#include <AP_HAL/AP_HAL.h> #include "AP_InertialSensor.h" #include "AP_InertialSensor_Backend.h" #include <AP_Logger/AP_Logger.h> #include <AP_BoardConfig/AP_BoardConfig.h> #if AP_MODULE_SUPPORTED #include <AP_Module/AP_Module.h> #include <stdio.h> #endif #define SENSOR_RATE_DEBUG 0 const extern AP_HAL::HAL& hal; AP_InertialSensor_Backend::AP_InertialSensor_Backend(AP_InertialSensor &imu) : _imu(imu) { } /* notify of a FIFO reset so we don't use bad data to update observed sensor rate */ void AP_InertialSensor_Backend::notify_accel_fifo_reset(uint8_t instance) { _imu._sample_accel_count[instance] = 0; _imu._sample_accel_start_us[instance] = 0; } /* notify of a FIFO reset so we don't use bad data to update observed sensor rate */ void AP_InertialSensor_Backend::notify_gyro_fifo_reset(uint8_t instance) { _imu._sample_gyro_count[instance] = 0; _imu._sample_gyro_start_us[instance] = 0; } // set the amount of oversamping a accel is doing void AP_InertialSensor_Backend::_set_accel_oversampling(uint8_t instance, uint8_t n) { _imu._accel_over_sampling[instance] = n; } // set the amount of oversamping a gyro is doing void AP_InertialSensor_Backend::_set_gyro_oversampling(uint8_t instance, uint8_t n) { _imu._gyro_over_sampling[instance] = n; } /* update the sensor rate for FIFO sensors FIFO sensors produce samples at a fixed rate, but the clock in the sensor may vary slightly from the system clock. This slowly adjusts the rate to the observed rate */ void AP_InertialSensor_Backend::_update_sensor_rate(uint16_t &count, uint32_t &start_us, float &rate_hz) const { uint32_t now = AP_HAL::micros(); if (start_us == 0) { count = 0; start_us = now; } else { count++; if (now - start_us > 1000000UL) { float observed_rate_hz = count * 1.0e6f / (now - start_us); #if 0 printf("IMU RATE: %.1f should be %.1f\n", observed_rate_hz, rate_hz); #endif float filter_constant = 0.98f; float upper_limit = 1.05f; float lower_limit = 0.95f; if (sensors_converging()) { // converge quickly for first 30s, then more slowly filter_constant = 0.8f; upper_limit = 2.0f; lower_limit = 0.5f; } observed_rate_hz = constrain_float(observed_rate_hz, rate_hz*lower_limit, rate_hz*upper_limit); rate_hz = filter_constant * rate_hz + (1-filter_constant) * observed_rate_hz; count = 0; start_us = now; } } } void AP_InertialSensor_Backend::_rotate_and_correct_accel(uint8_t instance, Vector3f &accel) { /* accel calibration is always done in sensor frame with this version of the code. That means we apply the rotation after the offsets and scaling. */ // rotate for sensor orientation accel.rotate(_imu._accel_orientation[instance]); #if HAL_INS_TEMPERATURE_CAL_ENABLE if (_imu.tcal_learning) { _imu.tcal[instance].update_accel_learning(accel, _imu.get_temperature(instance)); } #endif if (!_imu._calibrating_accel && (_imu._acal == nullptr #if HAL_INS_ACCELCAL_ENABLED || !_imu._acal->running() #endif )) { #if HAL_INS_TEMPERATURE_CAL_ENABLE // apply temperature corrections _imu.tcal[instance].correct_accel(_imu.get_temperature(instance), _imu.caltemp_accel[instance], accel); #endif // apply offsets accel -= _imu._accel_offset[instance]; // apply scaling const Vector3f &accel_scale = _imu._accel_scale[instance].get(); accel.x *= accel_scale.x; accel.y *= accel_scale.y; accel.z *= accel_scale.z; } // rotate to body frame if (_imu._board_orientation == ROTATION_CUSTOM && _imu._custom_rotation) { accel = *_imu._custom_rotation * accel; } else { accel.rotate(_imu._board_orientation); } } void AP_InertialSensor_Backend::_rotate_and_correct_gyro(uint8_t instance, Vector3f &gyro) { // rotate for sensor orientation gyro.rotate(_imu._gyro_orientation[instance]); #if HAL_INS_TEMPERATURE_CAL_ENABLE if (_imu.tcal_learning) { _imu.tcal[instance].update_gyro_learning(gyro, _imu.get_temperature(instance)); } #endif if (!_imu._calibrating_gyro) { #if HAL_INS_TEMPERATURE_CAL_ENABLE // apply temperature corrections _imu.tcal[instance].correct_gyro(_imu.get_temperature(instance), _imu.caltemp_gyro[instance], gyro); #endif // gyro calibration is always assumed to have been done in sensor frame gyro -= _imu._gyro_offset[instance]; } if (_imu._board_orientation == ROTATION_CUSTOM && _imu._custom_rotation) { gyro = *_imu._custom_rotation * gyro; } else { gyro.rotate(_imu._board_orientation); } } /* rotate gyro vector and add the gyro offset */ void AP_InertialSensor_Backend::_publish_gyro(uint8_t instance, const Vector3f &gyro) { if ((1U<<instance) & _imu.imu_kill_mask) { return; } _imu._gyro[instance] = gyro; _imu._gyro_healthy[instance] = true; // publish delta angle _imu._delta_angle[instance] = _imu._delta_angle_acc[instance]; _imu._delta_angle_dt[instance] = _imu._delta_angle_acc_dt[instance]; _imu._delta_angle_valid[instance] = true; _imu._delta_angle_acc[instance].zero(); _imu._delta_angle_acc_dt[instance] = 0; } void AP_InertialSensor_Backend::_notify_new_gyro_raw_sample(uint8_t instance, const Vector3f &gyro, uint64_t sample_us) { if ((1U<<instance) & _imu.imu_kill_mask) { return; } float dt; _update_sensor_rate(_imu._sample_gyro_count[instance], _imu._sample_gyro_start_us[instance], _imu._gyro_raw_sample_rates[instance]); uint64_t last_sample_us = _imu._gyro_last_sample_us[instance]; /* we have two classes of sensors. FIFO based sensors produce data at a very predictable overall rate, but the data comes in bunches, so we use the provided sample rate for deltaT. Non-FIFO sensors don't bunch up samples, but also tend to vary in actual rate, so we use the provided sample_us to get the deltaT. The difference between the two is whether sample_us is provided. */ if (sample_us != 0 && _imu._gyro_last_sample_us[instance] != 0) { dt = (sample_us - _imu._gyro_last_sample_us[instance]) * 1.0e-6f; _imu._gyro_last_sample_us[instance] = sample_us; } else { // don't accept below 40Hz if (_imu._gyro_raw_sample_rates[instance] < 40) { return; } dt = 1.0f / _imu._gyro_raw_sample_rates[instance]; _imu._gyro_last_sample_us[instance] = AP_HAL::micros64(); sample_us = _imu._gyro_last_sample_us[instance]; } #if AP_MODULE_SUPPORTED // call gyro_sample hook if any AP_Module::call_hook_gyro_sample(instance, dt, gyro); #endif // push gyros if optical flow present if (hal.opticalflow) { hal.opticalflow->push_gyro(gyro.x, gyro.y, dt); } // compute delta angle Vector3f delta_angle = (gyro + _imu._last_raw_gyro[instance]) * 0.5f * dt; // compute coning correction // see page 26 of: // Tian et al (2010) Three-loop Integration of GPS and Strapdown INS with Coning and Sculling Compensation // Available: http://www.sage.unsw.edu.au/snap/publications/tian_etal2010b.pdf // see also examples/coning.py Vector3f delta_coning = (_imu._delta_angle_acc[instance] + _imu._last_delta_angle[instance] * (1.0f / 6.0f)); delta_coning = delta_coning % delta_angle; delta_coning *= 0.5f; { WITH_SEMAPHORE(_sem); uint64_t now = AP_HAL::micros64(); if (now - last_sample_us > 100000U) { // zero accumulator if sensor was unhealthy for 0.1s _imu._delta_angle_acc[instance].zero(); _imu._delta_angle_acc_dt[instance] = 0; dt = 0; delta_angle.zero(); } // integrate delta angle accumulator // the angles and coning corrections are accumulated separately in the // referenced paper, but in simulation little difference was found between // integrating together and integrating separately (see examples/coning.py) _imu._delta_angle_acc[instance] += delta_angle + delta_coning; _imu._delta_angle_acc_dt[instance] += dt; // save previous delta angle for coning correction _imu._last_delta_angle[instance] = delta_angle; _imu._last_raw_gyro[instance] = gyro; #if HAL_WITH_DSP // capture gyro window for FFT analysis if (_imu._gyro_window_size > 0) { const Vector3f& scaled_gyro = gyro * _imu._gyro_raw_sampling_multiplier[instance]; _imu._gyro_window[instance][0].push(scaled_gyro.x); _imu._gyro_window[instance][1].push(scaled_gyro.y); _imu._gyro_window[instance][2].push(scaled_gyro.z); } #endif Vector3f gyro_filtered = gyro; // apply the notch filter if (_gyro_notch_enabled()) { gyro_filtered = _imu._gyro_notch_filter[instance].apply(gyro_filtered); } // apply the harmonic notch filter if (gyro_harmonic_notch_enabled()) { gyro_filtered = _imu._gyro_harmonic_notch_filter[instance].apply(gyro_filtered); } // apply the low pass filter last to attentuate any notch induced noise gyro_filtered = _imu._gyro_filter[instance].apply(gyro_filtered); // if the filtering failed in any way then reset the filters and keep the old value if (gyro_filtered.is_nan() || gyro_filtered.is_inf()) { _imu._gyro_filter[instance].reset(); _imu._gyro_notch_filter[instance].reset(); _imu._gyro_harmonic_notch_filter[instance].reset(); } else { _imu._gyro_filtered[instance] = gyro_filtered; } _imu._new_gyro_data[instance] = true; } if (!_imu.batchsampler.doing_post_filter_logging()) { log_gyro_raw(instance, sample_us, gyro); } else { log_gyro_raw(instance, sample_us, _imu._gyro_filtered[instance]); } } void AP_InertialSensor_Backend::log_gyro_raw(uint8_t instance, const uint64_t sample_us, const Vector3f &gyro) { AP_Logger *logger = AP_Logger::get_singleton(); if (logger == nullptr) { // should not have been called return; } if (should_log_imu_raw()) { Write_GYR(instance, sample_us, gyro); } else { if (!_imu.batchsampler.doing_sensor_rate_logging()) { _imu.batchsampler.sample(instance, AP_InertialSensor::IMU_SENSOR_TYPE_GYRO, sample_us, gyro); } } } /* rotate accel vector, scale and add the accel offset */ void AP_InertialSensor_Backend::_publish_accel(uint8_t instance, const Vector3f &accel) { if ((1U<<instance) & _imu.imu_kill_mask) { return; } _imu._accel[instance] = accel; _imu._accel_healthy[instance] = true; // publish delta velocity _imu._delta_velocity[instance] = _imu._delta_velocity_acc[instance]; _imu._delta_velocity_dt[instance] = _imu._delta_velocity_acc_dt[instance]; _imu._delta_velocity_valid[instance] = true; _imu._delta_velocity_acc[instance].zero(); _imu._delta_velocity_acc_dt[instance] = 0; if (_imu._accel_calibrator != nullptr && _imu._accel_calibrator[instance].get_status() == ACCEL_CAL_COLLECTING_SAMPLE) { Vector3f cal_sample = _imu._delta_velocity[instance]; // remove rotation. Note that we don't need to remove offsets or scale factor as those // are not applied when calibrating cal_sample.rotate_inverse(_imu._board_orientation); _imu._accel_calibrator[instance].new_sample(cal_sample, _imu._delta_velocity_dt[instance]); } } void AP_InertialSensor_Backend::_notify_new_accel_raw_sample(uint8_t instance, const Vector3f &accel, uint64_t sample_us, bool fsync_set) { if ((1U<<instance) & _imu.imu_kill_mask) { return; } float dt; _update_sensor_rate(_imu._sample_accel_count[instance], _imu._sample_accel_start_us[instance], _imu._accel_raw_sample_rates[instance]); uint64_t last_sample_us = _imu._accel_last_sample_us[instance]; /* we have two classes of sensors. FIFO based sensors produce data at a very predictable overall rate, but the data comes in bunches, so we use the provided sample rate for deltaT. Non-FIFO sensors don't bunch up samples, but also tend to vary in actual rate, so we use the provided sample_us to get the deltaT. The difference between the two is whether sample_us is provided. */ if (sample_us != 0 && _imu._accel_last_sample_us[instance] != 0) { dt = (sample_us - _imu._accel_last_sample_us[instance]) * 1.0e-6f; _imu._accel_last_sample_us[instance] = sample_us; } else { // don't accept below 40Hz if (_imu._accel_raw_sample_rates[instance] < 40) { return; } dt = 1.0f / _imu._accel_raw_sample_rates[instance]; _imu._accel_last_sample_us[instance] = AP_HAL::micros64(); sample_us = _imu._accel_last_sample_us[instance]; } #if AP_MODULE_SUPPORTED // call accel_sample hook if any AP_Module::call_hook_accel_sample(instance, dt, accel, fsync_set); #endif _imu.calc_vibration_and_clipping(instance, accel, dt); { WITH_SEMAPHORE(_sem); uint64_t now = AP_HAL::micros64(); if (now - last_sample_us > 100000U) { // zero accumulator if sensor was unhealthy for 0.1s _imu._delta_velocity_acc[instance].zero(); _imu._delta_velocity_acc_dt[instance] = 0; dt = 0; } // delta velocity _imu._delta_velocity_acc[instance] += accel * dt; _imu._delta_velocity_acc_dt[instance] += dt; _imu._accel_filtered[instance] = _imu._accel_filter[instance].apply(accel); if (_imu._accel_filtered[instance].is_nan() || _imu._accel_filtered[instance].is_inf()) { _imu._accel_filter[instance].reset(); } _imu.set_accel_peak_hold(instance, _imu._accel_filtered[instance]); _imu._new_accel_data[instance] = true; } if (!_imu.batchsampler.doing_post_filter_logging()) { log_accel_raw(instance, sample_us, accel); } else { log_accel_raw(instance, sample_us, _imu._accel_filtered[instance]); } } void AP_InertialSensor_Backend::_notify_new_accel_sensor_rate_sample(uint8_t instance, const Vector3f &accel) { if (!_imu.batchsampler.doing_sensor_rate_logging()) { return; } _imu.batchsampler.sample(instance, AP_InertialSensor::IMU_SENSOR_TYPE_ACCEL, AP_HAL::micros64(), accel); } void AP_InertialSensor_Backend::_notify_new_gyro_sensor_rate_sample(uint8_t instance, const Vector3f &gyro) { if (!_imu.batchsampler.doing_sensor_rate_logging()) { return; } _imu.batchsampler.sample(instance, AP_InertialSensor::IMU_SENSOR_TYPE_GYRO, AP_HAL::micros64(), gyro); } void AP_InertialSensor_Backend::log_accel_raw(uint8_t instance, const uint64_t sample_us, const Vector3f &accel) { AP_Logger *logger = AP_Logger::get_singleton(); if (logger == nullptr) { // should not have been called return; } if (should_log_imu_raw()) { Write_ACC(instance, sample_us, accel); } else { if (!_imu.batchsampler.doing_sensor_rate_logging()) { _imu.batchsampler.sample(instance, AP_InertialSensor::IMU_SENSOR_TYPE_ACCEL, sample_us, accel); } } } void AP_InertialSensor_Backend::_set_accel_max_abs_offset(uint8_t instance, float max_offset) { _imu._accel_max_abs_offsets[instance] = max_offset; } // set accelerometer error_count void AP_InertialSensor_Backend::_set_accel_error_count(uint8_t instance, uint32_t error_count) { _imu._accel_error_count[instance] = error_count; } // set gyro error_count void AP_InertialSensor_Backend::_set_gyro_error_count(uint8_t instance, uint32_t error_count) { _imu._gyro_error_count[instance] = error_count; } // increment accelerometer error_count void AP_InertialSensor_Backend::_inc_accel_error_count(uint8_t instance) { _imu._accel_error_count[instance]++; } // increment gyro error_count void AP_InertialSensor_Backend::_inc_gyro_error_count(uint8_t instance) { _imu._gyro_error_count[instance]++; } // return the requested loop rate at which samples will be made available in Hz uint16_t AP_InertialSensor_Backend::get_loop_rate_hz(void) const { // enum can be directly cast to Hz return (uint16_t)_imu._loop_rate; } /* publish a temperature value for an instance */ void AP_InertialSensor_Backend::_publish_temperature(uint8_t instance, float temperature) { if ((1U<<instance) & _imu.imu_kill_mask) { return; } _imu._temperature[instance] = temperature; #if HAL_HAVE_IMU_HEATER /* give the temperature to the control loop in order to keep it constant*/ if (instance == 0) { AP_BoardConfig *bc = AP::boardConfig(); if (bc) { bc->set_imu_temp(temperature); } } #endif } /* common gyro update function for all backends */ void AP_InertialSensor_Backend::update_gyro(uint8_t instance) { WITH_SEMAPHORE(_sem); if ((1U<<instance) & _imu.imu_kill_mask) { return; } if (_imu._new_gyro_data[instance]) { _publish_gyro(instance, _imu._gyro_filtered[instance]); // copy the gyro samples from the backend to the frontend window #if HAL_WITH_DSP _imu._gyro_raw[instance] = _imu._last_raw_gyro[instance] * _imu._gyro_raw_sampling_multiplier[instance]; #endif _imu._new_gyro_data[instance] = false; } // possibly update filter frequency if (_last_gyro_filter_hz != _gyro_filter_cutoff() || sensors_converging()) { _imu._gyro_filter[instance].set_cutoff_frequency(_gyro_raw_sample_rate(instance), _gyro_filter_cutoff()); _last_gyro_filter_hz = _gyro_filter_cutoff(); } // possily update the harmonic notch filter parameters if (!is_equal(_last_harmonic_notch_bandwidth_hz, gyro_harmonic_notch_bandwidth_hz()) || !is_equal(_last_harmonic_notch_attenuation_dB, gyro_harmonic_notch_attenuation_dB()) || sensors_converging()) { _imu._gyro_harmonic_notch_filter[instance].init(_gyro_raw_sample_rate(instance), gyro_harmonic_notch_center_freq_hz(), gyro_harmonic_notch_bandwidth_hz(), gyro_harmonic_notch_attenuation_dB()); _last_harmonic_notch_center_freq_hz = gyro_harmonic_notch_center_freq_hz(); _last_harmonic_notch_bandwidth_hz = gyro_harmonic_notch_bandwidth_hz(); _last_harmonic_notch_attenuation_dB = gyro_harmonic_notch_attenuation_dB(); } else if (!is_equal(_last_harmonic_notch_center_freq_hz, gyro_harmonic_notch_center_freq_hz())) { if (num_gyro_harmonic_notch_center_frequencies() > 1) { _imu._gyro_harmonic_notch_filter[instance].update(num_gyro_harmonic_notch_center_frequencies(), gyro_harmonic_notch_center_frequencies_hz()); } else { _imu._gyro_harmonic_notch_filter[instance].update(gyro_harmonic_notch_center_freq_hz()); } _last_harmonic_notch_center_freq_hz = gyro_harmonic_notch_center_freq_hz(); } // possily update the notch filter parameters if (!is_equal(_last_notch_center_freq_hz, _gyro_notch_center_freq_hz()) || !is_equal(_last_notch_bandwidth_hz, _gyro_notch_bandwidth_hz()) || !is_equal(_last_notch_attenuation_dB, _gyro_notch_attenuation_dB()) || sensors_converging()) { _imu._gyro_notch_filter[instance].init(_gyro_raw_sample_rate(instance), _gyro_notch_center_freq_hz(), _gyro_notch_bandwidth_hz(), _gyro_notch_attenuation_dB()); _last_notch_center_freq_hz = _gyro_notch_center_freq_hz(); _last_notch_bandwidth_hz = _gyro_notch_bandwidth_hz(); _last_notch_attenuation_dB = _gyro_notch_attenuation_dB(); } } /* common accel update function for all backends */ void AP_InertialSensor_Backend::update_accel(uint8_t instance) { WITH_SEMAPHORE(_sem); if ((1U<<instance) & _imu.imu_kill_mask) { return; } if (_imu._new_accel_data[instance]) { _publish_accel(instance, _imu._accel_filtered[instance]); _imu._new_accel_data[instance] = false; } // possibly update filter frequency if (_last_accel_filter_hz != _accel_filter_cutoff()) { _imu._accel_filter[instance].set_cutoff_frequency(_accel_raw_sample_rate(instance), _accel_filter_cutoff()); _last_accel_filter_hz = _accel_filter_cutoff(); } } bool AP_InertialSensor_Backend::should_log_imu_raw() const { if (_imu._log_raw_bit == (uint32_t)-1) { // tracker does not set a bit return false; } const AP_Logger *logger = AP_Logger::get_singleton(); if (logger == nullptr) { return false; } if (!logger->should_log(_imu._log_raw_bit)) { return false; } return true; } // log an unexpected change in a register for an IMU void AP_InertialSensor_Backend::log_register_change(uint32_t bus_id, const AP_HAL::Device::checkreg ®) { AP::logger().Write("IREG", "TimeUS,DevID,Bank,Reg,Val", "QUBBB", AP_HAL::micros64(), bus_id, reg.bank, reg.regnum, reg.value); }