Idle PID Coasting & Amplification Improvements (#589)

* PID Error Amplification Coef

* Add settings: useIacTableForCoasting,pidExtraForLowRpm,iacCoasting

* Modify interface for the new settings

* Run gen_config.bat and generate configs

* idlePositionSensitivityThreshold

* Remove cltCorrection from autoIdle() & more verbose debug

* Impl. idlePidRpmDeadZone and pidExtraForLowRpm; reset PID when deactivated

* Impl. useIacTableForCoasting+iacCoasting and idlePidRpmUpperLimit

firmware/controllers/algo/engine_configuration_generated_structures.h

@@ -1,4 +1,4 @@
-// this section was generated automatically by ConfigDefinition.jar based on rusefi_config.txt Thu Mar 22 08:12:47 EDT 2018
+// this section was generated automatically by ConfigDefinition.jar based on rusefi_config.txt Wed Mar 28 16:53:17 EEST 2018
 // begin
 #ifndef ENGINE_CONFIGURATION_GENERATED_H_
 #define ENGINE_CONFIGURATION_GENERATED_H_
@@ -648,7 +648,7 @@ typedef struct {
 	bool coastingFuelCutEnabled : 1;
 	/**
 	offset 376 bit 22 */
-	bool unused_board_984_22 : 1;
+	bool useIacTableForCoasting : 1;
 	/**
 	offset 376 bit 23 */
 	bool unused_board_984_23 : 1;
@@ -2117,9 +2117,28 @@ typedef struct {
 	 */
 	int16_t coastingFuelCutClt;
 	/**
+	 * Increases PID reaction for RPM<target by adding extra percent to PID-error
 	 * offset 3384
 	 */
-	int unusedEnd[774];
+	int16_t pidExtraForLowRpm;
+	/**
+	 * offset 3386
+	 */
+	int16_t unusedInt16;
+	/**
+	 * CLT-based idle position for coasting (used in Auto-PID Idle mode)
+	 * offset 3388
+	 */
+	float iacCoastingBins[CLT_CURVE_SIZE];
+	/**
+	 *  CLT-based idle position for coasting (used in Auto-PID Idle mode)
+	 * offset 3452
+	 */
+	float iacCoasting[CLT_CURVE_SIZE];
+	/**
+	 * offset 3516
+	 */
+	int unusedEnd[741];
 	/** total size 6480*/
 } engine_configuration_s;
 
@@ -2203,12 +2222,12 @@ typedef struct {
 	 */
 	float crankingCycleBins[CRANKING_CURVE_SIZE];
 	/**
-	 * CLT-based idle position multiplier for simple manual idle controller, or target RPM multiplier for PID-based idle
+	 * CLT-based idle position multiplier for simple manual idle controller
 	 * offset 10656
 	 */
 	float cltIdleCorrBins[CLT_CURVE_SIZE];
 	/**
-	 *  CLT-based idle position multiplier for simple manual idle controller, or target RPM multiplier for PID-based idle
+	 *  CLT-based idle position multiplier for simple manual idle controller
 	 * offset 10720
 	 */
 	float cltIdleCorr[CLT_CURVE_SIZE];
@@ -2365,4 +2384,4 @@ typedef struct {
 
 #endif
 // end
-// this section was generated automatically by ConfigDefinition.jar based on rusefi_config.txt Thu Mar 22 08:12:47 EDT 2018
+// this section was generated automatically by ConfigDefinition.jar based on rusefi_config.txt Wed Mar 28 16:53:17 EEST 2018

firmware/controllers/algo/rusefi_generated.h

@@ -588,8 +588,8 @@
 #define isFasterEngineSpinUpEnabled_offset_hex 3d8
 #define coastingFuelCutEnabled_offset 984
 #define coastingFuelCutEnabled_offset_hex 3d8
-#define unused_board_984_22_offset 984
-#define unused_board_984_22_offset_hex 3d8
+#define useIacTableForCoasting_offset 984
+#define useIacTableForCoasting_offset_hex 3d8
 #define unused_board_984_23_offset 984
 #define unused_board_984_23_offset_hex 3d8
 #define unused_board_984_24_offset 984
@@ -1560,8 +1560,16 @@
 #define coastingFuelCutTps_offset_hex d34
 #define coastingFuelCutClt_offset 3382
 #define coastingFuelCutClt_offset_hex d36
-#define unusedEnd_offset 3384
-#define unusedEnd_offset_hex d38
+#define pidExtraForLowRpm_offset 3384
+#define pidExtraForLowRpm_offset_hex d38
+#define unusedInt16_offset 3386
+#define unusedInt16_offset_hex d3a
+#define iacCoastingBins_offset 3388
+#define iacCoastingBins_offset_hex d3c
+#define iacCoasting_offset 3452
+#define iacCoasting_offset_hex d7c
+#define unusedEnd_offset 3516
+#define unusedEnd_offset_hex dbc
 #define cltCrankingCorrBins_offset 6480
 #define cltCrankingCorrBins_offset_hex 1950
 #define cltCrankingCorr_offset 6512

firmware/controllers/idle_thread.cpp

@@ -44,6 +44,8 @@ EXTERN_ENGINE
 ;
 
 static bool shouldResetPid = false;
+// we might reset PID state when the state is changed, but only if needed (See autoIdle())
+static bool mightResetPid = false;
 
 #if EFI_IDLE_INCREMENTAL_PID_CIC || defined(__DOXYGEN__)
 // Use new PID with CIC integrator
@@ -68,6 +70,10 @@ static percent_t currentIdlePosition = -100.0f;
  * the same as currentIdlePosition, but without adjustments (iacByTpsTaper, afterCrankingIACtaperDuration)
  */
 static percent_t baseIdlePosition = currentIdlePosition;
+/**
+ * When the IAC position value change is insignificant (lower than this threshold), leave the poor valve alone
+ */
+static percent_t idlePositionSensitivityThreshold = 1.0f;
 
 void idleDebug(const char *msg, percent_t value) {
 	scheduleMsg(logger, "idle debug: %s%.2f", msg, value);
@@ -163,9 +169,16 @@ percent_t getIdlePosition(void) {
 	return currentIdlePosition;
 }
 
-static float autoIdle(float cltCorrection) {
+static float autoIdle() {
 	percent_t tpsPos = getTPS(PASS_ENGINE_PARAMETER_SIGNATURE);
 	if (tpsPos > boardConfiguration->idlePidDeactivationTpsThreshold) {
+		// Don't store old I and D terms if PID doesn't work anymore.
+		// Otherwise they will affect the idle position much later, when the throttle is closed.
+		if (mightResetPid) {
+			mightResetPid = false;
+			shouldResetPid = true;
+		}
+
 		// just leave IAC position as is (but don't return currentIdlePosition - it may already contain additionalAir)
 		return baseIdlePosition;
 	}
@@ -180,7 +193,23 @@ static float autoIdle(float cltCorrection) {
 		targetRpm = interpolate2d("cltRpm", clt, CONFIG(cltIdleRpmBins), CONFIG(cltIdleRpm), CLT_CURVE_SIZE);
 	}
 
-	percent_t newValue = idlePid.getValue(targetRpm, getRpmE(engine), engineConfiguration->idleRpmPid.period);
+	// check if within the dead zone
+	int rpm = getRpmE(engine);
+	if (absI(rpm - targetRpm) <= CONFIG(idlePidRpmDeadZone))
+		return baseIdlePosition;
+
+	// When rpm < targetRpm, there's a risk of dropping RPM too low - and the engine dies out.
+	// So PID reaction should be increased by adding extra percent to PID-error:
+	percent_t errorAmpCoef = 1.0f;
+	if (rpm < targetRpm)
+		errorAmpCoef += (float)CONFIG(pidExtraForLowRpm) / PERCENT_MULT;
+	// If errorAmpCoef > 1.0, then PID thinks that RPM is lower than it is, and controls IAC more aggressively
+	idlePid.setErrorAmplification(errorAmpCoef);
+
+	percent_t newValue = idlePid.getValue(targetRpm, rpm, engineConfiguration->idleRpmPid.period);
+
+	// the state of PID has been changed, so we might reset it now, but only when needed (see idlePidDeactivationTpsThreshold)
+	mightResetPid = true;
 
 #if EFI_IDLE_INCREMENTAL_PID_CIC || defined(__DOXYGEN__)
 	// Treat the 'newValue' as if it contains not an actual IAC position, but an incremental delta.
@@ -192,6 +221,22 @@ static float autoIdle(float cltCorrection) {
 	newValue = minF(newValue, CONFIG(idleRpmPid.maxValue));
 #endif /* EFI_IDLE_INCREMENTAL_PID_CIC */
 
+	// Interpolate to the manual position when RPM is close to the upper RPM limit (if idlePidRpmUpperLimit is set).
+	// If RPM increases and the throttle is closed, then we're in coasting mode, and we should smoothly disable auto-pid.
+	// If we just leave IAC at baseIdlePosition (as in case of TPS deactivation threshold), RPM would get stuck. 
+	// That's why there's 'useIacTableForCoasting' setting which involves a separate IAC position table for coasting (iacCoasting).
+	// Currently it's user-defined. But eventually we'll use a real calculated and stored IAC position instead.
+	int idlePidLowerRpm = targetRpm + CONFIG(idlePidRpmDeadZone);
+	if (CONFIG(idlePidRpmUpperLimit) > 0) {
+		if (boardConfiguration->useIacTableForCoasting) {
+			percent_t iacPosForCoasting = interpolate2d("iacCoasting", clt, CONFIG(iacCoastingBins), CONFIG(iacCoasting), CLT_CURVE_SIZE);
+			newValue = interpolateClamped(idlePidLowerRpm, newValue, idlePidLowerRpm + CONFIG(idlePidRpmUpperLimit), iacPosForCoasting, rpm);
+		} else {
+			// Well, just leave it as is, without PID regulation...
+			newValue = baseIdlePosition;
+		}
+	}
+
 	return newValue;
 }
 
@@ -233,6 +278,7 @@ static msg_t ivThread(int param) {
 
 		float clt = engine->sensors.clt;
 		bool isRunning = engine->rpmCalculator.isRunning(PASS_ENGINE_PARAMETER_SIGNATURE);
+		// cltCorrection is used only for cranking or running in manual mode
 		float cltCorrection;
 		if (cisnan(clt))
 			cltCorrection = 1.0f;
@@ -259,7 +305,7 @@ static msg_t ivThread(int param) {
 				// let's re-apply CLT correction
 				iacPosition = manualIdleController(cltCorrection);
 			} else {
-				iacPosition = autoIdle(cltCorrection);
+				iacPosition = autoIdle();
 			}
 
 			// store 'base' iacPosition without adjustments
@@ -276,7 +322,8 @@ static msg_t ivThread(int param) {
 					engine->rpmCalculator.getRevolutionCounterSinceStart());
 		}
 
-		if (absF(iacPosition - currentIdlePosition) < 1) {
+		// The threshold is dependent on IAC type (see initIdleHardware())
+		if (absF(iacPosition - currentIdlePosition) < idlePositionSensitivityThreshold) {
 			continue; // value is pretty close, let's leave the poor valve alone
 		}
 
@@ -287,6 +334,7 @@ static msg_t ivThread(int param) {
 				idlePid.postState(&tsOutputChannels, 1000000);
 			} else {
 				tsOutputChannels.debugFloatField1 = iacPosition;
+				tsOutputChannels.debugIntField1 = iacMotor.getTargetPosition();
 			}
 #endif
 		}
@@ -379,13 +427,16 @@ static void initIdleHardware() {
 		iacMotor.initialize(boardConfiguration->idle.stepperStepPin, boardConfiguration->idle.stepperDirectionPin, 
 				engineConfiguration->stepperDirectionPinMode, engineConfiguration->idleStepperReactionTime, 
 				engineConfiguration->idleStepperTotalSteps, engineConfiguration->stepperEnablePin, logger);
+		// This greatly improves PID accuracy for steppers with a small number of steps
+		idlePositionSensitivityThreshold = 1.0f / engineConfiguration->idleStepperTotalSteps;
 	} else {
 		/**
 		 * Start PWM for idleValvePin
 		 */
 		startSimplePwmExt(&idleSolenoid, "Idle Valve", boardConfiguration->idle.solenoidPin, &enginePins.idleSolenoidPin,
 				boardConfiguration->idle.solenoidFrequency, boardConfiguration->manIdlePosition / 100,
 				applyIdleSolenoidPinState);
+		idlePositionSensitivityThreshold = 1.0f;
 	}
 }
 

firmware/controllers/math/pid.cpp

@@ -39,7 +39,7 @@ float Pid::getValue(float target, float input) {
 }
 
 float Pid::getRawValue(float target, float input, float dTime) {
-	float error = target - input;
+	float error = (target - input) * errorAmplificationCoef;
 	prevTarget = target;
 	prevInput = input;
 
@@ -74,6 +74,7 @@ void Pid::updateFactors(float pFactor, float iFactor, float dFactor) {
 void Pid::reset(void) {
 	dTerm = iTerm = 0;
 	prevResult = prevInput = prevTarget = prevError = 0;
+	errorAmplificationCoef = 1.0f;
 	resetCounter++;
 }
 
@@ -101,6 +102,10 @@ float Pid::getOffset(void) {
 	return pid->offset;
 }
 
+void Pid::setErrorAmplification(float coef) {
+	errorAmplificationCoef = coef;
+}
+
 #if EFI_PROD_CODE || EFI_SIMULATOR
 void Pid::postState(TunerStudioOutputChannels *tsOutputChannels) {
 	postState(tsOutputChannels, 1);

firmware/controllers/math/pid.h

@@ -41,6 +41,7 @@ class Pid {
 	float getOffset(void);
 	float getIntegration(void);
 	float getPrevError(void);
+	void setErrorAmplification(float coef);
 #if EFI_PROD_CODE || EFI_SIMULATOR
 	void postState(TunerStudioOutputChannels *tsOutputChannels);
 	void postState(TunerStudioOutputChannels *tsOutputChannels, int pMult);
@@ -60,6 +61,7 @@ class Pid {
 	float prevTarget;
 	float prevInput;
 	float prevResult;
+	float errorAmplificationCoef;
 
 private:
 	virtual void updateITerm(float value);

firmware/integration/rusefi_config.txt

@@ -550,7 +550,7 @@ bit is_enabled_spi_2
 	bit stepperForceParkingEveryRestart
 	bit isFasterEngineSpinUpEnabled
 	bit coastingFuelCutEnabled
-	bit unused_board_984_22
+	bit useIacTableForCoasting
 	bit unused_board_984_23
 	bit unused_board_984_24
 	bit unused_board_984_25
@@ -903,7 +903,13 @@ float[CRANKING_ADVANCE_CURVE_SIZE] crankingAdvance    ;Optional timing advance t
 	int16_t coastingFuelCutTps;percent between 0 and 100;"%",        1,     0,  0,    100,  0
 	int16_t coastingFuelCutClt;Fuel cutoff is deactivated if CLT<threshold;"C",        1,     0,  -100,    100,  0
 
-	int[774] unusedEnd;
+	int16_t pidExtraForLowRpm;+Increases PID reaction for RPM<target by adding extra percent to PID-error;"%",        1,     0,  0,    100,  0
+	int16_t unusedInt16;
+
+float[CLT_CURVE_SIZE] iacCoastingBins;CLT-based idle position for coasting (used in Auto-PID Idle mode);"C",        1,     0,   -100.0,    250.0,  2
+float[CLT_CURVE_SIZE] iacCoasting;    CLT-based idle position for coasting (used in Auto-PID Idle mode);"%",      1,     0,      0.0,    100.0,   2
+
+	int[741] unusedEnd;
 
 
 end_struct
@@ -934,8 +940,8 @@ float[IAT_CURVE_SIZE] iatFuelCorr;;"%",      1,     0,      0.0,    500.0,   2
 	float[CRANKING_CURVE_SIZE] crankingCycleCoef;;"%",      1,     0,      0.0,    500.0,   2
 	float[CRANKING_CURVE_SIZE] crankingCycleBins;;"counter",        1,     0,    -80.0,    170.0,  2
 
-float[CLT_CURVE_SIZE] cltIdleCorrBins;CLT-based idle position multiplier for simple manual idle controller, or target RPM multiplier for PID-based idle;"C",        1,     0,   -100.0,    250.0,  2
-float[CLT_CURVE_SIZE] cltIdleCorr;    CLT-based idle position multiplier for simple manual idle controller, or target RPM multiplier for PID-based idle;"%",      1,     0,      0.0,    1000.0,   2
+float[CLT_CURVE_SIZE] cltIdleCorrBins;CLT-based idle position multiplier for simple manual idle controller;"C",        1,     0,   -100.0,    250.0,  2
+float[CLT_CURVE_SIZE] cltIdleCorr;    CLT-based idle position multiplier for simple manual idle controller;"%",      1,     0,      0.0,    1000.0,   2
 
 float[MAF_DECODING_COUNT] mafDecoding;kg/hour value.\nBy the way 2.081989116 kg/h = 1 ft�/m;"kg/hour", 1, 0, -500.0, 4000.0, 2
 float[MAF_DECODING_COUNT] mafDecodingBins;; "V", 1, 0, -5.0, 150.0, 2

firmware/tunerstudio/rusefi.ini

@@ -63,7 +63,7 @@ enable2ndByteCanID = false
 
 ; see PAGE_0_SIZE in C source code    
 ; CONFIG_DEFINITION_START
-; this section was generated automatically by ConfigDefinition.jar based on rusefi_config.txt Sun Mar 25 09:12:10 EDT 2018
+; this section was generated automatically by ConfigDefinition.jar based on rusefi_config.txt Wed Mar 28 16:53:17 EEST 2018
 
 pageSize            = 20000
 page = 1
@@ -312,7 +312,7 @@ page = 1
 	stepperForceParkingEveryRestart= bits,    U32,   	984, [19:19], "false", "true"
 	isFasterEngineSpinUpEnabled= bits,    U32,   	984, [20:20], "false", "true"
 	coastingFuelCutEnabled	= bits,    U32,   	984, [21:21], "false", "true"
-	unused_board_984_22		= bits,    U32,   	984, [22:22], "false", "true"
+	useIacTableForCoasting	= bits,    U32,   	984, [22:22], "false", "true"
 	unused_board_984_23		= bits,    U32,   	984, [23:23], "false", "true"
 	unused_board_984_24		= bits,    U32,   	984, [24:24], "false", "true"
 	unused_board_984_25		= bits,    U32,   	984, [25:25], "false", "true"
@@ -783,7 +783,11 @@ page = 1
 	coastingFuelCutRpmLow			= scalar, S16,	3378,	"rpm", 1, 0, 0, 5000, 0
 	coastingFuelCutTps				= scalar, S16,	3380,	"%", 1, 0, 0, 100, 0
 	coastingFuelCutClt				= scalar, S16,	3382,	"C", 1, 0, -100, 100, 0
-;no TS info - skipping unusedEnd offset 3384
+	pidExtraForLowRpm				= scalar, S16,	3384,	"%", 1, 0, 0, 100, 0
+;no TS info - skipping unusedInt16 offset 3386
+	iacCoastingBins					= array, F32,	3388,	[16],	"C", 1, 0, -100.0, 250.0, 2
+	iacCoasting						= array, F32,	3452,	[16],	"%", 1, 0, 0.0, 100.0, 2
+;no TS info - skipping unusedEnd offset 3516
 	cltCrankingCorrBins				= array, F32,	6480,	[8],	"C", 1, 0, -100.0, 250.0, 2
 	cltCrankingCorr					= array, F32,	6512,	[8],	"%", 1, 0, 0.0, 500.0, 2
 	idleAdvanceBins					= array, F32,	6544,	[8],	"RPM", 1, 0, 0.0, 18000, 2
@@ -897,6 +901,7 @@ page = 1
 	slowAdcAlpha = "ExpAverage alpha coefficient"
 	dizzySparkOutputPin = "This implementation makes a pulse every time one of the coils is charged, using coil dwell for pulse width. See also tachOutputPin"
 	crankingIACposition = "IAC position during cranking"
+	pidExtraForLowRpm = "Increases PID reaction for RPM<target by adding extra percent to PID-error"
 
 
 ; CONFIG_DEFINITION_END
@@ -1264,6 +1269,14 @@ fileVersion = { 20171101 }
       yBins       = cltIdleCorr
       gauge       = CLTGauge
 
+	curve = iacCoastingCurve, "Coasting IAC Position for Auto-Idle"
+      columnLabel = "Coolant", "Multiplier"
+      xAxis       = -40, 120, 10
+      yAxis       =  0,  100, 10
+      xBins       = iacCoastingBins, coolant
+      yBins       = iacCoasting
+      gauge       = idleAirValvePositionGauge
+
 	curve = cltCrankingCurve, "Cranking IAC multiplier"
       columnLabel = "Coolant", "Multiplier"
       xAxis       = -40, 120, 10
@@ -1799,6 +1812,7 @@ menuDialog = main
 		subMenu = idleAdvanceCurve,			"Idle Ignition Advance", 0, {useSeparateAdvanceForIdle == 1}
 		subMenu = std_separator
 		subMenu = cltIdleCurve,				"Warmup Idle multiplier"
+		subMenu = iacCoastingCurve,			"Coasting IAC Position for Auto-Idle", 0, {useIacTableForCoasting == 1}
 
 	menu = "&Tuning"
 		subMenu = AccelEnrich,				"Accel/Decel Enrichment/Enleanment"
@@ -2411,15 +2425,17 @@ cmd_stop_engine              = "w\x00\x99\x00\x00"
 		field = "Min",									idleRpmPid_minValue
 		field = "Max",									idleRpmPid_maxValue
 		field = "period",								idleRpmPid_period
-		field = "RPM dead zone to deactivate IAC pid",	idlePidRpmDeadZone, { idleMode == 0}
-		field = "RPM upper limit to deactivate IAC pid",idlePidRpmUpperLimit, { idleMode == 0}
+		field = "RPM dead zone to deactivate IAC pid",	idlePidRpmDeadZone
+		field = "RPM upper limit to deactivate IAC pid",idlePidRpmUpperLimit
+		field = "PID Extra for low RPM",				pidExtraForLowRpm
 
 
 	dialog = idleSettings, "", yAxis
 		field = "!Automatic Mode is now Beta Version"
 		field = "Idle IAC control mode",					idleMode
 		field = "Use separate Ignition Table for idle",	useSeparateAdvanceForIdle
 		field = "Use separate VE Table for idle",		useSeparateVeForIdle
+		field = "Use separate IAC Table For Coasting",	useIacTableForCoasting, {idleMode == 0}
 		field = "TPS deactivation threshold",			idlePidDeactivationTpsThreshold
 		panel = idlePidSettings, { idleMode == 0}
 		field = "Extra IAC if Throttle Pressed",						iacByTpsTaper;