/****************************************************************************
*
* 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/parameter_update.h>
#include <uORB/topics/actuator_controls.h>
#include <uORB/topics/actuator_armed.h>
#include <uORB/topics/sensor_combined.h>
#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_local_position.h>
#include <uORB/topics/vehicle_global_position.h>
#include <uORB/topics/vehicle_gps_position.h>
#include <uORB/topics/optical_flow.h>
#include <mavlink/mavlink_log.h>
#include <poll.h>
#include <systemlib/err.h>
#include <geo/geo.h>
#include <systemlib/systemlib.h>
#include <drivers/drv_hrt.h>
#include "position_estimator_inav_params.h"
#include "inertial_filter.h"
#define MIN_VALID_W 0.00001f
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;
static const hrt_abstime gps_topic_timeout = 1000000; // GPS topic timeout = 1s
static const hrt_abstime flow_topic_timeout = 1000000; // optical flow topic timeout = 1s
static const hrt_abstime sonar_timeout = 150000; // sonar timeout = 150ms
static const hrt_abstime sonar_valid_timeout = 1000000; // estimate sonar distance during this time after sonar loss
static const hrt_abstime xy_src_timeout = 2000000; // estimate position during this time after position sources loss
static const uint32_t updates_counter_len = 1000000;
static const uint32_t pub_interval = 10000; // limit publish rate to 100 Hz
static const float max_flow = 1.0f; // max flow value that can be used, rad/s
__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) {
warnx("already running");
/* this is not an error */
exit(0);
}
verbose_mode = false;
if (argc > 1)
if (!strcmp(argv[2], "-v"))
verbose_mode = true;
thread_should_exit = false;
position_estimator_inav_task = task_spawn_cmd("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")) {
if (thread_running) {
warnx("stop");
thread_should_exit = true;
} else {
warnx("app not started");
}
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);
}
void write_debug_log(const char *msg, float dt, float x_est[3], float y_est[3], float z_est[3], float corr_acc[3], float corr_gps[3][2], float w_xy_gps_p, float w_xy_gps_v) {
FILE *f = fopen("/fs/microsd/inav.log", "a");
if (f) {
char *s = malloc(256);
snprintf(s, 256, "%llu %s\n\tdt=%.5f x_est=[%.5f %.5f %.5f] y_est=[%.5f %.5f %.5f] z_est=[%.5f %.5f %.5f]\n", hrt_absolute_time(), msg, dt, x_est[0], x_est[1], x_est[2], y_est[0], y_est[1], y_est[2], z_est[0], z_est[1], z_est[2]);
fputs(f, s);
snprintf(s, 256, "\tacc_corr=[%.5f %.5f %.5f] gps_pos_corr=[%.5f %.5f %.5f] gps_vel_corr=[%.5f %.5f %.5f] w_xy_gps_p=%.5f w_xy_gps_v=%.5f\n", corr_acc[0], corr_acc[1], corr_acc[2], corr_gps[0][0], corr_gps[1][0], corr_gps[2][0], corr_gps[0][1], corr_gps[1][1], corr_gps[2][1], w_xy_gps_p, w_xy_gps_v);
fputs(f, s);
free(s);
}
fclose(f);
}
/****************************************************************************
* 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, "[inav] started");
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_init_cnt = 0;
int baro_init_num = 200;
float baro_offset = 0.0f; // baro offset for reference altitude, initialized on start, then adjusted
float surface_offset = 0.0f; // ground level offset from reference altitude
float surface_offset_rate = 0.0f; // surface offset change rate
float alt_avg = 0.0f;
bool landed = true;
hrt_abstime landed_time = 0;
bool flag_armed = false;
uint32_t accel_counter = 0;
uint32_t baro_counter = 0;
bool ref_inited = false;
hrt_abstime ref_init_start = 0;
const hrt_abstime ref_init_delay = 1000000; // wait for 1s after 3D fix
uint16_t accel_updates = 0;
uint16_t baro_updates = 0;
uint16_t gps_updates = 0;
uint16_t attitude_updates = 0;
uint16_t flow_updates = 0;
hrt_abstime updates_counter_start = hrt_absolute_time();
hrt_abstime pub_last = hrt_absolute_time();
hrt_abstime t_prev = 0;
/* acceleration in NED frame */
float accel_NED[3] = { 0.0f, 0.0f, -CONSTANTS_ONE_G };
/* store error when sensor updates, but correct on each time step to avoid jumps in estimated value */
float corr_acc[] = { 0.0f, 0.0f, 0.0f }; // N E D
float acc_bias[] = { 0.0f, 0.0f, 0.0f }; // body frame
float corr_baro = 0.0f; // D
float corr_gps[3][2] = {
{ 0.0f, 0.0f }, // N (pos, vel)
{ 0.0f, 0.0f }, // E (pos, vel)
{ 0.0f, 0.0f }, // D (pos, vel)
};
float w_gps_xy = 1.0f;
float w_gps_z = 1.0f;
float corr_sonar = 0.0f;
float corr_sonar_filtered = 0.0f;
float corr_flow[] = { 0.0f, 0.0f }; // N E
float w_flow = 0.0f;
float sonar_prev = 0.0f;
hrt_abstime sonar_time = 0; // time of last sonar measurement (not filtered)
hrt_abstime sonar_valid_time = 0; // time of last sonar measurement used for correction (filtered)
hrt_abstime xy_src_time = 0; // time of last available position data
bool gps_valid = false; // GPS is valid
bool sonar_valid = false; // sonar is valid
bool flow_valid = false; // flow is valid
bool flow_accurate = false; // flow should be accurate (this flag not updated if flow_valid == false)
/* declare and safely initialize all structs */
struct actuator_controls_s actuator;
memset(&actuator, 0, sizeof(actuator));
struct actuator_armed_s armed;
memset(&armed, 0, sizeof(armed));
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;
memset(&local_pos, 0, sizeof(local_pos));
struct optical_flow_s flow;
memset(&flow, 0, sizeof(flow));
struct vehicle_global_position_s global_pos;
memset(&global_pos, 0, sizeof(global_pos));
/* subscribe */
int parameter_update_sub = orb_subscribe(ORB_ID(parameter_update));
int actuator_sub = orb_subscribe(ORB_ID_VEHICLE_ATTITUDE_CONTROLS);
int armed_sub = orb_subscribe(ORB_ID(actuator_armed));
int sensor_combined_sub = orb_subscribe(ORB_ID(sensor_combined));
int vehicle_attitude_sub = orb_subscribe(ORB_ID(vehicle_attitude));
int optical_flow_sub = orb_subscribe(ORB_ID(optical_flow));
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), &local_pos);
orb_advert_t vehicle_global_position_pub = orb_advertise(ORB_ID(vehicle_global_position), &global_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);
/* 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);
struct pollfd fds_init[1] = {
{ .fd = sensor_combined_sub, .events = POLLIN },
};
/* wait for initial baro value */
bool wait_baro = true;
thread_running = true;
while (wait_baro && !thread_should_exit) {
int ret = poll(fds_init, 1, 1000);
if (ret < 0) {
/* poll error */
mavlink_log_info(mavlink_fd, "[inav] poll error on init");
} else if (ret > 0) {
if (fds_init[0].revents & POLLIN) {
orb_copy(ORB_ID(sensor_combined), sensor_combined_sub, &sensor);
if (wait_baro && sensor.baro_counter != baro_counter) {
baro_counter = sensor.baro_counter;
/* mean calculation over several measurements */
if (baro_init_cnt < baro_init_num) {
baro_offset += sensor.baro_alt_meter;
baro_init_cnt++;
} else {
wait_baro = false;
baro_offset /= (float) baro_init_cnt;
warnx("baro offs: %.2f", baro_offset);
mavlink_log_info(mavlink_fd, "[inav] baro offs: %.2f", baro_offset);
local_pos.z_valid = true;
local_pos.v_z_valid = true;
}
}
}
}
}
/* main loop */
struct pollfd fds[1] = {
{ .fd = vehicle_attitude_sub, .events = POLLIN },
};
while (!thread_should_exit) {
int ret = poll(fds, 1, 20); // wait maximal 20 ms = 50 Hz minimum rate
hrt_abstime t = hrt_absolute_time();
if (ret < 0) {
/* poll error */
mavlink_log_info(mavlink_fd, "[inav] poll error on init");
continue;
} else if (ret > 0) {
/* act on attitude updates */
/* vehicle attitude */
orb_copy(ORB_ID(vehicle_attitude), vehicle_attitude_sub, &att);
attitude_updates++;
bool updated;
/* parameter update */
orb_check(parameter_update_sub, &updated);
if (updated) {
struct parameter_update_s update;
orb_copy(ORB_ID(parameter_update), parameter_update_sub, &update);
parameters_update(&pos_inav_param_handles, ¶ms);
}
/* actuator */
orb_check(actuator_sub, &updated);
if (updated) {
orb_copy(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, actuator_sub, &actuator);
}
/* armed */
orb_check(armed_sub, &updated);
if (updated) {
orb_copy(ORB_ID(actuator_armed), armed_sub, &armed);
/* reset ground level on arm */
if (armed.armed && !flag_armed) {
flag_armed = armed.armed;
baro_offset -= z_est[0];
corr_baro = 0.0f;
local_pos.ref_alt -= z_est[0];
local_pos.ref_timestamp = t;
z_est[0] = 0.0f;
alt_avg = 0.0f;
}
}
/* sensor combined */
orb_check(sensor_combined_sub, &updated);
if (updated) {
orb_copy(ORB_ID(sensor_combined), sensor_combined_sub, &sensor);
if (sensor.accelerometer_counter != accel_counter) {
if (att.R_valid) {
/* correct accel bias */
sensor.accelerometer_m_s2[0] -= acc_bias[0];
sensor.accelerometer_m_s2[1] -= acc_bias[1];
sensor.accelerometer_m_s2[2] -= acc_bias[2];
/* transform acceleration vector from body frame to NED frame */
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];
}
}
corr_acc[0] = accel_NED[0] - x_est[2];
corr_acc[1] = accel_NED[1] - y_est[2];
corr_acc[2] = accel_NED[2] + CONSTANTS_ONE_G - z_est[2];
} else {
memset(corr_acc, 0, sizeof(corr_acc));
}
accel_counter = sensor.accelerometer_counter;
accel_updates++;
}
if (sensor.baro_counter != baro_counter) {
corr_baro = baro_offset - sensor.baro_alt_meter - z_est[0];
baro_counter = sensor.baro_counter;
baro_updates++;
}
}
/* optical flow */
orb_check(optical_flow_sub, &updated);
if (updated) {
orb_copy(ORB_ID(optical_flow), optical_flow_sub, &flow);
if (flow.ground_distance_m > 0.31f && flow.ground_distance_m < 4.0f && att.R[2][2] > 0.7 && flow.ground_distance_m != sonar_prev) {
sonar_time = t;
sonar_prev = flow.ground_distance_m;
corr_sonar = flow.ground_distance_m + surface_offset + z_est[0];
corr_sonar_filtered += (corr_sonar - corr_sonar_filtered) * params.sonar_filt;
if (fabsf(corr_sonar) > params.sonar_err) {
/* correction is too large: spike or new ground level? */
if (fabsf(corr_sonar - corr_sonar_filtered) > params.sonar_err) {
/* spike detected, ignore */
corr_sonar = 0.0f;
sonar_valid = false;
} else {
/* new ground level */
surface_offset -= corr_sonar;
surface_offset_rate = 0.0f;
corr_sonar = 0.0f;
corr_sonar_filtered = 0.0f;
sonar_valid_time = t;
sonar_valid = true;
local_pos.surface_bottom_timestamp = t;
mavlink_log_info(mavlink_fd, "[inav] new surface level: %.2f", surface_offset);
}
} else {
/* correction is ok, use it */
sonar_valid_time = t;
sonar_valid = true;
}
}
float flow_q = flow.quality / 255.0f;
float dist_bottom = - z_est[0] - surface_offset;
if (dist_bottom > 0.3f && flow_q > params.flow_q_min && (t < sonar_valid_time + sonar_valid_timeout) && att.R[2][2] > 0.7) {
/* distance to surface */
float flow_dist = dist_bottom / att.R[2][2];
/* check if flow if too large for accurate measurements */
/* calculate estimated velocity in body frame */
float body_v_est[2] = { 0.0f, 0.0f };
for (int i = 0; i < 2; i++) {
body_v_est[i] = att.R[0][i] * x_est[1] + att.R[1][i] * y_est[1] + att.R[2][i] * z_est[1];
}
/* set this flag if flow should be accurate according to current velocity and attitude rate estimate */
flow_accurate = fabsf(body_v_est[1] / flow_dist - att.rollspeed) < max_flow &&
fabsf(body_v_est[0] / flow_dist + att.pitchspeed) < max_flow;
/* convert raw flow to angular flow */
float flow_ang[2];
flow_ang[0] = flow.flow_raw_x * params.flow_k;
flow_ang[1] = flow.flow_raw_y * params.flow_k;
/* flow measurements vector */
float flow_m[3];
flow_m[0] = -flow_ang[0] * flow_dist;
flow_m[1] = -flow_ang[1] * flow_dist;
flow_m[2] = z_est[1];
/* velocity in NED */
float flow_v[2] = { 0.0f, 0.0f };
/* project measurements vector to NED basis, skip Z component */
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 3; j++) {
flow_v[i] += att.R[i][j] * flow_m[j];
}
}
/* velocity correction */
corr_flow[0] = flow_v[0] - x_est[1];
corr_flow[1] = flow_v[1] - y_est[1];
/* adjust correction weight */
float flow_q_weight = (flow_q - params.flow_q_min) / (1.0f - params.flow_q_min);
w_flow = att.R[2][2] * flow_q_weight / fmaxf(1.0f, flow_dist);
/* if flow is not accurate, reduce weight for it */
// TODO make this more fuzzy
if (!flow_accurate)
w_flow *= 0.05f;
flow_valid = true;
} else {
w_flow = 0.0f;
flow_valid = false;
}
flow_updates++;
}
/* vehicle GPS position */
orb_check(vehicle_gps_position_sub, &updated);
if (updated) {
orb_copy(ORB_ID(vehicle_gps_position), vehicle_gps_position_sub, &gps);
if (gps.fix_type >= 3) {
/* hysteresis for GPS quality */
if (gps_valid) {
if (gps.eph_m > 10.0f || gps.epv_m > 10.0f) {
gps_valid = false;
mavlink_log_info(mavlink_fd, "[inav] GPS signal lost");
}
} else {
if (gps.eph_m < 5.0f && gps.epv_m < 5.0f) {
gps_valid = true;
mavlink_log_info(mavlink_fd, "[inav] GPS signal found");
}
}
} else {
gps_valid = false;
}
if (gps_valid) {
/* initialize reference position if needed */
if (!ref_inited) {
if (ref_init_start == 0) {
ref_init_start = t;
} else if (t > ref_init_start + ref_init_delay) {
ref_inited = true;
/* reference GPS position */
double lat = gps.lat * 1e-7;
double lon = gps.lon * 1e-7;
float alt = gps.alt * 1e-3;
local_pos.ref_lat = gps.lat;
local_pos.ref_lon = gps.lon;
local_pos.ref_alt = alt + z_est[0];
local_pos.ref_timestamp = t;
/* initialize projection */
map_projection_init(lat, lon);
warnx("init ref: lat=%.7f, lon=%.7f, alt=%.2f", lat, lon, alt);
mavlink_log_info(mavlink_fd, "[inav] init ref: lat=%.7f, lon=%.7f, alt=%.2f", lat, lon, alt);
}
}
if (ref_inited) {
/* project GPS lat lon to plane */
float gps_proj[2];
map_projection_project(gps.lat * 1e-7, gps.lon * 1e-7, &(gps_proj[0]), &(gps_proj[1]));
/* calculate correction for position */
corr_gps[0][0] = gps_proj[0] - x_est[0];
corr_gps[1][0] = gps_proj[1] - y_est[0];
corr_gps[2][0] = local_pos.ref_alt - gps.alt * 1e-3 - z_est[0];
/* calculate correction for velocity */
if (gps.vel_ned_valid) {
corr_gps[0][1] = gps.vel_n_m_s - x_est[1];
corr_gps[1][1] = gps.vel_e_m_s - y_est[1];
corr_gps[2][1] = gps.vel_d_m_s - z_est[1];
} else {
corr_gps[0][1] = 0.0f;
corr_gps[1][1] = 0.0f;
corr_gps[2][1] = 0.0f;
}
w_gps_xy = 1.0f / fmaxf(1.0f, gps.eph_m);
w_gps_z = 1.0f / fmaxf(1.0f, gps.epv_m);
}
} else {
/* no GPS lock */
memset(corr_gps, 0, sizeof(corr_gps));
ref_init_start = 0;
}
gps_updates++;
}
}
/* check for timeout on FLOW topic */
if ((flow_valid || sonar_valid) && t > flow.timestamp + flow_topic_timeout) {
flow_valid = false;
sonar_valid = false;
warnx("FLOW timeout");
mavlink_log_info(mavlink_fd, "[inav] FLOW timeout");
}
/* check for timeout on GPS topic */
if (gps_valid && t > gps.timestamp_position + gps_topic_timeout) {
gps_valid = false;
warnx("GPS timeout");
mavlink_log_info(mavlink_fd, "[inav] GPS timeout");
}
/* check for sonar measurement timeout */
if (sonar_valid && t > sonar_time + sonar_timeout) {
corr_sonar = 0.0f;
sonar_valid = false;
}
float dt = t_prev > 0 ? (t - t_prev) / 1000000.0f : 0.0f;
t_prev = t;
/* use GPS if it's valid and reference position initialized */
bool use_gps_xy = ref_inited && gps_valid && params.w_xy_gps_p > MIN_VALID_W;
bool use_gps_z = ref_inited && gps_valid && params.w_z_gps_p > MIN_VALID_W;
/* use flow if it's valid and (accurate or no GPS available) */
bool use_flow = flow_valid && (flow_accurate || !use_gps_xy);
/* try to estimate position during some time after position sources lost */
if (use_gps_xy || use_flow) {
xy_src_time = t;
}
bool can_estimate_xy = (t < xy_src_time + xy_src_timeout);
bool dist_bottom_valid = (t < sonar_valid_time + sonar_valid_timeout);
if (dist_bottom_valid) {
/* surface distance prediction */
surface_offset += surface_offset_rate * dt;
/* surface distance correction */
if (sonar_valid) {
surface_offset_rate -= corr_sonar * 0.5f * params.w_z_sonar * params.w_z_sonar * dt;
surface_offset -= corr_sonar * params.w_z_sonar * dt;
}
}
float w_xy_gps_p = params.w_xy_gps_p * w_gps_xy;
float w_xy_gps_v = params.w_xy_gps_v * w_gps_xy;
float w_z_gps_p = params.w_z_gps_p * w_gps_z;
/* reduce GPS weight if optical flow is good */
if (use_flow && flow_accurate) {
w_xy_gps_p *= params.w_gps_flow;
w_xy_gps_v *= params.w_gps_flow;
}
/* baro offset correction */
if (use_gps_z) {
float offs_corr = corr_gps[2][0] * w_z_gps_p * dt;
baro_offset += offs_corr;
baro_counter += offs_corr;
}
/* accelerometer bias correction */
float accel_bias_corr[3] = { 0.0f, 0.0f, 0.0f };
if (use_gps_xy) {
accel_bias_corr[0] -= corr_gps[0][0] * w_xy_gps_p * w_xy_gps_p;
accel_bias_corr[0] -= corr_gps[0][1] * w_xy_gps_v;
accel_bias_corr[1] -= corr_gps[1][0] * w_xy_gps_p * w_xy_gps_p;
accel_bias_corr[1] -= corr_gps[1][1] * w_xy_gps_v;
}
if (use_gps_z) {
accel_bias_corr[2] -= corr_gps[2][0] * w_z_gps_p * w_z_gps_p;
}
if (use_flow) {
accel_bias_corr[0] -= corr_flow[0] * params.w_xy_flow;
accel_bias_corr[1] -= corr_flow[1] * params.w_xy_flow;
}
accel_bias_corr[2] -= corr_baro * params.w_z_baro * params.w_z_baro;
/* transform error vector from NED frame to body frame */
for (int i = 0; i < 3; i++) {
float c = 0.0f;
for (int j = 0; j < 3; j++) {
c += att.R[j][i] * accel_bias_corr[j];
}
acc_bias[i] += c * params.w_acc_bias * dt;
}
/* inertial filter prediction for altitude */
inertial_filter_predict(dt, z_est);
/* inertial filter correction for altitude */
inertial_filter_correct(corr_baro, dt, z_est, 0, params.w_z_baro);
inertial_filter_correct(corr_gps[2][0], dt, z_est, 0, w_z_gps_p);
inertial_filter_correct(corr_acc[2], dt, z_est, 2, params.w_z_acc);
if (can_estimate_xy) {
/* inertial filter prediction for position */
inertial_filter_predict(dt, x_est);
inertial_filter_predict(dt, y_est);
if (!isfinite(x_est[0]) || !isfinite(y_est[0])) {
write_debug_log("BAD ESTIMATE AFTER PREDICTION", dt, x_est, y_est, z_est, corr_acc, corr_gps, w_xy_gps_p, w_xy_gps_v);
thread_should_exit = true;
}
/* inertial filter correction for position */
inertial_filter_correct(corr_acc[0], dt, x_est, 2, params.w_xy_acc);
inertial_filter_correct(corr_acc[1], dt, y_est, 2, params.w_xy_acc);
if (use_flow) {
inertial_filter_correct(corr_flow[0], dt, x_est, 1, params.w_xy_flow * w_flow);
inertial_filter_correct(corr_flow[1], dt, y_est, 1, params.w_xy_flow * w_flow);
}
if (use_gps_xy) {
inertial_filter_correct(corr_gps[0][0], dt, x_est, 0, w_xy_gps_p);
inertial_filter_correct(corr_gps[1][0], dt, y_est, 0, w_xy_gps_p);
if (gps.vel_ned_valid && t < gps.timestamp_velocity + gps_topic_timeout) {
inertial_filter_correct(corr_gps[0][1], dt, x_est, 1, w_xy_gps_v);
inertial_filter_correct(corr_gps[1][1], dt, y_est, 1, w_xy_gps_v);
}
}
if (!isfinite(x_est[0]) || !isfinite(y_est[0])) {
write_debug_log("BAD ESTIMATE AFTER CORRECTION", dt, x_est, y_est, z_est, corr_acc, corr_gps, w_xy_gps_p, w_xy_gps_v);
thread_should_exit = true;
}
}
/* detect land */
alt_avg += (- z_est[0] - alt_avg) * dt / params.land_t;
float alt_disp2 = - z_est[0] - alt_avg;
alt_disp2 = alt_disp2 * alt_disp2;
float land_disp2 = params.land_disp * params.land_disp;
/* get actual thrust output */
float thrust = armed.armed ? actuator.control[3] : 0.0f;
if (landed) {
if (alt_disp2 > land_disp2 && thrust > params.land_thr) {
landed = false;
landed_time = 0;
}
} else {
if (alt_disp2 < land_disp2 && thrust < params.land_thr) {
if (landed_time == 0) {
landed_time = t; // land detected first time
} else {
if (t > landed_time + params.land_t * 1000000.0f) {
landed = true;
landed_time = 0;
}
}
} else {
landed_time = 0;
}
}
if (verbose_mode) {
/* print updates rate */
if (t > updates_counter_start + updates_counter_len) {
float updates_dt = (t - updates_counter_start) * 0.000001f;
warnx(
"updates rate: accelerometer = %.1f/s, baro = %.1f/s, gps = %.1f/s, attitude = %.1f/s, flow = %.1f/s",
accel_updates / updates_dt,
baro_updates / updates_dt,
gps_updates / updates_dt,
attitude_updates / updates_dt,
flow_updates / updates_dt);
updates_counter_start = t;
accel_updates = 0;
baro_updates = 0;
gps_updates = 0;
attitude_updates = 0;
flow_updates = 0;
}
}
if (t > pub_last + pub_interval) {
pub_last = t;
/* publish local position */
local_pos.xy_valid = can_estimate_xy && use_gps_xy;
local_pos.v_xy_valid = can_estimate_xy;
local_pos.xy_global = local_pos.xy_valid && use_gps_xy;
local_pos.z_global = local_pos.z_valid && use_gps_z;
local_pos.x = x_est[0];
local_pos.vx = x_est[1];
local_pos.y = y_est[0];
local_pos.vy = y_est[1];
local_pos.z = z_est[0];
local_pos.vz = z_est[1];
local_pos.landed = landed;
local_pos.yaw = att.yaw;
local_pos.dist_bottom_valid = dist_bottom_valid;
if (local_pos.dist_bottom_valid) {
local_pos.dist_bottom = -z_est[0] - surface_offset;
local_pos.dist_bottom_rate = -z_est[1] - surface_offset_rate;
}
local_pos.timestamp = t;
orb_publish(ORB_ID(vehicle_local_position), vehicle_local_position_pub, &local_pos);
/* publish global position */
global_pos.valid = local_pos.xy_global;
if (local_pos.xy_global) {
double est_lat, est_lon;
map_projection_reproject(local_pos.x, local_pos.y, &est_lat, &est_lon);
global_pos.lat = (int32_t)(est_lat * 1e7d);
global_pos.lon = (int32_t)(est_lon * 1e7d);
global_pos.time_gps_usec = gps.time_gps_usec;
}
/* set valid values even if position is not valid */
if (local_pos.v_xy_valid) {
global_pos.vx = local_pos.vx;
global_pos.vy = local_pos.vy;
}
if (local_pos.z_valid) {
global_pos.relative_alt = -local_pos.z;
}
if (local_pos.z_global) {
global_pos.alt = local_pos.ref_alt - local_pos.z;
}
if (local_pos.v_z_valid) {
global_pos.vz = local_pos.vz;
}
global_pos.yaw = local_pos.yaw;
global_pos.timestamp = t;
orb_publish(ORB_ID(vehicle_global_position), vehicle_global_position_pub, &global_pos);
}
}
warnx("stopped");
mavlink_log_info(mavlink_fd, "[inav] stopped");
thread_running = false;
return 0;
}