fuel_math.cpp

Go to the documentation of this file.

/**
 * @file    fuel_math.cpp
 * @brief   Fuel amount calculation logic
 *
 *
 * @date May 27, 2013
 * @author Andrey Belomutskiy, (c) 2012-2020
 *
 * This file is part of rusEfi - see http://rusefi.com
 *
 * rusEfi 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.
 *
 * rusEfi 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 this program.
 * If not, see <http://www.gnu.org/licenses/>.
 *
 */
 
#include "pch.h"
 
#include "airmass.h"
#include "alphan_airmass.h"
#include "maf_airmass.h"
#include "speed_density_airmass.h"
#include "fuel_math.h"
#include "fuel_computer.h"
#include "injector_model.h"
#include "speed_density.h"
#include "speed_density_base.h"
#include "lua_hooks.h"
 
extern fuel_Map3D_t veMap;
static mapEstimate_Map3D_t mapEstimationTable{"mape"};
 
#if EFI_ENGINE_CONTROL
 
float getCrankingFuel3(float baseFuel, uint32_t revolutionCounterSinceStart) {
 
    float baseCrankingFuel;
    if (engineConfiguration->useRunningMathForCranking) {
        baseCrankingFuel = baseFuel;
    } else {
        // parameter is in milligrams, convert to grams
        baseCrankingFuel = engineConfiguration->cranking.baseFuel * 0.001f;
    }
 
    // Cranking fuel changes over time
    engine->engineState.crankingFuel.durationCoefficient = interpolate3d(
            config->crankingCycleFuelCoef,
            config->crankingCycleFuelCltBins, Sensor::getOrZero(SensorType::Clt),
            config->crankingCycleBins, revolutionCounterSinceStart
        );
 
    /**
     * Cranking fuel is different depending on engine coolant temperature
     * If the sensor is failed, use 20 deg C
     */
    auto clt = Sensor::get(SensorType::Clt).value_or(20);
    auto e0Mult = interpolate2d(clt, config->crankingFuelBins, config->crankingFuelCoef);
 
    bool alreadyWarned = false;
    if (e0Mult <= 0.1f) {
        warning(ObdCode::CUSTOM_ERR_ZERO_E0_MULT, "zero e0 multiplier");
        alreadyWarned = true;
    }
 
    if (engineConfiguration->flexCranking && Sensor::hasSensor(SensorType::FuelEthanolPercent)) {
        auto e85Mult = interpolate2d(clt, config->crankingFuelBins, config->crankingFuelCoefE100);
 
        if (e85Mult <= 0.1f) {
            warning(ObdCode::CUSTOM_ERR_ZERO_E85_MULT, "zero e85 multiplier");
            alreadyWarned = true;
        }
 
        // If failed flex sensor, default to 50% E
        auto flex = Sensor::get(SensorType::FuelEthanolPercent).value_or(50);
 
        engine->engineState.crankingFuel.coolantTemperatureCoefficient =
            interpolateClamped(
                0, e0Mult,
                85, e85Mult,
                flex
            );
    } else {
        engine->engineState.crankingFuel.coolantTemperatureCoefficient = e0Mult;
    }
 
    auto tps = Sensor::get(SensorType::DriverThrottleIntent);
    engine->engineState.crankingFuel.tpsCoefficient =
        tps.Valid
        ? interpolate2d(tps.Value, config->crankingTpsBins, config->crankingTpsCoef)
        : 1; // in case of failed TPS, don't correct.
 
    floatms_t crankingFuel = baseCrankingFuel
            * engine->engineState.crankingFuel.durationCoefficient
            * engine->engineState.crankingFuel.coolantTemperatureCoefficient
            * engine->engineState.crankingFuel.tpsCoefficient;
 
    engine->engineState.crankingFuel.fuel = crankingFuel * 1000;
 
    // don't re-warn for zero fuel when we already warned for a more specific problem
    if (!alreadyWarned && crankingFuel <= 0) {
        warning(ObdCode::CUSTOM_ERR_ZERO_CRANKING_FUEL, "Cranking fuel value %f", crankingFuel);
    }
    return crankingFuel;
}
 
float getRunningFuel(float baseFuel) {
    ScopePerf perf(PE::GetRunningFuel);
 
    float iatCorrection = engine->fuelComputer.running.intakeTemperatureCoefficient;
    float cltCorrection = engine->fuelComputer.running.coolantTemperatureCoefficient;
    float postCrankingFuelCorrection = engine->fuelComputer.running.postCrankingFuelCorrection;
    float baroCorrection = engine->engineState.baroCorrection;
 
    efiAssert(ObdCode::CUSTOM_ERR_ASSERT, !std::isnan(iatCorrection), "NaN iatCorrection", 0);
    efiAssert(ObdCode::CUSTOM_ERR_ASSERT, !std::isnan(cltCorrection), "NaN cltCorrection", 0);
    efiAssert(ObdCode::CUSTOM_ERR_ASSERT, !std::isnan(postCrankingFuelCorrection), "NaN postCrankingFuelCorrection", 0);
 
    float correction = baroCorrection * iatCorrection * cltCorrection * postCrankingFuelCorrection;
 
#if EFI_ANTILAG_SYSTEM
    correction *= (1 + engine->antilagController.fuelALSCorrection / 100);
#endif /* EFI_ANTILAG_SYSTEM */
 
#if EFI_LAUNCH_CONTROL
    correction *= engine->launchController.getFuelCoefficient();
#endif
 
    correction *= getLimpManager()->getLimitingFuelCorrection();
 
    float runningFuel = baseFuel * correction;
 
    efiAssert(ObdCode::CUSTOM_ERR_ASSERT, !std::isnan(runningFuel), "NaN runningFuel", 0);
 
    // Publish output state
    engine->fuelComputer.running.baseFuel = baseFuel * 1000;
    engine->fuelComputer.totalFuelCorrection = correction;
    engine->fuelComputer.running.fuel = runningFuel * 1000;
 
    return runningFuel;
}
 
static SpeedDensityAirmass sdAirmass(veMap, mapEstimationTable);
static MafAirmass mafAirmass(veMap);
static AlphaNAirmass alphaNAirmass(veMap);
 
AirmassModelBase* getAirmassModel(engine_load_mode_e mode) {
    switch (mode) {
        case LM_SPEED_DENSITY: return &sdAirmass;
        case LM_REAL_MAF: return &mafAirmass;
        case LM_ALPHA_N: return &alphaNAirmass;
#if EFI_LUA
        case LM_LUA: return &(getLuaAirmassModel());
#endif
#if EFI_UNIT_TEST
        case LM_MOCK: return engine->mockAirmassModel;
#endif
        default:
            firmwareError(ObdCode::CUSTOM_ERR_ASSERT, "Invalid airmass mode %d", engineConfiguration->fuelAlgorithm);
            return nullptr;
    }
}
 
float getMaxAirflowAtMap(float map) {
    return sdAirmass.getAirflow(Sensor::getOrZero(SensorType::Rpm), map, false);
}
 
#if EFI_ENGINE_CONTROL
 
// Per-cylinder base fuel mass
static float getBaseFuelMass(int rpm) {
    ScopePerf perf(PE::GetBaseFuel);
 
    // airmass modes - get airmass first, then convert to fuel
    auto model = getAirmassModel(engineConfiguration->fuelAlgorithm);
    efiAssert(ObdCode::CUSTOM_ERR_ASSERT, model != nullptr, "Invalid airmass mode", 0.0f);
 
    auto airmass = model->getAirmass(rpm, true);
 
    // Plop some state for others to read
    float normalizedCylinderFilling = 100 * airmass.CylinderAirmass / getStandardAirCharge();
    engine->fuelComputer.sdAirMassInOneCylinder = airmass.CylinderAirmass;
    engine->fuelComputer.normalizedCylinderFilling = normalizedCylinderFilling;
    engine->engineState.fuelingLoad = airmass.EngineLoadPercent;
    engine->engineState.ignitionLoad = engine->fuelComputer.getLoadOverride(airmass.EngineLoadPercent, engineConfiguration->ignOverrideMode);
 
    auto gramPerCycle = airmass.CylinderAirmass * engineConfiguration->cylindersCount;
    auto gramPerMs = rpm == 0 ? 0 : gramPerCycle / getEngineCycleDuration(rpm);
 
    // convert g/s -> kg/h
    engine->engineState.airflowEstimate = gramPerMs * 3600000 /* milliseconds per hour */ / 1000 /* grams per kg */;
 
    float baseFuelMass = engine->fuelComputer.getCycleFuel(airmass.CylinderAirmass, rpm, airmass.EngineLoadPercent);
 
    engine->engineState.baseFuel = baseFuelMass;
 
    if (std::isnan(baseFuelMass)) {
        // todo: we should not have this here but https://github.com/rusefi/rusefi/issues/1690
        return 0;
    }
 
    return baseFuelMass;
}
 
angle_t getInjectionOffset(float rpm, float load) {
    if (std::isnan(rpm)) {
        return 0; // error already reported
    }
 
    if (std::isnan(load)) {
        return 0; // error already reported
    }
 
    angle_t value = interpolate3d(
        config->injectionPhase,
        config->injPhaseLoadBins, load,
        config->injPhaseRpmBins, rpm
    );
 
    if (std::isnan(value)) {
        // we could be here while resetting configuration for example
        // huh? what? when do we have RPM while resetting configuration? is that CI edge case? shall we fix CI?
        warning(ObdCode::CUSTOM_ERR_6569, "phase map not ready");
        return 0;
    }
 
    angle_t result = value;
    wrapAngle(result, "inj offset#2", ObdCode::CUSTOM_ERR_6553);
    return result;
}
 
/**
 * Number of injections using each injector per engine cycle
 * @see getNumberOfSparks
 */
int getNumberOfInjections(injection_mode_e mode) {
    switch (mode) {
    case IM_SIMULTANEOUS:
    case IM_SINGLE_POINT:
        return engineConfiguration->cylindersCount;
    case IM_BATCH:
        return 2;
    case IM_SEQUENTIAL:
        return 1;
    default:
        firmwareError(ObdCode::CUSTOM_ERR_INVALID_INJECTION_MODE, "Unexpected injection_mode_e %d", mode);
        return 1;
    }
}
 
float getInjectionModeDurationMultiplier() {
    injection_mode_e mode = getCurrentInjectionMode();
 
    switch (mode) {
    case IM_SIMULTANEOUS: {
        auto cylCount = engineConfiguration->cylindersCount;
 
        if (cylCount == 0) {
            // we can end up here during configuration reset
            return 0;
        }
 
        return 1.0f / cylCount;
    }
    case IM_SEQUENTIAL:
    case IM_SINGLE_POINT:
        return 1;
    case IM_BATCH:
        return 0.5f;
    default:
        firmwareError(ObdCode::CUSTOM_ERR_INVALID_INJECTION_MODE, "Unexpected injection_mode_e %d", mode);
        return 0;
    }
}
 
percent_t getInjectorDutyCycle(int rpm) {
    floatms_t totalInjectiorAmountPerCycle = engine->engineState.injectionDuration * getNumberOfInjections(engineConfiguration->injectionMode);
    floatms_t engineCycleDuration = getEngineCycleDuration(rpm);
    return 100 * totalInjectiorAmountPerCycle / engineCycleDuration;
}
 
percent_t getInjectorDutyCycleStage2(int rpm) {
    floatms_t totalInjectiorAmountPerCycle = engine->engineState.injectionDurationStage2 * getNumberOfInjections(engineConfiguration->injectionMode);
    floatms_t engineCycleDuration = getEngineCycleDuration(rpm);
    return 100 * totalInjectiorAmountPerCycle / engineCycleDuration;
}
 
static float getCycleFuelMass(bool isCranking, float baseFuelMass) {
    if (isCranking) {
        return getCrankingFuel(baseFuelMass);
    } else {
        return getRunningFuel(baseFuelMass);
    }
}
 
/**
 * @returns Mass of each individual fuel injection, in grams
 *     in case of single point injection mode the amount of fuel into all cylinders, otherwise the amount for one cylinder
 */
float getInjectionMass(int rpm) {
    ScopePerf perf(PE::GetInjectionDuration);
 
    // Always update base fuel - some cranking modes use it
    float baseFuelMass = getBaseFuelMass(rpm);
 
    bool isCranking = engine->rpmCalculator.isCranking();
    float cycleFuelMass = getCycleFuelMass(isCranking, baseFuelMass);
    efiAssert(ObdCode::CUSTOM_ERR_ASSERT, !std::isnan(cycleFuelMass), "NaN cycleFuelMass", 0);
 
    if (engine->module<DfcoController>()->cutFuel()) {
        // If decel fuel cut, zero out fuel
        cycleFuelMass = 0;
    }
 
    float durationMultiplier = getInjectionModeDurationMultiplier();
    float injectionFuelMass = cycleFuelMass * durationMultiplier;
 
    // Prepare injector flow rate & deadtime
    engine->module<InjectorModelPrimary>()->prepare();
 
    if (engineConfiguration->enableStagedInjection) {
        engine->module<InjectorModelSecondary>()->prepare();
    }
 
    float tpsAccelEnrich = engine->tpsAccelEnrichment.getTpsEnrichment();
    efiAssert(ObdCode::CUSTOM_ERR_ASSERT, !std::isnan(tpsAccelEnrich), "NaN tpsAccelEnrich", 0);
    engine->engineState.tpsAccelEnrich = tpsAccelEnrich;
 
    float tpsAccelPerInjection = durationMultiplier * tpsAccelEnrich;
 
  if (engineConfiguration->tpsTpsPercentMode) {
    return injectionFuelMass * (1 + tpsAccelPerInjection);
  } else {
      // For legacy reasons, the TPS accel table is in units of milliseconds, so we have to convert BACK to mass
      float tpsFuelMass = engine->module<InjectorModelPrimary>()->getFuelMassForDuration(tpsAccelPerInjection);
      return injectionFuelMass + tpsFuelMass;
    }
}
#endif
 
/**
 * @brief   Initialize fuel map data structure
 * @note this method has nothing to do with fuel map VALUES - it's job
 * is to prepare the fuel map data structure for 3d interpolation
 */
void initFuelMap() {
    mapEstimationTable.initTable(config->mapEstimateTable, config->mapEstimateRpmBins, config->mapEstimateTpsBins);
}
 
/**
 * @brief Engine warm-up fuel correction.
 */
float getCltFuelCorrection() {
    const auto clt = Sensor::get(SensorType::Clt);
 
    if (!clt)
        return 1; // this error should be already reported somewhere else, let's just handle it
 
    return interpolate2d(clt.Value, config->cltFuelCorrBins, config->cltFuelCorr);
}
 
angle_t getCltTimingCorrection() {
    const auto clt = Sensor::get(SensorType::Clt);
 
    if (!clt)
        return 0; // this error should be already reported somewhere else, let's just handle it
 
    return interpolate2d(clt.Value, config->cltTimingBins, config->cltTimingExtra);
}
 
float getIatFuelCorrection() {
    const auto iat = Sensor::get(SensorType::Iat);
 
    if (!iat)
        return 1; // this error should be already reported somewhere else, let's just handle it
 
    return interpolate2d(iat.Value, config->iatFuelCorrBins, config->iatFuelCorr);
}
 
float getBaroCorrection() {
    if (Sensor::hasSensor(SensorType::BarometricPressure)) {
        // Default to 1atm if failed
        float pressure = Sensor::get(SensorType::BarometricPressure).value_or(101.325f);
 
        float correction = interpolate3d(
            config->baroCorrTable,
            config->baroCorrPressureBins, pressure,
            config->baroCorrRpmBins, Sensor::getOrZero(SensorType::Rpm)
        );
 
        if (std::isnan(correction) || correction < 0.01) {
            warning(ObdCode::OBD_Barometric_Press_Circ_Range_Perf, "Invalid baro correction %f", correction);
            return 1;
        }
 
        return correction;
    } else {
        return 1;
    }
}
 
percent_t getFuelALSCorrection(int rpm) {
#if EFI_ANTILAG_SYSTEM
        if (engine->antilagController.isAntilagCondition) {
            float throttleIntent = Sensor::getOrZero(SensorType::DriverThrottleIntent);
            auto AlsFuelAdd = interpolate3d(
            config->ALSFuelAdjustment,
            config->alsFuelAdjustmentLoadBins, throttleIntent,
            config->alsFuelAdjustmentrpmBins, rpm
        );
        return AlsFuelAdd;
    } else
#endif /* EFI_ANTILAG_SYSTEM */
    {
        return 0;
    }
}
 
#if EFI_ENGINE_CONTROL
/**
 * @return Duration of fuel injection while craning
 */
float getCrankingFuel(float baseFuel) {
    return getCrankingFuel3(baseFuel, engine->rpmCalculator.getRevolutionCounterSinceStart());
}
 
/**
 * Standard cylinder air charge - 100% VE at standard temperature, grams per cylinder
 *
 * Should we bother caching 'getStandardAirCharge' result or can we afford to run the math every time we calculate fuel?
 */
float getStandardAirCharge() {
    float totalDisplacement = engineConfiguration->displacement;
    float cylDisplacement = totalDisplacement / engineConfiguration->cylindersCount;
 
    // Calculation of 100% VE air mass in g/cyl - 1 cylinder filling at 1.204/L
    // 101.325kpa, 20C
    return idealGasLaw(cylDisplacement, 101.325f, 273.15f + 20.0f);
}
 
float getCylinderFuelTrim(size_t cylinderNumber, int rpm, float fuelLoad) {
    auto trimPercent = interpolate3d(
        config->fuelTrims[cylinderNumber].table,
        config->fuelTrimLoadBins, fuelLoad,
        config->fuelTrimRpmBins, rpm
    );
 
    // Convert from percent +- to multiplier
    // 5% -> 1.05
    // possible optimization: remove division by moving this scaling to TS level
    return (100 + trimPercent) / 100;
}
 
static Hysteresis stage2Hysteresis;
 
float getStage2InjectionFraction(int rpm, float load) {
    if (!engineConfiguration->enableStagedInjection) {
        return 0;
    }
 
    float frac = 0.01f * interpolate3d(
        config->injectorStagingTable,
        config->injectorStagingLoadBins, load,
        config->injectorStagingRpmBins, rpm
    );
 
    // don't allow very small fraction, with some hysteresis
    if (!stage2Hysteresis.test(frac, 0.1, 0.03)) {
        return 0;
    }
 
    // Clamp to 90%
    if (frac > 0.9) {
        frac = 0.9;
    }
 
    return frac;
}
 
#endif
#endif