terrain_estimator: add unit tests

test/CMakeLists.txt

@@ -51,6 +51,7 @@ set(SRCS
 	test_EKF_airspeed.cpp
 	test_EKF_withReplayData.cpp
 	test_EKF_flow.cpp
+	test_EKF_terrain_estimator.cpp
 	test_SensorRangeFinder.cpp
 	test_geo.cpp
    )

test/sensor_simulator/ekf_wrapper.cpp

@@ -177,6 +177,40 @@ bool EkfWrapper::isWindVelocityEstimated() const
 	return control_status.flags.wind;
 }
 
+void EkfWrapper::enableTerrainRngFusion()
+{
+	_ekf_params->terrain_fusion_mode |= TerrainFusionMask::TerrainFuseRangeFinder;
+}
+
+void EkfWrapper::disableTerrainRngFusion()
+{
+	_ekf_params->terrain_fusion_mode &= ~TerrainFusionMask::TerrainFuseRangeFinder;
+}
+
+bool EkfWrapper::isIntendingTerrainRngFusion() const
+{
+	terrain_fusion_status_u terrain_status;
+	terrain_status.value = _ekf->getTerrainEstimateSensorBitfield();
+	return terrain_status.flags.range_finder;
+}
+
+void EkfWrapper::enableTerrainFlowFusion()
+{
+	_ekf_params->terrain_fusion_mode |= TerrainFusionMask::TerrainFuseOpticalFlow;
+}
+
+void EkfWrapper::disableTerrainFlowFusion()
+{
+	_ekf_params->terrain_fusion_mode &= ~TerrainFusionMask::TerrainFuseOpticalFlow;
+}
+
+bool EkfWrapper::isIntendingTerrainFlowFusion() const
+{
+	terrain_fusion_status_u terrain_status;
+	terrain_status.value = _ekf->getTerrainEstimateSensorBitfield();
+	return terrain_status.flags.flow;
+}
+
 Eulerf EkfWrapper::getEulerAngles() const
 {
 	return Eulerf(_ekf->getQuaternion());

test/sensor_simulator/ekf_wrapper.h

@@ -89,6 +89,14 @@ public:
 
 	bool isWindVelocityEstimated() const;
 
+	void enableTerrainRngFusion();
+	void disableTerrainRngFusion();
+	bool isIntendingTerrainRngFusion() const;
+
+	void enableTerrainFlowFusion();
+	void disableTerrainFlowFusion();
+	bool isIntendingTerrainFlowFusion() const;
+
 	Eulerf getEulerAngles() const;
 	float getYawAngle() const;
 	matrix::Vector<float, 4> getQuaternionVariance() const;

test/sensor_simulator/flow.cpp

@@ -15,7 +15,7 @@ Flow::~Flow()
 
 void Flow::send(uint64_t time)
 {
-	_flow_data.dt = time - _time_last_data_sent;
+	_flow_data.dt = static_cast<float>(time - _time_last_data_sent) * 1e-6f;
 	_flow_data.time_us = time;
 	_ekf->setOpticalFlowData(_flow_data);
 }

test/test_EKF_flow.cpp

@@ -32,7 +32,7 @@
  ****************************************************************************/
 
 /**
- * Test the gps fusion
+ * Test the flow fusion
  * @author Kamil Ritz <ka.ritz@hotmail.com>
  */
 
@@ -89,8 +89,8 @@ TEST_F(EkfFlowTest, resetToFlowVelocityInAir)
 	const Vector2f simulated_horz_velocity(0.5f, -0.2f);
 	flowSample flow_sample = _sensor_simulator._flow.dataAtRest();
 	flow_sample.flow_xy_rad =
-		Vector2f(- simulated_horz_velocity(1) * flow_sample.dt / estimated_distance_to_ground,
-			   simulated_horz_velocity(0) * flow_sample.dt / estimated_distance_to_ground);
+		Vector2f( simulated_horz_velocity(1) * flow_sample.dt / estimated_distance_to_ground,
+			 -simulated_horz_velocity(0) * flow_sample.dt / estimated_distance_to_ground);
 	_sensor_simulator._flow.setData(flow_sample);
 	_ekf_wrapper.enableFlowFusion();
 	const float max_flow_rate = 5.f;

test/test_EKF_terrain_estimator.cpp

@@ -0,0 +1,176 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2020 ECL 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 the terrain estimator
+ * @author Mathieu Bresciani <brescianimathieu@gmail.com>
+ */
+
+#include <gtest/gtest.h>
+#include "EKF/ekf.h"
+#include "sensor_simulator/sensor_simulator.h"
+#include "sensor_simulator/ekf_wrapper.h"
+
+class EkfTerrainTest : public ::testing::Test {
+ public:
+
+	EkfTerrainTest(): ::testing::Test(),
+	_ekf{std::make_shared<Ekf>()},
+	_sensor_simulator(_ekf),
+	_ekf_wrapper(_ekf) {};
+
+	std::shared_ptr<Ekf> _ekf;
+	SensorSimulator _sensor_simulator;
+	EkfWrapper _ekf_wrapper;
+
+	// Setup the Ekf with synthetic measurements
+	void SetUp() override
+	{
+		_ekf->init(0);
+		_sensor_simulator.runSeconds(2);
+	}
+
+	// Use this method to clean up any memory, network etc. after each test
+	void TearDown() override
+	{
+	}
+
+	void runFlowAndRngScenario(const float rng_height, const float flow_height)
+	{
+		_sensor_simulator.startGps();
+		_ekf->set_min_required_gps_health_time(1e6);
+		_ekf_wrapper.enableGpsFusion();
+		_ekf_wrapper.setBaroHeight();
+		_sensor_simulator.runSeconds(2); // Run to pass the GPS checks
+
+		const Vector3f simulated_velocity(0.5f, -1.0f, 0.f);
+
+		// Configure GPS simulator data
+		_sensor_simulator._gps.setVelocity(simulated_velocity);
+		_sensor_simulator._gps.setPositionRateNED(simulated_velocity);
+
+		// Configure range finder simulator data
+		_sensor_simulator._rng.setData(rng_height, 100);
+		_sensor_simulator._rng.setLimits(0.1f, 20.f);
+		_sensor_simulator.startRangeFinder();
+
+		// Configure optical flow simulator data
+		flowSample flow_sample = _sensor_simulator._flow.dataAtRest();
+		flow_sample.flow_xy_rad =
+			Vector2f( simulated_velocity(1) * flow_sample.dt / flow_height,
+				 -simulated_velocity(0) * flow_sample.dt / flow_height);
+		_sensor_simulator._flow.setData(flow_sample);
+		const float max_flow_rate = 5.f;
+		const float min_ground_distance = 0.f;
+		const float max_ground_distance = 50.f;
+		_ekf->set_optical_flow_limits(max_flow_rate, min_ground_distance, max_ground_distance);
+		_sensor_simulator.startFlow();
+
+		_ekf->set_in_air_status(true);
+		_sensor_simulator.runSeconds(8);
+	}
+};
+
+TEST_F(EkfTerrainTest, setFlowAndRangeTerrainFusion)
+{
+	// WHEN: simulate being 5m above ground
+	// By default, both rng and flow aiding are active
+	const float simulated_distance_to_ground = 1.f;
+	_sensor_simulator._rng.setData(simulated_distance_to_ground, 100);
+	_sensor_simulator._rng.setLimits(0.1f, 9.f);
+	_sensor_simulator.startRangeFinder();
+	_ekf->set_in_air_status(true);
+	_sensor_simulator.runSeconds(1.5f);
+
+	// THEN: By default, both rng and flow aiding are active
+	EXPECT_TRUE(_ekf_wrapper.isIntendingTerrainRngFusion());
+	EXPECT_TRUE(_ekf_wrapper.isIntendingTerrainFlowFusion());
+	const float estimated_distance_to_ground = _ekf->getTerrainVertPos();
+	EXPECT_FLOAT_EQ(estimated_distance_to_ground, simulated_distance_to_ground);
+
+	// WHEN: rng fusion is disabled
+	_ekf_wrapper.disableTerrainRngFusion();
+	_sensor_simulator.runSeconds(0.2);
+
+	// THEN: only rng fusion should be disabled
+	EXPECT_FALSE(_ekf_wrapper.isIntendingTerrainRngFusion());
+	EXPECT_TRUE(_ekf_wrapper.isIntendingTerrainFlowFusion());
+
+	// WHEN: flow is now diabled
+	_ekf_wrapper.disableTerrainFlowFusion();
+	_sensor_simulator.runSeconds(0.2);
+
+	// THEN: flow is now also disabled
+	EXPECT_FALSE(_ekf_wrapper.isIntendingTerrainRngFusion());
+	EXPECT_FALSE(_ekf_wrapper.isIntendingTerrainFlowFusion());
+}
+
+TEST_F(EkfTerrainTest, testFlowForTerrainFusion)
+{
+	// GIVEN: flow for terrain enabled but not range finder
+	_ekf_wrapper.enableTerrainFlowFusion();
+	_ekf_wrapper.disableTerrainRngFusion();
+
+	// WHEN: the sensors do not agree
+	const float rng_height = 1.f;
+	const float flow_height = 5.f;
+	runFlowAndRngScenario(rng_height, flow_height);
+
+	// THEN: the estimator should use flow for terrain and the estimated terrain height
+	// should converge to the simulated height
+	EXPECT_FALSE(_ekf_wrapper.isIntendingTerrainRngFusion());
+	EXPECT_TRUE(_ekf_wrapper.isIntendingTerrainFlowFusion());
+
+	const float estimated_distance_to_ground = _ekf->getTerrainVertPos();
+	EXPECT_NEAR(estimated_distance_to_ground, flow_height, 0.5f);
+}
+
+TEST_F(EkfTerrainTest, testRngForTerrainFusion)
+{
+	// GIVEN: rng for terrain but not flow
+	_ekf_wrapper.disableTerrainFlowFusion();
+	_ekf_wrapper.enableTerrainRngFusion();
+
+	// WHEN: the sensors do not agree
+	const float rng_height = 1.f;
+	const float flow_height = 5.f;
+	runFlowAndRngScenario(rng_height, flow_height);
+
+	// THEN: the estimator should use rng for terrain and the estimated terrain height
+	// should converge to the simulated height
+	EXPECT_TRUE(_ekf_wrapper.isIntendingTerrainRngFusion());
+	EXPECT_FALSE(_ekf_wrapper.isIntendingTerrainFlowFusion());
+
+	const float estimated_distance_to_ground = _ekf->getTerrainVertPos();
+	EXPECT_NEAR(estimated_distance_to_ground, rng_height, 0.01f);
+}