View source for LAMKO 9.80 (Lambda Coordination)

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:

  
<u>Function Description</u>
 
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 &amp; LAMLGMKT do not go in the direction of zero because it directly affects the injection!

 
<u>Application Notes</u>
 
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

 
<u>Abbreviations</u>
                                                                                                                                                                                                                                                                                                                                                                                   
{| 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)
|-
| 
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
|}