disable closed loop boost below MAP threshold (#3206)

* boost minimum map

* changelog

firmware/CHANGELOG.md

@@ -31,6 +31,7 @@ All notable user-facing or behavior-altering changes will be documented in this
  - RUSEFI MSD now contains bundle-specific URL #2848
  - Nissan 4 cylinder QR trigger wheel #3118
  - 1-6-2-4-3-5 firing order for all our 911 fans!
+ - Add minimum MAP threshold for closed-loop boost control
 
 ### Fixed
  - Composite Logger uses same engineSnifferRpmThreshold setting as engine sniffer #3161

firmware/controllers/actuators/boost_control.cpp

@@ -106,6 +106,12 @@ expected<percent_t> BoostController::getClosedLoop(float target, float manifoldP
 		return 0;
 	}
 
+	if (manifoldPressure < CONFIG(minimumBoostClosedLoopMap)) {
+		// We're below the CL threshold, inhibit CL for now
+		m_pid.reset();
+		return 0;
+	}
+
 	float closedLoop = m_pid.getOutput(target, manifoldPressure, SLOW_CALLBACK_PERIOD_MS / 1000.0f);
 
 #if EFI_TUNER_STUDIO

firmware/integration/rusefi_config.txt

@@ -901,7 +901,7 @@ pin_output_mode_e hip9011IntHoldPinMode;
 	uint32_t verboseCanBaseAddress;;"", 1, 0, 0, 536870911, 0
 
 	uint8_t mc33_hvolt;;"v", 1, 0, 40, 70, 0
-	uint8_t unused761;;"", 1, 0, 0, 255, 0
+	uint8_t minimumBoostClosedLoopMap;+Minimum MAP before closed loop boost is enabled. Use to prevent misbehavior upon entering boost.;"kPa", 1, 0, 0, 255, 0
 
 output_pin_e acFanPin;+Optional Radiator Fan used with A/C
 	pin_output_mode_e acFanPinMode;

firmware/tunerstudio/rusefi.input

@@ -3381,6 +3381,7 @@ cmd_set_engine_type_default					= "@@TS_IO_TEST_COMMAND_char@@\x00\x31\x00\x00"
 ;Boost Closed Loop
 
          dialog = boostPidleft, ""
+		 	field = "Enable closed loop above",			minimumBoostClosedLoopMap, { isBoostControlEnabled && boostType == 1 }
             field = "P Gain", 	                         boostPid_pFactor, { isBoostControlEnabled && boostType == 1 }
 	        field = "I Gain",                            boostPid_iFactor, { isBoostControlEnabled && boostType == 1 }
 	        field = "D Gain",                            boostPid_dFactor, { isBoostControlEnabled && boostType == 1 }

unit_tests/tests/test_boost.cpp

@@ -87,11 +87,17 @@ TEST(BoostControl, ClosedLoop) {
 
 	// Enable closed loop
 	CONFIG(boostType) = CLOSED_LOOP;
+	// Minimum 75kpa
+	CONFIG(minimumBoostClosedLoopMap) = 75;
 
 	// At 0 RPM, closed loop is disabled
 	ENGINE(rpmCalculator.mockRpm) = 0;
 	EXPECT_EQ(0, bc.getClosedLoop(150, 100).value_or(-1000));
 
+	// too low MAP, disable closed loop
+	ENGINE(rpmCalculator.mockRpm) = 0;
+	EXPECT_EQ(0, bc.getClosedLoop(150, 50).value_or(-1000));
+
 	// With RPM, we should get an output
 	ENGINE(rpmCalculator.mockRpm) = 1000;
 	// Actual is below target -> positive output