/****************************************************************************
*
* Copyright (c) 2013, 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
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****************************************************************************/
/**
* @file mc_pos_control_main.cpp
* Multicopter position controller.
*
* The controller has two loops: P loop for position error and PID loop for velocity error.
* Output of velocity controller is thrust vector that splitted to thrust direction
* (i.e. rotation matrix for multicopter orientation) and thrust module (i.e. multicopter thrust itself).
* Controller doesn't use Euler angles for work, they generated only for more human-friendly control and logging.
*
* @author Anton Babushkin <anton.babushkin@me.com>
*/
#include <nuttx/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <math.h>
#include <poll.h>
#include <drivers/drv_hrt.h>
#include <arch/board/board.h>
#include <uORB/uORB.h>
#include <uORB/topics/vehicle_attitude_setpoint.h>
#include <uORB/topics/manual_control_setpoint.h>
#include <uORB/topics/actuator_controls.h>
#include <uORB/topics/vehicle_rates_setpoint.h>
#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_control_mode.h>
#include <uORB/topics/actuator_armed.h>
#include <uORB/topics/parameter_update.h>
#include <uORB/topics/vehicle_local_position.h>
#include <uORB/topics/position_setpoint_triplet.h>
#include <uORB/topics/vehicle_global_velocity_setpoint.h>
#include <uORB/topics/vehicle_local_position_setpoint.h>
#include <systemlib/param/param.h>
#include <systemlib/err.h>
#include <systemlib/systemlib.h>
#include <mathlib/mathlib.h>
#include <lib/geo/geo.h>
#include <mavlink/mavlink_log.h>
#define TILT_COS_MAX 0.7f
#define SIGMA 0.000001f
/**
* Multicopter position control app start / stop handling function
*
* @ingroup apps
*/
extern "C" __EXPORT int mc_pos_control_main(int argc, char *argv[]);
class MulticopterPositionControl
{
public:
/**
* Constructor
*/
MulticopterPositionControl();
/**
* Destructor, also kills task.
*/
~MulticopterPositionControl();
/**
* Start task.
*
* @return OK on success.
*/
int start();
private:
bool _task_should_exit; /**< if true, task should exit */
int _control_task; /**< task handle for task */
int _mavlink_fd; /**< mavlink fd */
int _att_sub; /**< vehicle attitude subscription */
int _att_sp_sub; /**< vehicle attitude setpoint */
int _control_mode_sub; /**< vehicle control mode subscription */
int _params_sub; /**< notification of parameter updates */
int _manual_sub; /**< notification of manual control updates */
int _arming_sub; /**< arming status of outputs */
int _local_pos_sub; /**< vehicle local position */
int _pos_sp_triplet_sub; /**< position setpoint triplet */
orb_advert_t _att_sp_pub; /**< attitude setpoint publication */
orb_advert_t _local_pos_sp_pub; /**< vehicle local position setpoint publication */
orb_advert_t _global_vel_sp_pub; /**< vehicle global velocity setpoint publication */
struct vehicle_attitude_s _att; /**< vehicle attitude */
struct vehicle_attitude_setpoint_s _att_sp; /**< vehicle attitude setpoint */
struct manual_control_setpoint_s _manual; /**< r/c channel data */
struct vehicle_control_mode_s _control_mode; /**< vehicle control mode */
struct actuator_armed_s _arming; /**< actuator arming status */
struct vehicle_local_position_s _local_pos; /**< vehicle local position */
struct position_setpoint_triplet_s _pos_sp_triplet; /**< vehicle global position setpoint triplet */
struct vehicle_local_position_setpoint_s _local_pos_sp; /**< vehicle local position setpoint */
struct vehicle_global_velocity_setpoint_s _global_vel_sp; /**< vehicle global velocity setpoint */
struct {
param_t thr_min;
param_t thr_max;
param_t z_p;
param_t z_vel_p;
param_t z_vel_i;
param_t z_vel_d;
param_t z_vel_max;
param_t z_ff;
param_t xy_p;
param_t xy_vel_p;
param_t xy_vel_i;
param_t xy_vel_d;
param_t xy_vel_max;
param_t xy_ff;
param_t tilt_max_air;
param_t land_speed;
param_t tilt_max_land;
} _params_handles; /**< handles for interesting parameters */
struct {
float thr_min;
float thr_max;
float tilt_max_air;
float land_speed;
float tilt_max_land;
math::Vector<3> pos_p;
math::Vector<3> vel_p;
math::Vector<3> vel_i;
math::Vector<3> vel_d;
math::Vector<3> vel_ff;
math::Vector<3> vel_max;
math::Vector<3> sp_offs_max;
} _params;
struct map_projection_reference_s _ref_pos;
float _ref_alt;
hrt_abstime _ref_timestamp;
bool _reset_pos_sp;
bool _reset_alt_sp;
math::Vector<3> _pos;
math::Vector<3> _pos_sp;
math::Vector<3> _vel;
math::Vector<3> _vel_sp;
math::Vector<3> _vel_prev; /**< velocity on previous step */
/**
* Update our local parameter cache.
*/
int parameters_update(bool force);
/**
* Update control outputs
*/
void control_update();
/**
* Check for changes in subscribed topics.
*/
void poll_subscriptions();
static float scale_control(float ctl, float end, float dz);
/**
* Update reference for local position projection
*/
void update_ref();
/**
* Reset position setpoint to current position
*/
void reset_pos_sp();
/**
* Reset altitude setpoint to current altitude
*/
void reset_alt_sp();
/**
* Select between barometric and global (AMSL) altitudes
*/
void select_alt(bool global);
/**
* Shim for calling task_main from task_create.
*/
static void task_main_trampoline(int argc, char *argv[]);
/**
* Main sensor collection task.
*/
void task_main();
};
namespace pos_control
{
/* oddly, ERROR is not defined for c++ */
#ifdef ERROR
# undef ERROR
#endif
static const int ERROR = -1;
MulticopterPositionControl *g_control;
}
MulticopterPositionControl::MulticopterPositionControl() :
_task_should_exit(false),
_control_task(-1),
_mavlink_fd(-1),
/* subscriptions */
_att_sub(-1),
_att_sp_sub(-1),
_control_mode_sub(-1),
_params_sub(-1),
_manual_sub(-1),
_arming_sub(-1),
_local_pos_sub(-1),
_pos_sp_triplet_sub(-1),
/* publications */
_att_sp_pub(-1),
_local_pos_sp_pub(-1),
_global_vel_sp_pub(-1),
_ref_alt(0.0f),
_ref_timestamp(0),
_reset_pos_sp(true),
_reset_alt_sp(true)
{
memset(&_att, 0, sizeof(_att));
memset(&_att_sp, 0, sizeof(_att_sp));
memset(&_manual, 0, sizeof(_manual));
memset(&_control_mode, 0, sizeof(_control_mode));
memset(&_arming, 0, sizeof(_arming));
memset(&_local_pos, 0, sizeof(_local_pos));
memset(&_pos_sp_triplet, 0, sizeof(_pos_sp_triplet));
memset(&_local_pos_sp, 0, sizeof(_local_pos_sp));
memset(&_global_vel_sp, 0, sizeof(_global_vel_sp));
memset(&_ref_pos, 0, sizeof(_ref_pos));
_params.pos_p.zero();
_params.vel_p.zero();
_params.vel_i.zero();
_params.vel_d.zero();
_params.vel_max.zero();
_params.vel_ff.zero();
_params.sp_offs_max.zero();
_pos.zero();
_pos_sp.zero();
_vel.zero();
_vel_sp.zero();
_vel_prev.zero();
_params_handles.thr_min = param_find("MPC_THR_MIN");
_params_handles.thr_max = param_find("MPC_THR_MAX");
_params_handles.z_p = param_find("MPC_Z_P");
_params_handles.z_vel_p = param_find("MPC_Z_VEL_P");
_params_handles.z_vel_i = param_find("MPC_Z_VEL_I");
_params_handles.z_vel_d = param_find("MPC_Z_VEL_D");
_params_handles.z_vel_max = param_find("MPC_Z_VEL_MAX");
_params_handles.z_ff = param_find("MPC_Z_FF");
_params_handles.xy_p = param_find("MPC_XY_P");
_params_handles.xy_vel_p = param_find("MPC_XY_VEL_P");
_params_handles.xy_vel_i = param_find("MPC_XY_VEL_I");
_params_handles.xy_vel_d = param_find("MPC_XY_VEL_D");
_params_handles.xy_vel_max = param_find("MPC_XY_VEL_MAX");
_params_handles.xy_ff = param_find("MPC_XY_FF");
_params_handles.tilt_max_air = param_find("MPC_TILTMAX_AIR");
_params_handles.land_speed = param_find("MPC_LAND_SPEED");
_params_handles.tilt_max_land = param_find("MPC_TILTMAX_LND");
/* fetch initial parameter values */
parameters_update(true);
}
MulticopterPositionControl::~MulticopterPositionControl()
{
if (_control_task != -1) {
/* task wakes up every 100ms or so at the longest */
_task_should_exit = true;
/* wait for a second for the task to quit at our request */
unsigned i = 0;
do {
/* wait 20ms */
usleep(20000);
/* if we have given up, kill it */
if (++i > 50) {
task_delete(_control_task);
break;
}
} while (_control_task != -1);
}
pos_control::g_control = nullptr;
}
int
MulticopterPositionControl::parameters_update(bool force)
{
bool updated;
struct parameter_update_s param_upd;
orb_check(_params_sub, &updated);
if (updated) {
orb_copy(ORB_ID(parameter_update), _params_sub, ¶m_upd);
}
if (updated || force) {
param_get(_params_handles.thr_min, &_params.thr_min);
param_get(_params_handles.thr_max, &_params.thr_max);
param_get(_params_handles.tilt_max_air, &_params.tilt_max_air);
_params.tilt_max_air = math::radians(_params.tilt_max_air);
param_get(_params_handles.land_speed, &_params.land_speed);
param_get(_params_handles.tilt_max_land, &_params.tilt_max_land);
_params.tilt_max_land = math::radians(_params.tilt_max_land);
float v;
param_get(_params_handles.xy_p, &v);
_params.pos_p(0) = v;
_params.pos_p(1) = v;
param_get(_params_handles.z_p, &v);
_params.pos_p(2) = v;
param_get(_params_handles.xy_vel_p, &v);
_params.vel_p(0) = v;
_params.vel_p(1) = v;
param_get(_params_handles.z_vel_p, &v);
_params.vel_p(2) = v;
param_get(_params_handles.xy_vel_i, &v);
_params.vel_i(0) = v;
_params.vel_i(1) = v;
param_get(_params_handles.z_vel_i, &v);
_params.vel_i(2) = v;
param_get(_params_handles.xy_vel_d, &v);
_params.vel_d(0) = v;
_params.vel_d(1) = v;
param_get(_params_handles.z_vel_d, &v);
_params.vel_d(2) = v;
param_get(_params_handles.xy_vel_max, &v);
_params.vel_max(0) = v;
_params.vel_max(1) = v;
param_get(_params_handles.z_vel_max, &v);
_params.vel_max(2) = v;
param_get(_params_handles.xy_ff, &v);
_params.vel_ff(0) = v;
_params.vel_ff(1) = v;
param_get(_params_handles.z_ff, &v);
_params.vel_ff(2) = v;
_params.sp_offs_max = _params.vel_max.edivide(_params.pos_p) * 2.0f;
}
return OK;
}
void
MulticopterPositionControl::poll_subscriptions()
{
bool updated;
orb_check(_att_sub, &updated);
if (updated) {
orb_copy(ORB_ID(vehicle_attitude), _att_sub, &_att);
}
orb_check(_att_sp_sub, &updated);
if (updated) {
orb_copy(ORB_ID(vehicle_attitude_setpoint), _att_sp_sub, &_att_sp);
}
orb_check(_control_mode_sub, &updated);
if (updated) {
orb_copy(ORB_ID(vehicle_control_mode), _control_mode_sub, &_control_mode);
}
orb_check(_manual_sub, &updated);
if (updated) {
orb_copy(ORB_ID(manual_control_setpoint), _manual_sub, &_manual);
}
orb_check(_arming_sub, &updated);
if (updated) {
orb_copy(ORB_ID(actuator_armed), _arming_sub, &_arming);
}
orb_check(_local_pos_sub, &updated);
if (updated) {
orb_copy(ORB_ID(vehicle_local_position), _local_pos_sub, &_local_pos);
}
}
float
MulticopterPositionControl::scale_control(float ctl, float end, float dz)
{
if (ctl > dz) {
return (ctl - dz) / (end - dz);
} else if (ctl < -dz) {
return (ctl + dz) / (end - dz);
} else {
return 0.0f;
}
}
void
MulticopterPositionControl::task_main_trampoline(int argc, char *argv[])
{
pos_control::g_control->task_main();
}
void
MulticopterPositionControl::update_ref()
{
if (_local_pos.ref_timestamp != _ref_timestamp) {
double lat_sp, lon_sp;
float alt_sp;
if (_ref_timestamp != 0) {
/* calculate current position setpoint in global frame */
map_projection_reproject(&_ref_pos, _pos_sp(0), _pos_sp(1), &lat_sp, &lon_sp);
alt_sp = _ref_alt - _pos_sp(2);
}
/* update local projection reference */
map_projection_init(&_ref_pos, _local_pos.ref_lat, _local_pos.ref_lon);
_ref_alt = _local_pos.ref_alt;
if (_ref_timestamp != 0) {
/* reproject position setpoint to new reference */
map_projection_project(&_ref_pos, lat_sp, lon_sp, &_pos_sp.data[0], &_pos_sp.data[1]);
_pos_sp(2) = -(alt_sp - _ref_alt);
}
_ref_timestamp = _local_pos.ref_timestamp;
}
}
void
MulticopterPositionControl::reset_pos_sp()
{
if (_reset_pos_sp) {
_reset_pos_sp = false;
_pos_sp(0) = _pos(0);
_pos_sp(1) = _pos(1);
mavlink_log_info(_mavlink_fd, "[mpc] reset pos sp: %.2f, %.2f", (double)_pos_sp(0), (double)_pos_sp(1));
}
}
void
MulticopterPositionControl::reset_alt_sp()
{
if (_reset_alt_sp) {
_reset_alt_sp = false;
_pos_sp(2) = _pos(2);
mavlink_log_info(_mavlink_fd, "[mpc] reset alt sp: %.2f", -(double)_pos_sp(2));
}
}
void
MulticopterPositionControl::task_main()
{
warnx("started");
_mavlink_fd = open(MAVLINK_LOG_DEVICE, 0);
mavlink_log_info(_mavlink_fd, "[mpc] started");
/*
* do subscriptions
*/
_att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
_att_sp_sub = orb_subscribe(ORB_ID(vehicle_attitude_setpoint));
_control_mode_sub = orb_subscribe(ORB_ID(vehicle_control_mode));
_params_sub = orb_subscribe(ORB_ID(parameter_update));
_manual_sub = orb_subscribe(ORB_ID(manual_control_setpoint));
_arming_sub = orb_subscribe(ORB_ID(actuator_armed));
_local_pos_sub = orb_subscribe(ORB_ID(vehicle_local_position));
_pos_sp_triplet_sub = orb_subscribe(ORB_ID(position_setpoint_triplet));
parameters_update(true);
/* initialize values of critical structs until first regular update */
_arming.armed = false;
/* get an initial update for all sensor and status data */
poll_subscriptions();
bool reset_int_z = true;
bool reset_int_z_manual = false;
bool reset_int_xy = true;
bool was_armed = false;
hrt_abstime t_prev = 0;
const float alt_ctl_dz = 0.2f;
const float pos_ctl_dz = 0.05f;
math::Vector<3> sp_move_rate;
sp_move_rate.zero();
math::Vector<3> thrust_int;
thrust_int.zero();
math::Matrix<3, 3> R;
R.identity();
/* wakeup source */
struct pollfd fds[1];
fds[0].fd = _local_pos_sub;
fds[0].events = POLLIN;
while (!_task_should_exit) {
/* wait for up to 500ms for data */
int pret = poll(&fds[0], (sizeof(fds) / sizeof(fds[0])), 500);
/* timed out - periodic check for _task_should_exit */
if (pret == 0) {
continue;
}
/* this is undesirable but not much we can do */
if (pret < 0) {
warn("poll error %d, %d", pret, errno);
continue;
}
poll_subscriptions();
parameters_update(false);
hrt_abstime t = hrt_absolute_time();
float dt = t_prev != 0 ? (t - t_prev) * 0.000001f : 0.0f;
t_prev = t;
if (_control_mode.flag_armed && !was_armed) {
/* reset setpoints and integrals on arming */
_reset_pos_sp = true;
_reset_alt_sp = true;
reset_int_z = true;
reset_int_xy = true;
}
was_armed = _control_mode.flag_armed;
update_ref();
if (_control_mode.flag_control_altitude_enabled ||
_control_mode.flag_control_position_enabled ||
_control_mode.flag_control_climb_rate_enabled ||
_control_mode.flag_control_velocity_enabled) {
_pos(0) = _local_pos.x;
_pos(1) = _local_pos.y;
_pos(2) = _local_pos.z;
_vel(0) = _local_pos.vx;
_vel(1) = _local_pos.vy;
_vel(2) = _local_pos.vz;
sp_move_rate.zero();
/* select control source */
if (_control_mode.flag_control_manual_enabled) {
/* manual control */
if (_control_mode.flag_control_altitude_enabled) {
/* reset alt setpoint to current altitude if needed */
reset_alt_sp();
/* move altitude setpoint with throttle stick */
sp_move_rate(2) = -scale_control(_manual.z - 0.5f, 0.5f, alt_ctl_dz);
}
if (_control_mode.flag_control_position_enabled) {
/* reset position setpoint to current position if needed */
reset_pos_sp();
/* move position setpoint with roll/pitch stick */
sp_move_rate(0) = _manual.x;
sp_move_rate(1) = _manual.y;
}
/* limit setpoint move rate */
float sp_move_norm = sp_move_rate.length();
if (sp_move_norm > 1.0f) {
sp_move_rate /= sp_move_norm;
}
/* scale to max speed and rotate around yaw */
math::Matrix<3, 3> R_yaw_sp;
R_yaw_sp.from_euler(0.0f, 0.0f, _att_sp.yaw_body);
sp_move_rate = R_yaw_sp * sp_move_rate.emult(_params.vel_max);
/* move position setpoint */
_pos_sp += sp_move_rate * dt;
/* check if position setpoint is too far from actual position */
math::Vector<3> pos_sp_offs;
pos_sp_offs.zero();
if (_control_mode.flag_control_position_enabled) {
pos_sp_offs(0) = (_pos_sp(0) - _pos(0)) / _params.sp_offs_max(0);
pos_sp_offs(1) = (_pos_sp(1) - _pos(1)) / _params.sp_offs_max(1);
}
if (_control_mode.flag_control_altitude_enabled) {
pos_sp_offs(2) = (_pos_sp(2) - _pos(2)) / _params.sp_offs_max(2);
}
float pos_sp_offs_norm = pos_sp_offs.length();
if (pos_sp_offs_norm > 1.0f) {
pos_sp_offs /= pos_sp_offs_norm;
_pos_sp = _pos + pos_sp_offs.emult(_params.sp_offs_max);
}
} else {
/* AUTO */
bool updated;
orb_check(_pos_sp_triplet_sub, &updated);
if (updated) {
orb_copy(ORB_ID(position_setpoint_triplet), _pos_sp_triplet_sub, &_pos_sp_triplet);
}
if (_pos_sp_triplet.current.valid) {
/* in case of interrupted mission don't go to waypoint but stay at current position */
_reset_pos_sp = true;
_reset_alt_sp = true;
/* project setpoint to local frame */
map_projection_project(&_ref_pos,
_pos_sp_triplet.current.lat, _pos_sp_triplet.current.lon,
&_pos_sp.data[0], &_pos_sp.data[1]);
_pos_sp(2) = -(_pos_sp_triplet.current.alt - _ref_alt);
/* update yaw setpoint if needed */
if (isfinite(_pos_sp_triplet.current.yaw)) {
_att_sp.yaw_body = _pos_sp_triplet.current.yaw;
}
} else {
/* no waypoint, loiter, reset position setpoint if needed */
reset_pos_sp();
reset_alt_sp();
}
}
/* fill local position setpoint */
_local_pos_sp.x = _pos_sp(0);
_local_pos_sp.y = _pos_sp(1);
_local_pos_sp.z = _pos_sp(2);
_local_pos_sp.yaw = _att_sp.yaw_body;
/* publish local position setpoint */
if (_local_pos_sp_pub > 0) {
orb_publish(ORB_ID(vehicle_local_position_setpoint), _local_pos_sp_pub, &_local_pos_sp);
} else {
_local_pos_sp_pub = orb_advertise(ORB_ID(vehicle_local_position_setpoint), &_local_pos_sp);
}
if (!_control_mode.flag_control_manual_enabled && _pos_sp_triplet.current.valid && _pos_sp_triplet.current.type == SETPOINT_TYPE_IDLE) {
/* idle state, don't run controller and set zero thrust */
R.identity();
memcpy(&_att_sp.R_body[0][0], R.data, sizeof(_att_sp.R_body));
_att_sp.R_valid = true;
_att_sp.roll_body = 0.0f;
_att_sp.pitch_body = 0.0f;
_att_sp.yaw_body = _att.yaw;
_att_sp.thrust = 0.0f;
_att_sp.timestamp = hrt_absolute_time();
/* publish attitude setpoint */
if (_att_sp_pub > 0) {
orb_publish(ORB_ID(vehicle_attitude_setpoint), _att_sp_pub, &_att_sp);
} else {
_att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &_att_sp);
}
} else {
/* run position & altitude controllers, calculate velocity setpoint */
math::Vector<3> pos_err = _pos_sp - _pos;
_vel_sp = pos_err.emult(_params.pos_p) + sp_move_rate.emult(_params.vel_ff);
if (!_control_mode.flag_control_altitude_enabled) {
_reset_alt_sp = true;
_vel_sp(2) = 0.0f;
}
if (!_control_mode.flag_control_position_enabled) {
_reset_pos_sp = true;
_vel_sp(0) = 0.0f;
_vel_sp(1) = 0.0f;
}
/* use constant descend rate when landing, ignore altitude setpoint */
if (!_control_mode.flag_control_manual_enabled && _pos_sp_triplet.current.valid && _pos_sp_triplet.current.type == SETPOINT_TYPE_LAND) {
_vel_sp(2) = _params.land_speed;
}
if (!_control_mode.flag_control_manual_enabled) {
/* limit 3D speed only in non-manual modes */
float vel_sp_norm = _vel_sp.edivide(_params.vel_max).length();
if (vel_sp_norm > 1.0f) {
_vel_sp /= vel_sp_norm;
}
}
_global_vel_sp.vx = _vel_sp(0);
_global_vel_sp.vy = _vel_sp(1);
_global_vel_sp.vz = _vel_sp(2);
/* publish velocity setpoint */
if (_global_vel_sp_pub > 0) {
orb_publish(ORB_ID(vehicle_global_velocity_setpoint), _global_vel_sp_pub, &_global_vel_sp);
} else {
_global_vel_sp_pub = orb_advertise(ORB_ID(vehicle_global_velocity_setpoint), &_global_vel_sp);
}
if (_control_mode.flag_control_climb_rate_enabled || _control_mode.flag_control_velocity_enabled) {
/* reset integrals if needed */
if (_control_mode.flag_control_climb_rate_enabled) {
if (reset_int_z) {
reset_int_z = false;
float i = _params.thr_min;
if (reset_int_z_manual) {
i = _manual.z;
if (i < _params.thr_min) {
i = _params.thr_min;
} else if (i > _params.thr_max) {
i = _params.thr_max;
}
}
thrust_int(2) = -i;
}
} else {
reset_int_z = true;
}
if (_control_mode.flag_control_velocity_enabled) {
if (reset_int_xy) {
reset_int_xy = false;
thrust_int(0) = 0.0f;
thrust_int(1) = 0.0f;
}
} else {
reset_int_xy = true;
}
/* velocity error */
math::Vector<3> vel_err = _vel_sp - _vel;
/* derivative of velocity error, not includes setpoint acceleration */
math::Vector<3> vel_err_d = (sp_move_rate - _vel).emult(_params.pos_p) - (_vel - _vel_prev) / dt;
_vel_prev = _vel;
/* thrust vector in NED frame */
math::Vector<3> thrust_sp = vel_err.emult(_params.vel_p) + vel_err_d.emult(_params.vel_d) + thrust_int;
if (!_control_mode.flag_control_velocity_enabled) {
thrust_sp(0) = 0.0f;
thrust_sp(1) = 0.0f;
}
if (!_control_mode.flag_control_climb_rate_enabled) {
thrust_sp(2) = 0.0f;
}
/* limit thrust vector and check for saturation */
bool saturation_xy = false;
bool saturation_z = false;
/* limit min lift */
float thr_min = _params.thr_min;
if (!_control_mode.flag_control_velocity_enabled && thr_min < 0.0f) {
/* don't allow downside thrust direction in manual attitude mode */
thr_min = 0.0f;
}
float tilt_max = _params.tilt_max_air;
/* adjust limits for landing mode */
if (!_control_mode.flag_control_manual_enabled && _pos_sp_triplet.current.valid &&
_pos_sp_triplet.current.type == SETPOINT_TYPE_LAND) {
/* limit max tilt and min lift when landing */
tilt_max = _params.tilt_max_land;
if (thr_min < 0.0f) {
thr_min = 0.0f;
}
}
/* limit min lift */
if (-thrust_sp(2) < thr_min) {
thrust_sp(2) = -thr_min;
saturation_z = true;
}
if (_control_mode.flag_control_velocity_enabled) {
/* limit max tilt */
if (thr_min >= 0.0f && tilt_max < M_PI / 2 - 0.05f) {
/* absolute horizontal thrust */
float thrust_sp_xy_len = math::Vector<2>(thrust_sp(0), thrust_sp(1)).length();
if (thrust_sp_xy_len > 0.01f) {
/* max horizontal thrust for given vertical thrust*/
float thrust_xy_max = -thrust_sp(2) * tanf(tilt_max);
if (thrust_sp_xy_len > thrust_xy_max) {
float k = thrust_xy_max / thrust_sp_xy_len;
thrust_sp(0) *= k;
thrust_sp(1) *= k;
saturation_xy = true;
}
}
}
} else {
/* thrust compensation for altitude only control mode */
float att_comp;
if (_att.R[2][2] > TILT_COS_MAX) {
att_comp = 1.0f / _att.R[2][2];
} else if (_att.R[2][2] > 0.0f) {
att_comp = ((1.0f / TILT_COS_MAX - 1.0f) / TILT_COS_MAX) * _att.R[2][2] + 1.0f;
saturation_z = true;
} else {
att_comp = 1.0f;
saturation_z = true;
}
thrust_sp(2) *= att_comp;
}
/* limit max thrust */
float thrust_abs = thrust_sp.length();
if (thrust_abs > _params.thr_max) {
if (thrust_sp(2) < 0.0f) {
if (-thrust_sp(2) > _params.thr_max) {
/* thrust Z component is too large, limit it */
thrust_sp(0) = 0.0f;
thrust_sp(1) = 0.0f;
thrust_sp(2) = -_params.thr_max;
saturation_xy = true;
saturation_z = true;
} else {
/* preserve thrust Z component and lower XY, keeping altitude is more important than position */
float thrust_xy_max = sqrtf(_params.thr_max * _params.thr_max - thrust_sp(2) * thrust_sp(2));
float thrust_xy_abs = math::Vector<2>(thrust_sp(0), thrust_sp(1)).length();
float k = thrust_xy_max / thrust_xy_abs;
thrust_sp(0) *= k;
thrust_sp(1) *= k;
saturation_xy = true;
}
} else {
/* Z component is negative, going down, simply limit thrust vector */
float k = _params.thr_max / thrust_abs;
thrust_sp *= k;
saturation_xy = true;
saturation_z = true;
}
thrust_abs = _params.thr_max;
}
/* update integrals */
if (_control_mode.flag_control_velocity_enabled && !saturation_xy) {
thrust_int(0) += vel_err(0) * _params.vel_i(0) * dt;
thrust_int(1) += vel_err(1) * _params.vel_i(1) * dt;
}
if (_control_mode.flag_control_climb_rate_enabled && !saturation_z) {
thrust_int(2) += vel_err(2) * _params.vel_i(2) * dt;
/* protection against flipping on ground when landing */
if (thrust_int(2) > 0.0f) {
thrust_int(2) = 0.0f;
}
}
/* calculate attitude setpoint from thrust vector */
if (_control_mode.flag_control_velocity_enabled) {
/* desired body_z axis = -normalize(thrust_vector) */
math::Vector<3> body_x;
math::Vector<3> body_y;
math::Vector<3> body_z;
if (thrust_abs > SIGMA) {
body_z = -thrust_sp / thrust_abs;
} else {
/* no thrust, set Z axis to safe value */
body_z.zero();
body_z(2) = 1.0f;
}
/* vector of desired yaw direction in XY plane, rotated by PI/2 */
math::Vector<3> y_C(-sinf(_att_sp.yaw_body), cosf(_att_sp.yaw_body), 0.0f);
if (fabsf(body_z(2)) > SIGMA) {
/* desired body_x axis, orthogonal to body_z */
body_x = y_C % body_z;
/* keep nose to front while inverted upside down */
if (body_z(2) < 0.0f) {
body_x = -body_x;
}
body_x.normalize();
} else {
/* desired thrust is in XY plane, set X downside to construct correct matrix,
* but yaw component will not be used actually */
body_x.zero();
body_x(2) = 1.0f;
}
/* desired body_y axis */
body_y = body_z % body_x;
/* fill rotation matrix */
for (int i = 0; i < 3; i++) {
R(i, 0) = body_x(i);
R(i, 1) = body_y(i);
R(i, 2) = body_z(i);
}
/* copy rotation matrix to attitude setpoint topic */
memcpy(&_att_sp.R_body[0][0], R.data, sizeof(_att_sp.R_body));
_att_sp.R_valid = true;
/* calculate euler angles, for logging only, must not be used for control */
math::Vector<3> euler = R.to_euler();
_att_sp.roll_body = euler(0);
_att_sp.pitch_body = euler(1);
/* yaw already used to construct rot matrix, but actual rotation matrix can have different yaw near singularity */
} else if (!_control_mode.flag_control_manual_enabled) {
/* autonomous altitude control without position control (failsafe landing),
* force level attitude, don't change yaw */
R.from_euler(0.0f, 0.0f, _att_sp.yaw_body);
/* copy rotation matrix to attitude setpoint topic */
memcpy(&_att_sp.R_body[0][0], R.data, sizeof(_att_sp.R_body));
_att_sp.R_valid = true;
_att_sp.roll_body = 0.0f;
_att_sp.pitch_body = 0.0f;
}
_att_sp.thrust = thrust_abs;
_att_sp.timestamp = hrt_absolute_time();
/* publish attitude setpoint */
if (_att_sp_pub > 0) {
orb_publish(ORB_ID(vehicle_attitude_setpoint), _att_sp_pub, &_att_sp);
} else {
_att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &_att_sp);
}
} else {
reset_int_z = true;
}
}
} else {
/* position controller disabled, reset setpoints */
_reset_alt_sp = true;
_reset_pos_sp = true;
reset_int_z = true;
reset_int_xy = true;
}
/* reset altitude controller integral (hovering throttle) to manual throttle after manual throttle control */
reset_int_z_manual = _control_mode.flag_armed && _control_mode.flag_control_manual_enabled && !_control_mode.flag_control_climb_rate_enabled;
}
warnx("stopped");
mavlink_log_info(_mavlink_fd, "[mpc] stopped");
_control_task = -1;
_exit(0);
}
int
MulticopterPositionControl::start()
{
ASSERT(_control_task == -1);
/* start the task */
_control_task = task_spawn_cmd("mc_pos_control",
SCHED_DEFAULT,
SCHED_PRIORITY_MAX - 5,
2048,
(main_t)&MulticopterPositionControl::task_main_trampoline,
nullptr);
if (_control_task < 0) {
warn("task start failed");
return -errno;
}
return OK;
}
int mc_pos_control_main(int argc, char *argv[])
{
if (argc < 1) {
errx(1, "usage: mc_pos_control {start|stop|status}");
}
if (!strcmp(argv[1], "start")) {
if (pos_control::g_control != nullptr) {
errx(1, "already running");
}
pos_control::g_control = new MulticopterPositionControl;
if (pos_control::g_control == nullptr) {
errx(1, "alloc failed");
}
if (OK != pos_control::g_control->start()) {
delete pos_control::g_control;
pos_control::g_control = nullptr;
err(1, "start failed");
}
exit(0);
}
if (!strcmp(argv[1], "stop")) {
if (pos_control::g_control == nullptr) {
errx(1, "not running");
}
delete pos_control::g_control;
pos_control::g_control = nullptr;
exit(0);
}
if (!strcmp(argv[1], "status")) {
if (pos_control::g_control) {
errx(0, "running");
} else {
errx(1, "not running");
}
}
warnx("unrecognized command");
return 1;
}