/home/travis/build/lis-epfl/MAVRIC_Library/control/attitude_error_estimator.hpp

/*******************************************************************************
 * Copyright (c) 2009-2016, MAV'RIC 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 of the copyright holder 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 HOLDER 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.
 ******************************************************************************/

/*******************************************************************************
 * \file attitude_error_estimator.hpp
 *
 * \author MAV'RIC Team
 * \author Julien Lecoeur
 *
 * \brief A quaternion-based attitude-error estimator, takes a reference
 * quaternion as input and provides angular errors for roll, pitch and yaw in
 * the local frame.
 *
 * \details  WARNING: For optimisation purpose, the computed errors are not in
 * radians:
 * With \f$ e_{roll} , e_{pitch}, e_{yaw} \f$ the true errors in radians around
 * the local roll, pitch and yaw axes,
 * this estimator returns
 * \f$ 2.sin( e_{roll} / 2 ), 2.sin( e_{pitch} / 2 ), 2.sin( e_{yaw} / 2 ) \f$
 *
 * For small angular errors, this approximation is sensible.
 *
 ******************************************************************************/


#ifndef ATTITUDE_ERROR_ESTIMATOR_HPP_
#define ATTITUDE_ERROR_ESTIMATOR_HPP_

#include "util/coord_conventions.hpp"
#include "util/quaternions.h"
#include "sensing/ahrs.hpp"

typedef struct
{
    quat_t quat_ref;            
    float rpy_errors[3];        
    const AHRS* ahrs;         
} attitude_error_estimator_t;


bool attitude_error_estimator_init(attitude_error_estimator_t* estimator, const AHRS* ahrs);


void attitude_error_estimator_set_quat_ref(attitude_error_estimator_t* estimator, const quat_t quat_ref);


void attitude_error_estimator_set_quat_ref_from_aero(attitude_error_estimator_t* estimator, const aero_attitude_t aero);


void attitude_error_estimator_set_quat_ref_from_rpy(attitude_error_estimator_t* estimator, const float rpy[3]);


bool attitude_error_estimator_update(attitude_error_estimator_t* estimator);


#endif /* ATTITUDE_ERROR_ESTIMATOR_HPP_ */