ZWGRU 23.110 (Fundamental Ignition Angle)
From Nefmoto
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
|
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 |
