/****************************************************************************
*
* 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 position_estimator_inav_main.c
* Model-identification based position estimator for multirotors
*/
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <fcntl.h>
#include <float.h>
#include <string.h>
#include <nuttx/config.h>
#include <nuttx/sched.h>
#include <sys/prctl.h>
#include <termios.h>
#include <errno.h>
#include <limits.h>
#include <math.h>
#include <uORB/uORB.h>
#include <uORB/topics/sensor_combined.h>
#include <uORB/topics/parameter_update.h>
#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_status.h>
#include <uORB/topics/vehicle_local_position.h>
#include <uORB/topics/vehicle_gps_position.h>
#include <mavlink/mavlink_log.h>
#include <poll.h>
#include <systemlib/geo/geo.h>
#include <systemlib/systemlib.h>
#include <systemlib/conversions.h>
#include <drivers/drv_hrt.h>
#include "position_estimator_inav_params.h"
#include "inertial_filter.h"
static bool thread_should_exit = false; /**< Deamon exit flag */
static bool thread_running = false; /**< Deamon status flag */
static int position_estimator_inav_task; /**< Handle of deamon task / thread */
static bool verbose_mode = false;
__EXPORT int position_estimator_inav_main(int argc, char *argv[]);
int position_estimator_inav_thread_main(int argc, char *argv[]);
static void usage(const char *reason);
/**
* Print the correct usage.
*/
static void usage(const char *reason)
{
if (reason)
fprintf(stderr, "%s\n", reason);
fprintf(stderr,
"usage: position_estimator_inav {start|stop|status} [-v]\n\n");
exit(1);
}
/**
* The position_estimator_inav_thread 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 position_estimator_inav_main(int argc, char *argv[])
{
if (argc < 1)
usage("missing command");
if (!strcmp(argv[1], "start")) {
if (thread_running) {
printf("position_estimator_inav already running\n");
/* this is not an error */
exit(0);
}
if (argc > 1)
if (!strcmp(argv[2], "-v"))
verbose_mode = true;
thread_should_exit = false;
position_estimator_inav_task = task_spawn("position_estimator_inav",
SCHED_RR, SCHED_PRIORITY_MAX - 5, 4096,
position_estimator_inav_thread_main,
(argv) ? (const char **) &argv[2] : (const char **) NULL);
exit(0);
}
if (!strcmp(argv[1], "stop")) {
thread_should_exit = true;
exit(0);
}
if (!strcmp(argv[1], "status")) {
if (thread_running) {
printf("\tposition_estimator_inav is running\n");
} else {
printf("\tposition_estimator_inav not started\n");
}
exit(0);
}
usage("unrecognized command");
exit(1);
}
/****************************************************************************
* main
****************************************************************************/
int position_estimator_inav_thread_main(int argc, char *argv[])
{
warnx("started.");
int mavlink_fd;
mavlink_fd = open(MAVLINK_LOG_DEVICE, 0);
mavlink_log_info(mavlink_fd, "[position_estimator_inav] started");
/* initialize values */
float x_est[3] = { 0.0f, 0.0f, 0.0f };
float y_est[3] = { 0.0f, 0.0f, 0.0f };
float z_est[3] = { 0.0f, 0.0f, 0.0f };
int baro_loop_cnt = 0;
int baro_loop_end = 70; /* measurement for 1 second */
float baro_alt0 = 0.0f; /* to determine while start up */
double lat_current = 0.0; //[°]] --> 47.0
double lon_current = 0.0; //[°]] -->8.5
double alt_current = 0.0; //[m] above MSL
/* declare and safely initialize all structs */
struct vehicle_status_s vehicle_status;
memset(&vehicle_status, 0, sizeof(vehicle_status));
/* make sure that baroINITdone = false */
struct sensor_combined_s sensor;
memset(&sensor, 0, sizeof(sensor));
struct vehicle_gps_position_s gps;
memset(&gps, 0, sizeof(gps));
struct vehicle_attitude_s att;
memset(&att, 0, sizeof(att));
struct vehicle_local_position_s pos;
memset(&pos, 0, sizeof(pos));
/* subscribe */
int parameter_update_sub = orb_subscribe(ORB_ID(parameter_update));
int vehicle_status_sub = orb_subscribe(ORB_ID(vehicle_status));
int sensor_combined_sub = orb_subscribe(ORB_ID(sensor_combined));
int vehicle_attitude_sub = orb_subscribe(ORB_ID(vehicle_attitude));
int vehicle_gps_position_sub = orb_subscribe(ORB_ID(vehicle_gps_position));
/* advertise */
orb_advert_t vehicle_local_position_pub = orb_advertise(ORB_ID(vehicle_local_position), &pos);
struct position_estimator_inav_params params;
struct position_estimator_inav_param_handles pos_inav_param_handles;
/* initialize parameter handles */
parameters_init(&pos_inav_param_handles);
bool local_flag_baroINITdone = false;
/* first parameters read at start up */
struct parameter_update_s param_update;
orb_copy(ORB_ID(parameter_update), parameter_update_sub, ¶m_update); /* read from param topic to clear updated flag */
/* first parameters update */
parameters_update(&pos_inav_param_handles, ¶ms);
/* wait for GPS fix, only then can we initialize the projection */
if (params.use_gps) {
struct pollfd fds_init[1] = {
{ .fd = vehicle_gps_position_sub, .events = POLLIN }
};
while (gps.fix_type < 3) {
if (poll(fds_init, 1, 5000)) {
if (fds_init[0].revents & POLLIN) {
/* Wait for the GPS update to propagate (we have some time) */
usleep(5000);
orb_copy(ORB_ID(vehicle_gps_position), vehicle_gps_position_sub, &gps);
}
}
static int printcounter = 0;
if (printcounter == 100) {
printcounter = 0;
warnx("waiting for GPS fix type 3...");
}
printcounter++;
}
/* get GPS position for first initialization */
orb_copy(ORB_ID(vehicle_gps_position), vehicle_gps_position_sub, &gps);
lat_current = ((double)(gps.lat)) * 1e-7;
lon_current = ((double)(gps.lon)) * 1e-7;
alt_current = gps.alt * 1e-3;
pos.home_lat = lat_current * 1e7;
pos.home_lon = lon_current * 1e7;
pos.home_timestamp = hrt_absolute_time();
/* initialize coordinates */
map_projection_init(lat_current, lon_current);
/* publish global position messages only after first GPS message */
}
warnx("initialized projection with: lat: %.10f, lon:%.10f", lat_current, lon_current);
hrt_abstime t_prev = 0;
thread_running = true;
uint32_t accel_counter = 0;
hrt_abstime accel_t = 0;
float accel_dt = 0.0f;
uint32_t baro_counter = 0;
hrt_abstime baro_t = 0;
hrt_abstime gps_t = 0;
uint16_t accel_updates = 0;
uint16_t baro_updates = 0;
uint16_t gps_updates = 0;
uint16_t attitude_updates = 0;
hrt_abstime updates_counter_start = hrt_absolute_time();
uint32_t updates_counter_len = 1000000;
hrt_abstime pub_last = hrt_absolute_time();
uint32_t pub_interval = 4000; // limit publish rate to 250 Hz
/* main loop */
struct pollfd fds[5] = {
{ .fd = parameter_update_sub, .events = POLLIN },
{ .fd = vehicle_status_sub, .events = POLLIN },
{ .fd = vehicle_attitude_sub, .events = POLLIN },
{ .fd = sensor_combined_sub, .events = POLLIN },
{ .fd = vehicle_gps_position_sub, .events = POLLIN }
};
printf("[position_estimator_inav] main loop started\n");
while (!thread_should_exit) {
bool accelerometer_updated = false;
bool baro_updated = false;
bool gps_updated = false;
float proj_pos_gps[3] = { 0.0f, 0.0f, 0.0f };
int ret = poll(fds, params.use_gps ? 5 : 4, 10); // wait maximal this 10 ms = 100 Hz minimum rate
hrt_abstime t = hrt_absolute_time();
if (ret < 0) {
/* poll error */
warnx("subscriptions poll error.");
thread_should_exit = true;
continue;
} else if (ret > 0) {
/* parameter update */
if (fds[0].revents & POLLIN) {
/* read from param to clear updated flag */
struct parameter_update_s update;
orb_copy(ORB_ID(parameter_update), parameter_update_sub,
&update);
/* update parameters */
parameters_update(&pos_inav_param_handles, ¶ms);
}
/* vehicle status */
if (fds[1].revents & POLLIN) {
orb_copy(ORB_ID(vehicle_status), vehicle_status_sub,
&vehicle_status);
}
/* vehicle attitude */
if (fds[2].revents & POLLIN) {
orb_copy(ORB_ID(vehicle_attitude), vehicle_attitude_sub, &att);
attitude_updates++;
}
/* sensor combined */
if (fds[3].revents & POLLIN) {
orb_copy(ORB_ID(sensor_combined), sensor_combined_sub, &sensor);
if (sensor.accelerometer_counter > accel_counter) {
accelerometer_updated = true;
accel_counter = sensor.accelerometer_counter;
accel_updates++;
accel_dt = accel_t > 0 ? (t - accel_t) / 1000000.0f : 0.0f;
accel_t = t;
}
if (sensor.baro_counter > baro_counter) {
baro_updated = true;
baro_counter = sensor.baro_counter;
baro_updates++;
}
/* barometric pressure estimation at start up */
if (!local_flag_baroINITdone && baro_updated) {
/* mean calculation over several measurements */
if (baro_loop_cnt < baro_loop_end) {
baro_alt0 += sensor.baro_alt_meter;
baro_loop_cnt++;
} else {
baro_alt0 /= (float)(baro_loop_cnt);
local_flag_baroINITdone = true;
mavlink_log_info(mavlink_fd, "[position_estimator_inav] baro_alt0 = %.2f", baro_alt0);
}
}
}
if (params.use_gps) {
/* vehicle GPS position */
if (fds[4].revents & POLLIN) {
/* new GPS value */
orb_copy(ORB_ID(vehicle_gps_position), vehicle_gps_position_sub, &gps);
/* project GPS lat lon (Geographic coordinate system) to plane */
map_projection_project(((double)(gps.lat)) * 1e-7,
((double)(gps.lon)) * 1e-7, &(proj_pos_gps[0]),
&(proj_pos_gps[1]));
proj_pos_gps[2] = (float)(gps.alt * 1e-3);
gps_updated = true;
pos.valid = gps.fix_type >= 3;
gps_updates++;
}
} else {
pos.valid = true;
}
}
/* end of poll return value check */
float dt = t_prev > 0 ? (t - t_prev) / 1000000.0 : 0.0f;
t_prev = t;
if (att.R_valid) {
/* transform acceleration vector from UAV frame to NED frame */
float accel_NED[3];
for (int i = 0; i < 3; i++) {
accel_NED[i] = 0.0f;
for (int j = 0; j < 3; j++) {
accel_NED[i] += att.R[i][j] * sensor.accelerometer_m_s2[j];
}
}
accel_NED[2] += CONSTANTS_ONE_G;
/* inertial filter prediction for altitude */
inertial_filter_predict(dt, z_est);
/* inertial filter correction for altitude */
if (local_flag_baroINITdone && baro_updated) {
if (baro_t > 0) {
inertial_filter_correct((t - baro_t) / 1000000.0f, z_est, 0, baro_alt0 - sensor.baro_alt_meter, params.w_alt_baro);
}
baro_t = t;
}
if (accelerometer_updated) {
inertial_filter_correct(accel_dt, z_est, 2, accel_NED[2], params.w_alt_acc);
}
if (params.use_gps) {
/* inertial filter prediction for position */
inertial_filter_predict(dt, x_est);
inertial_filter_predict(dt, y_est);
/* inertial filter correction for position */
if (gps_updated) {
if (gps_t > 0) {
float gps_dt = (t - gps_t) / 1000000.0f;
inertial_filter_correct(gps_dt, x_est, 0, proj_pos_gps[0], params.w_pos_gps_p);
inertial_filter_correct(gps_dt, x_est, 1, gps.vel_n_m_s, params.w_pos_gps_v);
inertial_filter_correct(gps_dt, y_est, 0, proj_pos_gps[1], params.w_pos_gps_p);
inertial_filter_correct(gps_dt, y_est, 1, gps.vel_e_m_s, params.w_pos_gps_v);
}
gps_t = t;
}
if (accelerometer_updated) {
inertial_filter_correct(accel_dt, x_est, 2, accel_NED[0], params.w_pos_acc);
inertial_filter_correct(accel_dt, y_est, 2, accel_NED[1], params.w_pos_acc);
}
}
}
if (verbose_mode) {
/* print updates rate */
if (t - updates_counter_start > updates_counter_len) {
float updates_dt = (t - updates_counter_start) * 0.000001f;
printf(
"[position_estimator_inav] updates rate: accelerometer = %.1f/s, baro = %.1f/s, gps = %.1f/s, attitude = %.1f/s\n",
accel_updates / updates_dt,
baro_updates / updates_dt,
gps_updates / updates_dt,
attitude_updates / updates_dt);
updates_counter_start = t;
accel_updates = 0;
baro_updates = 0;
gps_updates = 0;
attitude_updates = 0;
}
}
if (t - pub_last > pub_interval) {
pub_last = t;
pos.x = x_est[0];
pos.vx = x_est[1];
pos.y = y_est[0];
pos.vy = y_est[1];
pos.z = z_est[0];
pos.vz = z_est[1];
pos.timestamp = hrt_absolute_time();
if ((isfinite(pos.x)) && (isfinite(pos.vx))
&& (isfinite(pos.y))
&& (isfinite(pos.vy))
&& (isfinite(pos.z))
&& (isfinite(pos.vz))) {
orb_publish(ORB_ID(vehicle_local_position), vehicle_local_position_pub, &pos);
}
}
}
warnx("exiting.");
mavlink_log_info(mavlink_fd, "[position_estimator_inav] exiting");
thread_running = false;
return 0;
}