LAMFAW 7.100 (Driver's Requested Lambda) - Revision history

TTQS at 15:24, 4 December 2011

2011-12-04T15:24:25Z

TTQS at 15:22, 4 December 2011

2011-12-04T15:22:28Z

TTQS at 15:20, 4 December 2011

2011-12-04T15:20:21Z

TTQS at 15:18, 4 December 2011

2011-12-04T15:18:30Z

TTQS: Created page with "See the ''funktionsrahmen'' for the following diagrams: lamfaw-lamfaw lamfaw-lamkr lamfaw-lamwl lamfaw-lamfadisable lamfaw-lamrlmin lamfaw-initialise Function De..."

2011-12-04T15:16:45Z

Created page with "See the ''funktionsrahmen'' for the following diagrams: lamfaw-lamfaw lamfaw-lamkr lamfaw-lamwl lamfaw-lamfadisable lamfaw-lamrlmin lamfaw-initialise Function De..."

New page

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

lamfaw-lamfaw

lamfaw-lamkr

lamfaw-lamwl

lamfaw-lamfadisable

lamfaw-lamrlmin

lamfaw-initialise

Function Description

The function LAMFAW brings about an enrichment of the fuel-air mixture via lamfa_w when the driver demands maximum torque via mrfa_w. This then corresponds to the full-load enrichment. The intervention to the mixture via lamfa_w can be delayed via the delay time TLAFA. During turbocharger overboost, an additional enrichment is applied by a delta-lambda from the characteristic DLAMOB.

For the time TLAMFAS, an enrichment via the driver’s request as a function of altitude (LAMFAS) can be prevented (see sub-function LAMFADISABLE). Triggering of this time will be initiated if B_kh = true, LAMFA <1.0 and the altitude at which the function is disabled (as defined in LAMFAS) has been reached.

In this way, a reproducible driving cycle can also be achieved at higher altitudes.

During a torque reduction, e.g. traction control intervention, engine speed limiter, etc. the enrichment via the map LAMFAW can be disabled by setting CWMFAW Bit 1 = true.

In the sub-function LAMKR, an enrichment can be implemented during ignition angle intervention.

The sub-function LAMWL can be used for the enrichment during warm-up. If this procedure is used, tank-venting via the function LAMKO is not switched off.

In the sub-function LAMRLMIN, an enrichment via LAMRLMN is active for low loads (rl). This improves the combustion efficiency at low loads. If CWLAMFAW bit 2 is set, then the emergency fuel tank breather is disabled during lamrlmn-intervention.

Application Notes

A delay time TLAFA > 0 can only be applied when the mixture intervention via lamfa_w should be delayed.

Map LAMFA:

Engine speed sample points: 1000, 1400, 1800, 2200, 2600, 3000, 3400, 3800, 4200, 4600, 5000, 5400, 5800, 6200, 6600, 7000 rpm

mrfa_w sample points: 70, 80, 90, 100, 110, 120 %

Map values of 1.0

DLAMOB comprises the delta-lambda, so that an additional mixture enrichment is implemented in overboost mode.

Sample points for engine speed: implemented as a group characteristic SNM06GKUB

Neutralization of the function by data:

LAMFA = 1.0 and DLAMOB = 0.0 ---> lamfa_w is then 1.0

The time TLAMFAS must be selected so that no large gradients are caused in the driver’s requested enrichment (typically 240 s).

The characteristic LAMFAS contains values from 0 to 1. If the value is 0, enrichment via the altitude effect is active. Values other than 0 deactivate enrichment via LAMFA, if B_kh = true and LAMFA values are < 1.0.

The characteristic LAMFAS is not interpolated, which means that the characteristic initial value remains constant until a node is crossed.

For the fho-sample points of the characteristic LAMFAS, the following relationship applies: fho = 1
– altitude [m]/10,000 m

Since the variable fho has a quantization of 4/256 = 0.015625, this resolution must be considered when determining the switch-off. Similarly, there is a potential altitude deviation of ± 250 m because of the sensor tolerance.

For the calculation of the lower or upper threshold of fho, the following relationship applies for a nominal altitude cut-off threshold:

Lower altitude cut-off threshold:

fho [phys] = 1 – ((nominal altitude [m] – 250 m ) /10,000)

---> fho[Ink] = Integer (fho[phys]/0.015625) + 1Ink

---> fho upper limit [phys] = (1 – fho[Ink] x 0.015625)

---> Altitude upper limit = (1 – fho upper limit [phys]) x 10,000

Upper altitude cut-off threshold:

fho [phys] = 1 – ((nominal altitude [m] + 250 m)/10,000)

---> fho[Ink] = Integer (fho[phys]/0.015625)

---> fho lower limit [phys] = fho[Ink] x 0.015625

---> Altitude lower limit = (1 – fho lower limit [phys]) x 10,000

This produces the following values:

{| border="1"
|-
|
Nominal
altitude
|
2,200 m
|
1,600 m
|
|-
|
Altitude
upper limit
|
2,500 m
|
1,875 m
|
The altitude upper limit is the fho lower limit!
|-
|
fho lower limit
|
0.75
|
0.8125
|-
|
Altitude lower limit
|
1,875 m
|
1,250 m
|
|-
|
fho upper limit
|
0.8125
|
0.875
|
|}

Thus, the characteristic LAMFAS is parameterized as follows for the nominal altitude of 2,200 m:

{| border="1"
|-
|
fho
|
0.734375
|
0.7500
|
0.8125
|-
|
Value
|
0
|
1
|
0
|-
|
|
Enrichment active
|
Enrichment inactive
|
Enrichment active
|}

Switching off the altitude-dependent enrichment suppression: LAMFAS = 0, TLAMFAS = 0

Values for lambda intervention lamfawkr_w during ignition angle retardation:

ZKLAMFAW: 2 s

ZKWLAFWL: 2 s

DLAMFAW: 0.01

KFLAMKR: Engine speed sample points: Group characteristic SNM06GKUB
rl sample points: Group characteristic SRL06GKUB
Map values: All are 1.0 ---> no weighting active

KFLAMKRL: dzlamfaw sample points: Group characteristic SDZ0 6GKUB
rl sample points: Group characteristic SRL06GKUB
Map values: All are 1.0 ---> lambda intervention not active

DLAMTANS: Ambient temperature sample points: 50.25, 60, 70.5, 80.25 °C
Map values: All are 0 ---> lambda intervention not active

KFLAFWL: Engine speed sample points: Group characteristic SNM06GKUB
rl sample points: Group characteristic SRL06GKUB
Map values: All are 0 ---> lambda intervention not active
''In the map, delta values are entered, –0.1 ''''--->'' '' lamfwl_w = 0.9!''

DLAMOB: Engine speed sample points: Group characteristic SNM06GKUB
Map values: All are 0 ---> no additional enrichment during overboost
''In the map, delta values are entered + 0.1 ''''--->'' ''lamfa = lamfaw – 0.1!''

RLLAMMN: Engine speed sample points: Group characteristic SNM06GKUB
Map values: 0% ---> enrichment via LAMRLMN not active

LAMRLMN: Engine speed sample points: Group characteristic SNM06GKUB
Map values: 1.0 ---> lambda = 1.0 (no enrichment)

CWLAMFAW Bit 0: 0: dzwlamfaw = min (0, dzwwl)

1: dzwlamfaw = min (0, (dzwwl + wkrma)). Default value = 0.

CWLAMFAW Bit 1: 0: LAMFAW also during torque reduction, e.g. via traction control, engine speed limiter, etc. active

1: no enrichment via LAMFAW during torque reduction (milsol < mifa)

CWLAMFAW Bit 2: 0: B_ldeffw is always false ---> emergency fuel tank breather also during lamrlmn_w-intervention active

1: B_ldeffw dependent on lamrlmn_w-activation, when B_ldeffw = true, emergency fuel tank breather disabled, i.e. fuel tank breather valve shuts.

CWLAMFAW Bit 3: 0: Disable driver’s requested lambda activation through catalyst heating enabled

1: Disable driver’s requested lambda activation through catalyst heating not possible

CWLAMFAW Bit 4: 0: lamfwl_w dependent on B_stend and VZ1-term

1: lamfwl_w not dependent on B_stend and VZ1-term

Group characteristic for engine speed sample points: SNM06GKUB: 760, 1520, 2560, 3520, 4560, 5520 rpm

Group characteristic for relative load sample points: SRL06GKUB: 20, 40, 60, 80, 90 %

Group characteristic for engine temperature sample points: STM0 8GKUB: –15, 0, 20, 40.5, 60, 75, 85.5, 105 °C

Group characteristic for dzwlamfaw sample points: SDZ06GKUB: –30, –20, –15, –10, –5, 0 degrees

{| border="1"
|-
|
'''Parameter'''
|
'''Description'''
|-
|
CWLAMFAW
|
Codeword LAMFAW
|-
|
DLAMFAW
|
Threshold
value for activating enrichment via driver’s request
|-
|
DLAMOB
|
Delta lambda during overboost
|-
|
DLAMTANS
|
Air temperature-dependent
enrichment
|-
|
GANGFAW
|
Gear
threshold for deactivating driver’s request at altitude
|-
|
KFLAFWL
|
Offset engine target lambda
|-
|
KFLAMKR
|
Weighting
factor for enrichment during ignition angle retardation
|-
|
KFLAMKRL
|
Enrichment
during ignition angle retardation
|-
|
LAMFA
|
Driver’s requested lambda
|-
|
LAMFAS
|
Disable driver’s requested
lambda
|-
|
LAMRLMN
|
Lambda
control when rl < RLLAMMN to improve the combustion efficiency
|-
|
RLLAMMN
|
Minimum
requested load threshold for enrichment due to combustion efficiency
|-
|
SDZ06GKUB
|
Sample
point distribution for KFLAMKRL
|-
|
SNM06GKUB
|
Sample
point distribution for KFLAMKR, DLAMOB
|-
|
SRL06GKUB
|
Sample
point distribution for KFLAMKRL, KFLAFWL, KFLAMKR
|-
|
STM08GKUB
|
8 engine
temperature sample point distribution for KFLAFWL
|-
|
SY TURBO
|
System constant: turbocharger
|-
|
TLAFA
|
Delay time
with driver’s requested lambda active
|-
|
TLAMFAS
|
Delay time
with driver’s requested lambda at altitude active
|-
|
TMSTFWMN
|
Minimum
engine start temperature for deactivating driver’s request at altitude
|-
|
TMSTFWMX
|
Maximum
engine start temperature for deactivating driver’s request at altitude
|-
|
TNSTFWMN
|
Minimum
time after start for deactivating driver’s request at altitude
|-
|
TNSTFWMX
|
Maximum
time after start for deactivating driver’s request at altitude
|-
|
ZKLAMFAW
|
Time
constant filtering enrichment via driver’s request
|-
|
ZKWLAFWL
|
Time
constant weighting offset engine target lambda
|-
|
'''Variable'''
|
'''Description'''
|-
|
B_KH
|
Condition flag: catalyst
heating
|-
|
B_LAMFAS
|
Condition
flag: disable driver’s requested lambda
|-
|
B_LAMFASA
|
Condition
flag: altitude-dependent disabling time for driver’s requested lambda is
required
|-
|
B_LAMFASH
|
Condition
flag: altitude-dependent disabling time for driver’s requested lambda is active
|-
|
B_LDEFFW
|
Condition
flag: defined target lambda (cylinder bank 1) via driver’s request
|-
|
B_LDOB
|
Condition flag: overboost
active
|-
|
B_SAB
|
Condition
flag: overrun fuel cut-off readiness
|-
|
B_STEND
|
Condition
flag: end of start conditions reached
|-
|
DZWLAMFAW
|
Delta
ignition angle during knock control intervention or warm-up for enrichment
via lambda
|-
|
DZWWL
|
Delta
ignition angle during warm-up
|-
|
FHO
|
Altitude correction factor
|-
|
GANGI
|
Actual gear
|-
|
LAMFAWKR_W
|
during ignition angle retardation
(knock control), WL
|-
|
LAMFAWS W
|
Driver’s
requested target lambda steady-state part
|-
|
LAMFAW_W
|
Driver’s
requested target lambda part from map LAMFA
|-
|
LAMFA_W
|
Driver’s
requested target lambda (word)
|-
|
LAMFWL_W
|
Offset
engine target lambda during warm-up
|-
|
LAMRLMN_W
|
Target
lambda control to improve the combustion efficiency at lower relative loads
|-
|
MIFA_W
|
Indexed driver’s
requested engine torque
|-
|
MILSOL_W
|
Driver’s
requested torque for cylinder charge path
|-
|
MRFA_W
|
Relative driver’s
requested torque from cruise control and throttle pedal
|-
|
NMOT
|
Engine speed
|-
|
RL
|
Relative cylinder charge
|-
|
TANS
|
Ambient air temperature
|-
|
TMOT
|
Engine temperature
|-
|
TMST
|
Engine start temperature
|-
|
TNST_W
|
Time after
end of start conditions
|-
|
WKRMA
|
Average
value of the individual cylinder ignition angle retardation (knock control),
general (in emergency mode with safety margin)
|}

[[Category:ME7]]

@@ Line 215: / Line 215: @@
 Map values: All are 0 ---> lambda intervention not active
-''In the map, delta values are entered, –0.1 ''''--->'' '' lamfwl_w = 0.9!''
+''In the map, delta values are entered, –0.1 ---> lamfwl_w = 0.9!''
@@ Line 222: / Line 222: @@
 Map values: All are 0 ---> no additional enrichment during overboost
-''In the map, delta values are entered + 0.1 ''''--->'' ''lamfa = lamfaw – 0.1!''
+''In the map, delta values are entered + 0.1 ---> lamfa = lamfaw – 0.1!''

@@ Line 104: / Line 104: @@
 |-
+|
-Nominal
+Nominal altitude
 altitude
+|
 ,200 m
@@ Line 113: / Line 112: @@
 |-
+|
-Altitude
+Altitude upper limit
 upper limit
+|
 ,500 m
@@ Line 193: / Line 191: @@
 KFLAMKR: Engine speed sample points: Group characteristic SNM06GKUB
 rl sample points: Group characteristic SRL06GKUB
 Map values: All are 1.0 ---> no weighting active
 KFLAMKRL: dzlamfaw sample points: Group characteristic SDZ0 6GKUB
 rl sample points: Group characteristic SRL06GKUB
 Map values: All are 1.0 ---> lambda intervention not active
 DLAMTANS: Ambient temperature sample points: 50.25, 60, 70.5, 80.25 °C
 Map values: All are 0 ---> lambda intervention not active
 KFLAFWL: Engine speed sample points: Group characteristic SNM06GKUB
 rl sample points: Group characteristic SRL06GKUB
 Map values: All are 0 ---> lambda intervention not active
 ''In the map, delta values are entered, –0.1 ''''--->'' '' lamfwl_w = 0.9!''
 DLAMOB: Engine speed sample points: Group characteristic SNM06GKUB
 Map values: All are 0 ---> no additional enrichment during overboost
 ''In the map, delta values are entered + 0.1 ''''--->'' ''lamfa = lamfaw – 0.1!''
 RLLAMMN: Engine speed sample points: Group characteristic SNM06GKUB
 Map values: 0% ---> enrichment via LAMRLMN not active
 LAMRLMN: Engine speed sample points: Group characteristic SNM06GKUB
 Map values: 1.0 ---> lambda = 1.0 (no enrichment)

@@ Line 267: / Line 267: @@
 DLAMFAW
+|
-Threshold
+Threshold value for activating enrichment via driver’s request
 value for activating enrichment via driver’s request
 |-
+|
@@ Line 278: / Line 277: @@
 DLAMTANS
+|
-Air temperature-dependent
+Air temperature-dependent enrichment
 enrichment
 |-
+|
@@ Line 295: / Line 293: @@
 KFLAMKR
+|
-Weighting
+Weighting factor for enrichment during ignition angle retardation
 factor for enrichment during ignition angle retardation
 |-
+|
@@ Line 312: / Line 309: @@
 LAMFAS
+|
-Disable driver’s requested
+Disable driver’s requested lambda
 lambda
 |-
+|
@@ Line 324: / Line 320: @@
 RLLAMMN
+|
-Minimum
+Minimum requested load threshold for enrichment due to combustion efficiency
 requested load threshold for enrichment due to combustion efficiency
 |-
+|
 SDZ06GKUB
+|
-Sample
+Sample point distribution for KFLAMKRL
 point distribution for KFLAMKRL
 |-
+|
@@ Line 342: / Line 336: @@
 SRL06GKUB
+|
-Sample
+Sample point distribution for KFLAMKRL, KFLAFWL, KFLAMKR
 point distribution for KFLAMKRL, KFLAFWL, KFLAMKR
 |-
+|
@@ Line 359: / Line 352: @@
 TLAFA
+|
-Delay time
+Delay time with driver’s requested lambda active
 with driver’s requested lambda active
 |-
+|
 TLAMFAS
+|
-Delay time
+Delay time with driver’s requested lambda at altitude active
 with driver’s requested lambda at altitude active
 |-
+|
@@ Line 483: / Line 474: @@
 LAMFAWKR_W
+|
-during ignition angle retardation (knock control), WL
+Driver’s requested target lambda during ignition angle retardation (knock control), WL
 |-
+|
 LAMFAWS W
+|
-Driver’s
+Driver’s requested target lambda steady-state part
 requested target lambda steady-state part
 |-
+|
@@ Line 499: / Line 489: @@
 LAMFA_W
+|
-Driver’s
+Driver’s requested target lambda (word)
 requested target lambda (word)
 |-
+|
 LAMFWL_W
+|
-Offset
+Offset engine target lambda during warm-up
 engine target lambda during warm-up
 |-
+|
@@ Line 516: / Line 504: @@
 MIFA_W
+|
-Indexed driver’s
+Indexed driver’s requested engine torque
 requested engine torque
 |-
+|
 MILSOL_W
+|
-Driver’s
+Driver’s requested torque for cylinder charge path
 requested torque for cylinder charge path
 |-
+|

@@ Line 468: / Line 468: @@
 DZWWL
+|
-Delta
+Delta ignition angle during warm-up
 ignition angle during warm-up
 |-
+|
@@ Line 484: / Line 483: @@
 LAMFAWKR_W
+|
-during ignition angle retardation
+during ignition angle retardation (knock control), WL
 (knock control), WL
 |-
+|
@@ Line 496: / Line 494: @@
 LAMFAW_W
+|
-Driver’s
+Driver’s requested target lambda part from map LAMFA
 requested target lambda part from map LAMFA
 |-
+|
@@ Line 514: / Line 511: @@
 LAMRLMN_W
+|
-Target
+Target lambda control to improve the combustion efficiency at lower relative loads
 lambda control to improve the combustion efficiency at lower relative loads
 |-
+|
@@ Line 532: / Line 528: @@
 MRFA_W
+|
-Relative driver’s
+Relative driver’s requested torque from cruise control and throttle pedal
 requested torque from cruise control and throttle pedal
 |-
+|
@@ Line 563: / Line 558: @@
 TNST_W
+|
-Time after
+Time after end of start conditions
 end of start conditions
 |-
+|
@@ Line 570: / Line 564: @@
+|
 Average
-value of the individual cylinder ignition angle retardation (knock control),
+value of the individual cylinder ignition angle retardation (knock control), general (in emergency mode with safety margin)
 general (in emergency mode with safety margin)
 |}
 [[Category:ME7]]