ardupilot/libraries/AP_Compass/AP_Compass_SITL.cpp

130 lines
4.3 KiB
C++

#include "AP_Compass_SITL.h"
#include <AP_HAL/AP_HAL.h>
#include <AP_Common/Semaphore.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
extern const AP_HAL::HAL& hal;
AP_Compass_SITL::AP_Compass_SITL()
: _sitl(AP::sitl())
{
if (_sitl != nullptr) {
_compass._setup_earth_field();
for (uint8_t i=0; i<SITL_NUM_COMPASSES; i++) {
// default offsets to correct value
_compass.set_offsets(i, _sitl->mag_ofs);
_compass_instance[i] = register_compass();
set_dev_id(_compass_instance[i], AP_HAL::Device::make_bus_id(AP_HAL::Device::BUS_TYPE_SITL, i, 0, DEVTYPE_SITL));
// save so the compass always comes up configured in SITL
save_dev_id(_compass_instance[i]);
}
// make first compass external
set_external(_compass_instance[0], true);
hal.scheduler->register_timer_process(FUNCTOR_BIND(this, &AP_Compass_SITL::_timer, void));
}
}
/*
create correction matrix for diagnonals and off-diagonals
*/
void AP_Compass_SITL::_setup_eliptical_correcion(void)
{
Vector3f diag = _sitl->mag_diag.get();
if (diag.is_zero()) {
diag(1,1,1);
}
const Vector3f &diagonals = diag;
const Vector3f &offdiagonals = _sitl->mag_offdiag;
if (diagonals == _last_dia && offdiagonals == _last_odi) {
return;
}
_eliptical_corr = Matrix3f(diagonals.x, offdiagonals.x, offdiagonals.y,
offdiagonals.x, diagonals.y, offdiagonals.z,
offdiagonals.y, offdiagonals.z, diagonals.z);
if (!_eliptical_corr.invert()) {
_eliptical_corr.identity();
}
_last_dia = diag;
_last_odi = offdiagonals;
}
void AP_Compass_SITL::_timer()
{
// TODO: Refactor delay buffer with AP_Baro_SITL.
// Sampled at 100Hz
uint32_t now = AP_HAL::millis();
if ((now - _last_sample_time) < 10) {
return;
}
_last_sample_time = now;
// calculate sensor noise and add to 'truth' field in body frame
// units are milli-Gauss
Vector3f noise = rand_vec3f() * _sitl->mag_noise;
Vector3f new_mag_data = _sitl->state.bodyMagField + noise;
// add delay
uint32_t best_time_delta = 1000; // initialise large time representing buffer entry closest to current time - delay.
uint8_t best_index = 0; // initialise number representing the index of the entry in buffer closest to delay.
// storing data from sensor to buffer
if (now - last_store_time >= 10) { // store data every 10 ms.
last_store_time = now;
if (store_index > buffer_length-1) { // reset buffer index if index greater than size of buffer
store_index = 0;
}
buffer[store_index].data = new_mag_data; // add data to current index
buffer[store_index].time = last_store_time; // add time to current index
store_index = store_index + 1; // increment index
}
// return delayed measurement
uint32_t delayed_time = now - _sitl->mag_delay; // get time corresponding to delay
// find data corresponding to delayed time in buffer
for (uint8_t i=0; i<=buffer_length-1; i++) {
// find difference between delayed time and time stamp in buffer
uint32_t time_delta = abs((int32_t)(delayed_time - buffer[i].time));
// if this difference is smaller than last delta, store this time
if (time_delta < best_time_delta) {
best_index= i;
best_time_delta = time_delta;
}
}
if (best_time_delta < 1000) { // only output stored state if < 1 sec retrieval error
new_mag_data = buffer[best_index].data;
}
_setup_eliptical_correcion();
new_mag_data = _eliptical_corr * new_mag_data;
new_mag_data -= _sitl->mag_ofs.get();
for (uint8_t i=0; i<SITL_NUM_COMPASSES; i++) {
Vector3f f = new_mag_data;
if (i == 0) {
// rotate the first compass, allowing for testing of external compass rotation
f.rotate_inverse((enum Rotation)_sitl->mag_orient.get());
f.rotate(get_board_orientation());
}
accumulate_sample(f, _compass_instance[i], 10);
}
}
void AP_Compass_SITL::read()
{
for (uint8_t i=0; i<SITL_NUM_COMPASSES; i++) {
drain_accumulated_samples(_compass_instance[i], nullptr);
}
}
#endif