accel_enrichment.cpp

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/**
 * @file    accel_enrichment.cpp
 * @brief   Acceleration enrichment calculator
 *
 * In this file we have three strategies for acceleration/deceleration fuel correction
 *
 * 1) MAP rate-of-change correction
 * 2) TPS rate-of-change correction
 * 3) fuel film/wal wetting correction
 *   AWC Added to Wall Coefficient, %
 *   AWA Added to Wall Amount
 *   SOC Sucked Off wall Coefficient, %
 *   SOA Sucked Off wall amount
 *   WF  current on-Wall Fuel amount
 *
 *
 * http://rusefi.com/wiki/index.php?title=Manual:Software:Fuel_Control
 * @date Apr 21, 2014
 * @author Dmitry Sidin
 * @author Andrey Belomutskiy, (c) 2012-2020
 * @author Matthew Kennedy
 */
 
#include "pch.h"
#include "accel_enrichment.h"
#include "tunerstudio.h"
 
 
// on this level we do not distinguish between multiplier and 'ms adder' modes
float TpsAccelEnrichment::getTpsEnrichment() {
    ScopePerf perf(PE::GetTpsEnrichment);
 
    // If predictive MAP mode is active, the old "adder" logic is disabled.
    if (engineConfiguration->accelEnrichmentMode == AE_MODE_PREDICTIVE_MAP) {
        return 0;
    }
 
    if (engineConfiguration->tpsAccelLookback == 0) {
        // If disabled, return 0.
        return 0;
    }
 
#if EFI_TUNER_STUDIO
    if (isTuningVeNow()) {
        return 0;
    }
#endif
 
    float rpm = Sensor::getOrZero(SensorType::Rpm);
    if (rpm < engineConfiguration->cranking.rpm) {
        return 0;
    }
 
    if (isAboveAccelThreshold) {
        valueFromTable = interpolate3d(config->tpsTpsAccelTable,
            config->tpsTpsAccelToRpmBins, tpsTo,
            config->tpsTpsAccelFromRpmBins, tpsFrom);
        extraFuel = valueFromTable;
        m_timeSinceAccel.reset();
    } else if (isBelowDecelThreshold) {
        extraFuel = deltaTps * engineConfiguration->tpsDecelEnleanmentMultiplier;
        m_timeSinceAccel.reset();
    } else {
        extraFuel = 0;
    }
 
    // Fractional enrichment (fuel portions are accumulated and split between several engine cycles.
    // This is a crude imitation of carburetor's acceleration pump.
    isFractionalEnrichment = engineConfiguration->tpsAccelFractionPeriod > 1 || engineConfiguration->tpsAccelFractionDivisor > 1.0f;
    if (isFractionalEnrichment) {
        // make sure both values are non-zero
        float periodF = std::max<int>(engineConfiguration->tpsAccelFractionPeriod, 1);
        float divisor = std::max(engineConfiguration->tpsAccelFractionDivisor, 1.0f);
 
        // if current extra fuel portion is not "strong" enough, then we keep up the "pump pressure" with the accumulated portion
        floatms_t maxExtraFuel = std::max(extraFuel, accumulatedValue);
        // use only a fixed fraction of the accumulated portion
        fractionalInjFuel = maxExtraFuel / divisor;
 
        // update max counters
        maxExtraPerCycle = std::max(extraFuel, maxExtraPerCycle);
        maxInjectedPerPeriod = std::max(fractionalInjFuel, maxInjectedPerPeriod);
 
        // evenly split it between several engine cycles
        extraFuel = fractionalInjFuel / periodF;
    } else {
        resetFractionValues();
    }
 
    float mult = interpolate2d(rpm, config->tpsTspCorrValuesBins,
                        config->tpsTspCorrValues);
    if (mult != 0 && (mult < 0.01 || mult > 100)) {
        mult = 1;
    }
 
    return extraFuel * mult;
}
 
void TpsAccelEnrichment::onEngineCycleTps() {
    // we update values in handleFuel() directly by calling onNewValue()
 
    onUpdateInvocationCounter++;
 
    // we used some extra fuel during the current cycle, so we "charge" our "acceleration pump" with it
    accumulatedValue -= maxExtraPerPeriod;
    maxExtraPerPeriod = std::max(maxExtraPerCycle, maxExtraPerPeriod);
    maxExtraPerCycle = 0;
    accumulatedValue += maxExtraPerPeriod;
 
    // update the accumulated value every 'Period' engine cycles
    isTimeToResetAccumulator = --cycleCnt <= 0;
    if (isTimeToResetAccumulator) {
        maxExtraPerPeriod = 0;
 
        // we've injected this portion during the cycle, so we set what's left for the next cycle
        accumulatedValue -= maxInjectedPerPeriod;
        maxInjectedPerPeriod = 0;
 
        // it's an infinitely convergent series, so we set a limit at some point
        // (also make sure that accumulatedValue is positive, for safety)
        static const floatms_t smallEpsilon = 0.001f;
        belowEpsilon = accumulatedValue < smallEpsilon;
        if (belowEpsilon) {
            accumulatedValue = 0;
        }
 
        // reset the counter
        cycleCnt = engineConfiguration->tpsAccelFractionPeriod;
    }
}
 
int TpsAccelEnrichment::getMaxDeltaIndex() {
    int len = minI(cb.getSize(), cb.getCount());
    tooShort = len < 2;
    if (tooShort) {
        return 0;
    }
    int ci = cb.currentIndex - 1;
    float maxValue = cb.get(ci) - cb.get(ci - 1);
    int resultIndex = ci;
 
    // todo: 'get' method is maybe a bit heavy because of the branching
    // todo: this could be optimized with some careful magic
 
    for (int i = 1; i<len - 1;i++) {
        float v = cb.get(ci - i) - cb.get(ci - i - 1);
        if (v > maxValue) {
            maxValue = v;
            resultIndex = ci - i;
        }
    }
 
    return resultIndex;
}
 
float TpsAccelEnrichment::getMaxDelta() {
    int index = getMaxDeltaIndex();
 
    return (cb.get(index) - (cb.get(index - 1)));
}
 
void TpsAccelEnrichment::resetAE() {
    cb.clear();
    resetFractionValues();
}
 
void TpsAccelEnrichment::resetFractionValues() {
    accumulatedValue = 0;
    maxExtraPerCycle = 0;
    maxExtraPerPeriod = 0;
    maxInjectedPerPeriod = 0;
    cycleCnt = 0;
}
 
void TpsAccelEnrichment::setLength(int length) {
    cb.setSize(length);
}
 
void TpsAccelEnrichment::onNewValue(float currentValue) {
    // Push new value in to the history buffer
    cb.add(currentValue);
 
    // Update deltas
    int maxDeltaIndex = getMaxDeltaIndex();
    tpsFrom = cb.get(maxDeltaIndex - 1);
    tpsTo = cb.get(maxDeltaIndex);
    deltaTps = tpsTo - tpsFrom;
 
    // Update threshold detection
    isAboveAccelThreshold = deltaTps > engineConfiguration->tpsAccelEnrichmentThreshold;
 
    // If an acceleration event just happened, latch the flag so it can be read once.
    if (isAboveAccelThreshold) {
        m_accelEventJustOccurred = true;
    }
 
    // TODO: can deltaTps actually be negative? Will this ever trigger?
    isBelowDecelThreshold = deltaTps < -engineConfiguration->tpsDecelEnleanmentThreshold;
}
 
bool TpsAccelEnrichment::isAccelEventTriggered() {
    // Read the flag
    bool result = m_accelEventJustOccurred;
    // Reset it so we only fire once per event
    m_accelEventJustOccurred = false;
    return result;
}
 
TpsAccelEnrichment::TpsAccelEnrichment() {
    resetAE();
    cb.setSize(4);
}
 
void TpsAccelEnrichment::onConfigurationChange(engine_configuration_s const* /*previousConfig*/) {
    constexpr float slowCallbackPeriodSecond = SLOW_CALLBACK_PERIOD_MS / 1000.0f;
    int length = engineConfiguration->tpsAccelLookback / slowCallbackPeriodSecond;
 
    if (length < 1) {
        efiPrintf("setTpsAccelLen: Length should be positive [%d]", length);
        return;
    }
 
    setLength(length);
}
 
float TpsAccelEnrichment::getTimeSinceAcell() const {
    return m_timeSinceAccel.getElapsedSeconds();
}
 
void initAccelEnrichment() {
    engine->module<TpsAccelEnrichment>()->onConfigurationChange(nullptr);
}