/* Copyright (c) 2014 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.
*
****************************************************************************/
/**
* @file mc_att_control_base.h
*
* @author Roman Bapst <bapstr@ethz.ch>
*
*/
#include "mc_att_control_base.h"
#include <geo/geo.h>
#include <math.h>
#ifdef CONFIG_ARCH_ARM
#else
#include <cmath>
using namespace std;
#endif
MulticopterAttitudeControlBase::MulticopterAttitudeControlBase() :
_task_should_exit(false), _control_task(-1),
_actuators_0_circuit_breaker_enabled(false),
/* performance counters */
_loop_perf(perf_alloc(PC_ELAPSED, "mc_att_control"))
{
memset(&_v_att, 0, sizeof(_v_att));
memset(&_v_att_sp, 0, sizeof(_v_att_sp));
memset(&_v_rates_sp, 0, sizeof(_v_rates_sp));
memset(&_manual_control_sp, 0, sizeof(_manual_control_sp));
memset(&_v_control_mode, 0, sizeof(_v_control_mode));
memset(&_actuators, 0, sizeof(_actuators));
memset(&_armed, 0, sizeof(_armed));
_params.att_p.zero();
_params.rate_p.zero();
_params.rate_i.zero();
_params.rate_d.zero();
_params.yaw_ff = 0.0f;
_params.yaw_rate_max = 0.0f;
_params.man_roll_max = 0.0f;
_params.man_pitch_max = 0.0f;
_params.man_yaw_max = 0.0f;
_params.acro_rate_max.zero();
_rates_prev.zero();
_rates_sp.zero();
_rates_int.zero();
_thrust_sp = 0.0f;
_att_control.zero();
_I.identity();
// setup standard gains
_params.att_p(0) = 5.0;
_params.rate_p(0) = 0.05;
_params.rate_i(0) = 0.0;
_params.rate_d(0) = 0.003;
/* pitch gains */
_params.att_p(1) = 5.0;
_params.rate_p(1) = 0.05;
_params.rate_i(1) = 0.0;
_params.rate_d(1) = 0.003;
/* yaw gains */
_params.att_p(2) = 2.8;
_params.rate_p(2) = 0.2;
_params.rate_i(2) = 0.1;
_params.rate_d(2) = 0.0;
_params.yaw_rate_max = 0.5;
_params.yaw_ff = 0.5;
_params.man_roll_max = 0.6;
_params.man_pitch_max = 0.6;
_params.man_yaw_max = 0.6;
}
MulticopterAttitudeControlBase::~MulticopterAttitudeControlBase() {
}
void MulticopterAttitudeControlBase::vehicle_attitude_setpoint_poll() {
}
void MulticopterAttitudeControlBase::control_attitude(float dt) {
float yaw_sp_move_rate = 0.0f;
bool publish_att_sp = false;
if (_v_control_mode.flag_control_manual_enabled) {
/* manual input, set or modify attitude setpoint */
if (_v_control_mode.flag_control_velocity_enabled
|| _v_control_mode.flag_control_climb_rate_enabled) {
/* in assisted modes poll 'vehicle_attitude_setpoint' topic and modify it */
vehicle_attitude_setpoint_poll();
}
if (!_v_control_mode.flag_control_climb_rate_enabled) {
/* pass throttle directly if not in altitude stabilized mode */
_v_att_sp.thrust = _manual_control_sp.z;
publish_att_sp = true;
}
if (!_armed.armed) {
/* reset yaw setpoint when disarmed */
_reset_yaw_sp = true;
}
/* move yaw setpoint in all modes */
if (_v_att_sp.thrust < 0.1f) {
// TODO
//if (_status.condition_landed) {
/* reset yaw setpoint if on ground */
// reset_yaw_sp = true;
//}
} else {
/* move yaw setpoint */
yaw_sp_move_rate = _manual_control_sp.r * _params.man_yaw_max;
_v_att_sp.yaw_body = _wrap_pi(
_v_att_sp.yaw_body + yaw_sp_move_rate * dt);
float yaw_offs_max = _params.man_yaw_max / _params.att_p(2);
float yaw_offs = _wrap_pi(_v_att_sp.yaw_body - _v_att.yaw);
if (yaw_offs < -yaw_offs_max) {
_v_att_sp.yaw_body = _wrap_pi(_v_att.yaw - yaw_offs_max);
} else if (yaw_offs > yaw_offs_max) {
_v_att_sp.yaw_body = _wrap_pi(_v_att.yaw + yaw_offs_max);
}
_v_att_sp.R_valid = false;
publish_att_sp = true;
}
/* reset yaw setpint to current position if needed */
if (_reset_yaw_sp) {
_reset_yaw_sp = false;
_v_att_sp.yaw_body = _v_att.yaw;
_v_att_sp.R_valid = false;
publish_att_sp = true;
}
if (!_v_control_mode.flag_control_velocity_enabled) {
/* update attitude setpoint if not in position control mode */
_v_att_sp.roll_body = _manual_control_sp.y * _params.man_roll_max;
_v_att_sp.pitch_body = -_manual_control_sp.x
* _params.man_pitch_max;
_v_att_sp.R_valid = false;
publish_att_sp = true;
}
} else {
/* in non-manual mode use 'vehicle_attitude_setpoint' topic */
vehicle_attitude_setpoint_poll();
/* reset yaw setpoint after non-manual control mode */
_reset_yaw_sp = true;
}
_thrust_sp = _v_att_sp.thrust;
/* construct attitude setpoint rotation matrix */
math::Matrix<3, 3> R_sp;
if (_v_att_sp.R_valid) {
/* rotation matrix in _att_sp is valid, use it */
R_sp.set(&_v_att_sp.R_body[0][0]);
} else {
/* rotation matrix in _att_sp is not valid, use euler angles instead */
R_sp.from_euler(_v_att_sp.roll_body, _v_att_sp.pitch_body,
_v_att_sp.yaw_body);
/* copy rotation matrix back to setpoint struct */
memcpy(&_v_att_sp.R_body[0][0], &R_sp.data[0][0],
sizeof(_v_att_sp.R_body));
_v_att_sp.R_valid = true;
}
// /* publish the attitude setpoint if needed */
// if (publish_att_sp) {
// _v_att_sp.timestamp = hrt_absolute_time();
//
// if (_att_sp_pub > 0) {
// orb_publish(ORB_ID(vehicle_attitude_setpoint), _att_sp_pub,
// &_v_att_sp);
//
// } else {
// _att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint),
// &_v_att_sp);
// }
// }
/* rotation matrix for current state */
math::Matrix<3, 3> R;
R.set(_v_att.R);
/* all input data is ready, run controller itself */
/* try to move thrust vector shortest way, because yaw response is slower than roll/pitch */
math::Vector < 3 > R_z(R(0, 2), R(1, 2), R(2, 2));
math::Vector < 3 > R_sp_z(R_sp(0, 2), R_sp(1, 2), R_sp(2, 2));
/* axis and sin(angle) of desired rotation */
math::Vector < 3 > e_R = R.transposed() * (R_z % R_sp_z);
/* calculate angle error */
float e_R_z_sin = e_R.length();
float e_R_z_cos = R_z * R_sp_z;
/* calculate weight for yaw control */
float yaw_w = R_sp(2, 2) * R_sp(2, 2);
/* calculate rotation matrix after roll/pitch only rotation */
math::Matrix<3, 3> R_rp;
if (e_R_z_sin > 0.0f) {
/* get axis-angle representation */
float e_R_z_angle = atan2f(e_R_z_sin, e_R_z_cos);
math::Vector < 3 > e_R_z_axis = e_R / e_R_z_sin;
e_R = e_R_z_axis * e_R_z_angle;
/* cross product matrix for e_R_axis */
math::Matrix<3, 3> e_R_cp;
e_R_cp.zero();
e_R_cp(0, 1) = -e_R_z_axis(2);
e_R_cp(0, 2) = e_R_z_axis(1);
e_R_cp(1, 0) = e_R_z_axis(2);
e_R_cp(1, 2) = -e_R_z_axis(0);
e_R_cp(2, 0) = -e_R_z_axis(1);
e_R_cp(2, 1) = e_R_z_axis(0);
/* rotation matrix for roll/pitch only rotation */
R_rp = R
* (_I + e_R_cp * e_R_z_sin
+ e_R_cp * e_R_cp * (1.0f - e_R_z_cos));
} else {
/* zero roll/pitch rotation */
R_rp = R;
}
/* R_rp and R_sp has the same Z axis, calculate yaw error */
math::Vector < 3 > R_sp_x(R_sp(0, 0), R_sp(1, 0), R_sp(2, 0));
math::Vector < 3 > R_rp_x(R_rp(0, 0), R_rp(1, 0), R_rp(2, 0));
e_R(2) = atan2f((R_rp_x % R_sp_x) * R_sp_z, R_rp_x * R_sp_x) * yaw_w;
if (e_R_z_cos < 0.0f) {
/* for large thrust vector rotations use another rotation method:
* calculate angle and axis for R -> R_sp rotation directly */
math::Quaternion q;
q.from_dcm(R.transposed() * R_sp);
math::Vector < 3 > e_R_d = q.imag();
e_R_d.normalize();
e_R_d *= 2.0f * atan2f(e_R_d.length(), q(0));
/* use fusion of Z axis based rotation and direct rotation */
float direct_w = e_R_z_cos * e_R_z_cos * yaw_w;
e_R = e_R * (1.0f - direct_w) + e_R_d * direct_w;
}
/* calculate angular rates setpoint */
_rates_sp = _params.att_p.emult(e_R);
/* limit yaw rate */
_rates_sp(2) = math::constrain(_rates_sp(2), -_params.yaw_rate_max,
_params.yaw_rate_max);
/* feed forward yaw setpoint rate */
_rates_sp(2) += yaw_sp_move_rate * yaw_w * _params.yaw_ff;
}
void MulticopterAttitudeControlBase::control_attitude_rates(float dt) {
/* reset integral if disarmed */
if (!_armed.armed) {
_rates_int.zero();
}
/* current body angular rates */
math::Vector < 3 > rates;
rates(0) = _v_att.rollspeed;
rates(1) = _v_att.pitchspeed;
rates(2) = _v_att.yawspeed;
/* angular rates error */
math::Vector < 3 > rates_err = _rates_sp - rates;
_att_control = _params.rate_p.emult(rates_err)
+ _params.rate_d.emult(_rates_prev - rates) / dt + _rates_int;
_rates_prev = rates;
/* update integral only if not saturated on low limit */
if (_thrust_sp > MIN_TAKEOFF_THRUST) {
for (int i = 0; i < 3; i++) {
if (fabsf(_att_control(i)) < _thrust_sp) {
float rate_i = _rates_int(i)
+ _params.rate_i(i) * rates_err(i) * dt;
if (isfinite(
rate_i) && rate_i > -RATES_I_LIMIT && rate_i < RATES_I_LIMIT &&
_att_control(i) > -RATES_I_LIMIT && _att_control(i) < RATES_I_LIMIT) {
_rates_int(i) = rate_i;
}
}
}
}
}
void MulticopterAttitudeControlBase::set_actuator_controls() {
_actuators.control[0] = (isfinite(_att_control(0))) ? _att_control(0) : 0.0f;
_actuators.control[1] = (isfinite(_att_control(1))) ? _att_control(1) : 0.0f;
_actuators.control[2] = (isfinite(_att_control(2))) ? _att_control(2) : 0.0f;
_actuators.control[3] = (isfinite(_thrust_sp)) ? _thrust_sp : 0.0f;
}
void MulticopterAttitudeControlBase::set_attitude(const Eigen::Quaternion<double> attitude) {
math::Quaternion quat;
quat(0) = (float)attitude.w();
quat(1) = (float)attitude.x();
quat(2) = (float)attitude.y();
quat(3) = (float)attitude.z();
_v_att.q[0] = quat(0);
_v_att.q[1] = quat(1);
_v_att.q[2] = quat(2);
_v_att.q[3] = quat(3);
math::Matrix<3,3> Rot = quat.to_dcm();
_v_att.R[0][0] = Rot(0,0);
_v_att.R[1][0] = Rot(1,0);
_v_att.R[2][0] = Rot(2,0);
_v_att.R[0][1] = Rot(0,1);
_v_att.R[1][1] = Rot(1,1);
_v_att.R[2][1] = Rot(2,1);
_v_att.R[0][2] = Rot(0,2);
_v_att.R[1][2] = Rot(1,2);
_v_att.R[2][2] = Rot(2,2);
_v_att.R_valid = true;
}
void MulticopterAttitudeControlBase::set_attitude_rates(const Eigen::Vector3d& angular_rate) {
// check if this is consistent !!!
_v_att.rollspeed = angular_rate(0);
_v_att.pitchspeed = angular_rate(1);
_v_att.yawspeed = angular_rate(2);
}
void MulticopterAttitudeControlBase::set_attitude_reference(const Eigen::Vector4d& control_attitude_thrust_reference) {
_v_att_sp.roll_body = control_attitude_thrust_reference(0);
_v_att_sp.pitch_body = control_attitude_thrust_reference(1);
_v_att_sp.yaw_body = control_attitude_thrust_reference(2);
_v_att_sp.thrust = (control_attitude_thrust_reference(3) -30)*(-1)/30;
// setup rotation matrix
math::Matrix<3,3> Rot_sp;
Rot_sp.from_euler(_v_att_sp.roll_body,_v_att_sp.pitch_body,_v_att_sp.yaw_body);
_v_att_sp.R_body[0][0] = Rot_sp(0,0);
_v_att_sp.R_body[1][0] = Rot_sp(1,0);
_v_att_sp.R_body[2][0] = Rot_sp(2,0);
_v_att_sp.R_body[0][1] = Rot_sp(0,1);
_v_att_sp.R_body[1][1] = Rot_sp(1,1);
_v_att_sp.R_body[2][1] = Rot_sp(2,1);
_v_att_sp.R_body[0][2] = Rot_sp(0,2);
_v_att_sp.R_body[1][2] = Rot_sp(1,2);
_v_att_sp.R_body[2][2] = Rot_sp(2,2);
}
void MulticopterAttitudeControlBase::get_mixer_input(Eigen::Vector4d& motor_inputs) {
motor_inputs(0) = _actuators.control[0];
motor_inputs(1) = _actuators.control[1];
motor_inputs(2) = _actuators.control[2];
motor_inputs(3) = _actuators.control[3];
}
