/****************************************************************************
*
* 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 <drivers/drv_hrt.h>
#include "position_estimator_inav_params.h"
#include "kalman_filter_inertial.h"
#include "acceleration_transform.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[]);
/**
* Print the correct usage.
*/
static void usage(const char *reason);
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[]) {
/* welcome user */
printf("[position_estimator_inav] started\n");
static int mavlink_fd;
mavlink_fd = open(MAVLINK_LOG_DEVICE, 0);
mavlink_log_info(mavlink_fd, "[position_estimator_inav] started");
/* initialize values */
static float x_est[3] = { 0.0f, 0.0f, 0.0f };
static float y_est[3] = { 0.0f, 0.0f, 0.0f };
static float z_est[3] = { 0.0f, 0.0f, 0.0f };
const static float dT_const_120 = 1.0f / 120.0f;
const static float dT2_const_120 = 1.0f / 120.0f / 120.0f / 2.0f;
bool use_gps = false;
int baro_loop_cnt = 0;
int baro_loop_end = 70; /* measurement for 1 second */
float baro_alt0 = 0.0f; /* to determin while start up */
const static float const_earth_gravity = 9.81f;
static double lat_current = 0.0d; //[°]] --> 47.0
static double lon_current = 0.0d; //[°]] -->8.5
static double alt_current = 0.0d; //[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 local_pos_est;
memset(&local_pos_est, 0, sizeof(local_pos_est));
/* 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 local_pos_est_pub = orb_advertise(
ORB_ID(vehicle_local_position), &local_pos_est);
struct position_estimator_inav_params pos_inav_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; /* in any case disable baroINITdone */
/* FIRST PARAMETER READ at START UP*/
struct parameter_update_s param_update;
orb_copy(ORB_ID(parameter_update), parameter_update_sub, ¶m_update); /* read from param to clear updated flag */
/* FIRST PARAMETER UPDATE */
parameters_update(&pos_inav_param_handles, &pos_inav_params);
/* END FIRST PARAMETER UPDATE */
/* wait until gps signal turns valid, only then can we initialize the projection */
if (use_gps) {
struct pollfd fds_init[1] = { { .fd = vehicle_gps_position_sub,
.events = POLLIN } };
while (gps.fix_type < 3) {
/* wait for GPS updates, BUT READ VEHICLE STATUS (!)
* this choice is critical, since the vehicle status might not
* actually change, if this app is started after GPS lock was
* aquired.
*/
if (poll(fds_init, 1, 5000)) { /* poll only two first subscriptions */
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;
printf("[position_estimator_inav] wait for GPS fix type 3\n");
}
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;
/* initialize coordinates */
map_projection_init(lat_current, lon_current);
/* publish global position messages only after first GPS message */
}
printf("[position_estimator_inav] initialized projection with: lat: %.10f, lon:%.10f\n",
lat_current, lon_current);
hrt_abstime last_time = 0;
thread_running = true;
static int printatt_counter = 0;
uint32_t accelerometer_counter = 0;
uint32_t baro_counter = 0;
uint16_t accelerometer_updates = 0;
uint16_t baro_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 = 5000; // limit publish rate to 200 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;
int ret = poll(fds, 5, 10); // wait maximal this 10 ms = 100 Hz minimum rate
if (ret < 0) {
/* poll error */
if (verbose_mode)
printf("[position_estimator_inav] subscriptions poll error\n");
} 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, &pos_inav_params);
}
/* 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);
}
/* sensor combined */
if (fds[3].revents & POLLIN) {
orb_copy(ORB_ID(sensor_combined), sensor_combined_sub, &sensor);
if (sensor.accelerometer_counter > accelerometer_counter) {
accelerometer_updated = true;
accelerometer_counter = sensor.accelerometer_counter;
accelerometer_updates++;
}
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;
char str[80];
sprintf(str, "[position_estimator_inav] barometer initialized with alt0 = %.2f", baro_alt0);
printf("%s\n", str);
mavlink_log_info(mavlink_fd, str);
}
}
}
if (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);
static float local_pos_gps[3] = { 0.0f, 0.0f, 0.0f }; /* output variables from tangent plane mapping */
/* Project gps lat lon (Geographic coordinate system) to plane */
map_projection_project(((double) (gps.lat)) * 1e-7,
((double) (gps.lon)) * 1e-7, &(local_pos_gps[0]),
&(local_pos_gps[1]));
local_pos_gps[2] = (float) (gps.alt * 1e-3);
}
}
} /* end of poll return value check */
hrt_abstime t = hrt_absolute_time();
float dt = (t - last_time) / 1000000.0;
last_time = t;
/* calculate corrected acceleration vector in UAV frame */
float accel_corr[3];
acceleration_correct(accel_corr, sensor.accelerometer_raw, pos_inav_params.acc_T, pos_inav_params.acc_offs);
/* 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] * accel_corr[j];
}
}
accel_NED[2] += const_earth_gravity;
/* kalman filter prediction */
kalman_filter_inertial_predict(dt, z_est);
/* prepare vectors for kalman filter correction */
float z_meas[2]; // position, acceleration
bool use_z[2] = { false, false };
if (local_flag_baroINITdone && baro_updated) {
z_meas[0] = baro_alt0 - sensor.baro_alt_meter; // Z = -alt
use_z[0] = true;
}
if (accelerometer_updated) {
z_meas[1] = accel_NED[2];
use_z[1] = true;
}
if (use_z[0] || use_z[1]) {
/* correction */
kalman_filter_inertial_update(z_est, z_meas, pos_inav_params.k, use_z);
}
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] accelerometer_updates_rate = %.1/s, baro_updates_rate = %.1f/s\n", accelerometer_updates / updates_dt, baro_updates / updates_dt);
updates_counter_start = t;
accelerometer_updates = 0;
baro_updates = 0;
}
}
if (t - pub_last > pub_interval) {
pub_last = t;
local_pos_est.x = 0.0f;
local_pos_est.vx = 0.0f;
local_pos_est.y = 0.0f;
local_pos_est.vy = 0.0f;
local_pos_est.z = z_est[0];
local_pos_est.vz = z_est[1];
local_pos_est.timestamp = hrt_absolute_time();
if ((isfinite(local_pos_est.x)) && (isfinite(local_pos_est.vx))
&& (isfinite(local_pos_est.y))
&& (isfinite(local_pos_est.vy))
&& (isfinite(local_pos_est.z))
&& (isfinite(local_pos_est.vz))) {
orb_publish(ORB_ID(
vehicle_local_position), local_pos_est_pub,
&local_pos_est);
}
}
}
printf("[position_estimator_inav] exiting.\n");
mavlink_log_info(mavlink_fd, "[position_estimator_inav] exiting");
thread_running = false;
return 0;
}