test: add test for range finder fusion while on ground

src/modules/ekf2/test/CMakeLists.txt

@@ -62,3 +62,4 @@ px4_add_unit_gtest(SRC test_EKF_yaw_estimator.cpp LINKLIBS ecl_EKF ecl_sensor_si
 px4_add_unit_gtest(SRC test_EKF_yaw_fusion_generated.cpp LINKLIBS ecl_EKF ecl_test_helper)
 px4_add_unit_gtest(SRC test_SensorRangeFinder.cpp LINKLIBS ecl_EKF ecl_sensor_sim)
 px4_add_unit_gtest(SRC test_EKF_drag_fusion.cpp LINKLIBS ecl_EKF ecl_sensor_sim)
+px4_add_unit_gtest(SRC test_EKF_grounded.cpp LINKLIBS ecl_EKF ecl_sensor_sim)

src/modules/ekf2/test/test_EKF_grounded.cpp

@@ -0,0 +1,98 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2025 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * Test EKF altitude estimation while grounded and using Rangefinder as primary alt source
+ */
+
+#include <gtest/gtest.h>
+#include "EKF/ekf.h"
+#include "sensor_simulator/sensor_simulator.h"
+#include "sensor_simulator/ekf_wrapper.h"
+#include "test_helper/reset_logging_checker.h"
+
+class EkfGroundedTest : public ::testing::Test
+{
+public:
+
+	EkfGroundedTest(): ::testing::Test(),
+		_ekf{std::make_shared<Ekf>()},
+		_sensor_simulator(_ekf),
+		_ekf_wrapper(_ekf) {};
+
+	std::shared_ptr<Ekf> _ekf;
+	SensorSimulator _sensor_simulator;
+	EkfWrapper _ekf_wrapper;
+
+	void SetUp() override
+	{
+		// Init EKF
+		_ekf->init(0);
+		_sensor_simulator.runSeconds(0.1);
+		_ekf->set_in_air_status(false);
+		_ekf->set_vehicle_at_rest(true);
+
+		_sensor_simulator._rng.setData(0.1f, 100);
+		_sensor_simulator._rng.setLimits(0.1f, 25.f);
+
+		_sensor_simulator.startGps();
+		_sensor_simulator.startBaro();
+		_sensor_simulator.startRangeFinder();
+
+		// Set Range as primary height source
+		_ekf_wrapper.setRangeHeightRef();
+
+		// Enable fusion for all height sources
+		_ekf_wrapper.enableBaroHeightFusion();
+		_ekf_wrapper.enableGpsHeightFusion();
+		_ekf_wrapper.enableRangeHeightFusion();
+
+		// Give EKF time for GPS
+		_sensor_simulator.runSeconds(20);
+	}
+};
+
+TEST_F(EkfGroundedTest, rangeFinderOnGround)
+{
+	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::RANGE);
+	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());
+	EXPECT_TRUE(_ekf_wrapper.isIntendingRangeHeightFusion());
+	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
+
+	float distance = 0.17f;
+	_sensor_simulator._rng.setData(distance, 100);
+
+	_sensor_simulator.runSeconds(60);
+
+	EXPECT_NEAR(_ekf->getLatLonAlt().altitude(), 0, 0.5f);
+}