/*
calculate the trim_roll and trim_pitch. This is used for redoing the
trim without needing a full accel cal
*/
bool AP_InertialSensor::calibrate_trim(float &trim_roll, float &trim_pitch)
{
Vector3f level_sample;
// exit immediately if calibration is already in progress
if (_calibrating) {
return false;
}
_calibrating = true;
const uint8_t update_dt_milliseconds = (uint8_t)(1000.0f/get_sample_rate()+0.5f);
// wait 100ms for ins filter to rise
for (uint8_t k=0; k<100/update_dt_milliseconds; k++) {
wait_for_sample();
update();
hal.scheduler->delay(update_dt_milliseconds);
}
uint32_t num_samples = 0;
while (num_samples < 400/update_dt_milliseconds) {
wait_for_sample();
// read samples from ins
update();
// capture sample
Vector3f samp;
samp = get_accel(0);
level_sample += samp;
if (!get_accel_health(0)) {
goto failed;
}
hal.scheduler->delay(update_dt_milliseconds);
num_samples++;
}
level_sample /= num_samples;
if (!_calculate_trim(level_sample, trim_roll, trim_pitch)) {
goto failed;
}
_calibrating = false;
return true;
failed:
_calibrating = false;
return false;
}
bool AP_InertialSensor_VRBRAIN::update(void)
{
if (!wait_for_sample(100)) {
return false;
}
// get the latest sample from the sensor drivers
_get_sample();
for (uint8_t k=0; k<_num_accel_instances; k++) {
_previous_accel[k] = _accel[k];
_accel[k] = _accel_in[k];
_accel[k].rotate(_board_orientation);
_accel[k].x *= _accel_scale[k].get().x;
_accel[k].y *= _accel_scale[k].get().y;
_accel[k].z *= _accel_scale[k].get().z;
_accel[k] -= _accel_offset[k];
}
for (uint8_t k=0; k<_num_gyro_instances; k++) {
_gyro[k] = _gyro_in[k];
_gyro[k].rotate(_board_orientation);
_gyro[k] -= _gyro_offset[k];
}
if (_last_filter_hz != _mpu6000_filter) {
_set_filter_frequency(_mpu6000_filter);
_last_filter_hz = _mpu6000_filter;
}
_have_sample_available = false;
return true;
}
bool AP_InertialSensor_L3GD20::update( void )
{
// wait for at least 1 sample
if (!wait_for_sample(1000)) {
return false;
}
// disable timer procs for mininum time
hal.scheduler->suspend_timer_procs();
_gyro[0] = Vector3f(_gyro_sum.x, _gyro_sum.y, _gyro_sum.z);
_num_samples = _sum_count;
_gyro_sum.zero();
_sum_count = 0;
hal.scheduler->resume_timer_procs();
_gyro[0].rotate(_board_orientation);
_gyro[0] *= _gyro_scale / _num_samples;
_gyro[0] -= _gyro_offset[0];
// if (_last_filter_hz != _L3GD20_filter) {
// if (_spi_sem->take(10)) {
// _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_LOW);
// _set_filter_register(_L3GD20_filter, 0);
// _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_HIGH);
// _error_count = 0;
// _spi_sem->give();
// }
// }
return true;
}
/*
update gyro and accel values from backends
*/
void AP_InertialSensor::update(void)
{
// during initialisation update() may be called without
// wait_for_sample(), and a wait is implied
wait_for_sample();
if (!_hil_mode) {
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
// mark sensors unhealthy and let update() in each backend
// mark them healthy via _rotate_and_offset_gyro() and
// _rotate_and_offset_accel()
_gyro_healthy[i] = false;
_accel_healthy[i] = false;
}
for (uint8_t i=0; i<_backend_count; i++) {
_backends[i]->update();
}
// adjust health status if a sensor has a non-zero error count
// but another sensor doesn't.
bool have_zero_accel_error_count = false;
bool have_zero_gyro_error_count = false;
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
if (_accel_healthy[i] && _accel_error_count[i] == 0) {
have_zero_accel_error_count = true;
}
if (_gyro_healthy[i] && _gyro_error_count[i] == 0) {
have_zero_gyro_error_count = true;
}
}
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
if (_gyro_healthy[i] && _gyro_error_count[i] != 0 && have_zero_gyro_error_count) {
// we prefer not to use a gyro that has had errors
_gyro_healthy[i] = false;
}
if (_accel_healthy[i] && _accel_error_count[i] != 0 && have_zero_accel_error_count) {
// we prefer not to use a accel that has had errors
_accel_healthy[i] = false;
}
}
// set primary to first healthy accel and gyro
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
if (_gyro_healthy[i]) {
_primary_gyro = i;
break;
}
}
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
if (_accel_healthy[i]) {
_primary_accel = i;
break;
}
}
}
_have_sample = false;
}
bool AP_InertialSensor_MPU6000::update( void )
{
int32_t sum[7];
float count_scale;
Vector3f accel_scale = _accel_scale.get();
// wait for at least 1 sample
if (!wait_for_sample(1000)) {
return false;
}
// disable timer procs for mininum time
hal.scheduler->suspend_timer_procs();
/** ATOMIC SECTION w/r/t TIMER PROCESS */
{
for (int i=0; i<7; i++) {
sum[i] = _sum[i];
_sum[i] = 0;
}
_num_samples = _count;
_count = 0;
}
hal.scheduler->resume_timer_procs();
count_scale = 1.0f / _num_samples;
_gyro = Vector3f(_gyro_data_sign[0] * sum[_gyro_data_index[0]],
_gyro_data_sign[1] * sum[_gyro_data_index[1]],
_gyro_data_sign[2] * sum[_gyro_data_index[2]]);
_gyro.rotate(_board_orientation);
_gyro *= _gyro_scale * count_scale;
_gyro -= _gyro_offset;
_accel = Vector3f(_accel_data_sign[0] * sum[_accel_data_index[0]],
_accel_data_sign[1] * sum[_accel_data_index[1]],
_accel_data_sign[2] * sum[_accel_data_index[2]]);
_accel.rotate(_board_orientation);
_accel *= count_scale * MPU6000_ACCEL_SCALE_1G;
_accel.x *= accel_scale.x;
_accel.y *= accel_scale.y;
_accel.z *= accel_scale.z;
_accel -= _accel_offset;
_temp = _temp_to_celsius(sum[_temp_data_index] * count_scale);
if (_last_filter_hz != _mpu6000_filter) {
if (_spi_sem->take(10)) {
_set_filter_register(_mpu6000_filter, 0);
_spi_sem->give();
}
}
return true;
}
bool AP_InertialSensor_MPU9250::update( void )
{
// wait for at least 1 sample
if (!wait_for_sample(1000)) {
return false;
}
_previous_accel[0] = _accel[0];
// disable timer procs for mininum time
hal.scheduler->suspend_timer_procs();
_gyro[0] = Vector3f(_gyro_sum.x, _gyro_sum.y, _gyro_sum.z);
_accel[0] = Vector3f(_accel_sum.x, _accel_sum.y, _accel_sum.z);
_num_samples = _sum_count;
_accel_sum.zero();
_gyro_sum.zero();
_sum_count = 0;
hal.scheduler->resume_timer_procs();
_gyro[0].rotate(_board_orientation);
_gyro[0] *= _gyro_scale / _num_samples;
_gyro[0] -= _gyro_offset[0];
_accel[0].rotate(_board_orientation);
_accel[0] *= MPU9250_ACCEL_SCALE_1G / _num_samples;
// rotate for bbone default
_accel[0].rotate(ROTATION_ROLL_180_YAW_90);
_gyro[0].rotate(ROTATION_ROLL_180_YAW_90);
#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF
// PXF has an additional YAW 180
_accel[0].rotate(ROTATION_YAW_180);
_gyro[0].rotate(ROTATION_YAW_180);
#endif
Vector3f accel_scale = _accel_scale[0].get();
_accel[0].x *= accel_scale.x;
_accel[0].y *= accel_scale.y;
_accel[0].z *= accel_scale.z;
_accel[0] -= _accel_offset[0];
if (_last_filter_hz != _mpu6000_filter) {
if (_spi_sem->take(10)) {
_spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_LOW);
_set_filter_register(_mpu6000_filter, 0);
_spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_HIGH);
_error_count = 0;
_spi_sem->give();
}
}
return true;
}
// TODO finish
bool AP_InertialSensor_LSM9DS0::_update( void )
{
// wait for at least 1 sample
if (!wait_for_sample(1000)) {
return false;
}
imu._previous_accel[0] = imu._accel[0];
// disable timer procs for mininum time
hal.scheduler->suspend_timer_procs();
imu._gyro[0] = Vector3f(_gyro_sum.x, _gyro_sum.y, _gyro_sum.z);
imu._accel[0] = Vector3f(_accel_sum.x, _accel_sum.y, _accel_sum.z);
// _mag[0] = Vector3f(_mag_sum.x, _mag_sum.y, _mag_sum.z);
// TODO divide num_samples
_num_samples_g = _sum_count_g;
_num_samples_xm = _sum_count_xm;
_accel_sum.zero();
_gyro_sum.zero();
_sum_count_g = 0;
_sum_count_xm = 0;
hal.scheduler->resume_timer_procs();
imu._gyro[0].rotate(imu._board_orientation);
imu._gyro[0] *= _gRes / _num_samples_g;
imu._gyro[0] -= imu._gyro_offset[0];
imu._accel[0].rotate(imu._board_orientation);
imu._accel[0] *= _aRes / _num_samples_xm;
Vector3f accel_scaling = imu._accel_scale[0].get();
imu._accel[0].x *= accel_scaling.x;
imu._accel[0].y *= accel_scaling.y;
imu._accel[0].z *= accel_scaling.z;
imu._accel[0] -= imu._accel_offset[0];
// // Configure mag
// _mag[0] *= _mRes / _num_samples_xm;
// if (_last_filter_hz != _mpu6000_filter) {
// if (_spi_sem->take(10)) {
// _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_LOW);
// _set_filter_register(_mpu6000_filter, 0);
// _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_HIGH);
// _error_count = 0;
// _spi_sem->give();
// }
// }
return true;
}
bool AP_InertialSensor_ITG3200::update( void )
{
int32_t sum[7];
float count_scale;
Vector3f accel_scale = _accel_scale.get();
// wait for at least 1 sample
wait_for_sample();
// disable interrupts for mininum time
hal.scheduler->suspend_timer_procs();
/** ATOMIC SECTION w/r/t TIMER PROCESS */
{
for (int i=0; i<7; i++) {
sum[i] = _sum[i];
_sum[i] = 0;
}
_num_samples = _count;
_count = 0;
}
hal.scheduler->resume_timer_procs();
count_scale = 1.0f / _num_samples;
_gyro = Vector3f(_gyro_data_sign[0] * sum[_gyro_data_index[0]],
_gyro_data_sign[1] * sum[_gyro_data_index[1]],
_gyro_data_sign[2] * sum[_gyro_data_index[2]]);
_gyro.rotate(_board_orientation);
_gyro *= _gyro_scale * count_scale;
_gyro -= _gyro_offset;
_accel = Vector3f(_accel_data_sign[0] * sum[_accel_data_index[0]],
_accel_data_sign[1] * sum[_accel_data_index[1]],
_accel_data_sign[2] * sum[_accel_data_index[2]]);
_accel.rotate(_board_orientation);
_accel *= count_scale * _accel_scale_1G;
_accel.x *= accel_scale.x;
_accel.y *= accel_scale.y;
_accel.z *= accel_scale.z;
_accel -= _accel_offset;
_temp = _temp_to_celsius(sum[_temp_data_index] * count_scale);
return true;
}
bool AP_InertialSensor_MPU6000_Ext::update( void )
{
// wait for at least 1 sample
if (!wait_for_sample(1000)) {
return false;
}
_previous_accel[0] = _accel[0];
// disable timer procs for mininum time
hal.scheduler->suspend_timer_procs();
_gyro[0] = Vector3f(_gyro_sum.x, _gyro_sum.y, _gyro_sum.z);
_accel[0] = Vector3f(_accel_sum.x, _accel_sum.y, _accel_sum.z);
_num_samples = _sum_count;
_accel_sum.zero();
_gyro_sum.zero();
_temp[0] = _temp_sum;
_temp_sum = 0;
_sum_count = 0;
hal.scheduler->resume_timer_procs();
_gyro[0].rotate(_board_orientation);
_gyro[0] *= _gyro_scale / _num_samples;
_gyro[0] -= _gyro_offset[0];
_accel[0].rotate(_board_orientation);
_accel[0] *= MPU6000_ACCEL_SCALE_1G / _num_samples;
Vector3f accel_scale = _accel_scale[0].get();
_accel[0].x *= accel_scale.x;
_accel[0].y *= accel_scale.y;
_accel[0].z *= accel_scale.z;
_accel[0] -= _accel_offset[0];
_temp[0] = _temp_to_celsius(_temp[0] / _num_samples);
if (_last_filter_hz != _mpu6000_filter) {
if (_spi_sem->take(10)) {
_spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_LOW);
_set_filter_register(_mpu6000_filter, 0);
_spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_HIGH);
_error_count = 0;
_spi_sem->give();
}
}
return true;
}
bool AP_InertialSensor_VRBRAIN::update( void )
{
// wait for at least 1 sample
if (!wait_for_sample(100)) {
return false;
}
_previous_accel[0] = _accel[0];
// disable timer procs for mininum time
hal.scheduler->suspend_timer_procs();
_accel[0] = _accel_filtered;
_accel_samples = 0;
_gyro[0] = _gyro_filtered;
_gyro_samples = 0;
_temp[0] = _temp_filtered;
hal.scheduler->resume_timer_procs();
_accel[0].rotate(_board_orientation);
_accel[0] *= MPU6000_ACCEL_SCALE_1G;
Vector3f accel_scale = _accel_scale[0].get();
_accel[0].x *= accel_scale.x;
_accel[0].y *= accel_scale.y;
_accel[0].z *= accel_scale.z;
_accel[0] -= _accel_offset[0];
_gyro[0].rotate(_board_orientation);
_gyro[0] *= _gyro_scale;
_gyro[0] -= _gyro_offset[0];
_temp[0] = _temp_to_celsius(_temp[0]);
if (_last_filter_hz != _mpu6000_filter) {
_set_filter_frequency(_mpu6000_filter);
_last_filter_hz = _mpu6000_filter;
}
return true;
}
/*
update the accel and gyro vectors
*/
bool AP_InertialSensor_MPU9250::update( void )
{
if (!wait_for_sample(1000)) {
return false;
}
_previous_accel[0] = _accel[0];
// pull the data from the timer shared data buffer
uint8_t idx = _shared_data_idx;
_gyro[0] = _shared_data[idx]._gyro_filtered;
_accel[0] = _shared_data[idx]._accel_filtered;
_gyro[0].rotate(_board_orientation);
_gyro[0] *= GYRO_SCALE;
_gyro[0] -= _gyro_offset[0];
_accel[0].rotate(_board_orientation);
_accel[0] *= MPU9250_ACCEL_SCALE_1G;
// rotate for bbone default
_accel[0].rotate(ROTATION_ROLL_180_YAW_90);
_gyro[0].rotate(ROTATION_ROLL_180_YAW_90);
#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF
// PXF has an additional YAW 180
_accel[0].rotate(ROTATION_YAW_180);
_gyro[0].rotate(ROTATION_YAW_180);
#endif
Vector3f accel_scale = _accel_scale[0].get();
_accel[0].x *= accel_scale.x;
_accel[0].y *= accel_scale.y;
_accel[0].z *= accel_scale.z;
_accel[0] -= _accel_offset[0];
if (_last_filter_hz != _mpu6000_filter) {
_set_filter(_mpu6000_filter);
_last_filter_hz = _mpu6000_filter;
}
_have_sample_available = false;
return true;
}
bool AP_InertialSensor_LSM303D::update( void )
{
// wait for at least 1 sample
if (!wait_for_sample(1000)) {
return false;
}
// disable timer procs for mininum time
hal.scheduler->suspend_timer_procs();
_accel[0] = Vector3f(_accel_sum.x, _accel_sum.y, _accel_sum.z);
// _mag[0] = Vector3f(_mag_sum.x, _mag_sum.y, _mag_sum.z);
_num_samples = _sum_count;
_accel_sum.zero();
_mag_sum.zero();
_sum_count = 0;
hal.scheduler->resume_timer_procs();
_accel[0].rotate(_board_orientation);
// TODO change this for the corresponding value
// _accel[0] *= MPU6000_ACCEL_SCALE_1G / _num_samples;
// Vector3f accel_scale = _accel_scale[0].get();
// _accel[0].x *= accel_scale.x;
// _accel[0].y *= accel_scale.y;
// _accel[0].z *= accel_scale.z;
// _accel[0] -= _accel_offset[0];
// TODO similarly put mag values in _mag and scale them
// if (_last_filter_hz != _LSM303D_filter) {
// if (_spi_sem->take(10)) {
// _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_LOW);
// _set_filter_register(_LSM303D_filter, 0);
// _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_HIGH);
// _error_count = 0;
// _spi_sem->give();
// }
// }
return true;
}
// calibrate_accel - perform accelerometer calibration including providing user
// instructions and feedback Gauss-Newton accel calibration routines borrowed
// from Rolfe Schmidt blog post describing the method:
// http://chionophilous.wordpress.com/2011/10/24/accelerometer-calibration-iv-1-implementing-gauss-newton-on-an-atmega/
// original sketch available at
// http://rolfeschmidt.com/mathtools/skimetrics/adxl_gn_calibration.pde
bool AP_InertialSensor::calibrate_accel(AP_InertialSensor_UserInteract* interact,
float &trim_roll,
float &trim_pitch)
{
Vector3f samples[6];
Vector3f new_offsets;
Vector3f new_scaling;
Vector3f orig_offset;
Vector3f orig_scale;
// backup original offsets and scaling
orig_offset = _accel_offset.get();
orig_scale = _accel_scale.get();
// clear accelerometer offsets and scaling
_accel_offset = Vector3f(0,0,0);
_accel_scale = Vector3f(1,1,1);
// capture data from 6 positions
for (int8_t i=0; i<6; i++) {
const prog_char_t *msg;
// display message to user
switch ( i ) {
case 0:
msg = PSTR("level");
break;
case 1:
msg = PSTR("on its LEFT side");
break;
case 2:
msg = PSTR("on its RIGHT side");
break;
case 3:
msg = PSTR("nose DOWN");
break;
case 4:
msg = PSTR("nose UP");
break;
default: // default added to avoid compiler warning
case 5:
msg = PSTR("on its BACK");
break;
}
interact->printf_P(
PSTR("Place APM %S and press any key.\n"), msg);
// wait for user input
interact->blocking_read();
// clear out any existing samples from ins
update();
// average 32 samples
samples[i] = Vector3f();
uint8_t num_samples = 0;
while (num_samples < 32) {
if (!wait_for_sample(1000)) {
interact->printf_P(PSTR("Failed to get INS sample\n"));
return false;
}
// read samples from ins
update();
// capture sample
samples[i] += get_accel();
hal.scheduler->delay(10);
num_samples++;
}
samples[i] /= num_samples;
}
// run the calibration routine
bool success = _calibrate_accel(samples, new_offsets, new_scaling);
interact->printf_P(PSTR("Offsets: %.2f %.2f %.2f\n"),
new_offsets.x, new_offsets.y, new_offsets.z);
interact->printf_P(PSTR("Scaling: %.2f %.2f %.2f\n"),
new_scaling.x, new_scaling.y, new_scaling.z);
if (success) {
interact->printf_P(PSTR("Calibration successful\n"));
// set and save calibration
_accel_offset.set(new_offsets);
_accel_scale.set(new_scaling);
_save_parameters();
// calculate the trims as well and pass back to caller
_calculate_trim(samples[0], trim_roll, trim_pitch);
return true;
}
interact->printf_P(PSTR("Calibration FAILED\n"));
// restore original scaling and offsets
_accel_offset.set(orig_offset);
_accel_scale.set(orig_scale);
return false;
}
/*
update gyro and accel values from backends
*/
void AP_InertialSensor::update(void)
{
// during initialisation update() may be called without
// wait_for_sample(), and a wait is implied
wait_for_sample();
if (!_hil_mode) {
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
// mark sensors unhealthy and let update() in each backend
// mark them healthy via _publish_gyro() and
// _publish_accel()
_gyro_healthy[i] = false;
_accel_healthy[i] = false;
_delta_velocity_valid[i] = false;
_delta_angle_valid[i] = false;
}
for (uint8_t i=0; i<_backend_count; i++) {
_backends[i]->update();
}
// clear accumulators
for (uint8_t i = 0; i < INS_MAX_INSTANCES; i++) {
_delta_velocity_acc[i].zero();
_delta_velocity_acc_dt[i] = 0;
_delta_angle_acc[i].zero();
_delta_angle_acc_dt[i] = 0;
}
if (!_startup_error_counts_set) {
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
_accel_startup_error_count[i] = _accel_error_count[i];
_gyro_startup_error_count[i] = _gyro_error_count[i];
}
if (_startup_ms == 0) {
_startup_ms = AP_HAL::millis();
} else if (AP_HAL::millis()-_startup_ms > 2000) {
_startup_error_counts_set = true;
}
}
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
if (_accel_error_count[i] < _accel_startup_error_count[i]) {
_accel_startup_error_count[i] = _accel_error_count[i];
}
if (_gyro_error_count[i] < _gyro_startup_error_count[i]) {
_gyro_startup_error_count[i] = _gyro_error_count[i];
}
}
// adjust health status if a sensor has a non-zero error count
// but another sensor doesn't.
bool have_zero_accel_error_count = false;
bool have_zero_gyro_error_count = false;
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
if (_accel_healthy[i] && _accel_error_count[i] <= _accel_startup_error_count[i]) {
have_zero_accel_error_count = true;
}
if (_gyro_healthy[i] && _gyro_error_count[i] <= _gyro_startup_error_count[i]) {
have_zero_gyro_error_count = true;
}
}
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
if (_gyro_healthy[i] && _gyro_error_count[i] > _gyro_startup_error_count[i] && have_zero_gyro_error_count) {
// we prefer not to use a gyro that has had errors
_gyro_healthy[i] = false;
}
if (_accel_healthy[i] && _accel_error_count[i] > _accel_startup_error_count[i] && have_zero_accel_error_count) {
// we prefer not to use a accel that has had errors
_accel_healthy[i] = false;
}
}
// set primary to first healthy accel and gyro
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
if (_gyro_healthy[i] && _use[i]) {
_primary_gyro = i;
break;
}
}
for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
if (_accel_healthy[i] && _use[i]) {
_primary_accel = i;
break;
}
}
}
_have_sample = false;
}
// calibrate_accel - perform accelerometer calibration including providing user
// instructions and feedback Gauss-Newton accel calibration routines borrowed
// from Rolfe Schmidt blog post describing the method:
// http://chionophilous.wordpress.com/2011/10/24/accelerometer-calibration-iv-1-implementing-gauss-newton-on-an-atmega/
// original sketch available at
// http://rolfeschmidt.com/mathtools/skimetrics/adxl_gn_calibration.pde
bool AP_InertialSensor::calibrate_accel(AP_InertialSensor_UserInteract* interact,
float &trim_roll,
float &trim_pitch)
{
uint8_t num_accels = min(get_accel_count(), INS_MAX_INSTANCES);
Vector3f samples[INS_MAX_INSTANCES][6];
Vector3f new_offsets[INS_MAX_INSTANCES];
Vector3f new_scaling[INS_MAX_INSTANCES];
Vector3f orig_offset[INS_MAX_INSTANCES];
Vector3f orig_scale[INS_MAX_INSTANCES];
uint8_t num_ok = 0;
for (uint8_t k=0; k<num_accels; k++) {
// backup original offsets and scaling
orig_offset[k] = _accel_offset[k].get();
orig_scale[k] = _accel_scale[k].get();
// clear accelerometer offsets and scaling
_accel_offset[k] = Vector3f(0,0,0);
_accel_scale[k] = Vector3f(1,1,1);
}
// capture data from 6 positions
for (uint8_t i=0; i<6; i++) {
const prog_char_t *msg;
// display message to user
switch ( i ) {
case 0:
msg = PSTR("level");
break;
case 1:
msg = PSTR("on its LEFT side");
break;
case 2:
msg = PSTR("on its RIGHT side");
break;
case 3:
msg = PSTR("nose DOWN");
break;
case 4:
msg = PSTR("nose UP");
break;
default: // default added to avoid compiler warning
case 5:
msg = PSTR("on its BACK");
break;
}
interact->printf_P(
PSTR("Place vehicle %S and press any key.\n"), msg);
// wait for user input
if (!interact->blocking_read()) {
//No need to use interact->printf_P for an error, blocking_read does this when it fails
goto failed;
}
// clear out any existing samples from ins
update();
// average 32 samples
for (uint8_t k=0; k<num_accels; k++) {
samples[k][i] = Vector3f();
}
uint8_t num_samples = 0;
while (num_samples < 32) {
wait_for_sample();
// read samples from ins
update();
// capture sample
for (uint8_t k=0; k<num_accels; k++) {
samples[k][i] += get_accel(k);
}
hal.scheduler->delay(10);
num_samples++;
}
for (uint8_t k=0; k<num_accels; k++) {
samples[k][i] /= num_samples;
}
}
// run the calibration routine
for (uint8_t k=0; k<num_accels; k++) {
bool success = _calibrate_accel(samples[k], new_offsets[k], new_scaling[k]);
interact->printf_P(PSTR("Offsets[%u]: %.2f %.2f %.2f\n"),
(unsigned)k,
new_offsets[k].x, new_offsets[k].y, new_offsets[k].z);
interact->printf_P(PSTR("Scaling[%u]: %.2f %.2f %.2f\n"),
(unsigned)k,
new_scaling[k].x, new_scaling[k].y, new_scaling[k].z);
if (success) num_ok++;
}
if (num_ok == num_accels) {
interact->printf_P(PSTR("Calibration successful\n"));
for (uint8_t k=0; k<num_accels; k++) {
// set and save calibration
_accel_offset[k].set(new_offsets[k]);
_accel_scale[k].set(new_scaling[k]);
}
_save_parameters();
check_3D_calibration();
// calculate the trims as well from primary accels and pass back to caller
_calculate_trim(samples[0][0], trim_roll, trim_pitch);
return true;
}
failed:
interact->printf_P(PSTR("Calibration FAILED\n"));
// restore original scaling and offsets
for (uint8_t k=0; k<num_accels; k++) {
_accel_offset[k].set(orig_offset[k]);
_accel_scale[k].set(orig_scale[k]);
}
return false;
}
// calibrate_accel - perform accelerometer calibration including providing user
// instructions and feedback Gauss-Newton accel calibration routines borrowed
// from Rolfe Schmidt blog post describing the method:
// http://chionophilous.wordpress.com/2011/10/24/accelerometer-calibration-iv-1-implementing-gauss-newton-on-an-atmega/
// original sketch available at
// http://rolfeschmidt.com/mathtools/skimetrics/adxl_gn_calibration.pde
bool AP_InertialSensor::calibrate_accel(AP_InertialSensor_UserInteract* interact,
float &trim_roll,
float &trim_pitch)
{
uint8_t num_accels = min(get_accel_count(), INS_MAX_INSTANCES);
Vector3f samples[INS_MAX_INSTANCES][6];
Vector3f new_offsets[INS_MAX_INSTANCES];
Vector3f new_scaling[INS_MAX_INSTANCES];
Vector3f orig_offset[INS_MAX_INSTANCES];
Vector3f orig_scale[INS_MAX_INSTANCES];
uint8_t num_ok = 0;
// exit immediately if calibration is already in progress
if (_calibrating) {
return false;
}
_calibrating = true;
/*
we do the accel calibration with no board rotation. This avoids
having to rotate readings during the calibration
*/
enum Rotation saved_orientation = _board_orientation;
_board_orientation = ROTATION_NONE;
for (uint8_t k=0; k<num_accels; k++) {
// backup original offsets and scaling
orig_offset[k] = _accel_offset[k].get();
orig_scale[k] = _accel_scale[k].get();
// clear accelerometer offsets and scaling
_accel_offset[k] = Vector3f(0,0,0);
_accel_scale[k] = Vector3f(1,1,1);
}
memset(samples, 0, sizeof(samples));
// capture data from 6 positions
for (uint8_t i=0; i<6; i++) {
const prog_char_t *msg;
// display message to user
switch ( i ) {
case 0:
msg = PSTR("level");
break;
case 1:
msg = PSTR("on its LEFT side");
break;
case 2:
msg = PSTR("on its RIGHT side");
break;
case 3:
msg = PSTR("nose DOWN");
break;
case 4:
msg = PSTR("nose UP");
break;
default: // default added to avoid compiler warning
case 5:
msg = PSTR("on its BACK");
break;
}
interact->printf_P(
PSTR("Place vehicle %S and press any key.\n"), msg);
// wait for user input
if (!interact->blocking_read()) {
//No need to use interact->printf_P for an error, blocking_read does this when it fails
goto failed;
}
const uint8_t update_dt_milliseconds = (uint8_t)(1000.0f/get_sample_rate()+0.5f);
// wait 100ms for ins filter to rise
for (uint8_t k=0; k<100/update_dt_milliseconds; k++) {
wait_for_sample();
update();
hal.scheduler->delay(update_dt_milliseconds);
}
uint32_t num_samples = 0;
while (num_samples < 400/update_dt_milliseconds) {
wait_for_sample();
// read samples from ins
update();
// capture sample
for (uint8_t k=0; k<num_accels; k++) {
Vector3f samp;
if(get_delta_velocity(k,samp) && _delta_velocity_dt[k] > 0) {
samp /= _delta_velocity_dt[k];
} else {
samp = get_accel(k);
}
samples[k][i] += samp;
if (!get_accel_health(k)) {
interact->printf_P(PSTR("accel[%u] not healthy"), (unsigned)k);
goto failed;
}
}
hal.scheduler->delay(update_dt_milliseconds);
num_samples++;
}
for (uint8_t k=0; k<num_accels; k++) {
samples[k][i] /= num_samples;
}
}
// run the calibration routine
for (uint8_t k=0; k<num_accels; k++) {
if (!_check_sample_range(samples[k], saved_orientation, interact)) {
interact->printf_P(PSTR("Insufficient accel range"));
continue;
}
bool success = _calibrate_accel(samples[k], new_offsets[k], new_scaling[k], saved_orientation);
interact->printf_P(PSTR("Offsets[%u]: %.2f %.2f %.2f\n"),
(unsigned)k,
(double)new_offsets[k].x, (double)new_offsets[k].y, (double)new_offsets[k].z);
interact->printf_P(PSTR("Scaling[%u]: %.2f %.2f %.2f\n"),
(unsigned)k,
(double)new_scaling[k].x, (double)new_scaling[k].y, (double)new_scaling[k].z);
if (success) num_ok++;
}
if (num_ok == num_accels) {
interact->printf_P(PSTR("Calibration successful\n"));
for (uint8_t k=0; k<num_accels; k++) {
// set and save calibration
_accel_offset[k].set(new_offsets[k]);
_accel_scale[k].set(new_scaling[k]);
}
for (uint8_t k=num_accels; k<INS_MAX_INSTANCES; k++) {
// clear unused accelerometer's scaling and offsets
_accel_offset[k] = Vector3f(0,0,0);
_accel_scale[k] = Vector3f(0,0,0);
}
_save_parameters();
/*
calculate the trims as well from primary accels
We use the original board rotation for this sample
*/
Vector3f level_sample = samples[0][0];
level_sample.rotate(saved_orientation);
_calculate_trim(level_sample, trim_roll, trim_pitch);
_board_orientation = saved_orientation;
_calibrating = false;
return true;
}
failed:
interact->printf_P(PSTR("Calibration FAILED\n"));
// restore original scaling and offsets
for (uint8_t k=0; k<num_accels; k++) {
_accel_offset[k].set(orig_offset[k]);
_accel_scale[k].set(orig_scale[k]);
}
_board_orientation = saved_orientation;
_calibrating = false;
return false;
}
