clt based rpm limit (#4267)

firmware/controllers/limp_manager.cpp

@@ -10,15 +10,20 @@ void LimpManager::updateState(int rpm, efitick_t nowNt) {
 	Clearable allowFuel = engineConfiguration->isInjectionEnabled;
 	Clearable allowSpark = engineConfiguration->isIgnitionEnabled;
 
-	// User-configured hard RPM limit
-	if (rpm > engineConfiguration->rpmHardLimit) {
-		warning(CUSTOM_OBD_NAN_INJECTION, "Hit hard limit %d", engineConfiguration->rpmHardLimit);
-		if (engineConfiguration->cutFuelOnHardLimit) {
-			allowFuel.clear(ClearReason::HardLimit);
-		}
+	{
+		// User-configured hard RPM limit, either constant or CLT-lookup
+		float revLimit = engineConfiguration->useCltBasedRpmLimit
+			? interpolate2d(Sensor::get(SensorType::Clt).value_or(0), engineConfiguration->cltRevLimitRpmBins, engineConfiguration->cltRevLimitRpm)
+			: (float)engineConfiguration->rpmHardLimit;
 
-		if (engineConfiguration->cutSparkOnHardLimit) {
-			allowSpark.clear(ClearReason::HardLimit);
+		if (rpm > revLimit) {
+			if (engineConfiguration->cutFuelOnHardLimit) {
+				allowFuel.clear(ClearReason::HardLimit);
+			}
+
+			if (engineConfiguration->cutSparkOnHardLimit) {
+				allowSpark.clear(ClearReason::HardLimit);
+			}
 		}
 	}
 

firmware/integration/rusefi_config.txt

@@ -1023,7 +1023,7 @@ end_struct
 	bit invertSecondaryTriggerSignal;+This setting flips the signal from the secondary engine speed sensor.
 	
 bit cutFuelOnHardLimit,"yes","no"
-bit cutSparkOnHardLimit,"yes","no"
+bit cutSparkOnHardLimit,"yes","no";Be careful enabling this: some engines are known to self-disassemble their valvetrain with a spark cut. Fuel cut is much safer.
 bit launchFuelCutEnable
 bit launchSparkCutEnable;+This is the Cut Mode normally used
 	bit boardUseCrankPullUp,"Hall","VR"
@@ -1071,7 +1071,7 @@ bit useIacPidMultTable;+This flag allows to use a special 'PID Multiplier' table
 bit isBoostControlEnabled
 bit launchSmoothRetard;+Interpolates the Ignition Retard from 0 to 100% within the RPM Range
 bit isPhaseSyncRequiredForIgnition;Some engines are OK running semi-random sequential while other engine require phase synchronization
-	bit unused1476b8
+bit useCltBasedRpmLimit,"yes","no";If enabled, use a curve for RPM limit (based on coolant temperature) instead of a constant value.
 bit unused_1484_bit_24
 bit unused_1484_bit_25
 bit unused_1484_bit_26
@@ -1352,8 +1352,8 @@ custom stepper_num_micro_steps_e 1 bits, U08,	@OFFSET@,	[0:3], @@stepper_num_mic
 	linear_sensor_s highPressureFuel;
 	linear_sensor_s lowPressureFuel;
 
-int8_t[CLT_LIMITER_CURVE_SIZE] cltRevLimitRpmBins;CLT-based target RPM for hard limit depending on CLT like on Lexus LFA;"C", 1, 0, -70, 120, 0
-uint16_t[CLT_LIMITER_CURVE_SIZE] cltRevLimitRpm;See idleRpmPid;"", 1, 0, 0, 8000, 0
+int8_t[CLT_LIMITER_CURVE_SIZE] cltRevLimitRpmBins;;"C", 1, 0, -40, 120, 0
+uint16_t[CLT_LIMITER_CURVE_SIZE] cltRevLimitRpm;;"RPM", 1, 0, 0, 20000, 0
 
 gppwm_note_t[SCRIPT_CURVE_COUNT iterate] scriptCurveName;
 

firmware/tunerstudio/rusefi.input

@@ -486,6 +486,14 @@ enable2ndByteCanID = false
       yBins       = crankingFuelCoefE100
       gauge       = CLTGauge
 
+	curve = cltRevLimitCurve, ""
+	  columnLabel = "Coolant", "RPM Limit"
+	  xAxis      = -40, 120, 9
+	  yAxis      = 0, 8000, 9
+	  xBins      = cltRevLimitRpmBins, coolant
+	  yBins      = cltRevLimitRpm
+	  gauge      = CLTGauge
+
 	curve = etbTpsBiasCurve, "Electronic TB Bias Curve"
       columnLabel = "TPS", "duty bias"
       xAxis       =  0, 50, 11
@@ -1374,6 +1382,7 @@ menuDialog = main
 	menu = "&Base &Engine"
 		subMenu = engineChars,				"Base engine"
 		subMenu = limitsAndFallback,		"Limits and fallbacks"
+		subMenu = cltRevLimitCurve,			"CLT-based RPM Limit", 0, { (cutFuelOnHardLimit || cutSparkOnHardLimit) && useCltBasedRpmLimit }
 		subMenu = triggerConfiguration,		"Trigger"
 		subMenu = triggerConfiguration_IO, "Advanced Trigger"
 		subMenu = triggerConfiguration_gap, "Trigger Gap Override"
@@ -3306,7 +3315,8 @@ cmd_set_engine_type_default					= "@@TS_IO_TEST_COMMAND_char@@\x00\x31\x00\x00"
 	dialog = limitsSettings, "Limits"
 		field = "Cut fuel on RPM limit",				cutFuelOnHardLimit
 		field = "Cut spark on RPM limit",				cutSparkOnHardLimit
-        field = "RPM hard limit",                       rpmHardLimit, { cutFuelOnHardLimit || cutSparkOnHardLimit }
+		field = "Use CLT-based RPM limit curve",		useCltBasedRpmLimit, { cutFuelOnHardLimit || cutSparkOnHardLimit }
+        field = "RPM hard limit",                       rpmHardLimit, { (cutFuelOnHardLimit || cutSparkOnHardLimit) &&  !useCltBasedRpmLimit }
 		field = "Boost cut pressure",					boostCutPressure
 		field = "Minimum oil pressure after start",		minOilPressureAfterStart
 

unit_tests/tests/test_limp.cpp

@@ -43,6 +43,56 @@ TEST(limp, revLimit) {
 	EXPECT_TRUE(dut.allowInjection());
 }
 
+TEST(limp, revLimitCltBased) {
+	EngineTestHelper eth(TEST_ENGINE);
+
+	engineConfiguration->rpmHardLimit = 2500;
+
+	// Configure CLT-based rev limit curve
+	engineConfiguration->useCltBasedRpmLimit = true;
+	copyArray(engineConfiguration->cltRevLimitRpmBins, { 10, 20, 30, 40 });
+	copyArray(engineConfiguration->cltRevLimitRpm, { 1000, 2000, 3000, 4000 });
+
+	LimpManager dut;
+
+	// Check low temperature first
+	Sensor::setMockValue(SensorType::Clt, 10);
+
+	// Under rev limit, inj/ign allowed
+	dut.updateState(900, 0);
+	EXPECT_TRUE(dut.allowIgnition());
+	EXPECT_TRUE(dut.allowInjection());
+
+	// Over rev limit, no injection
+	dut.updateState(1100, 0);
+	EXPECT_FALSE(dut.allowIgnition());
+	EXPECT_FALSE(dut.allowInjection());
+
+	// Now recover back to under limit
+	dut.updateState(900, 0);
+	EXPECT_TRUE(dut.allowIgnition());
+	EXPECT_TRUE(dut.allowInjection());
+
+
+	// Check middle temperature
+	Sensor::setMockValue(SensorType::Clt, 35);
+
+	// Under rev limit, inj/ign allowed
+	dut.updateState(3400, 0);
+	EXPECT_TRUE(dut.allowIgnition());
+	EXPECT_TRUE(dut.allowInjection());
+
+	// Over rev limit, no injection
+	dut.updateState(3600, 0);
+	EXPECT_FALSE(dut.allowIgnition());
+	EXPECT_FALSE(dut.allowInjection());
+
+	// Now recover back to under limit
+	dut.updateState(3400, 0);
+	EXPECT_TRUE(dut.allowIgnition());
+	EXPECT_TRUE(dut.allowInjection());
+}
+
 TEST(limp, boostCut) {
 	EngineTestHelper eth(TEST_ENGINE);