Difference between revisions of "Lambda drivers (LAMFAW)"

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''This is a translation from the [[Funktionsrahmen]]''
+
See the ''funktionsrahmen'' for the following diagrams:
  
LAMFAW Abbreviations
+
lamfaw-lamfaw
{| cellspacing="10"
+
! Parameter  
+
lamfaw-lamkr
! Source-X   
+
! Source-Y  
+
lamfaw-lamwl
! Type     
+
 
! Designation
+
lamfaw-lamfadisable
 +
 +
lamfaw-lamrlmin
 +
 +
lamfaw-initialise
 +
 
 +
 
 +
<u>Function Description</u>
 +
 
 +
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 &lt;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.
 +
 
 +
 
 +
<u>Application Notes</u>
 +
 
 +
A delay time TLAFA &gt; 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 &#8203;&#8203;from 0 to 1. If the value is 0, enrichment via the altitude effect is active. Values &#8203;&#8203;other than 0 deactivate enrichment via LAMFA, if B_kh = true and LAMFA values &#8203;&#8203;are &lt; 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:
 +
 
 +
 
 +
<u>Lower altitude cut-off threshold:</u>
 +
 
 +
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
 +
 
 +
 
 +
<u>Upper altitude cut-off threshold:</u>
 +
 
 +
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"
 
|-
 
|-
|CWLAMFAW  ||             ||          ||FW        ||Codeword LAMFAW
+
|  
 +
Nominal
 +
altitude
 +
|  
 +
2,200 m
 +
|  
 +
1,600 m
 +
|
 
|-
 
|-
|DLAMFAW    ||             ||          ||FW        ||Threshold for activation enrichment of driver request                       
+
|  
 +
Altitude
 +
upper limit
 +
|  
 +
2,500 m
 +
|  
 +
1,875 m
 +
|  
 +
The altitude upper limit is the fho lower limit!
 
|-
 
|-
|DLAMOB    ||NMOT        ||          ||KL        ||Delta Lambda at overboost                                                   
+
|  
 +
fho lower limit
 +
|  
 +
0.75
 +
|  
 +
0.8125
 
|-
 
|-
|DLAMTANS  ||TANS        ||          ||KL        ||Air temperature dependent enrichment                                       
+
|  
 +
Altitude lower limit
 +
|  
 +
1,875 m
 +
|  
 +
1,250 m
 +
|
 
|-
 
|-
|GANGFAW    ||             ||         ||FW        ||Response threshold for disabling driver request in the amount               
+
|  
 +
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"
 
|-
 
|-
|KFLAFWL    ||TMOT        ||RL        ||KF        ||Offset Lambda engine theoretical                                           
+
|  
 +
fho
 +
|  
 +
0.734375
 +
|  
 +
0.7500
 +
|  
 +
0.8125
 
|-
 
|-
|KFLAMKR    ||NMOT        ||RL        ||KF        ||Weighting factor for enrichment at ignition retard                         
+
|  
 +
Value
 +
|  
 +
0
 +
|  
 +
1
 +
|  
 +
0
 
|-
 
|-
|KFLAMKRL  ||DZWLAMFAW    ||RL        ||KF        ||Enrichment at ignition retard                                               
+
|
 +
|  
 +
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 &lt; 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"
 
|-
 
|-
|LAMFA      ||NMOT        ||MRFA_W    ||KF        ||Lambda driver request                                                       
+
|  
 +
'''Parameter'''
 +
|  
 +
'''Description'''
 
|-
 
|-
|LAMFAS    ||FHO          ||          ||KL        ||Lambda driver request lock                                                 
+
|  
 +
CWLAMFAW
 +
|  
 +
Codeword LAMFAW
 
|-
 
|-
|LAMRLMN    ||            ||          ||FW        ||Lambda precontrol with rl <RLLAMMN to improve the combustibility           
+
|  
 +
DLAMFAW
 +
|  
 +
Threshold
 +
value for activating enrichment via driver’s request
 
|-
 
|-
|RLLAMMN    ||NMOT        ||          ||KL        ||RL-min threshold of enrichment for combustibility                           
+
|  
 +
DLAMOB
 +
|  
 +
Delta lambda during overboost
 
|-
 
|-
|SDZ06GKUB  ||DZWLAMFAW    ||          ||SV        ||Interpolation points KFLAMKRL                                               
+
|  
 +
DLAMTANS
 +
|  
 +
Air temperature-dependent
 +
enrichment
 
|-
 
|-
|SNM06GKUB  ||NMOT        ||          ||SV        ||Interpolation points KFLAMKR, DLAMOB                                       
+
|  
 +
GANGFAW
 +
|  
 +
Gear
 +
threshold for deactivating driver’s request at altitude
 
|-
 
|-
|SRL06GKUB  ||RL          ||          ||SV        ||Interpolation points KFLAMKRL, KFLAFWL, KFLAMKR                             
+
|  
 +
KFLAFWL
 +
|  
 +
Offset engine target lambda
 
|-
 
|-
|STM08GKUB  ||TMOT        ||          ||SV        ||8 engine temperature Interpolation points for KFLAFWL                       
+
|  
 +
KFLAMKR
 +
|  
 +
Weighting
 +
factor for enrichment during ignition angle retardation
 
|-
 
|-
|SY_TURBO  ||            ||          ||SYS (REF) ||Turbocharger system constant                                               
+
|  
 +
KFLAMKRL
 +
|  
 +
Enrichment
 +
during ignition angle retardation
 
|-
 
|-
|TLAFA      ||            ||          ||FW        ||Lambda driver request delay time to active                                 
+
|  
 +
LAMFA
 +
|  
 +
Driver’s requested lambda
 
|-
 
|-
|TLAMFAS    ||            ||          ||FW        ||Delay time to Lambda driver request in the amount of active                 
+
|  
 +
LAMFAS
 +
|  
 +
Disable driver’s requested
 +
lambda
 
|-
 
|-
|TMSTFWMN  ||            ||          ||FW        ||Minimum temperature for engine start disabling driver's request in the amount
+
|  
 +
LAMRLMN
 +
|  
 +
Lambda
 +
control when rl &lt; RLLAMMN to improve the combustion efficiency
 
|-
 
|-
|TMSTFWMX  ||            ||          ||FW        ||maximum temperature for engine start disabling driver request in the amount 
+
|  
 +
RLLAMMN
 +
|  
 +
Minimum
 +
requested load threshold for enrichment due to combustion efficiency
 
|-
 
|-
|TNSTFWMN  ||            ||          ||FW        ||minimum time to start for disabled driver request in the amount             
+
|  
 +
SDZ06GKUB
 +
|  
 +
Sample
 +
point distribution for KFLAMKRL
 
|-
 
|-
|TNSTFWMX  ||            ||          ||FW        ||maximum time to start for disabled driver request in the amount             
+
|  
 +
SNM06GKUB
 +
|  
 +
Sample
 +
point distribution for KFLAMKR, DLAMOB
 
|-
 
|-
|ZKLAMFAW  ||            ||          ||FW        ||Filtering time constant enrichment by driver request                       
+
|  
 +
SRL06GKUB
 +
|  
 +
Sample
 +
point distribution for KFLAMKRL, KFLAFWL, KFLAMKR
 
|-
 
|-
|ZKWLAFWL  ||            ||          ||FW        ||Time constant weighting offset Lambda engine theoretical                   
+
|  
 +
STM08GKUB
 +
|  
 +
8 engine
 +
temperature sample point distribution for KFLAFWL
 
|-
 
|-
|
+
|  
 +
SY TURBO
 +
|
 +
System constant: turbocharger
 
|-
 
|-
! Variable 
+
|
! Source   
+
TLAFA
!
+
|
! Type     
+
Delay time
! Designation
+
with driver’s requested lambda active
 
|-
 
|-
|B_KH      ||            ||          ||EIN  ||Kat-heating condition                                                     
+
|  
 +
TLAMFAS
 +
|  
 +
Delay time
 +
with driver’s requested lambda at altitude active
 
|-
 
|-
|B_LAMFAS  ||LAMFAW        ||        ||LOK  ||Ban on Lambda driver request activation                             
+
|  
 +
TMSTFWMN
 +
|  
 +
Minimum
 +
engine start temperature for deactivating driver’s request at altitude
 
|-
 
|-
|B_LAMFASA  ||LAMFAW        ||        ||LOK  ||Height-dependent blocking time for Lambda driver request requested   
+
|  
 +
TMSTFWMX
 +
|  
 +
Maximum
 +
engine start temperature for deactivating driver’s request at altitude
 
|-
 
|-
|B_LAMFASH  ||LAMFAW        ||        ||LOK  ||Height-dependent blocking time for Lambda driver request is active   
+
|  
 +
TNSTFWMN
 +
|  
 +
Minimum
 +
time after start for deactivating driver’s request at altitude
 
|-
 
|-
|B_LDEFFW  ||LAMFAW        ||        ||AUS  ||Condition: custom-Lambda Bank1 set by driver request                
+
|  
 +
TNSTFWMX
 +
|  
 +
Maximum
 +
time after start for deactivating driver’s request at altitude
 
|-
 
|-
|B_LDOB    ||LDRUE          ||        ||EIN  ||Condition: overboost active                                                 
+
|  
 +
ZKLAMFAW
 +
|  
 +
Time
 +
constant filtering enrichment via driver’s request
 
|-
 
|-
|B_SAB      ||MSF            ||        ||EIN  ||Condition: Power switch standby                                                 
+
|  
 +
ZKWLAFWL
 +
|  
 +
Time
 +
constant weighting offset engine target lambda
 
|-
 
|-
|B_STEND    ||BBSTT          ||        ||EIN  ||Condition: Start condition reached the end                                             
+
|  
 +
'''Variable'''
 +
|  
 +
'''Description'''
 
|-
 
|-
|DZWLAMFAW  ||LAMFAW        ||        ||LOK  ||Delta firing angle at KR-or warm-up procedure for enrichment of Lambda
+
|  
 +
B_KH
 +
|  
 +
Condition flag: catalyst
 +
heating
 
|-
 
|-
|DZWWL      ||ZWWL          ||        ||EIN  ||Delta firing angle of warm-up                                                 
+
|  
 +
B_LAMFAS
 +
|  
 +
Condition
 +
flag: disable driver’s requested lambda
 
|-
 
|-
|FHO        ||GGDSAS        ||        ||EIN  ||Height correction factor                                                     
+
|  
 +
B_LAMFASA
 +
|  
 +
Condition
 +
flag: altitude-dependent disabling time for driver’s requested lambda is
 +
required
 
|-
 
|-
|GANGI      ||BBGANG        ||        ||EIN  ||Actual speed                                                                 
+
|  
 +
B_LAMFASH
 +
|  
 +
Condition
 +
flag: altitude-dependent disabling time for driver’s requested lambda is active
 
|-
 
|-
|LAMFAWKR_W ||LAMFAW        ||        ||LOK  ||Lambda desired driver request ignition retard at KR, WL             
+
|  
 +
B_LDEFFW
 +
|  
 +
Condition
 +
flag: defined target lambda (cylinder bank 1) via driver’s request
 
|-
 
|-
|LAMFAWS_W  ||LAMFAW        ||        ||LOK  ||Lambda desired driver request steady share                           
+
|  
 +
B_LDOB
 +
|  
 +
Condition flag: overboost
 +
active
 
|-
 
|-
|LAMFAW_W  ||LAMFAW        ||        ||LOK  ||Lambda desired driver request portion of map LAMFA                       
+
|  
 +
B_SAB
 +
|  
 +
Condition
 +
flag: overrun fuel cut-off readiness
 
|-
 
|-
|LAMFA_W    ||LAMFAW        ||        ||AUS  ||Lambda target driver request (word)                                       
+
|  
 +
B_STEND
 +
|  
 +
Condition
 +
flag: end of start conditions reached
 
|-
 
|-
|LAMFWL_W  ||LAMFAW        ||        ||LOK  ||Offset Motor lambda target in the warm-up                                
+
|  
 +
DZWLAMFAW
 +
|  
 +
Delta
 +
ignition angle during knock control intervention or warm-up for enrichment
 +
via lambda
 
|-
 
|-
|LAMRLMN_W  ||LAMFAW        ||        ||LOK  ||Lambda desired precontrol to improve the combustibility at low rl       
+
|  
 +
DZWWL
 +
|  
 +
Delta
 +
ignition angle during warm-up
 
|-
 
|-
|MIFA_W    ||MDFAW          ||        ||EIN  ||indicated engine torque driver request                                       
+
|  
 +
FHO
 +
|  
 +
Altitude correction factor
 
|-
 
|-
|MILSOL_W  ||MDKOL          ||        ||EIN  ||Driver torque request for filling                                     
+
|  
 +
GANGI
 +
|  
 +
Actual gear
 
|-
 
|-
|MRFA_W    ||MDFAW          ||        ||EIN  ||Relatives driver request moment of FGR (cruise control?) and pedal                             
+
|  
 +
LAMFAWKR_W
 +
|  
 +
during ignition angle retardation
 +
(knock control), WL
 
|-
 
|-
|NMOT      ||BGNMOT        ||        ||EIN  ||Motor speed                                                                       
+
|  
 +
LAMFAWS W
 +
|  
 +
Driver’s
 +
requested target lambda steady-state part
 
|-
 
|-
|RL        ||BGSRM          ||        ||EIN  ||relative air charge                                                               
+
|  
 +
LAMFAW_W
 +
|  
 +
Driver’s
 +
requested target lambda part from map LAMFA
 
|-
 
|-
|TANS      ||GGTFA          ||        ||EIN  ||Intake air - temperature                                                           
+
|  
 +
LAMFA_W
 +
|  
 +
Driver’s
 +
requested target lambda (word)
 
|-
 
|-
|TMOT      ||GGTFM          ||        ||EIN  ||Motor temperature                                                                 
+
|  
 +
LAMFWL_W
 +
|  
 +
Offset
 +
engine target lambda during warm-up
 
|-
 
|-
|TMST      ||GGTFM          ||        ||EIN  ||Engine starting temperature                                                       
+
|  
 +
LAMRLMN_W
 +
|  
 +
Target
 +
lambda control to improve the combustion efficiency at lower relative loads
 
|-
 
|-
|TNST_W    ||BBSTT          ||        ||EIN  ||Time after start-end                                                             
+
|  
 +
MIFA_W
 +
|  
 +
Indexed driver’s
 +
requested engine torque
 
|-
 
|-
|WKRMA      ||KRRA          ||        ||EIN  ||Average of the ZW-retardation KR, in general (in emergency mode with certainty) 
+
|  
|}
+
MILSOL_W
 
+
|  
=LAMFAW Functional Description=
+
Driver’s
 
+
requested torque for cylinder charge path
The function LAMFAW lamfa_w implemented by way of an "enrichment" of the mixture when the driver calls for maximum torque by way of mrfa_w. This corresponds to the full-load enrichment since then. Can over the delay time of the engagement by way of TLAFA lamfa_w on the Mixture may be delayed. While the turbocharger boost over an additives has additionally "enrichment" is a Delta-Lambda from the characteristic DLAMOB. For the time TLAMFAS can as a function of height (LAMFAS) an enrichment by way of driver's request to be prevented (see sub-function LAMFADISABLE. The trigger this time will be lost if B_kh = true, LAMFA <1.0 and as defined in LAMFAS High barrier applies. This may also at greater height of a reproducible driving cycle can be maintained. When torque reduction e.g. ASR intervention, nmax .. can about CWMFAW Bit1 = true, the enrichment by way of the map LAMFAW locked be. In the partial function LAMKR intervened in an enrichment ignition angle can be realized. The partial function can be used for enrichment LAMWL whereas the warm-up can be used. If this procedure is used, the Tanks with air cooling over the function LAMKO not switched off. In the partial function is LAMRLMIN with small loads (rl) an enrichment by way of LAMRLMN active. This serves to improve the Flammability of small loads. If CWLAMFAW Bit2 set, then whereas lamrlmn-intervention of the limp mode canister ventilation closed.
+
|-
 
+
|
=LAMFAW Application Notes=
+
MRFA_W
 
+
|
The delay time is only TLAFA> 0 to apply when the intervention should be delayed mixture of lamfa_w.
+
Relative driver’s
 
+
requested torque from cruise control and throttle pedal
LAMFA map:
+
|-
 
+
|
Interpolation points for nmot: 1000, 1400, 1800, 2200, 2600, 3000, 3400, 3800, 4200, 4600, 5000, 5400, 5800, 6200, 6600, 7000 1/min
+
NMOT
Interpolation points for mrfa_w 70, 80, 90, 100, 110, 120%
+
|
Map values 1.0
+
Engine speed
 
+
|-
DLAMOB contains the delta-lambda, to which shall be implemented in overboost mode an extra mixture enrichment. Interpolation points nmot for: implements as a group characteristic SNM06GKUB
+
|
 
+
RL
Neutralization of the function by data:
+
|
<pre>LAMFA DLAMOB = 1.0 and = 0.0 ---> lamfa_w is then 1.0</pre>
+
Relative cylinder charge
 
+
|-
The time TLAMFAS is to be applied so that when the "big climbs" the driver's enrichment is not active (typically 240s)
+
|
 
+
TANS
The characteristic LAMFAS contains values ??from 0 .. 1. A value of 0 no enrichment is effectively banned on the air. Values other than 0 bring about a ban on the enrichment of LAMFA, when are B_kh = true and values ??in LAMFA <1.0 The characteristic LAMFAS is not interpolated, which means that the characteristic initial value remains constant until a reference point exceeded.
+
|
 
+
Ambient air temperature
For fho-support points of the curve LAMFAS following relationship: fho = 1 - height [m] / 10000m
+
|-
Since the size of fho has a quantization of 4 / 256 = 0.015625, in the definition of switch-off this resolution be considered. Similarly, the basis of the sensor tolerance possible height deviation of + - 250 m
+
|
 
+
TMOT
To calculate the lower and upper threshold of fho is valid for a nominal cut-off levels following relationship:
+
|
 
+
Engine temperature
lower threshold high shutdown:
+
|-
<pre>fho [phys] = 1 - ((nominal height [m] -250) / 10000) -> fho [Ink] = Integer (fho [phys] / 0.015625) + 1Ink
+
|
                                            -> fho ceiling [phys] = (1 - fho [Ink] * 0.015625)
+
TMST
                                            -> height limit = (1 - fho ceiling [phys]) * 10000</pre>
+
|
+
Engine start temperature
upper threshold high shutdown:
+
|-
<pre>fho [phys] = 1 - ((nominal height [m]+ 250) / 10000) -> fho [Ink] = Integer (fho [phys] / 0.015625)
+
|
                                            -> fho lower limit [phys] = fho [Ink] * 0.015625
+
TNST_W
                                            -> height limit = (1 - fho lower limit [phys]) * 10000</pre>
+
|
 
+
Time after
This produces the following values
+
end of start conditions
<pre>Nominal height                    2200m  1600
+
|-
 
+
|
Ceiling height of                  2500m  1875m
+
WKRMA
                                                    !!!!! Ceiling height is fho lower limit
+
|
fho lower limit                    0.75    0.8125
+
Average
 
+
value of the individual cylinder ignition angle retardation (knock control),
Height limit                      1875m  1250m
+
general (in emergency mode with safety margin)
 
+
|}                                                                                                 
fho limit                          0.8125  0.875
+
 
+
Thus, the following parameterization of the curve LAMFAS for the nominal amount of 2200:
+
 
+
                          fho        0.734375      0.75    0.8125
+
                          Values ??0                    1.0      0
+
Enrichment active <-------+                        +------> enrichment active
+
                                      <--+--->
+
                                                            + - enrichment inactive
+
Shutdown of the height dependent suppression of enrichment: LAMFAS = 0, = 0 TLAMFAS</pre>
+
 
+
 
+
Lambda values for engagement in lamfawkr_w ignition retard:
+
<pre>
+
ZKLAMFAW: 2 s
+
ZKWLAFWL: 2 s
+
DLAMFAW: 0.01
+
 
+
KFLAMKR:  Interpolation points nmot:    Group characteristics SNM06GKUB
+
          Interpolation points rl:      Group characteristics SRL06GKUB
+
          Map items                      complete 1.0 ---> no weighting active
+
 
+
KFLAMKRL: Interpolation points dzlamfaw: Group characteristics SDZ06GKUB
+
          Interpolation points rl:      group characteristic SRL06GKUB
+
          Map items                      complete 1.0 -> Lambda intervention is not active
+
 
+
DLAMTANS: Interpolation points tans:    50.25 60,  70.5,  80.25 C
+
          Map values ??completely 0 -> Lambda intervention is not active
+
 
+
KFLAFWL:  Interpolation points nmot:    Group characteristics SNM06GKUB
+
          Interpolation points  rl:      Group characteristics SRL06GKUB
+
          Map values??:                    completely 0 -> Lambda intervention is not active
+
                                          ! In the map delta values are entered, -0.1 -> lamfwl_w = 0.9
+
 
+
DLAMOB:  Interpolation points nmot:      Group characteristics SNM06GKUB
+
          Map values??;                    complete 0 -> no ADDITIONAL enrichment in turbo overboost
+
                                          ! In the map-delta values are entered +0.1 ---> lamfa = lamfaw - 0.1
+
 
+
RLLAMMN: Interpolation points nmot:      Group characteristics SNM06GKUB
+
          Characteristic values:          0% -> not about enriching LAMRLMN active
+
 
+
LAMRLMN: Interpolation points nmot:      Group characteristics SNM06GKUB
+
          Characteristic values??:          1.0 -> lambda = 1.0 (no enrichment)
+
 
+
CWLAMFAW Bit0: 0: dzwlamfaw = min (0, dzwwl)
+
                1: dzwlamfaw = min (0, (+ dzwwl wkrma)) default = 0
+
 
+
CWLAMFAW Bit1: 0: LAMFAW example, even with torque reduction on ASR, nmax .. active
+
                1: no enrichment of LAMFAW at torque reduction (milsol <MIFA)
+
 
+
CWLAMFAW Bit2: 0: B_ldeffw is always false -> tank ventilation emergency active when lamrlmn_w engagement
+
                1: B_ldeffw lamrlmn_w dependent activation if B_ldeffw = true,
+
                  Tank vent blocked emergency, i.e. TEV includes
+
 
+
CWLAMFAW Bit3: 0: ban Lambda-FW-activation possible by catalytic converter heating
+
                1: ban Lambda-FW-activation by catalytic converter heating is not possible
+
 
+
CWLAMFAW bit4: 0: lamfwl_w dependent on B_stend and VZ1-element
+
                1: lamfwl_w independent of B_stend and VZ1-element
+
+
Group characteristic for nmot Interpolation points:      SNM06GKUB 760, 1520, 2560, 3520, 4560, 5520 1/min
+
Group characteristic for rl Interpolation points:        SRL06GKUB  20,  40,  60,  80,  90%
+
Group characteristic for tmot Interpolation points:      STM08GKUB -15,    0,  20, 40.5,  60,        75, 85.5, 105 C
+
Group characteristic for dzwlamfaw Interpolation points: SDZ06GKUB -30,  -20,  -15,  -10,  -5,  0 degree</pre>
+
 
+
''Special thanks to [http://www.nefariousmotorsports.com/forum/index.php/topic,555.0title,.html phila_dot] for translating this section.''
+
  
[[Category:Motronic]]
+
[[Category:ME7]]

Latest revision as of 07:14, 4 December 2011

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:

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:


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

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)

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