/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
* Author: @author Ivan Ovinnikov <oivan@ethz.ch>
* Modifications: Doug Weibel <douglas.weibel@colorado.edu>
*
* 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 fixedwing_control.c
* Implementation of a fixed wing attitude and position controller.
*/
#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 <time.h>
#include <arch/board/up_hrt.h>
#include <arch/board/board.h>
#include <uORB/uORB.h>
#include <uORB/topics/vehicle_global_position.h>
#include <uORB/topics/vehicle_global_position_setpoint.h>
#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_status.h>
#include <uORB/topics/vehicle_attitude_setpoint.h>
#include <uORB/topics/manual_control_setpoint.h>
#include <uORB/topics/actuator_controls.h>
#include <systemlib/param/param.h>
#include <systemlib/pid/pid.h>
#include <systemlib/geo/geo.h>
#include <systemlib/systemlib.h>
#include <uORB/topics/debug_key_value.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 */
/**
* Deamon management function.
*/
__EXPORT int fixedwing_control_main(int argc, char *argv[]);
/**
* Mainloop of deamon.
*/
int fixedwing_control_thread_main(int argc, char *argv[]);
/**
* Print the correct usage.
*/
static void usage(const char *reason);
/*
* Controller parameters, accessible via MAVLink
*
*/
// Roll control parameters
PARAM_DEFINE_FLOAT(FW_ROLLRATE_P, 0.3f);
// Need to add functionality to suppress integrator windup while on the ground
// Suggested value of FW_ROLLRATE_I is 0.0 till this is in place
PARAM_DEFINE_FLOAT(FW_ROLLRATE_I, 0.0f);
PARAM_DEFINE_FLOAT(FW_ROLLRATE_AWU, 0.0f);
PARAM_DEFINE_FLOAT(FW_ROLLRATE_LIM, 0.7f); // Roll rate limit in radians/sec
PARAM_DEFINE_FLOAT(FW_ROLL_P, 0.3f);
PARAM_DEFINE_FLOAT(FW_ROLL_LIM, 0.7f); // Roll angle limit in radians
//Pitch control parameters
PARAM_DEFINE_FLOAT(FW_PITCHRATE_P, 0.3f);
// Need to add functionality to suppress integrator windup while on the ground
// Suggested value of FW_PITCHRATE_I is 0.0 till this is in place
PARAM_DEFINE_FLOAT(FW_PITCHRATE_I, 0.0f);
PARAM_DEFINE_FLOAT(FW_PITCHRATE_AWU, 0.0f);
PARAM_DEFINE_FLOAT(FW_PITCHRATE_LIM, 0.35f); // Pitch rate limit in radians/sec
PARAM_DEFINE_FLOAT(FW_PITCH_P, 0.3f);
PARAM_DEFINE_FLOAT(FW_PITCH_LIM, 0.35f); // Pitch angle limit in radians
struct fw_att_control_params {
float rollrate_p;
float rollrate_i;
float rollrate_awu;
float rollrate_lim;
float roll_p;
float roll_lim;
float pitchrate_p;
float pitchrate_i;
float pitchrate_awu;
float pitchrate_lim;
float pitch_p;
float pitch_lim;
};
struct fw_att_control_param_handles {
param_t rollrate_p;
param_t rollrate_i;
param_t rollrate_awu;
param_t rollrate_lim;
param_t roll_p;
param_t roll_lim;
param_t pitchrate_p;
param_t pitchrate_i;
param_t pitchrate_awu;
param_t pitchrate_lim;
param_t pitch_p;
param_t pitch_lim;
};
// TO_DO - Navigation control will be moved to a separate app
// Attitude control will just handle the inner angle and rate loops
// to control pitch and roll, and turn coordination via rudder and
// possibly throttle compensation for battery voltage sag.
PARAM_DEFINE_FLOAT(FW_HEADING_P, 0.1f);
PARAM_DEFINE_FLOAT(FW_HEADING_LIM, 0.15f);
struct fw_pos_control_params {
float heading_p;
float heading_lim;
};
struct fw_pos_control_param_handles {
param_t heading_p;
param_t heading_lim;
};
/**
* Initialize all parameter handles and values
*
*/
static int att_parameters_init(struct fw_att_control_param_handles *h);
/**
* Update all parameters
*
*/
static int att_parameters_update(const struct fw_att_control_param_handles *h, struct fw_att_control_params *p);
/**
* Initialize all parameter handles and values
*
*/
static int pos_parameters_init(struct fw_pos_control_param_handles *h);
/**
* Update all parameters
*
*/
static int pos_parameters_update(const struct fw_pos_control_param_handles *h, struct fw_pos_control_params *p);
/**
* The fixed wing control main thread.
*
* The main loop executes continously and calculates the control
* response.
*
* @param argc number of arguments
* @param argv argument array
*
* @return 0
*
*/
int fixedwing_control_thread_main(int argc, char *argv[])
{
/* read arguments */
bool verbose = false;
for (int i = 1; i < argc; i++) {
if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--verbose") == 0) {
verbose = true;
}
}
/* welcome user */
printf("[fixedwing control] started\n");
/* output structs */
struct actuator_controls_s actuators;
struct vehicle_attitude_setpoint_s att_sp;
memset(&att_sp, 0, sizeof(att_sp));
/* publish actuator controls */
for (unsigned i = 0; i < NUM_ACTUATOR_CONTROLS; i++)
actuators.control[i] = 0.0f;
orb_advert_t actuator_pub = orb_advertise(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, &actuators);
orb_advert_t att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &att_sp);
/* Subscribe to global position, attitude and rc */
/* declare and safely initialize all structs */
struct vehicle_status_s state;
memset(&state, 0, sizeof(state));
struct vehicle_attitude_s att;
memset(&att_sp, 0, sizeof(att_sp));
struct manual_control_setpoint_s manual;
memset(&manual, 0, sizeof(manual));
/* subscribe to attitude, motor setpoints and system state */
struct vehicle_global_position_s global_pos;
int global_pos_sub = orb_subscribe(ORB_ID(vehicle_global_position));
struct vehicle_global_position_setpoint_s global_setpoint;
int global_setpoint_sub = orb_subscribe(ORB_ID(vehicle_global_position_setpoint));
int att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
int att_setpoint_sub = orb_subscribe(ORB_ID(vehicle_attitude_setpoint));
int state_sub = orb_subscribe(ORB_ID(vehicle_status));
int manual_sub = orb_subscribe(ORB_ID(manual_control_setpoint));
/* Mainloop setup */
unsigned int loopcounter = 0;
uint64_t last_run = 0;
uint64_t last_run_pos = 0;
bool global_sp_updated_set_once = false;
struct fw_att_control_params p;
struct fw_att_control_param_handles h;
struct fw_pos_control_params ppos;
struct fw_pos_control_param_handles hpos;
/* initialize the pid controllers */
att_parameters_init(&h);
att_parameters_update(&h, &p);
pos_parameters_init(&hpos);
pos_parameters_update(&hpos, &ppos);
// TO_DO Fix output limit functionallity of PID controller or add that function elsewhere
PID_t roll_rate_controller;
pid_init(&roll_rate_controller, p.rollrate_p, p.rollrate_i, 0.0f, p.rollrate_awu,
p.rollrate_lim,PID_MODE_DERIVATIV_NONE);
PID_t roll_angle_controller;
pid_init(&roll_angle_controller, p.roll_p, 0.0f, 0.0f, 0.0f,
p.roll_lim,PID_MODE_DERIVATIV_NONE);
PID_t pitch_rate_controller;
pid_init(&pitch_rate_controller, p.pitchrate_p, p.pitchrate_i, 0.0f, p.pitchrate_awu,
p.pitchrate_lim,PID_MODE_DERIVATIV_NONE);
PID_t pitch_angle_controller;
pid_init(&pitch_angle_controller, p.pitch_p, 0.0f, 0.0f, 0.0f,
p.pitch_lim,PID_MODE_DERIVATIV_NONE);
PID_t heading_controller;
pid_init(&heading_controller, ppos.heading_p, 0.0f, 0.0f, 0.0f,
100.0f,PID_MODE_DERIVATIV_SET); // Temporary arbitrarily large limit
// XXX remove in production
/* advertise debug value */
struct debug_key_value_s dbg = { .key = "", .value = 0.0f };
orb_advert_t pub_dbg = orb_advertise(ORB_ID(debug_key_value), &dbg);
// This is the top of the main loop
while(!thread_should_exit) {
struct pollfd fds[1] = {
{ .fd = att_sub, .events = POLLIN },
};
int ret = poll(fds, 1, 1000);
if (ret < 0) {
/* XXX this is seriously bad - should be an emergency */
} else if (ret == 0) {
/* XXX this means no sensor data - should be critical or emergency */
printf("[fixedwing control] WARNING: Not getting attitude - estimator running?\n");
} else {
// FIXME SUBSCRIBE
if (loopcounter % 100 == 0) {
att_parameters_update(&h, &p);
pos_parameters_update(&hpos, &ppos);
pid_set_parameters(&roll_rate_controller, p.rollrate_p, p.rollrate_i, 0.0f,
p.rollrate_awu, p.rollrate_lim);
pid_set_parameters(&roll_angle_controller, p.roll_p, 0.0f, 0.0f,
0.0f, p.roll_lim);
pid_set_parameters(&pitch_rate_controller, p.pitchrate_p, p.pitchrate_i, 0.0f,
p.pitchrate_awu, p.pitchrate_lim);
pid_set_parameters(&pitch_angle_controller, p.pitch_p, 0.0f, 0.0f,
0.0f, p.pitch_lim);
pid_set_parameters(&heading_controller, ppos.heading_p, 0.0f, 0.0f, 0.0f, 90.0f);
//printf("[fixedwing control debug] p: %8.4f, i: %8.4f, limit: %8.4f \n",
//p.rollrate_p, p.rollrate_i, p.rollrate_lim);
}
/* if position updated, run position control loop */
bool pos_updated;
orb_check(global_pos_sub, &pos_updated);
bool global_sp_updated;
orb_check(global_setpoint_sub, &global_sp_updated);
if (global_sp_updated) {
global_sp_updated_set_once = true;
}
/* checking has to happen before the read, as the read clears the changed flag */
/* get a local copy of system state */
orb_copy(ORB_ID(vehicle_status), state_sub, &state);
/* get a local copy of manual setpoint */
orb_copy(ORB_ID(manual_control_setpoint), manual_sub, &manual);
/* get a local copy of attitude */
orb_copy(ORB_ID(vehicle_attitude), att_sub, &att);
/* get a local copy of attitude setpoint */
//orb_copy(ORB_ID(vehicle_attitude_setpoint), att_setpoint_sub, &att_sp);
// XXX update to switch between external attitude reference and the
// attitude calculated here
char name[10];
if (pos_updated) {
/* get position */
orb_copy(ORB_ID(vehicle_global_position), global_pos_sub, &global_pos);
if (global_sp_updated_set_once) {
orb_copy(ORB_ID(vehicle_global_position_setpoint), global_setpoint_sub, &global_setpoint);
/* calculate delta T */
const float deltaT = (hrt_absolute_time() - last_run) / 1000000.0f;
last_run = hrt_absolute_time();
/* calculate bearing error */
float target_bearing = get_bearing_to_next_waypoint(global_pos.lat / (double)1e7d, global_pos.lon / (double)1e7d,
global_setpoint.lat / (double)1e7d, global_setpoint.lon / (double)1e7d);
/* shift error to prevent wrapping issues */
float bearing_error = target_bearing - att.yaw;
if (loopcounter % 2 == 0) {
sprintf(name, "hdng err1");
memcpy(dbg.key, name, sizeof(name));
dbg.value = bearing_error;
orb_publish(ORB_ID(debug_key_value), pub_dbg, &dbg);
}
if (bearing_error < M_PI_F) {
bearing_error += 2.0f * M_PI_F;
}
if (bearing_error > M_PI_F) {
bearing_error -= 2.0f * M_PI_F;
}
if (loopcounter % 2 != 0) {
sprintf(name, "hdng err2");
memcpy(dbg.key, name, sizeof(name));
dbg.value = bearing_error;
orb_publish(ORB_ID(debug_key_value), pub_dbg, &dbg);
}
/* calculate roll setpoint, do this artificially around zero */
att_sp.roll_body = pid_calculate(&heading_controller, bearing_error,
0.0f, att.yawspeed, deltaT);
/* limit roll angle output */
if (att_sp.roll_body > ppos.heading_lim) {
att_sp.roll_body = ppos.heading_lim;
heading_controller.saturated = 1;
}
if (att_sp.roll_body < -ppos.heading_lim) {
att_sp.roll_body = -ppos.heading_lim;
heading_controller.saturated = 1;
}
att_sp.pitch_body = 0.0f;
att_sp.yaw_body = 0.0f;
} else {
/* no setpoint, maintain level flight */
att_sp.roll_body = 0.0f;
att_sp.pitch_body = 0.0f;
att_sp.yaw_body = 0.0f;
}
att_sp.thrust = 0.7f;
}
/* calculate delta T */
const float deltaTpos = (hrt_absolute_time() - last_run_pos) / 1000000.0f;
last_run_pos = hrt_absolute_time();
if (verbose && (loopcounter % 20 == 0)) {
printf("[fixedwing control] roll sp: %8.4f, \n", att_sp.roll_body);
}
// actuator control[0] is aileron (or elevon roll control)
// Commanded roll rate from P controller on roll angle
float roll_rate_command = pid_calculate(&roll_angle_controller, att_sp.roll_body,
att.roll, 0.0f, deltaTpos);
// actuator control from PI controller on roll rate
actuators.control[0] = pid_calculate(&roll_rate_controller, roll_rate_command,
att.rollspeed, 0.0f, deltaTpos);
// actuator control[1] is elevator (or elevon pitch control)
// Commanded pitch rate from P controller on pitch angle
float pitch_rate_command = pid_calculate(&pitch_angle_controller, att_sp.pitch_body,
att.pitch, 0.0f, deltaTpos);
// actuator control from PI controller on pitch rate
actuators.control[1] = pid_calculate(&pitch_rate_controller, pitch_rate_command,
att.pitchspeed, 0.0f, deltaTpos);
// actuator control[3] is throttle
actuators.control[3] = att_sp.thrust;
/* publish attitude setpoint (for MAVLink) */
orb_publish(ORB_ID(vehicle_attitude_setpoint), att_sp_pub, &att_sp);
/* publish actuator setpoints (for mixer) */
orb_publish(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, actuator_pub, &actuators);
loopcounter++;
}
}
printf("[fixedwing_control] exiting.\n");
thread_running = false;
return 0;
}
static void
usage(const char *reason)
{
if (reason)
fprintf(stderr, "%s\n", reason);
fprintf(stderr, "usage: fixedwing_control {start|stop|status}\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_create().
*/
int fixedwing_control_main(int argc, char *argv[])
{
if (argc < 1)
usage("missing command");
if (!strcmp(argv[1], "start")) {
if (thread_running) {
printf("fixedwing_control already running\n");
/* this is not an error */
exit(0);
}
thread_should_exit = false;
deamon_task = task_spawn("fixedwing_control",
SCHED_DEFAULT,
SCHED_PRIORITY_MAX - 20,
4096,
fixedwing_control_thread_main,
(argv) ? (const char **)&argv[2] : (const char **)NULL);
thread_running = true;
exit(0);
}
if (!strcmp(argv[1], "stop")) {
thread_should_exit = true;
exit(0);
}
if (!strcmp(argv[1], "status")) {
if (thread_running) {
printf("\tfixedwing_control is running\n");
} else {
printf("\tfixedwing_control not started\n");
}
exit(0);
}
usage("unrecognized command");
exit(1);
}
static int att_parameters_init(struct fw_att_control_param_handles *h)
{
/* PID parameters */
h->rollrate_p = param_find("FW_ROLLRATE_P");
h->rollrate_i = param_find("FW_ROLLRATE_I");
h->rollrate_awu = param_find("FW_ROLLRATE_AWU");
h->rollrate_lim = param_find("FW_ROLLRATE_LIM");
h->roll_p = param_find("FW_ROLL_P");
h->roll_lim = param_find("FW_ROLL_LIM");
h->pitchrate_p = param_find("FW_PITCHRATE_P");
h->pitchrate_i = param_find("FW_PITCHRATE_I");
h->pitchrate_awu = param_find("FW_PITCHRATE_AWU");
h->pitchrate_lim = param_find("FW_PITCHRATE_LIM");
h->pitch_p = param_find("FW_PITCH_P");
h->pitch_lim = param_find("FW_PITCH_LIM");
return OK;
}
static int att_parameters_update(const struct fw_att_control_param_handles *h, struct fw_att_control_params *p)
{
param_get(h->rollrate_p, &(p->rollrate_p));
param_get(h->rollrate_i, &(p->rollrate_i));
param_get(h->rollrate_awu, &(p->rollrate_awu));
param_get(h->rollrate_lim, &(p->rollrate_lim));
param_get(h->roll_p, &(p->roll_p));
param_get(h->roll_lim, &(p->roll_lim));
param_get(h->pitchrate_p, &(p->pitchrate_p));
param_get(h->pitchrate_i, &(p->pitchrate_i));
param_get(h->pitchrate_awu, &(p->pitchrate_awu));
param_get(h->pitchrate_lim, &(p->pitchrate_lim));
param_get(h->pitch_p, &(p->pitch_p));
param_get(h->pitch_lim, &(p->pitch_lim));
return OK;
}
static int pos_parameters_init(struct fw_pos_control_param_handles *h)
{
/* PID parameters */
h->heading_p = param_find("FW_HEADING_P");
h->heading_lim = param_find("FW_HEADING_LIM");
return OK;
}
static int pos_parameters_update(const struct fw_pos_control_param_handles *h, struct fw_pos_control_params *p)
{
param_get(h->heading_p, &(p->heading_p));
param_get(h->heading_lim, &(p->heading_lim));
return OK;
}