Knock fuel trim and deacceleration (#7024)

* - knock fuel trim
- knock disable suppression then deceleration

* - knock disable suppression then deceleration syntax fix

* - knock disable suppression for test reapply

* - knock disable suppression for test reapply fix

* - knock fuel trim tests

---------

Co-authored-by: 3er0.1ive <3er0.1ive@veeroute.com>

firmware/controllers/engine_cycle/knock_controller.cpp

@@ -66,20 +66,23 @@ void KnockControllerBase::onKnockSenseCompleted(uint8_t cylinderNumber, float db
 		auto retardFraction = engineConfiguration->knockRetardAggression * 0.01f;
 		auto retardAmount = distToMinimum * retardFraction;
 
+    // TODO: remove magic 30% m_maximumFuelTrim?
+    auto maximumFuelTrim = 0.3f;
+
 		auto  trimFuelFraction = engineConfiguration->knockFuelTrimAggression * 0.01f;
-		float trimFuelPersent = clampF(0.0, (float)engineConfiguration->knockFuelTrim, 30.0);
-		float trimFuelCoeff = (trimFuelPersent / 100.f);
-		float trimFuelAmount = trimFuelCoeff * trimFuelFraction;
+		float trimFuelPercent = clampF(0.f, (float)engineConfiguration->knockFuelTrim, maximumFuelTrim * 100.f);
+		float trimFuelAmountPercent = trimFuelPercent * trimFuelFraction;
+		float trimFuelAmount = trimFuelAmountPercent / 100.f;
 
 		{
 			// Adjust knock retard under lock
 			chibios_rt::CriticalSectionLocker csl;
 
 			auto newRetard = m_knockRetard + retardAmount;
-			m_knockRetard = clampF(0, newRetard, m_maximumRetard);
+			m_knockRetard = clampF(0.f, newRetard, m_maximumRetard);
 
 			auto newFuelTrim = m_knockFuelTrimMultiplier + trimFuelAmount;
-			m_knockFuelTrimMultiplier = clampF(0.0, newFuelTrim, 0.3); // TODO: remove magic 30%
+			m_knockFuelTrimMultiplier = clampF(0.f, newFuelTrim, maximumFuelTrim);
 		}
 	}
 }
@@ -103,7 +106,7 @@ void KnockControllerBase::onFastCallback() {
 	constexpr auto callbackPeriodSeconds = FAST_CALLBACK_PERIOD_MS / 1000.0f;
 
 	auto applyRetardAmount = engineConfiguration->knockRetardReapplyRate * callbackPeriodSeconds;
-	auto applyFuelAmount = engineConfiguration->knockFuelTrimReapplyRate * callbackPeriodSeconds;
+	auto applyFuelAmount = engineConfiguration->knockFuelTrimReapplyRate * 0.01f * callbackPeriodSeconds;
 
 	// disable knock suppression then deceleration
 	auto TPSValue = Sensor::getOrZero(SensorType::Tps1);
@@ -132,7 +135,7 @@ void KnockControllerBase::onFastCallback() {
 		// Reduce fuel trim at the requested rate
 		float newTrim = m_knockFuelTrimMultiplier - applyFuelAmount;
 
-		// don't allow retard to go negative
+		// don't allow trim to go negative
 		if (newTrim < 0) {
 			m_knockFuelTrimMultiplier = 0;
 		} else {

firmware/integration/rusefi_config.txt

@@ -1723,7 +1723,7 @@ linear_sensor_s auxLinear4
 
 uint8_t autoscale knockSuppressMinTps;Below TPS value all knock suppression will be disabled.;"%", 1, 0, 0, 100, 1
 uint8_t autoscale knockFuelTrimAggression;Fuel to odd when a knock event occurs. Advice: 5% (mild), 10% (turbo/high comp.), 15% (high knock, e.g. GDI), 20% (spicy lump),;"%", 0.1, 0, 0, 20, 1
-uint8_t autoscale knockFuelTrimReapplyRate;After a knock event, reapply fuel at this rate.;"deg/s", 0.1, 0, 0, 10, 1
+uint8_t autoscale knockFuelTrimReapplyRate;After a knock event, reapply fuel at this rate.;"1%/s", 0.1, 0, 0, 10, 1
 uint8_t autoscale knockFuelTrim;Fuel trim when knock, max 30%;"%", 1, 0, 0, 30, 1
 
 	float knockSpectrumSensitivity;;"sense", 1, 0, 0, 1, 2

unit_tests/tests/test_knock.cpp

@@ -92,3 +92,84 @@ TEST(Knock, Reapply) {
 	// Should have no knock retard
 	EXPECT_FLOAT_EQ(dut.getKnockRetard(), 0);
 }
+
+TEST(Knock, FuelTrim) {
+	EngineTestHelper eth(engine_type_e::TEST_ENGINE);
+
+	// Aggression of 10%
+	engineConfiguration->knockFuelTrimAggression = 10;
+	engineConfiguration->knockFuelTrim = 30;
+
+	MockKnockController dut;
+	dut.onFastCallback();
+
+	// No trim unless we knock
+	ASSERT_FLOAT_EQ(dut.getFuelTrimMultiplier(), 1.0);
+
+	// Send some weak knocks, should yield no response
+	for (size_t i = 0; i < 10; i++) {
+		dut.onKnockSenseCompleted(0, 10, 0);
+	}
+
+	EXPECT_FLOAT_EQ(dut.getFuelTrimMultiplier(), 1.0);
+
+	// Send a strong knock!
+	dut.onKnockSenseCompleted(0, 30, 0);
+
+	// Should retard 10% of the distance between current timing and "maximum"
+	EXPECT_FLOAT_EQ(dut.getFuelTrimMultiplier(), 1.03);
+
+	// Send tons of strong knocks, make sure we don't go over the configured limit
+	for (size_t i = 0; i < 100; i++) {
+		dut.onKnockSenseCompleted(0, 30, 0);
+	}
+
+	EXPECT_FLOAT_EQ(dut.getFuelTrimMultiplier(), 1.3);
+}
+
+TEST(Knock, FuelTrimReapply) {
+	EngineTestHelper eth(engine_type_e::TEST_ENGINE);
+
+	MockKnockController dut;
+	dut.onFastCallback();
+
+	// Aggression of 100%
+	engineConfiguration->knockFuelTrimAggression = 10;
+	// Apply 1%/second
+	engineConfiguration->knockFuelTrimReapplyRate = 1;
+
+  // fuel trim 30%
+	engineConfiguration->knockFuelTrim = 30;
+
+	// disable suppress for test
+	engineConfiguration->knockSuppressMinTps = 0;
+
+	// Send a strong knock!
+	dut.onKnockSenseCompleted(0, 30, 0);
+
+  // 100% trim
+  float trim = 1.03;
+
+	// Should retard 100% of the distance between current timing and "maximum"
+	EXPECT_FLOAT_EQ(dut.getFuelTrimMultiplier(), trim);
+
+	constexpr auto fastPeriodSec = FAST_CALLBACK_PERIOD_MS / 1000.0f;
+
+	// call the fast callback, should reapply 1% trim * callback period
+	dut.onFastCallback();
+	EXPECT_FLOAT_EQ(dut.getFuelTrimMultiplier(), trim - 0.01f * fastPeriodSec);
+
+	// 10 updates total
+	for (size_t i = 0; i < 9; i++) {
+		dut.onFastCallback();
+	}
+	EXPECT_FLOAT_EQ(dut.getFuelTrimMultiplier(), trim - 10 * 0.01f * fastPeriodSec);
+
+	// Spend a long time without knock
+	for (size_t i = 0; i < 2000; i++) {
+		dut.onFastCallback();
+	}
+
+	// Should have no knock retard
+	EXPECT_FLOAT_EQ(dut.getFuelTrimMultiplier(), 1.0);
+}