ekf2: only allow ref sensor to reset height

src/modules/ekf2/EKF/aid_sources/barometer/baro_height_control.cpp

@@ -126,7 +126,7 @@ void Ekf::controlBaroHeightFusion(const imuSample &imu_sample)
 
 				const bool is_fusion_failing = isTimedOut(aid_src.time_last_fuse, _params.hgt_fusion_timeout_max);
 
-				if (isHeightResetRequired()) {
+				if (isHeightResetRequired() && (_height_sensor_ref == HeightSensor::BARO)) {
 					// All height sources are failing
 					ECL_WARN("%s height fusion reset required, all height sources failing", HGT_SRC_NAME);
 
@@ -142,10 +142,13 @@ void Ekf::controlBaroHeightFusion(const imuSample &imu_sample)
 					aid_src.time_last_fuse = imu_sample.time_us;
 
 				} else if (is_fusion_failing) {
-					// Some other height source is still working
 					ECL_WARN("stopping %s height fusion, fusion failing", HGT_SRC_NAME);
 					stopBaroHgtFusion();
-					_baro_hgt_faulty = true;
+
+					if (isRecent(_time_last_hgt_fuse, _params.hgt_fusion_timeout_max)) {
+						// Some other height source is still working
+						_baro_hgt_faulty = true;
+					}
 				}
 
 			} else {

src/modules/ekf2/EKF/aid_sources/external_vision/ev_height_control.cpp

@@ -142,7 +142,7 @@ void Ekf::controlEvHeightFusion(const imuSample &imu_sample, const extVisionSamp
 
 			const bool is_fusion_failing = isTimedOut(aid_src.time_last_fuse, _params.hgt_fusion_timeout_max);
 
-			if (isHeightResetRequired() && quality_sufficient) {
+			if (isHeightResetRequired() && quality_sufficient && (_height_sensor_ref == HeightSensor::EV)) {
 				// All height sources are failing
 				ECL_WARN("%s fusion reset required, all height sources failing", AID_SRC_NAME);
 				_information_events.flags.reset_hgt_to_ev = true;

src/modules/ekf2/EKF/aid_sources/gnss/gnss_height_control.cpp

@@ -100,12 +100,12 @@ void Ekf::controlGnssHeightFusion(const gnssSample &gps_sample)
 
 				const bool is_fusion_failing = isTimedOut(aid_src.time_last_fuse, _params.hgt_fusion_timeout_max);
 
-				if (isHeightResetRequired()) {
+				if (isHeightResetRequired() && (_height_sensor_ref == HeightSensor::GNSS)) {
 					// All height sources are failing
 					ECL_WARN("%s height fusion reset required, all height sources failing", HGT_SRC_NAME);
 
 					_information_events.flags.reset_hgt_to_gps = true;
-					resetVerticalPositionTo(-(measurement - bias_est.getBias()), measurement_var);
+					resetVerticalPositionTo(aid_src.observation, measurement_var);
 					bias_est.setBias(_state.pos(2) + measurement);
 
 					aid_src.time_last_fuse = _time_delayed_us;

src/modules/ekf2/EKF/aid_sources/range_finder/range_height_control.cpp

@@ -173,7 +173,7 @@ void Ekf::controlRangeHaglFusion(const imuSample &imu_sample)
 
 				const bool is_fusion_failing = isTimedOut(aid_src.time_last_fuse, _params.hgt_fusion_timeout_max);
 
-				if (isHeightResetRequired() && _control_status.flags.rng_hgt) {
+				if (isHeightResetRequired() && _control_status.flags.rng_hgt && (_height_sensor_ref == HeightSensor::RANGE)) {
 					// All height sources are failing
 					ECL_WARN("%s height fusion reset required, all height sources failing", HGT_SRC_NAME);
 

src/modules/ekf2/test/sensor_simulator/gps.h

@@ -66,6 +66,7 @@ class Gps: public Sensor
 	void setPdop(const float pdop);
 
 	gnssSample getDefaultGpsData();
+	const gnssSample &getData() const { return _gps_data; }
 
 private:
 	void send(uint64_t time) override;

src/modules/ekf2/test/test_EKF_height_fusion.cpp

@@ -261,6 +261,93 @@ TEST_F(EkfHeightFusionTest, gpsRefFailOver)
 	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::UNKNOWN);
 }
 
+TEST_F(EkfHeightFusionTest, gpsRefAllHgtFailReset)
+{
+	// GIVEN: EKF that fuses GNSS (reference) and baro
+	_sensor_simulator.startBaro();
+	_sensor_simulator.startGps();
+	_ekf_wrapper.setGpsHeightRef();
+	_ekf_wrapper.enableBaroHeightFusion();
+	_ekf_wrapper.enableGpsHeightFusion();
+
+	_sensor_simulator.runSeconds(11);
+	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
+	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());
+	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::GNSS);
+
+	const Vector3f previous_position = _ekf->getPosition();
+
+	ResetLoggingChecker reset_logging_checker(_ekf);
+	reset_logging_checker.capturePreResetState();
+
+	// WHEN:
+	const float gnss_height_step = 10.f;
+	_sensor_simulator._gps.stepHeightByMeters(gnss_height_step);
+
+	const float baro_height_step = 5.f;
+	_sensor_simulator._baro.setData(_sensor_simulator._baro.getData() + baro_height_step);
+	_sensor_simulator.runSeconds(15);
+
+	// THEN: then the fusion of both sensors starts to fail and the height is reset to the
+	// reference sensor (GNSS)
+	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
+	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());
+
+	const Vector3f new_position = _ekf->getPosition();
+	EXPECT_NEAR(new_position(2), previous_position(2) - gnss_height_step, 0.2f);
+
+	// Also check the reset counters to make sure the reset logic triggered
+	reset_logging_checker.capturePostResetState();
+	EXPECT_TRUE(reset_logging_checker.isVerticalVelocityResetCounterIncreasedBy(1));
+	EXPECT_TRUE(reset_logging_checker.isVerticalPositionResetCounterIncreasedBy(1));
+}
+
+TEST_F(EkfHeightFusionTest, baroRefAllHgtFailReset)
+{
+	// GIVEN: EKF that fuses GNSS and baro (reference)
+	_sensor_simulator.startBaro();
+	_sensor_simulator.startGps();
+	_ekf_wrapper.setBaroHeightRef();
+	_ekf_wrapper.enableBaroHeightFusion();
+	_ekf_wrapper.enableGpsHeightFusion();
+
+	_sensor_simulator.runSeconds(11);
+	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
+	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());
+	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::BARO);
+
+	const Vector3f previous_position = _ekf->getPosition();
+
+	ResetLoggingChecker reset_logging_checker(_ekf);
+	reset_logging_checker.capturePreResetState();
+
+	// WHEN:
+	const float gnss_height_step = 10.f;
+	_sensor_simulator._gps.stepHeightByMeters(gnss_height_step);
+
+	const float baro_height_step = 5.f;
+	_sensor_simulator._baro.setData(_sensor_simulator._baro.getData() + baro_height_step);
+	_sensor_simulator.runSeconds(20);
+
+	// THEN: then the fusion of both sensors starts to fail and the height is reset to the
+	// reference sensor (baro)
+	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
+	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());
+
+	const Vector3f new_position = _ekf->getPosition();
+	EXPECT_NEAR(new_position(2), previous_position(2) - baro_height_step, 0.2f);
+
+	// Also check the reset counters to make sure the reset logic triggered
+	reset_logging_checker.capturePostResetState();
+
+	// The velocity does not reset as baro only provides height measurement
+	EXPECT_TRUE(reset_logging_checker.isVerticalVelocityResetCounterIncreasedBy(0));
+
+	// The height resets twice in a row as the baro innovation is not corrected after a height
+	// reset and triggers a new reset at the next iteration
+	EXPECT_TRUE(reset_logging_checker.isVerticalPositionResetCounterIncreasedBy(2));
+}
+
 TEST_F(EkfHeightFusionTest, changeEkfOriginAlt)
 {
 	_sensor_simulator.startBaro();