fuelAndIgnitionCalcs.c

Go to the documentation of this file.

/* FreeEMS - the open source engine management system
 *
 * Copyright 2008-2013 Fred Cooke
 *
 * This file is part of the FreeEMS project.
 *
 * FreeEMS software is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * FreeEMS software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with any FreeEMS software.  If not, see http://www.gnu.org/licenses/
 *
 * We ask that if you make any changes to this file you email them upstream to
 * us at admin(at)diyefi(dot)org or, even better, fork the code on github.com!
 *
 * Thank you for choosing FreeEMS to run your engine!
 */


/** @file
 *
 * @ingroup measurementsAndCalculations
 *
 * @brief Fuel and ignition calculations.
 *
 * This file contains all of the main fuel and ignition calculations based
 * upon the variables that we have already determined in previous stages.
 */


#define FUELANDIGNITIONCALCS_C
#include "inc/freeEMS.h"
#include "inc/utils.h"
#include "inc/locationIDs.h"
#include "inc/tableLookup.h"
#include "inc/fuelAndIgnitionCalcs.h"


/**
 * Final fuel and ignition calculations. Using a variety of primary algorithms
 * calculate a base pulsewidth and then apply various corrections to it such as
 * injector dead time, transient fuel correction, engine temperature enrichment
 * and per cylinder trims. The ignition timing and fuel injection timing are
 * also determined here, as are the various limiters and cuts.
 */
void calculateFuelAndIgnition(){
    unsigned short airInletTemp = CoreVars->IAT; /* All except MAF use this. */
    /* Determine the type of air flow data */
    if(!(fixedConfigs2.algorithmSettings.algorithmType)){
        /* Look up VE with RPM and MAP */
        DerivedVars->VEMain = lookupMainTable(CoreVars->RPM, CoreVars->MAP, VETableMainLocationID);
        /* This won't overflow until 512kPa or about 60psi of boost with 128% VE. */
        DerivedVars->AirFlow = ((unsigned long)CoreVars->MAP * DerivedVars->VEMain) / VE(100);
        /* Result is 450 - 65535 always. */
    }else if(fixedConfigs2.algorithmSettings.algorithmType == ALGO_ALPHA_N){
        /* Look up Airflow with RPM and TPS */
        DerivedVars->AirFlow = lookupMainTable(CoreVars->RPM, CoreVars->TPS, AirflowTableLocationID); /* Tuned air flow without density information */
    }else if(fixedConfigs2.algorithmSettings.algorithmType == ALGO_MAF){
        DerivedVars->AirFlow = CoreVars->MAF; /* Just fix temperature at appropriate level to provide correct Lambda */
        /// @todo TODO figure out what the correct "temperature" is to make MAF work correctly!
        airInletTemp = DEGREES_C(20); // Room temperature?
    }else if(fixedConfigs2.algorithmSettings.algorithmType == ALGO_SD_AN_BLEND){
        /* Look up VE with RPM and MAP */
        DerivedVars->VEMain = lookupMainTable(CoreVars->RPM, CoreVars->MAP, VETableMainLocationID);
        /* This won't overflow until 512kPa or about 60psi of boost with 128% VE. */
        KeyUserDebugs.speedDensityAirFlow = ((unsigned long)CoreVars->MAP * DerivedVars->VEMain) / VE(100);

        /* Look up Airflow with RPM and TPS */
        KeyUserDebugs.alphaNAirFlow = lookupMainTable(CoreVars->RPM, CoreVars->TPS, AirflowTableLocationID); /* Tuned air flow without density information */

        KeyUserDebugs.blendAlphaNPercent = lookupTwoDTableUS((twoDTableUS*)&TablesA.SmallTablesA.blendVersusRPMTable, CoreVars->RPM);

        unsigned short airflowSD = safeScale(KeyUserDebugs.speedDensityAirFlow, SHORTMAX - KeyUserDebugs.blendAlphaNPercent, SHORTMAX);
        unsigned short airflowAN = safeScale(KeyUserDebugs.alphaNAirFlow, KeyUserDebugs.blendAlphaNPercent, SHORTMAX);

        DerivedVars->AirFlow = safeAdd(airflowSD, airflowAN);
    }else{ /* Default to no fuel delivery and error */
        DerivedVars->AirFlow = 0;
    }


    /* This won't overflow until well past 125C inlet, 1.5 Lambda and fuel as dense as water */
    DerivedVars->densityAndFuel = (((unsigned long)((unsigned long)airInletTemp * DerivedVars->Lambda) / LAMBDA(1.0)) * fixedConfigs1.engineSettings.densityOfFuelAtSTP) / FUEL_DENSITY(FUEL_DENSITY_UNIT_FACTOR);
    /* Result is 7500 - 60000 always. TODO clean up the last item on the above line */

    /* Divisors for air inlet temp and pressure :
     * #define airInletTempDivisor 100
     * #define airPressureDivisor 100
     * cancel each other out! all others are used. */

    DerivedVars->BasePW = (bootFuelConst * DerivedVars->AirFlow) / DerivedVars->densityAndFuel;

    /*&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*/




    /*&&&&&&&&&&&&&&&&&&&&&&&&&&&& Apply All Corrections PCFC, ETE, IDT, TFC etc &&&&&&&&&&&&&&&&&&&&&&&&&&&*/

    /* Apply the corrections after calculating */
    DerivedVars->EffectivePW = safeTrim(DerivedVars->BasePW, DerivedVars->TFCTotal);
    DerivedVars->EffectivePW = safeScale(DerivedVars->EffectivePW, DerivedVars->ETE, SHORT4TH);


//  unsigned char channel; // the declaration of this variable is used in multiple loops below.
//
//  /* "Calculate" the individual fuel pulse widths */
//  for(channel = 0; channel < INJECTION_CHANNELS; channel++){ /// @todo TODO make injector channels come from config, not defines.
//      /* Add or subtract the per cylinder fuel trims */
//      unsigned short channelPW;
//      channelPW = safeScale(DerivedVars->EffectivePW, TablesB.SmallTablesB.perCylinderFuelTrims[channel]);
//
//      /* Add on the IDT to get the final value and put it into the array */
//      //outputEventPulseWidthsMath[channel] = safeAdd(channelPW, DerivedVars->IDT); do not re-enable this without fixing it properly...
//  }

    // Make sure we don't have a PW if PW is supposed to be zero, ie, zero the IDT as well.
    if(!(DerivedVars->EffectivePW)){
        DerivedVars->IDT = 0; // This also makes fuel and electrical duty work consistently in external apps.
    }

    /* Reference PW for comparisons etc */
    DerivedVars->RefPW = safeAdd(DerivedVars->EffectivePW, DerivedVars->IDT);
    /*&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*/

/// @todo accumulate errors such that we know what sort of PW WOULD have been requested and enable a "over duty cut" to protect boosted users with insufficient injector size on cold nights

/// TODO @todo FIXME part of to schedule or not to schedule should be : (masterPulseWidth > injectorMinimumPulseWidth)
// IE, NOT in the decoders... KISS in the decoders. This is a hangover from (very) early decoder dev

//  for(channel = 0;channel < INJECTION_CHANNELS;channel++){ /// @todo TODO make injector channels come from config, not defines.
        //injectorMainAdvances[channel] = IDT blah blah.
//  }

    /* "Calculate" the nominal total pulse width before per channel corrections */
    masterPulseWidth = safeAdd((DerivedVars->EffectivePW / fixedConfigs1.schedulingSettings.numberOfInjectionsPerEngineCycle), DerivedVars->IDT); // div by number of injections per cycle, configured above
    // but requires to know how big a cycle is, 1/4 1, 1/2, etc

    // Note, conversions to address and then pointer are necessary to avoid error on direct cast
    // Cuts and limiters TODO move these to their own special place?
    // TODO Make source of threshold either struct or temp based curve for these

    if(fixedConfigs1.cutAndLimiterSettings.cutsEnabled.IgnitionRPM){
        unsigned short confirmedReenableThreshold = fixedConfigs1.cutAndLimiterSettings.IgnitionRPM.reenableThreshold;
        if(confirmedReenableThreshold >= fixedConfigs1.cutAndLimiterSettings.IgnitionRPM.disableThreshold){
            confirmedReenableThreshold = fixedConfigs1.cutAndLimiterSettings.IgnitionRPM.disableThreshold / 2;
        }
        if(CoreVars->RPM > fixedConfigs1.cutAndLimiterSettings.IgnitionRPM.disableThreshold){
            ((ignitionCutFlags *)&KeyUserDebugs.ignitionCuts)->IgnitionRPM = 1;
        }else if(CoreVars->RPM < confirmedReenableThreshold){
            ((ignitionCutFlags *)&KeyUserDebugs.ignitionCuts)->IgnitionRPM = 0;
        }
    }

    if(fixedConfigs1.cutAndLimiterSettings.cutsEnabled.InjectionRPM){
        unsigned short confirmedReenableThreshold = fixedConfigs1.cutAndLimiterSettings.InjectionRPM.reenableThreshold;
        if(confirmedReenableThreshold >= fixedConfigs1.cutAndLimiterSettings.InjectionRPM.disableThreshold){
            confirmedReenableThreshold = fixedConfigs1.cutAndLimiterSettings.InjectionRPM.disableThreshold / 2;
        }
        if(CoreVars->RPM > fixedConfigs1.cutAndLimiterSettings.InjectionRPM.disableThreshold){
            ((injectionCutFlags *)&KeyUserDebugs.injectionCuts)->InjectionRPM = 1;
        }else if(CoreVars->RPM < confirmedReenableThreshold){
            ((injectionCutFlags *)&KeyUserDebugs.injectionCuts)->InjectionRPM = 0;
        }
    }

    // TODO add time based lock out as well as threshold based as threshold could re-enable too quickly
    if(fixedConfigs1.cutAndLimiterSettings.cutsEnabled.InjOverBoost || fixedConfigs1.cutAndLimiterSettings.cutsEnabled.IgnOverBoost){
        unsigned short confirmedReenableThreshold = fixedConfigs1.cutAndLimiterSettings.OverBoost.reenableThreshold;
        if(confirmedReenableThreshold >= fixedConfigs1.cutAndLimiterSettings.OverBoost.disableThreshold){
            confirmedReenableThreshold = fixedConfigs1.cutAndLimiterSettings.OverBoost.disableThreshold / 2;
        }
        if(CoreVars->MAP > fixedConfigs1.cutAndLimiterSettings.OverBoost.disableThreshold){
            ((injectionCutFlags *)&KeyUserDebugs.injectionCuts)->InjOverBoost = fixedConfigs1.cutAndLimiterSettings.cutsEnabled.InjOverBoost;
            ((ignitionCutFlags *)&KeyUserDebugs.ignitionCuts)->IgnOverBoost = fixedConfigs1.cutAndLimiterSettings.cutsEnabled.IgnOverBoost;
        }else if(CoreVars->MAP < confirmedReenableThreshold){
            ((injectionCutFlags *)&KeyUserDebugs.injectionCuts)->InjOverBoost = 0;
            ((ignitionCutFlags *)&KeyUserDebugs.ignitionCuts)->IgnOverBoost = 0;
        }
    }
}