/****************************************************************************
*
* Copyright (C) 2013 Anton Babushkin. All rights reserved.
* Author: Anton Babushkin <rk3dov@gmail.com>
*
* 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 multirotor_pos_control.c
*
* Multirotor position controller
*/
#include <nuttx/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <stdbool.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <debug.h>
#include <termios.h>
#include <time.h>
#include <sys/prctl.h>
#include <drivers/drv_hrt.h>
#include <uORB/uORB.h>
#include <uORB/topics/parameter_update.h>
#include <uORB/topics/vehicle_status.h>
#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/manual_control_setpoint.h>
#include <uORB/topics/vehicle_attitude_setpoint.h>
#include <uORB/topics/vehicle_local_position.h>
#include <uORB/topics/vehicle_local_position_setpoint.h>
#include <uORB/topics/vehicle_global_position_setpoint.h>
#include <uORB/topics/vehicle_global_velocity_setpoint.h>
#include <systemlib/systemlib.h>
#include <systemlib/pid/pid.h>
#include <mavlink/mavlink_log.h>
#include "multirotor_pos_control_params.h"
#include "thrust_pid.h"
static bool thread_should_exit = false; /**< Deamon exit flag */
static bool thread_running = false; /**< Deamon status flag */
static int deamon_task; /**< Handle of deamon task / thread */
__EXPORT int multirotor_pos_control_main(int argc, char *argv[]);
/**
* Mainloop of position controller.
*/
static int multirotor_pos_control_thread_main(int argc, char *argv[]);
/**
* Print the correct usage.
*/
static void usage(const char *reason);
static float scale_control(float ctl, float end, float dz);
static float norm(float x, float y);
static void usage(const char *reason)
{
if (reason)
fprintf(stderr, "%s\n", reason);
fprintf(stderr, "usage: deamon {start|stop|status} [-p <additional params>]\n\n");
exit(1);
}
/**
* The deamon app only briefly exists to start
* the background job. The stack size assigned in the
* Makefile does only apply to this management task.
*
* The actual stack size should be set in the call
* to task_spawn().
*/
int multirotor_pos_control_main(int argc, char *argv[])
{
if (argc < 1)
usage("missing command");
if (!strcmp(argv[1], "start")) {
if (thread_running) {
warnx("already running");
/* this is not an error */
exit(0);
}
warnx("start");
thread_should_exit = false;
deamon_task = task_spawn_cmd("multirotor_pos_control",
SCHED_DEFAULT,
SCHED_PRIORITY_MAX - 60,
4096,
multirotor_pos_control_thread_main,
(argv) ? (const char **)&argv[2] : (const char **)NULL);
exit(0);
}
if (!strcmp(argv[1], "stop")) {
warnx("stop");
thread_should_exit = true;
exit(0);
}
if (!strcmp(argv[1], "status")) {
if (thread_running) {
warnx("app is running");
} else {
warnx("app not started");
}
exit(0);
}
usage("unrecognized command");
exit(1);
}
static float 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;
}
}
static float norm(float x, float y)
{
return sqrtf(x * x + y * y);
}
static int multirotor_pos_control_thread_main(int argc, char *argv[])
{
/* welcome user */
warnx("started");
static int mavlink_fd;
mavlink_fd = open(MAVLINK_LOG_DEVICE, 0);
mavlink_log_info(mavlink_fd, "[mpc] started");
/* structures */
struct vehicle_status_s status;
memset(&status, 0, sizeof(status));
struct vehicle_attitude_s att;
memset(&att, 0, sizeof(att));
struct vehicle_attitude_setpoint_s att_sp;
memset(&att_sp, 0, sizeof(att_sp));
struct manual_control_setpoint_s manual;
memset(&manual, 0, sizeof(manual));
struct vehicle_local_position_s local_pos;
memset(&local_pos, 0, sizeof(local_pos));
struct vehicle_local_position_setpoint_s local_pos_sp;
memset(&local_pos_sp, 0, sizeof(local_pos_sp));
struct vehicle_global_position_setpoint_s global_pos_sp;
memset(&global_pos_sp, 0, sizeof(local_pos_sp));
struct vehicle_global_velocity_setpoint_s global_vel_sp;
memset(&global_vel_sp, 0, sizeof(global_vel_sp));
/* subscribe to attitude, motor setpoints and system state */
int param_sub = orb_subscribe(ORB_ID(parameter_update));
int state_sub = orb_subscribe(ORB_ID(vehicle_status));
int att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
int att_sp_sub = orb_subscribe(ORB_ID(vehicle_attitude_setpoint));
int manual_sub = orb_subscribe(ORB_ID(manual_control_setpoint));
int local_pos_sp_sub = orb_subscribe(ORB_ID(vehicle_local_position_setpoint));
int local_pos_sub = orb_subscribe(ORB_ID(vehicle_local_position));
int global_pos_sp_sub = orb_subscribe(ORB_ID(vehicle_global_position_setpoint));
/* publish setpoint */
orb_advert_t local_pos_sp_pub = orb_advertise(ORB_ID(vehicle_local_position_setpoint), &local_pos_sp);
orb_advert_t global_vel_sp_pub = orb_advertise(ORB_ID(vehicle_global_velocity_setpoint), &global_vel_sp);
orb_advert_t att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &att_sp);
bool reset_sp_alt = true;
bool reset_sp_pos = true;
hrt_abstime t_prev = 0;
/* integrate in NED frame to estimate wind but not attitude offset */
const float alt_ctl_dz = 0.2f;
const float pos_ctl_dz = 0.05f;
float home_alt = 0.0f;
hrt_abstime home_alt_t = 0;
uint64_t local_home_timestamp = 0;
static PID_t xy_pos_pids[2];
static PID_t xy_vel_pids[2];
static PID_t z_pos_pid;
static thrust_pid_t z_vel_pid;
thread_running = true;
struct multirotor_position_control_params params;
struct multirotor_position_control_param_handles params_h;
parameters_init(¶ms_h);
parameters_update(¶ms_h, ¶ms);
for (int i = 0; i < 2; i++) {
pid_init(&(xy_pos_pids[i]), params.xy_p, 0.0f, params.xy_d, 1.0f, 0.0f, PID_MODE_DERIVATIV_SET, 0.02f);
pid_init(&(xy_vel_pids[i]), params.xy_vel_p, params.xy_vel_i, params.xy_vel_d, 1.0f, params.slope_max, PID_MODE_DERIVATIV_CALC_NO_SP, 0.02f);
}
pid_init(&z_pos_pid, params.z_p, 0.0f, params.z_d, 1.0f, 0.0f, PID_MODE_DERIVATIV_SET, 0.02f);
thrust_pid_init(&z_vel_pid, params.z_vel_p, params.z_vel_i, params.z_vel_d, -params.thr_max, -params.thr_min, PID_MODE_DERIVATIV_CALC_NO_SP, 0.02f);
int paramcheck_counter = 0;
bool global_pos_sp_updated = false;
while (!thread_should_exit) {
orb_copy(ORB_ID(vehicle_status), state_sub, &status);
/* check parameters at 1 Hz*/
paramcheck_counter++;
if (paramcheck_counter == 50) {
bool param_updated;
orb_check(param_sub, ¶m_updated);
if (param_updated) {
parameters_update(¶ms_h, ¶ms);
for (int i = 0; i < 2; i++) {
pid_set_parameters(&(xy_pos_pids[i]), params.xy_p, 0.0f, params.xy_d, 1.0f, 0.0f);
pid_set_parameters(&(xy_vel_pids[i]), params.xy_vel_p, params.xy_vel_i, params.xy_vel_d, 1.0f, params.slope_max);
}
pid_set_parameters(&z_pos_pid, params.z_p, 0.0f, params.z_d, 1.0f, params.z_vel_max);
thrust_pid_set_parameters(&z_vel_pid, params.z_vel_p, params.z_vel_i, params.z_vel_d, -params.thr_max, -params.thr_min);
}
paramcheck_counter = 0;
}
/* only check global position setpoint updates but not read */
if (!global_pos_sp_updated) {
orb_check(global_pos_sp_sub, &global_pos_sp_updated);
}
/* Check if controller should act */
bool act = status.flag_system_armed && (
/* SAS modes */
(
status.flag_control_manual_enabled &&
status.manual_control_mode == VEHICLE_MANUAL_CONTROL_MODE_SAS && (
status.manual_sas_mode == VEHICLE_MANUAL_SAS_MODE_ALTITUDE ||
status.manual_sas_mode == VEHICLE_MANUAL_SAS_MODE_SIMPLE
)
) ||
/* AUTO mode */
status.state_machine == SYSTEM_STATE_AUTO
);
hrt_abstime t = hrt_absolute_time();
float dt;
if (t_prev != 0) {
dt = (t - t_prev) * 0.000001f;
} else {
dt = 0.0f;
}
t_prev = t;
if (act) {
orb_copy(ORB_ID(manual_control_setpoint), manual_sub, &manual);
orb_copy(ORB_ID(vehicle_attitude), att_sub, &att);
orb_copy(ORB_ID(vehicle_attitude_setpoint), att_sp_sub, &att_sp);
orb_copy(ORB_ID(vehicle_local_position), local_pos_sub, &local_pos);
if (status.state_machine == SYSTEM_STATE_AUTO) {
//orb_copy(ORB_ID(vehicle_local_position_setpoint), local_pos_sp_sub, &local_pos_sp);
if (local_pos.home_timestamp != local_home_timestamp) {
local_home_timestamp = local_pos.home_timestamp;
/* init local projection using local position home */
double lat_home = local_pos.home_lat * 1e-7;
double lon_home = local_pos.home_lon * 1e-7;
map_projection_init(lat_home, lon_home);
warnx("local pos home: lat = %.10f, lon = %.10f", lat_home, lon_home);
mavlink_log_info(mavlink_fd, "local pos home: %.7f, %.7f", lat_home, lon_home);
}
if (global_pos_sp_updated) {
global_pos_sp_updated = false;
orb_copy(ORB_ID(vehicle_global_position_setpoint), global_pos_sp_sub, &global_pos_sp);
double sp_lat = global_pos_sp.lat * 1e-7;
double sp_lon = global_pos_sp.lon * 1e-7;
/* project global setpoint to local setpoint */
map_projection_project(sp_lat, sp_lon, &(local_pos_sp.x), &(local_pos_sp.y));
if (global_pos_sp.altitude_is_relative) {
local_pos_sp.z = -global_pos_sp.altitude;
} else {
local_pos_sp.z = local_pos.home_alt - global_pos_sp.altitude;
}
warnx("new setpoint: lat = %.10f, lon = %.10f, x = %.2f, y = %.2f", sp_lat, sp_lon, local_pos_sp.x, local_pos_sp.y);
mavlink_log_info(mavlink_fd, "new setpoint: %.7f, %.7f, %.2f, %.2f", sp_lat, sp_lon, local_pos_sp.x, local_pos_sp.y);
/* publish local position setpoint as projection of global position setpoint */
orb_publish(ORB_ID(vehicle_local_position_setpoint), local_pos_sp_pub, &local_pos_sp);
}
}
if (status.flag_control_manual_enabled && reset_sp_alt) {
reset_sp_alt = false;
local_pos_sp.z = local_pos.z;
z_vel_pid.integral = -manual.throttle; // thrust PID uses Z downside
mavlink_log_info(mavlink_fd, "reset alt setpoint: z = %.2f, throttle = %.2f", local_pos_sp.z, manual.throttle);
}
if (status.flag_control_manual_enabled && status.manual_sas_mode == VEHICLE_MANUAL_SAS_MODE_SIMPLE && reset_sp_pos) {
reset_sp_pos = false;
local_pos_sp.x = local_pos.x;
local_pos_sp.y = local_pos.y;
xy_vel_pids[0].integral = 0.0f;
xy_vel_pids[1].integral = 0.0f;
mavlink_log_info(mavlink_fd, "reset pos setpoint: x = %.2f, y = %.2f", local_pos_sp.x, local_pos_sp.y);
}
float z_sp_offs_max = params.z_vel_max / params.z_p * 2.0f;
float xy_sp_offs_max = params.xy_vel_max / params.xy_p * 2.0f;
float sp_move_rate[3] = { 0.0f, 0.0f, 0.0f };
/* manual control */
if (status.flag_control_manual_enabled) {
if (local_pos.home_timestamp != home_alt_t) {
if (home_alt_t != 0) {
/* home alt changed, don't follow large ground level changes in manual flight */
local_pos_sp.z += local_pos.home_alt - home_alt;
}
home_alt_t = local_pos.home_timestamp;
home_alt = local_pos.home_alt;
}
/* move altitude setpoint with manual controls */
float z_sp_ctl = scale_control(manual.throttle - 0.5f, 0.5f, alt_ctl_dz);
if (z_sp_ctl != 0.0f) {
sp_move_rate[2] = -z_sp_ctl * params.z_vel_max;
local_pos_sp.z += sp_move_rate[2] * dt;
if (local_pos_sp.z > local_pos.z + z_sp_offs_max) {
local_pos_sp.z = local_pos.z + z_sp_offs_max;
} else if (local_pos_sp.z < local_pos.z - z_sp_offs_max) {
local_pos_sp.z = local_pos.z - z_sp_offs_max;
}
}
if (status.manual_sas_mode == VEHICLE_MANUAL_SAS_MODE_SIMPLE) {
/* move position setpoint with manual controls */
float pos_pitch_sp_ctl = scale_control(-manual.pitch / params.rc_scale_pitch, 1.0f, pos_ctl_dz);
float pos_roll_sp_ctl = scale_control(manual.roll / params.rc_scale_roll, 1.0f, pos_ctl_dz);
if (pos_pitch_sp_ctl != 0.0f || pos_roll_sp_ctl != 0.0f) {
/* calculate direction and increment of control in NED frame */
float xy_sp_ctl_dir = att.yaw + atan2f(pos_roll_sp_ctl, pos_pitch_sp_ctl);
float xy_sp_ctl_speed = norm(pos_pitch_sp_ctl, pos_roll_sp_ctl) * params.xy_vel_max;
sp_move_rate[0] = cosf(xy_sp_ctl_dir) * xy_sp_ctl_speed;
sp_move_rate[1] = sinf(xy_sp_ctl_dir) * xy_sp_ctl_speed;
local_pos_sp.x += sp_move_rate[0] * dt;
local_pos_sp.y += sp_move_rate[1] * dt;
/* limit maximum setpoint from position offset and preserve direction
* fail safe, should not happen in normal operation */
float pos_vec_x = local_pos_sp.x - local_pos.x;
float pos_vec_y = local_pos_sp.y - local_pos.y;
float pos_vec_norm = norm(pos_vec_x, pos_vec_y) / xy_sp_offs_max;
if (pos_vec_norm > 1.0f) {
local_pos_sp.x = local_pos.x + pos_vec_x / pos_vec_norm;
local_pos_sp.y = local_pos.y + pos_vec_y / pos_vec_norm;
}
}
}
}
/* run position & altitude controllers, calculate velocity setpoint */
global_vel_sp.vz = pid_calculate(&z_pos_pid, local_pos_sp.z, local_pos.z, local_pos.vz, dt);
if (status.manual_sas_mode == VEHICLE_MANUAL_SAS_MODE_SIMPLE || status.state_machine == SYSTEM_STATE_AUTO) {
/* calculate velocity set point in NED frame */
global_vel_sp.vx = pid_calculate(&xy_pos_pids[0], local_pos_sp.x, local_pos.x, local_pos.vx, dt);
global_vel_sp.vy = pid_calculate(&xy_pos_pids[1], local_pos_sp.y, local_pos.y, local_pos.vy, dt);
/* limit horizontal speed */
float xy_vel_sp_norm = norm(global_vel_sp.vx, global_vel_sp.vy) / params.xy_vel_max;
if (xy_vel_sp_norm > 1.0f) {
global_vel_sp.vx /= xy_vel_sp_norm;
global_vel_sp.vy /= xy_vel_sp_norm;
}
} else {
reset_sp_pos = true;
global_vel_sp.vx = 0.0f;
global_vel_sp.vy = 0.0f;
}
/* publish new velocity setpoint */
orb_publish(ORB_ID(vehicle_global_velocity_setpoint), global_vel_sp_pub, &global_vel_sp);
/* run velocity controllers, calculate thrust vector */
float thrust_sp[3] = { 0.0f, 0.0f, 0.0f };
thrust_sp[2] = thrust_pid_calculate(&z_vel_pid, global_vel_sp.vz, local_pos.vz, dt);
if (status.manual_sas_mode == VEHICLE_MANUAL_SAS_MODE_SIMPLE || status.state_machine == SYSTEM_STATE_AUTO) {
/* calculate velocity set point in NED frame */
thrust_sp[0] = pid_calculate(&xy_vel_pids[0], global_vel_sp.vx, local_pos.vx, 0.0f, dt);
thrust_sp[1] = pid_calculate(&xy_vel_pids[1], global_vel_sp.vy, local_pos.vy, 0.0f, dt);
}
/* thrust_vector now contains desired acceleration (but not in m/s^2) in NED frame */
/* limit horizontal part of thrust */
float thrust_xy_dir = atan2f(thrust_sp[1], thrust_sp[0]);
float thrust_xy_norm = norm(thrust_sp[0], thrust_sp[1]);
if (thrust_xy_norm > params.slope_max) {
thrust_xy_norm = params.slope_max;
}
/* use approximation: slope ~ sin(slope) = force */
/* convert direction to body frame */
thrust_xy_dir -= att.yaw;
if (status.manual_sas_mode == VEHICLE_MANUAL_SAS_MODE_SIMPLE || status.state_machine == SYSTEM_STATE_AUTO) {
/* calculate roll and pitch */
att_sp.roll_body = sinf(thrust_xy_dir) * thrust_xy_norm;
att_sp.pitch_body = -cosf(thrust_xy_dir) * thrust_xy_norm / cosf(att_sp.roll_body); // reverse pitch
}
/* attitude-thrust compensation */
float att_comp;
if (att.R[2][2] > 0.8f)
att_comp = 1.0f / att.R[2][2];
else if (att.R[2][2] > 0.0f)
att_comp = ((1.0f / 0.8f - 1.0f) / 0.8f) * att.R[2][2] + 1.0f;
else
att_comp = 1.0f;
att_sp.thrust = -thrust_sp[2] * att_comp;
att_sp.timestamp = hrt_absolute_time();
if (status.flag_control_manual_enabled) {
/* publish local position setpoint in manual mode */
orb_publish(ORB_ID(vehicle_local_position_setpoint), local_pos_sp_pub, &local_pos_sp);
}
/* publish new attitude setpoint */
orb_publish(ORB_ID(vehicle_attitude_setpoint), att_sp_pub, &att_sp);
} else {
reset_sp_alt = true;
reset_sp_pos = true;
}
/* run at approximately 50 Hz */
usleep(20000);
}
warnx("stopped");
mavlink_log_info(mavlink_fd, "[mpc] stopped");
thread_running = false;
fflush(stdout);
return 0;
}