PX4-Autopilot/src/modules/sensors/vehicle_acceleration/VehicleAcceleration.cpp

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#include "VehicleAcceleration.hpp"

#include <px4_platform_common/log.h>

using namespace matrix;
using namespace time_literals;

namespace sensors
{

VehicleAcceleration::VehicleAcceleration() :
	ModuleParams(nullptr),
	WorkItem(MODULE_NAME, px4::wq_configurations::att_pos_ctrl),
	_corrections(this, SensorCorrections::SensorType::Accelerometer)
{
	_lp_filter.set_cutoff_frequency(kInitialRateHz, _param_imu_accel_cutoff.get());
}

VehicleAcceleration::~VehicleAcceleration()
{
	Stop();
}

bool VehicleAcceleration::Start()
{
	// force initial updates
	ParametersUpdate(true);

	// sensor_selection needed to change the active sensor if the primary stops updating
	if (!_sensor_selection_sub.registerCallback()) {
		PX4_ERR("sensor_selection callback registration failed");
		return false;
	}

	ScheduleNow();
	return true;
}

void VehicleAcceleration::Stop()
{
	Deinit();

	// clear all registered callbacks
	for (auto &sub : _sensor_sub) {
		sub.unregisterCallback();
	}

	_sensor_selection_sub.unregisterCallback();
}

void VehicleAcceleration::CheckFilters()
{
	// check filter periodically (roughly once every 1-3 seconds depending on sensor configuration)
	if (_interval_count > 2500) {
		bool sample_rate_changed = false;

		// calculate sensor update rate
		const float sample_interval_avg = _interval_sum / _interval_count;

		if (PX4_ISFINITE(sample_interval_avg) && (sample_interval_avg > 0.0f)) {

			const float update_rate_hz = 1.e6f / sample_interval_avg;

			if ((fabsf(update_rate_hz) > 0.0f) && PX4_ISFINITE(update_rate_hz)) {
				_update_rate_hz = update_rate_hz;

				// check if sample rate error is greater than 1%
				if ((fabsf(_update_rate_hz - _filter_sample_rate) / _filter_sample_rate) > 0.01f) {
					sample_rate_changed = true;
				}
			}
		}

		const bool lp_updated = (fabsf(_lp_filter.get_cutoff_freq() - _param_imu_accel_cutoff.get()) > 0.01f);

		if (sample_rate_changed || lp_updated) {
			PX4_DEBUG("resetting filters, sample rate: %.3f Hz -> %.3f Hz", (double)_filter_sample_rate, (double)_update_rate_hz);
			_filter_sample_rate = _update_rate_hz;

			// update software low pass filters
			_lp_filter.set_cutoff_frequency(_filter_sample_rate, _param_imu_accel_cutoff.get());
			_lp_filter.reset(_acceleration_prev);
		}

		// reset sample interval accumulator
		_timestamp_sample_last = 0;
	}
}

void VehicleAcceleration::SensorBiasUpdate(bool force)
{
	if (_estimator_sensor_bias_sub.updated() || force) {
		estimator_sensor_bias_s bias;

		if (_estimator_sensor_bias_sub.copy(&bias)) {
			if (bias.accel_device_id == _selected_sensor_device_id) {
				_bias = Vector3f{bias.accel_bias};

			} else {
				_bias.zero();
			}
		}
	}
}

bool VehicleAcceleration::SensorSelectionUpdate(bool force)
{
	if (_sensor_selection_sub.updated() || (_selected_sensor_device_id == 0) || force) {
		sensor_selection_s sensor_selection{};
		_sensor_selection_sub.copy(&sensor_selection);

		if (_selected_sensor_device_id != sensor_selection.accel_device_id) {
			// clear all registered callbacks
			for (auto &sub : _sensor_sub) {
				sub.unregisterCallback();
			}

			for (int i = 0; i < MAX_SENSOR_COUNT; i++) {
				sensor_accel_s report{};
				_sensor_sub[i].copy(&report);

				if ((report.device_id != 0) && (report.device_id == sensor_selection.accel_device_id)) {
					if (_sensor_sub[i].registerCallback()) {
						PX4_DEBUG("selected sensor changed %d -> %d", _selected_sensor_sub_index, i);

						// record selected sensor (array index)
						_selected_sensor_sub_index = i;
						_selected_sensor_device_id = sensor_selection.accel_device_id;

						// clear bias and corrections
						_bias.zero();

						_corrections.set_device_id(report.device_id);

						// reset sample interval accumulator on sensor change
						_timestamp_sample_last = 0;

						return true;
					}
				}
			}

			PX4_ERR("unable to find or subscribe to selected sensor (%d)", sensor_selection.accel_device_id);
			_selected_sensor_device_id = 0;
			_selected_sensor_sub_index = 0;
		}
	}

	return false;
}

void VehicleAcceleration::ParametersUpdate(bool force)
{
	// Check if parameters have changed
	if (_params_sub.updated() || force) {
		// clear update
		parameter_update_s param_update;
		_params_sub.copy(&param_update);

		updateParams();

		_corrections.ParametersUpdate();
	}
}

void VehicleAcceleration::Run()
{
	// update corrections first to set _selected_sensor
	bool selection_updated = SensorSelectionUpdate();

	_corrections.SensorCorrectionsUpdate(selection_updated);
	SensorBiasUpdate(selection_updated);
	ParametersUpdate();

	bool sensor_updated = _sensor_sub[_selected_sensor_sub_index].updated();

	// process all outstanding messages
	while (sensor_updated || selection_updated) {
		selection_updated = false;

		sensor_accel_s sensor_data;

		if (_sensor_sub[_selected_sensor_sub_index].copy(&sensor_data)) {

			if (sensor_updated) {
				// collect sample interval average for filters
				if ((_timestamp_sample_last > 0) && (sensor_data.timestamp_sample > _timestamp_sample_last)) {
					_interval_sum += (sensor_data.timestamp_sample - _timestamp_sample_last);
					_interval_count++;

				} else {
					_interval_sum = 0.f;
					_interval_count = 0.f;
				}

				_timestamp_sample_last = sensor_data.timestamp_sample;
			}

			CheckFilters();

			// Filter: apply low-pass
			const Vector3f accel_filtered = _lp_filter.apply(Vector3f{sensor_data.x, sensor_data.y, sensor_data.z});

			_acceleration_prev = accel_filtered;

			// publish once all new samples are processed
			sensor_updated = _sensor_sub[_selected_sensor_sub_index].updated();

			if (!sensor_updated) {
				// correct for in-run bias errors
				const Vector3f accel = _corrections.Correct(accel_filtered) - _bias;

				// Publish vehicle_acceleration
				vehicle_acceleration_s v_acceleration;
				v_acceleration.timestamp_sample = sensor_data.timestamp_sample;
				accel.copyTo(v_acceleration.xyz);
				v_acceleration.timestamp = hrt_absolute_time();
				_vehicle_acceleration_pub.publish(v_acceleration);

				_last_publish = v_acceleration.timestamp_sample;
				return;
			}
		}
	}
}

void VehicleAcceleration::PrintStatus()
{
	PX4_INFO("selected sensor: %d (%d)", _selected_sensor_device_id, _selected_sensor_sub_index);
	PX4_INFO("bias: [%.3f %.3f %.3f]", (double)_bias(0), (double)_bias(1), (double)_bias(2));

	PX4_INFO("sample rate: %.3f Hz", (double)_update_rate_hz);

	_corrections.PrintStatus();
}

} // namespace sensors