View source for MDFUE 8.50 (Setpoint for Air Mass from Load Torque)

<u>MDFUE 8.50 Function Description</u>
  
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

  
<u>Application Notes</u>

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