AttitudeControlTest.cpp

Go to the documentation of this file.

/****************************************************************************
 *
 *   Copyright (C) 2019 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.
 *
 ****************************************************************************/

#include <gtest/gtest.h>
#include <AttitudeControl.hpp>
#include <mathlib/math/Functions.hpp>

using namespace matrix;

TEST(AttitudeControlTest, AllZeroCase)
{
    AttitudeControl attitude_control;
    Vector3f rate_setpoint = attitude_control.update(Quatf(), Quatf(), 0.f);
    EXPECT_EQ(rate_setpoint, Vector3f());
}

class AttitudeControlConvergenceTest : public ::testing::Test
{
public:
    AttitudeControlConvergenceTest()
    {
        _attitude_control.setProportionalGain(Vector3f(.5f, .6f, .3f));
        _attitude_control.setRateLimit(Vector3f(100, 100, 100));
    }

    void checkConvergence()
    {
        int i; // need function scope to check how many steps
        Vector3f rate_setpoint(1000, 1000, 1000);

        for (i = 100; i > 0; i--) {
            // run attitude control to get rate setpoints
            const Vector3f rate_setpoint_new = _attitude_control.update(_quat_state, _quat_goal, 0.f);
            // rotate the simulated state quaternion according to the rate setpoint
            _quat_state = _quat_state * Quatf(AxisAnglef(rate_setpoint_new));

            // expect the error and hence also the output to get smaller with each iteration
            if (rate_setpoint_new.norm() >= rate_setpoint.norm()) {
                break;
            }

            rate_setpoint = rate_setpoint_new;
        }

        EXPECT_EQ(adaptAntipodal(_quat_state), adaptAntipodal(_quat_goal));
        // it shouldn't have taken longer than an iteration timeout to converge
        EXPECT_GT(i, 0);
    }

    Quatf adaptAntipodal(const Quatf q)
    {
        for (int i = 0; i < 4; i++) {
            if (fabs(q(i)) > FLT_EPSILON) {
                return q * math::sign(q(i));
            }
        }

        return q;
    }

    AttitudeControl _attitude_control;
    Quatf _quat_state;
    Quatf _quat_goal;
};

TEST_F(AttitudeControlConvergenceTest, AttitudeControlConvergence)
{
    const int inputs = 8;

    const Quatf QArray[inputs] = {
        Quatf(),
        Quatf(0, 1, 0, 0),
        Quatf(0, 0, 1, 0),
        Quatf(0, 0, 0, 1),
        Quatf(0.698f, 0.024f, -0.681f, -0.220f),
        Quatf(-0.820f, -0.313f, 0.225f, -0.423f),
        Quatf(0.599f, -0.172f, 0.755f, -0.204f),
        Quatf(0.216f, -0.662f, 0.290f, -0.656f)
    };

    for (int i = 0; i < inputs; i++) {
        for (int j = 0; j < inputs; j++) {
            printf("--- Input combination: %d %d\n", i, j);
            _quat_state = QArray[i];
            _quat_goal = QArray[j];
            _quat_state.normalize();
            _quat_goal.normalize();
            checkConvergence();
        }
    }
}