKATS, a high accuracy is required for tikatm!

{| border="1"
|-
|
Parameter
|
Description
|-
|
ATMTAKR
|
Correction
for the manifold temperature
|-
|
ATMTANS
|
Temperature
correction for the exhaust gas temperature model
|-
|
DTUMTAT
|
Offset:
intake air temperature ® ambient temperature
|-
|
FATMRML
|
Factor
for the difference between exhaust gas & exhaust pipe wall temperature
|-
|
FATMRML2
|
Factor
for the difference between exhaust gas & exhaust pipe wall temperature, cylinder
bank 2
|-
|
FATRKRML
|
Factor
for the difference between exhaust gas & wall temperature in the manifold
|-
|
FATRKRML2
|
Factor
for the difference between exhaust gas & wall temperature in the manifold,
cylinder bank 2
|-
|
FWMABGW
|
Factor
for heat quantity during repeated starts for pre-cat exhaust gas dew points
|-
|
FWMABGW2
|
Factor
for heat quantity during repeated starts for pre-cat exhaust gas dew points,
cylinder bank 2
|-
|
FWMKATW
|
Factor
for heat quantities during repeated starts for dew points after main catalyst
|-
|
FWMKATW2
|
Factor
for heat quantities during repeated starts for dew points after main catalyst,
cylinder bank 2
|-
|
IMTUMTAT
|
Integration
threshold air mass for determining ambient temperature from TANS
|-
|
KATMEXML
|
Exothermic
reaction temperature in catalyst, tkatm
|-
|
KATMEXML2
|
Exothermic
reaction temperature in catalyst, cylinder bank 2
|-
|
KATMIEXML
|
Exothermic
reaction temperature in catalyst, tikatm
|-
|
KATMIEXML2
|
Exothermic
reaction temperature in catalyst, tikatm, cylinder bank 2
|-
|
KFATLAK
|
Map for
lambda correction for manifold exhaust gas temperature
|-
|
KFATLAK2
|
Map for
lambda correction for manifold exhaust gas temperature, cylinder bank 2
|-
|
KFATMABKA
|
Factor
for exhaust gas temperature decrease as a function of stop time and ambient
temperature
|-
|
KFATMABKA2
|
Factor
for exhaust gas temperature decrease as a function of stop time and ambient
temperature, cylinder bank 2
|-
|
KFATMABKK
|
Factor
for reducing the catalyst temperature as a function of stop time and ambient
temperature
|-
|
KFATMABKK2
|
Factor
for reducing the catalyst temperature as a function of stop time and ambient
temperature, cylinder bank 2
|-
|
KFATMKR
|
Map for
steady-state manifold exhaust gas temperature as a function of engine speed
and relative cylinder charge
|-
|
KFATMKR2
|
Map for
steady-state manifold exhaust gas temperature, cylinder bank 2
|-
|
KFATMLA
|
Map for
exhaust gas temperature correction as a function of lambda
|-
|
KFATMLA2
|
Map for
exhaust gas temperature correction as a function of lambda, cylinder bank 2
|-
|
KFATMZW
|
Map for
exhaust gas temperature correction as a function of igntion angle correction
|-
|
KFATMZW2
|
Map for
exhaust gas temperature correction as a function of ignition angle, cylinder
bank 2
|-
|
KFATZWK
|
Map for
ignition angle correction for manifold gas temperature
|-
|
KFATZWK2
|
Map for
ignition angle correction for manifold gas temperature, cylinder bank 2
|-
|
KFTATM
|
Map for
exhaust gas temperature as a function of engine speed and relative cylinder
charge
|-
|
KFTATM2
|
Map for
exhaust gas temperature as a function of engine speed and relative cylinder
charge for cylinder bank 2
|-
|
KFWMABG
|
Map for
heat quantity threshold exhaust gas dew points
|-
|
KFWMABG2
|
Map for
heat quantity threshold exhaust gas dew points, cylinder bank 2
|-
|
KFWMKAT
|
Map for
heat quantity threshold dew points after catalyst
|-
|
KFWMKAT2
|
Map for
heat quantity threshold dew points after catalyst, cylinder bank 2
|-
|
KLATMILAE
|
Exothermic
temperature decrease through enrichment, tikatm
|-
|
KLATMILAE2
|
Exothermic
temperature decrease through enrichment, tikatm, Bank 2
|-
|
KLATMIZWE
|
Exothermic
temperature decrease in catalyst at later ignition angles, tikatm
|-
|
KLATMIZWE2
|
Exothermic
temperature decrease in catalyst at later ignition angles, tikatm, Bank 2
|-
|
KLATMLAE
|
Exothermic
temperature decrease through enrichment
|-
|
KLATMLAE2
|
Exothermic
temperature decrease through enrichment, cylinder bank 2
|-
|
KLATMZWE
|
Exothermic
temperature decrease in catalyst at later ignition angles, tkatm
|-
|
KLATMZWE2
|
Exothermic
temperature decrease in catalyst at later ignition angles, cylinder bank 2
|-
|
NTUMTAT
|
Speed
threshold for determining ambient temperature from TANS
|-
|
SEZ06TMUB
|
Sample
point distribution, ignition angle efficiency
|-
|
SLX06TMUW
|
Sample
point distribution, desired lambda
|-
|
SLY06TMUW
|
Sample
point distribution, desired lambda, cylinder bank 2
|-
|
SML06TMUW
|
Sample
point distribution, air mass, 6 sample points
|-
|
SML07TMUW
|
Sample
point distribution, air mass, 7 sample points
|-
|
SMT06TMUW
|
Sample
point distribution, air mass, 6 sample points
|-
|
ST107TMUB
|
Sample
point distribution, start temperature at front probe
|-
|
ST207TMUB
|
Sample
point distribution, start temperature at front probe, cylinder bank 2
|-
|
ST307TMUB
|
Sample point
distribution, start temperature at rear probe
|-
|
ST407TMUB
|
Sample
point distribution, start temperature at rear probe, cylinder bank 2
|-
|
STM05TMUB
|
Sample
point distribution, engine start temperature
|-
|
STS06TMUW
|
Sample
point distribution, exhaust gas mass flow
|-
|
STU05TMUB
|
Sample
point distribution, simulated ambient temperature
|-
|
SY_STERVK
|
System
constant condition: stereo before catalyst
|-
|
SY_TURBO
|
System
constant: turbocharger
|-
|
TABGMEX
|
Exhaust
gas temperature below the catalyst switch-off temperature
|-
|
TASTBFA
|
Model temperature
before pre-cat initial value via B_faatm requirement
|-
|
TATMKH
|
Exhaust
gas temperature correction via catalyst heating active
|-
|
TATMKH2
|
Exhaust
gas temperature correction via catalyst heating active, cylinder bank 2
|-
|
TATMKRSA
|
Exhaust
gas temperature correction in manifold via boost switch-off
|-
|
TATMKW
|
Exhaust
gas temperature correction with catalyst warming active
|-
|
TATMSA
|
Exhaust
gas temperature correction via boost cut-off
|-
|
TATMSAE
|
Exothermic
temperature increase in boost
|-
|
TATMSAE2
|
Exothermic
temperature increase in boost, cylinder bank 2
|-
|
TATMSTI
|
Initial
value for tabgm, tkatm intial value through power fail
|-
|
TATMTMOT
|
Engine temperature
warmer Motor, for temperature correction during cold start conditions
|-
|
TATMTP
|
Exhaust
gas dew point temperature
|-
|
TATMTRKH
|
Exhaust
gas temperature correction via thermal reaction catalyst heating
|-
|
TATMTRKH2
|
Exhaust
gas temperature correction via thermal reaction catalyst heating, cylinder bank
2
|-
|
TATMWMK
|
Temperature
offset for calculating heat quantities
|-
|
TIKATMOE
|
Temperature
correction in catalyst without exothermic reaction, tikatm
|-
|
TKATMOE
|
Temperature
correction near catalyst without exothermic reaction, tkatm
|-
|
TKSTBFA
|
Model temperature
post-cat initial value via B_faatm requirement
|-
|
TNLATM
|
Minimum
ECU delay time for exhaust gas temperature model – Abstellzeit
|-
|
TNLATMTM
|
When
tmot > threshold ECU delay requirement B_nlatm = 1
|-
|
TNLATMTU
|
When
tumg (tatu – ATM) > threshold ECU delay requirement
|-
|
TUMTAIT
|
Initialising
value for ambient temperature from TANS
|-
|
VTUMTAT
|
Vehicle
speed threshold for TANS ® ambient temperature
|-
|
WMABGKH
|
Factor
for heat quantity correction via catalyst heating for dew points
|-
|
WMABGKH2
|
Factor
for heat quantity correction via catalyst heating for dew points, cylinder bank
2
|-
|
WMKATKH
|
Factor
for heat quantity correction via catalyst heating for dew points after
catalyst
|-
|
WMKATKH2
|
Factor
for heat quantity correction via catalyst heating for dew points after
catalyst, cylinder bank 2
|-
|
ZATAKRML
|
Time
constant for exhaust gas temperature model (manifold)
|-
|
ZATAKRML2
|
Time
constant for exhaust gas temperature model (manifold), cylinder bank 2
|-
|
ZATMAML
|
Time
constant for exhaust gas temperature model
|-
|
ZATMAML2
|
Time
constant for exhaust gas temperature model, cylinder bank 2
|-
|
ZATMIKKML
|
Time
constant for catalyst temperature model – Temperature in catalyst tikatm during
cooling
|-
|
ZATMIKKML2
|
Time
constant for catalyst temperature model – Temperature in catalyst tikatm
during cooling, bank 2
|-
|
ZATMIKML
|
Time
constant for catalyst temperature model – Temperature in catalyst, tikatm
|-
|
ZATMIKML2
|
Time
constant for catalyst temperature model – Temperature in catalyst, cylinder bank
2
|-
|
ZATMKKML
|
Time
constant for catalyst temperature model – catalyst temperature tkatm during
cooling
|-
|
ZATMKKML2
|
Time
constant for catalyst temperature model – catalyst temperature tkatm during
cooling, bank 2
|-
|
ZATMKML
|
Time
constant for catalyst temperature model – catalyst temperature tkatm
|-
|
ZATMKML2
|
Time
constant for catalyst temperature model – catalyst temperature, cylinder bank
2
|-
|
ZATMRML
|
Time
constant for exhaust gas temperature model – exhaust pipe wall temperature
|-
|
ZATMRML2
|
Time
constant for exhaust gas temperature model – exhaust pipe wall temperature Bank
2
|-
|
ZATRKRML
|
Time
constant for exhaust gas temperature model – manifold wall temperature
|-
|
ZATRKRML2
|
Time
constant for exhaust gas temperature model – manifold wall temperature, cylinder
bank 2
|-
|
Variable
|
Description
|-
|
B_ATMLL
|
Condition
for time constant during cooling at idle
|-
|
B_ATMLL2
|
Condition
for time constant during cooling at idle
|-
|
B_ATMST
|
Condition
for tabgmst, tkatmst initial value calculation
|-
|
B_ATMST2
|
Condition
for tabgmst, tkatmst calculation, cylinder bank 2
|-
|
B_ATMTPA
|
Condition:
dew point before catalyst exceeded
|-
|
B_ATMTPA2
|
Condition:
dew point 2 before catalyst exceeded
|-
|
B_ATMTPF
|
Condition:
dew point before catalyst exceeded (last trip)
|-
|
B_ATMTPF2
|
Condition:
dew point before catalyst exceeded (last trip) cylinder bank 2
|-
|
B_ATMTPK
|
Condition:
dew point after catalyst exceeded
|-
|
B_ATMTPK2
|
Condition:
dew point 2 after catalyst exceeded
|-
|
B_ATMTPL
|
Condition: dew point after catalyst exceeded (last trip)
|-
|
B_ATMTPL2
|
Condition: dew point after catalyst exceeded (last trip) cylinder bank 2
|-
|
B_FAATM
|
Condition: functional requirements for dew
point end times
|-
|
B_KH
|
Condition: catalyst heating
|-
|
B_KW
|
Condition: catalyst warming
|-
|
B_LL
|
Condition: idle
|-
|
B_NACHL
|
Condition: ECU delay
|-
|
B_NACHLEND
|
Condition: ECU delay ended
|-
|
B_NLATM
|
Condition: ECU delay exhaust gas temperature
model probe protection
|-
|
B_PWF
|
Condition: Power fail
|-
|
B_SA
|
Condition: Overrun cut-off
|-
|
B_ST
|
Condition: Start
|-
|
B_STEND
|
Condition: End of start conditions achieved
|-
|
B_STNDNL
|
Condition: Beginning of ECU delay or end of
start conditions (1 ® 0)
|-
|
B_TFU
|
Condition: Ambient temperature sensor
available
|-
|
B_TRKH
|
Condition: Catalyst heating, thermal reaction
effective
|-
|
B_UHRRMIN
|
Condition: timer with a relative number of
minutes
|-
|
B_UHRRSEC
|
Condition: timer with a relative number of
minutes
|-
|
DFP_TA
|
ECU internal error path number: intake air
temperature TANS (charge air)
|-
|
DFP_TUM
|
ECU Internal error path number: ambient
temperature
|-
|
ETAZWIMT
|
Actual ignition angle efficiency average for exhaust
gas temperature model (200 ms)
|-
|
ETAZWIST
|
Actual ignition angle efficiency
|-
|
E_TA
|
Error flag: TANS
|-
|
E_TUM
|
Error flag: ambient temperature tumg
|-
|
IMLATM
|
Integral of air mass flows from engine start
bis Max.wert
|-
|
IMLATM_W
|
Integral of air mass flows from end of start
conditions up to the maximum value, (Word)
|-
|
IWMATM2_W
|
Heat quantity for Condensation - dew points
exhaust gas/catalyst (word), cylinder bank 2
|-
|
IWMATM_W
|
Heat quantity for Condensation - dew points
exhaust gas/catalyst (word)
|-
|
LAMSBG2_W
|
Desired lambda limit (word), cylinder bank 2
|-
|
LAMSBG_W
|
Desired lambda limit (word)
|-
|
ML_W
|
Filtered air mass flow (word)
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
TABGKRM2_W
|
Exhaust gas temperature in manifold from the
model, cylinder bank 2
|-
|
TABGKRM_W
|
Exhaust gas temperature in manifold from the
model
|-
|
TABGM
|
Exhaust gas temperature before catalyst from
the model
|-
|
TABGM2
|
Exhaust gas temperature before catalyst from
the model, cylinder bank 2
|-
|
TABGM2_W
|
Exhaust gas temperature before catalyst from
the model (word) cylinder bank 2
|-
|
TABGMAB
|
Exhaust gas temperature during engine
switch-off
|-
|
TABGMAB2
|
Exhaust gas temperature during engine
switch-off (model) cylinder bank 2
|-
|
TABGMST
|
Exhaust gas temperature at engine start
|-
|
TABGMST2
|
Exhaust gas temperature at engine start,
cylinder bank 2
|-
|
TABGM_W
|
Exhaust gas temperature before catalyst from
the model (word)
|-
|
TABSTATM_W
|
Stop time in ECU delay for exhaust gas
temperature model
|-
|
TABSTMX_W
|
Stop time maximum query for exhaust gas
temperature model
|-
|
TABST_W
|
Stop time
|-
|
TAKRKF
|
Steady-state manifold exhaust gas temperature without
correction
|-
|
TAKRKF2
|
Steady-state manifold exhaust gas temperature
without correction, cylinder bank 2
|-
|
TAKRSTC
|
Steady-state exhaust gas temperature in
manifold in °C
|-
|
TAKRSTC2
|
Steady-state exhaust gas temperature in
manifold, cylinder bank 2
|-
|
TANS
|
Intake air temperature
|-
|
TATAKRML
|
Output from PT1 element: exhaust gas
temperature influence on tabgkrm
|-
|
TATAKRML2
|
Output from PT1 element: exhaust gas
temperature influence on tabgkrm, cylinder bank 2
|-
|
TATMAML
|
Output from PT1 element: exhaust gas
temperature influence on tabgm
|-
|
TATMAML2
|
Output from PT1 element: exhaust gas
temperature influence on tabgm, cylinder bank 2
|-
|
TATMKF
|
Exhaust gas temperature before catalyst from map
KFTATM
|-
|
TATMKF2
|
Exhaust gas temperature before catalyst from map
KFTATM, cylinder bank 2
|-
|
TATMRML
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgm
|-
|
TATMRML2
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgm, cylinder bank 2
|-
|
TATMSTA
|
Exhaust gas temperature before catalyst from
the steady-state model
|-
|
TATMSTA2
|
Exhaust gas temperature before catalyst from
the steady-state model, cylinder bank 2
|-
|
TATRKRML
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgkrm
|-
|
TATRKRML2
|
Output from PT1 element: exhaust pipe wall
temperature effect from tabgkrm, cylinder bank 2
|-
|
TATU
|
Intake air temperature or ambient temperature
|-
|
TEXOIKM2_W
|
Exotherme temperature increase in catalyst for
tikatm, cylinder bank 2
|-
|
TEXOIKM_W
|
Exotherme temperature increase in catalyst for
tikatm
|-
|
TEXOM2_W
|
Exotherme temperature increase in catalyst for
tkatm2, cylinder bank 2
|-
|
TEXOM_W
|
Exotherme temperature increase in catalyst for
tkatm
|-
|
TIKATM
|
Exhaust gas temperature in catalyst from the
model
|-
|
TIKATM2
|
Exhaust gas temperature in catalyst from the
model, cylinder bank 2
|-
|
TIKATM2_W
|
Exhaust gas temperature in catalyst from the
model, cylinder bank 2
|-
|
TIKATM W
|
Exhaust gas temperature in catalyst from the
model
|-
|
TKATM
|
Catalyst temperature from the model
|-
|
TKATM2
|
Catalyst temperature from the model, cylinder
bank 2
|-
|
TKATM2_W
|
Catalyst temperature from the model (word),
cylinder bank 2
|-
|
TKATMAB
|
Exhaust gas temperature after catalyst through
engine switch-off (model)
|-
|
TKATMAB2
|
Exhaust gas temperature after catalyst through
engine switch-off (model), cylinder bank 2
|-
|
TKATMST
|
Catalyst temperature model initial value as a
function of switch-off value, switch-off time
|-
|
TKATMST2
|
Catalyst temperature model initial value as a
function of switch-off value, switch-off time, bank 2
|-
|
TKATM_W
|
Catalyst temperature from the model (word)
|-
|
TMOT
|
Engine temperature
|-
|
TMST
|
Engine start temperature
|-
|
TUMG
|
Ambient
temperature
|-
|
VFZG
|
Vehicle
speed
|-
|
ZWMATM
|
Counter
for repeated starts and factor for heat quantity threshold
|-
|
ZWMATM2
|
Counter
for repeated starts and factor for heat quantity threshold, cylinder bank 2
|-
|
ZWMATMF
|
Counter
for repeated starts and factor for heat quantity threshold upstream
|-
|
ZWMATMF2
|
Counter
for repeated starts and factor for heat quantity threshold upstream, cylinder
bank 2
|}

[[Category:ME7]]

LAMKO 9.80 (Lambda Coordination)

2012-01-07T17:04:26Z

TTQS: Created page with "See the ''funktionsrahmen'' for the following diagrams: lamko-main: Function overview lamko-lamsel: Sub-function: lambda target selection for cylinder bank 1: LAMSEL lamko-..."

See the ''funktionsrahmen'' for the following diagrams:

lamko-main: Function overview

lamko-lamsel: Sub-function: lambda target selection for cylinder bank 1: LAMSEL

lamko-lamsel2: Sub-function: lambda target selection for cylinder bank 2: LAMSEL2

lamko-lamlim: Sub-function: LAMLIM: lambda limit engine running

lamko-lamkh: Sub-function: lambda intervention for catalyst heating in cylinder bank 1: LAMKH

lamko-lamkh2: Sub-function: lambda intervention for catalyst heating in cylinder bank 2: LAMKH2

lamko-lamdsk: Sub-function: lambda intervention for diagnosis (cylinder bank 1): LAMDSK

lamko-lamdsk2: Sub-function: lambda intervention for diagnosis (cylinder bank 2): LAMDSK2

lamko-lss1kor: Sub-function: lambda target correction via lambda probe (cylinder bank 1): LSS1KOR

lamko-lss2kor: Sub-function: lambda target correction via lambda probe (cylinder bank 2): LSS2KOR

lamko-init: Initialisation values:

Function Description

Lambda = 1.0 will be specified in the combustion chamber through the pilot control of fuel injection in module ESVST 4.20. The lambda coordination function LAMKO specifies which engine operating point the combustion chamber operates at lambda = 1.0. The position of the switch is a measure of the priority of the corresponding lambda intervention.

The highest priority is catalyst protection (LASOAB), followed by component protection or driver’s desired value then catalyst clear out and catalyst heating.

Component protection for manifold(s), exhaust valve(s) and turbocharger(s) is implemented via the inputs lambts_w and lambts2_w. The input lambts2_w is only available if the system constant SY_STERBTS = true. This is only set for projects with stereo exhaust tracts which occurs when the two banks have very different exhaust gas temperatures for the engine same operating point.

For projects with exhaust gas temperature control via exhaust gas temperature sensors, correction control of the additive part dlamatr_w is included.

From start to end of warm-up lamnswl_w is active unless catalyst heating through secondary air is requested.

At the beginning of catalytic converter heating, a factor flakh from module LAKH for lamnswl_w is passed to lambda for catalyst heating lamkh_w. When catalyst heating is terminated it is passed back again with flakh to lamnswl_w. For systems with secondary air injection (B_slsfz), the lambda engine target (lamsbg_w) is calculated by means of the secondary air dilution arising from target lambda at the lambda probe lamsons_w via multiplication by the secondary air dilution factor flamsl_w.

The two sub-functions LSS1KOR and LSS2KOR correct the rounding error in the calculation of lamsons_w about 1.0 so that two-point lambda control is not unnecessarily shut down.

In normal operation, the lambda target (lamsbg) is provided by lamfa_w or lambts_w.

The two inputs lamlash_w and lamelsh_w are provided for diagnosis of the post-catalyst lambda probes. With these inputs, a change in the post-cat lambda probe voltage via a lambda intervention is implemented.

For catalyst diagnosis, lamdskt_w or lamdskt2_w are designated for the future of lambda intervention. This intervention is activated by condition flags B_lamdkt or B_dlamdkt2 whereas the intervention with index 2 is only available with SY_STERVK or SY_STERHK.

On catalyst clear-out, the target lambda is determined by lamka unless an even richer mixture is requested via lamnswl_w (especially when the engine is still cold).

Via the lambda intervention lamau_w, the exhaust emission test AU implements a lambda intervention for the catalyst check. For this purpose the system constant SY_AAU must be set in the project. The intervention is implemented when B_auakt = true.

At fuel injector switch off (B_evab, Bevab2 = true) the target lambda value is specified by the constant LASOAB. Thus, this can be achieved that in the associated exhaust tract of the deactivated cylinders so that no surplus hydrocarbons arise in the other cylinders when the entire cylinder bank is operated under lean conditions (e.g. LASOAB = 1.05) for catalyst protection.

For the torque calculation, the basic-lambda variable lambas is made available as the average of the two cylinder banks.

When a high lambda-dynamic situation occurs outside of warm-up, the catalytic converter heating range (B_lamnse = true) is no longer required and the computation
time frame is transferred from 10 ms to 100 ms.

Then, via the switches, the actually selected lambda (lamsubg_w) is limited via either of the two lambda thresholds LAMLGFTM (or LAMFLGSL with secondary air
operation) and LAMLGMTM to the rich and lean engine operating limits.

If the lambda requirements for diagnostic functions, catalyst clear out or catalyst heating are active, the fuel tank breather must be prohibited, so that it serves
bit B_lamsdef or either B_ldef and B_ldef2 for twin cylinder bank systems.

IMPORTANT: It must be ensured that the lean operating limits LAMLGMTM & LAMLGMKT do not go in the direction of zero because it directly affects the injection!

Application Notes

Data for initial application:

CWLAMKH = 0

LASOAB 1.05

LAMLGFTM = LAMFLGSL = 0.77

Sample points for LAMFLGSL: imlatm = 2, 4, 6, 8, 10, 12 kg

LAMLGMTM sample points for tmot are not freely selectable, since the group tmot line is a function of ESWL

Value = 1.2

LAMSOSUF = 0.998779

LAMSOSOF = 1.001221 equivalent to 5 increments difference of 1.0

The inputs lamka_w and lamka2_w are inactive if the lambda value ³ 2. The catalyst clear out function sets this value in the inactive case at lambda = 8.0.

CWLAMKH = 1: Minimum value of lamnswl_w or lamkhe_w to act
CWLAMKH = 0: lamkhe acts directly

Abbreviations

{| border="1"
|-
|
Parameter
|
Description
|-
|
CWLAMKH
|
Code word for lambda coordination during catalyst heating
|-
|
LAMFLGSL
|
Lambda engine operating limit fett bei Sekundärlufteinblasung
|-
|
LAMLGFKT
|
Rich lambda operating limit during
short test
|-
|
LAMLGFTM
|
Rich lambda operating limit
|-
|
LAMLGMKT
|
Lean lambda operating limit during
short test
|-
|
LAMLGMTM
|
Lean lambda operating limit
|-
|
LAMSOSOF
|
Lambda probe target upper limit for 1.0-window
|-
|
LAMSOSUF
|
Lambda probe target lower limit for 1.0-window
|-
|
LASOAB
|
Target lambda value during cylinder bank deactivation
|-
|
STM12ESUB
|
Sample point distribution for engine temperature (tmot)
|-
|
SY_AAU
|
System constant: calibrator specification of target lambda for exhaust
emissions test (AU) is possible
|-
|
SY_ATR
|
System constant: exhaust gas temperature control is available
|-
|
SY_DKAT
|
System constant: status information about the system’s available catalyst
diagnostics
|-
|
SY_DLSHV
|
System constant: condition module DLSHV (post-catalyst probe swapping) available
|-
|
SY_STERBTS
|
System constant: exhaust gas bank selective component protection
|-
|
SY_STERHK
|
System constant: condition stereo lambda control post-catalyst
|-
|
SY_STERVK
|
System constant: condition stereo lambda control pre-catalyst
|-
|
Variable
|
Description
|-
|
B_AUAKT
|
Condition flag: exhaust emissions test active
|-
|
B_BEVAB
|
Condition flag: injector shut-off in cylinder bank 1
|-
|
B_BEVAB2
|
Condition flag: injector shut-off in cylinder bank 2
|-
|
B_DSLA
|
Adaptation phase: determining secondary air mass
|-
|
B_FA
|
Condition flag: general function requirement
|-
|
B_FALSH
|
Condition flag: function requirement post-catalyst lambda probe for
cylinder bank 1
|-
|
B_FALSH2
|
Condition flag: function requirement post-catalyst lambda probe for
cylinder bank 2
|-
|
B_FASLA
|
Condition flag: external requirement to activate secondary air
|-
|
B_KH
|
Condition flag: catalyst heating
|-
|
B_LALGF
|
Condition flag: rich lambda operating limit active (cylinder bank 1)
|-
|
B_LALGF2
|
Condition flag: rich lambda operating limit active (cylinder bank 2)
|-
|
B_LAMBTS
|
Lambda for component protection is active (cylinder bank 1)
|-
|
B_LAMBTS2
|
Lambda for component protection is active (cylinder bank 2)
|-
|
B_LAMDIAG
|
Target lambda for diagnostic function requirement
|-
|
B_LAMDKT
|
Lambda target intervention for catalyst diagnose active
|-
|
B_LAMDKT2
|
Lambda target intervention for catalyst diagnose active
|-
|
B_LAMKA
|
Lambda for catalyst clear out active
|-
|
B_LAMKA2
|
Lambda for catalyst clear out active
|-
|
B_LAMKH
|
Condition flag: target lambda for catalyst heaing active
|-
|
B_LAMKHE
|
No lambda requirement from module LAKH
|-
|
B_LAMLASH
|
Condition flag for enleanment in module LAMKO (cylinder bank 1)
|-
|
B_LAMLASH2
|
Condition flag for enleanment in module LAMKO (cylinder bank 2)
|-
|
B_LAMLSHV
|
Condition flag for enleanment or enrichment in module LAMKO
|-
|
B_LAMLSHV2
|
Condition flag for enleanment or enrichment in module LAMKO Bank 2
|-
|
B_LAMNSE
|
Condition flag: end of lamns_w calculation
|-
|
B_LAMNSWL
|
Lambda engine target for post-start and warm-up active
|-
|
B_LAMSDEF
|
Condition flag: defined target lambda
|-
|
B_LDEF
|
Condition flag: defined target lambda (cylinder bank 1)
|-
|
B_LDEF2
|
Condition flag: defined target lambda (cylinder bank 2)
|-
|
B_LDEFFW
|
Condition flag: defined target lambda (cylinder bank 1) via driver’s
request
|-
|
B_SLS
|
Condition flag: secondary air control active
|-
|
B_SLSFZ
|
Condition flag: secondary air control is installed in the vehicle
|-
|
DLAMATR W
|
Delta target lambda from exhaust gas temperature regulation (cylinder
bank 1)
|-
|
DLAMATR2_W
|
Delta target lambda from exhaust gas temperature regulation (cylinder bank
2)
|-
|
FLAMKH
|
Factor for controlling lambda-engine target during catalyst heaing
|-
|
FLAMSL_W
|
Factor for lambda adjustment via secondary air (cylinder bank 1)
|-
|
FLAMSL2_W
|
Factor for lambda adjustment via secondary air (cylinder bank 2)
|-
|
IMLATM
|
Integrated air mass flow from engine start to the maximum value
|-
|
LAMAU_W
|
Lambda for exhaust emission test
|-
|
LAMBAS
|
Basic lambda
|-
|
LAMBTS_W
|
Lambda for component protection (cylinder bank 1)
|-
|
LAMBTS2_W
|
Lambda for component protection (cylinder bank 2)
|-
|
LAMDKT_W
|
Target lambda for catalyst diagnostics (cylinder bank 1)
|-
|
LAMDKT2_W
|
Target lambda for catalyst diagnostics (cylinder bank 2)
|-
|
LAMELSH_W
|
Target lambda for electric probe diagnostics post-catalyst (Kurztrip, cylinder
bank 1)
|-
|
LAMELSH2_W
|
Target lambda for electric probe diagnostics post-catalyst (Kurztrip, cylinder
bank 2)
|-
|
LAMFA_W
|
Target driver’s requested lambda (word)
|-
|
LAMKA_W
|
Target lambda value catalyst clear out (cylinder bank 1)
|-
|
LAMKA2_W
|
Target lambda value catalyst clear out (cylinder bank 2)
|-
|
LAMKH_W
|
Lambda-engine target during catalyst heaing (word, cylinder bank 1)
|-
|
LAMKH2 W
|
Lambda-engine target during catalyst heaing (word, cylinder bank 2)
|-
|
LAMKHE_W
|
Lambda-engine target during catalyst heaing, effective (cylinder bank 1)
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|
LAMKHE2_W
|
Lambda-enging target during catalyst heaing, effective (cylinder bank 2)
|-
|
LAMLASH_W
|
Target lambda for test vibration check post-catalyst (cylinder bank 1)
|-
|
LAMLASH2_W
|
Target lambda for test vibration check post-catalyst (cylinder bank 2)
|-
|
LAMLGFMN
|
Lambda engine rich operating limit
|-
|
LAMLGM
|
Lean lambda operating limit
|-
|
LAMLSHV_W
|
Target lambda for test post-catalyst probe substitution (cylinder bank 1)
|-
|
LAMLSHV2_W
|
Target lambda for test post-catalyst probe substitution (cylinder bank 2)
|-
|
LAMNSWL_W
|
Lambda-engine target for post-start and warm-up
|-
|
LAMS2_W
|
Target lambda (word)
|-
|
LAMSBG_W
|
Target lambda limit (word, cylinder bank 1)
|-
|
LAMSBG2_W
|
Target lambda limit (word, cylinder bank 2)
|-
|
LAMSONS_W
|
Target lambda value based on the lambda probe installation location
(cylinder bank 1)
|-
|
LAMSONS2_W
|
Target lambda value based on the lambda probe installation location (cylinder
bank 2)
|-
|
LAMSOS_W
|
Target lambda value based on the lambda probe installation location
(cylinder bank 1)
|-
|
LAMSOS2_W
|
Target lambda value based on the lambda probe installation location (cylinder
bank 2)
|-
|
LAMSUBG_W
|
Unlimited target lambda (word, cylinder bank 1)
|-
|
LAMSUBG2_W
|
Unlimited target lambda (word, cylinder bank 2)
|-
|
LAMS_W
|
Target lambda (word)
|-
|
LAMVOA_W
|
Lambda pilot control without additive part (cylinder bank 1)
|-
|
LAMVOA2 W
|
Lambda pilot control without additive part (cylinder bank 2)
|-
|
TMOT
|
Engine temperature
|}