/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
* Author: Tobias Naegeli <naegelit@student.ethz.ch>
* Lorenz Meier <lm@inf.ethz.ch>
*
* 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
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****************************************************************************/
/*
* @file attitude_estimator_ekf_main.c
*
* Extended Kalman Filter for Attitude Estimation.
*/
#include <nuttx/config.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <poll.h>
#include <fcntl.h>
#include <v1.0/common/mavlink.h>
#include <float.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/vehicle_attitude.h>
#include <arch/board/up_hrt.h>
#include "codegen/attitudeKalmanfilter_initialize.h"
#include "codegen/attitudeKalmanfilter.h"
__EXPORT int attitude_estimator_ekf_main(int argc, char *argv[]);
// #define N_STATES 6
// #define PROJECTION_INITIALIZE_COUNTER_LIMIT 5000
// #define REPROJECTION_COUNTER_LIMIT 125
static unsigned int loop_interval_alarm = 4500; // loop interval in microseconds
static float dt = 1;
/* 0, 0, -9.81, 1, 1, 1, wo (gyro offset), w */
/* state vector x has the following entries [ax,ay,az||mx,my,mz||wox,woy,woz||wx,wy,wz]' */
static float z_k[9] = {0}; /**< Measurement vector */
static float x_aposteriori_k[9] = {0}; /**< */
static float x_aposteriori[9] = {0};
static float P_aposteriori_k[81] = {100.f, 0, 0, 0, 0, 0, 0, 0, 0,
0, 100.f, 0, 0, 0, 0, 0, 0, 0,
0, 0, 100.f, 0, 0, 0, 0, 0, 0,
0, 0, 0, 100.f, 0, 0, 0, 0, 0,
0, 0, 0, 0, 100.f, 0, 0, 0, 0,
0, 0, 0, 0, 0, 100.f, 0, 0, 0,
0, 0, 0, 0, 0, 0, 100.f, 0, 0,
0, 0, 0, 0, 0, 0, 0, 100.f, 0,
0, 0, 0, 0, 0, 0, 0, 0, 100.f,
0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0,
};
static float P_aposteriori[81] = {100.f, 0, 0, 0, 0, 0, 0, 0, 0,
0, 100.f, 0, 0, 0, 0, 0, 0, 0,
0, 0, 100.f, 0, 0, 0, 0, 0, 0,
0, 0, 0, 100.f, 0, 0, 0, 0, 0,
0, 0, 0, 0, 100.f, 0, 0, 0, 0,
0, 0, 0, 0, 0, 100.f, 0, 0, 0,
0, 0, 0, 0, 0, 0, 100.f, 0, 0,
0, 0, 0, 0, 0, 0, 0, 100.f, 0,
0, 0, 0, 0, 0, 0, 0, 0, 100.f,
0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0,
}; /**< init: diagonal matrix with big values */
static float knownConst[20] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}; /**< knownConst has the following entries [PrvaA,PrvarM,PrvarWO,PrvarW||MsvarA,MsvarM,MsvarW] */
static float Rot_matrix[9] = {1.f, 0, 0,
0, 1.f, 0,
0, 0, 1.f
}; /**< init: identity matrix */
/*
* [Rot_matrix,x_aposteriori,P_aposteriori] = attitudeKalmanfilter(dt,z_k,x_aposteriori_k,P_aposteriori_k,knownConst)
*/
/*
* EKF Attitude Estimator main function.
*
* Estimates the attitude recursively once started.
*
* @param argc number of commandline arguments (plus command name)
* @param argv strings containing the arguments
*/
int attitude_estimator_ekf_main(int argc, char *argv[])
{
// print text
printf("Extended Kalman Filter Attitude Estimator initialized..\n\n");
fflush(stdout);
int overloadcounter = 19;
/* Initialize filter */
attitudeKalmanfilter_initialize();
/* store start time to guard against too slow update rates */
uint64_t last_run = hrt_absolute_time();
struct sensor_combined_s raw = {0};
struct vehicle_attitude_s att = {};
uint64_t last_data = 0;
uint64_t last_measurement = 0;
/* subscribe to raw data */
int sub_raw = orb_subscribe(ORB_ID(sensor_combined));
/* advertise attitude */
orb_advert_t pub_att = orb_advertise(ORB_ID(vehicle_attitude), &att);
int loopcounter = 0;
int printcounter = 0;
/* Main loop*/
while (true) {
struct pollfd fds[1] = {
{ .fd = sub_raw, .events = POLLIN },
};
int ret = poll(fds, 1, 1000);
/* check for a timeout */
if (ret == 0) {
/* */
/* update successful, copy data on every 2nd run and execute filter */
} else {
orb_copy(ORB_ID(sensor_combined), sub_raw, &raw);
/* Calculate data time difference in seconds */
dt = (raw.timestamp - last_measurement) / 1000000.0f;
last_measurement = raw.timestamp;
/* scale from 14 bit to m/s2 */
z_k[3] = raw.accelerometer_m_s2[0];
z_k[4] = raw.accelerometer_raw[1];
z_k[5] = raw.accelerometer_raw[2];
z_k[0] = raw.magnetometer_ga[0];
z_k[1] = raw.magnetometer_ga[1];
z_k[2] = raw.magnetometer_ga[2];
/* Fill in gyro measurements */
z_k[6] = raw.gyro_rad_s[0];
z_k[7] = raw.gyro_rad_s[1];
z_k[8] = raw.gyro_rad_s[2];
uint64_t now = hrt_absolute_time();
unsigned int time_elapsed = now - last_run;
last_run = now;
if (time_elapsed > loop_interval_alarm) {
//TODO: add warning, cpu overload here
if (overloadcounter == 20) {
printf("CPU OVERLOAD DETECTED IN ATTITUDE ESTIMATOR BLACK MAGIC (%lu > %lu)\n", time_elapsed, loop_interval_alarm);
overloadcounter = 0;
}
overloadcounter++;
}
int8_t update_vect[9] = {1, 1, 1, 1, 1, 1, 1, 1, 1};
float euler[3];
int32_t z_k_sizes = 9;
float u[4] = {0.0f, 0.0f, 0.0f, 0.0f};
uint64_t timing_start = hrt_absolute_time();
attitudeKalmanfilter(dt, update_vect, z_k, &z_k_sizes, u, x_aposteriori_k, P_aposteriori_k, knownConst, euler,
Rot_matrix, x_aposteriori, P_aposteriori);
/* swap values for next iteration */
memcpy(P_aposteriori_k, P_aposteriori, sizeof(P_aposteriori_k));
memcpy(x_aposteriori_k, x_aposteriori, sizeof(x_aposteriori_k));
uint64_t timing_diff = hrt_absolute_time() - timing_start;
/* print rotation matrix every 200th time */
if (printcounter % 200 == 0) {
printf("EKF attitude iteration: %d, runtime: %d us, dt: %d us (%d Hz)\n", loopcounter, (int)timing_diff, (int)(dt * 1000000.0f), (int)(1.0f / dt));
printf("roll: %8.4f\tpitch: %8.4f\tyaw:%8.4f", euler[0], euler[1], euler[2]);
printf("\n%d\t%d\t%d\n%d\t%d\t%d\n%d\t%d\t%d\n", (int)(Rot_matrix[0] * 100), (int)(Rot_matrix[1] * 100), (int)(Rot_matrix[2] * 100),
(int)(Rot_matrix[3] * 100), (int)(Rot_matrix[4] * 100), (int)(Rot_matrix[5] * 100),
(int)(Rot_matrix[6] * 100), (int)(Rot_matrix[7] * 100), (int)(Rot_matrix[8] * 100));
}
printcounter++;
if (last_data > 0 && raw.timestamp - last_data > 8000) printf("sensor data missed! (%llu)\n", raw.timestamp - last_data);
last_data = raw.timestamp;
/* send out */
att.timestamp = raw.timestamp;
att.roll = euler.x;
att.pitch = euler.y;
att.yaw = euler.z;
// att.rollspeed = rates.x;
// att.pitchspeed = rates.y;
// att.yawspeed = rates.z;
// Broadcast
orb_publish(ORB_ID(vehicle_attitude), pub_att, &att);
}
loopcounter++;
}
/* Should never reach here */
return 0;
}
