PX4-Autopilot/src/modules/commander/failure_detector/FailureDetector.cpp

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/**
* @file FailureDetector.cpp
*
* @author Mathieu Bresciani	<brescianimathieu@gmail.com>
*
*/

#include "FailureDetector.hpp"

using namespace time_literals;

FailureDetector::FailureDetector(ModuleParams *parent) :
	ModuleParams(parent)
{
}

bool FailureDetector::update(const vehicle_status_s &vehicle_status)
{
	uint8_t previous_status = _status;

	if (isAttitudeStabilized(vehicle_status)) {
		updateAttitudeStatus();

		if (_param_fd_ext_ats_en.get()) {
			updateExternalAtsStatus();
		}

	} else {
		_status &= ~(FAILURE_ROLL | FAILURE_PITCH | FAILURE_ALT | FAILURE_EXT);
	}

	if (_param_escs_en.get()) {
		updateEscsStatus(vehicle_status);
	}

	return _status != previous_status;
}

bool FailureDetector::isAttitudeStabilized(const vehicle_status_s &vehicle_status)
{
	bool attitude_is_stabilized{false};
	const uint8_t vehicle_type = vehicle_status.vehicle_type;
	const uint8_t nav_state = vehicle_status.nav_state;

	if (vehicle_type == vehicle_status_s::VEHICLE_TYPE_ROTARY_WING) {
		attitude_is_stabilized =  nav_state != vehicle_status_s::NAVIGATION_STATE_ACRO &&
					  nav_state != vehicle_status_s::NAVIGATION_STATE_RATTITUDE;

	} else if (vehicle_type == vehicle_status_s::VEHICLE_TYPE_FIXED_WING) {
		attitude_is_stabilized =  nav_state != vehicle_status_s::NAVIGATION_STATE_MANUAL &&
					  nav_state != vehicle_status_s::NAVIGATION_STATE_ACRO &&
					  nav_state != vehicle_status_s::NAVIGATION_STATE_RATTITUDE;
	}

	return attitude_is_stabilized;
}

void FailureDetector::updateAttitudeStatus()
{
	vehicle_attitude_s attitude;

	if (_vehicule_attitude_sub.update(&attitude)) {

		const matrix::Eulerf euler(matrix::Quatf(attitude.q));
		const float roll(euler.phi());
		const float pitch(euler.theta());

		const float max_roll_deg = _param_fd_fail_r.get();
		const float max_pitch_deg = _param_fd_fail_p.get();
		const float max_roll(fabsf(math::radians(max_roll_deg)));
		const float max_pitch(fabsf(math::radians(max_pitch_deg)));

		const bool roll_status = (max_roll > 0.0f) && (fabsf(roll) > max_roll);
		const bool pitch_status = (max_pitch > 0.0f) && (fabsf(pitch) > max_pitch);

		hrt_abstime time_now = hrt_absolute_time();

		// Update hysteresis
		_roll_failure_hysteresis.set_hysteresis_time_from(false, (hrt_abstime)(1_s * _param_fd_fail_r_ttri.get()));
		_pitch_failure_hysteresis.set_hysteresis_time_from(false, (hrt_abstime)(1_s * _param_fd_fail_p_ttri.get()));
		_roll_failure_hysteresis.set_state_and_update(roll_status, time_now);
		_pitch_failure_hysteresis.set_state_and_update(pitch_status, time_now);

		// Update bitmask
		_status &= ~(FAILURE_ROLL | FAILURE_PITCH);

		if (_roll_failure_hysteresis.get_state()) {
			_status |= FAILURE_ROLL;
		}

		if (_pitch_failure_hysteresis.get_state()) {
			_status |= FAILURE_PITCH;
		}
	}
}

void FailureDetector::updateExternalAtsStatus()
{
	pwm_input_s pwm_input;

	if (_pwm_input_sub.update(&pwm_input)) {

		uint32_t pulse_width = pwm_input.pulse_width;
		bool ats_trigger_status = (pulse_width >= (uint32_t)_param_fd_ext_ats_trig.get()) && (pulse_width < 3_ms);

		hrt_abstime time_now = hrt_absolute_time();

		// Update hysteresis
		_ext_ats_failure_hysteresis.set_hysteresis_time_from(false, 100_ms); // 5 consecutive pulses at 50hz
		_ext_ats_failure_hysteresis.set_state_and_update(ats_trigger_status, time_now);

		_status &= ~FAILURE_EXT;

		if (_ext_ats_failure_hysteresis.get_state()) {
			_status |= FAILURE_EXT;
		}
	}
}

void FailureDetector::updateEscsStatus(const vehicle_status_s &vehicle_status)
{
	hrt_abstime time_now = hrt_absolute_time();

	if (vehicle_status.arming_state == vehicle_status_s::ARMING_STATE_ARMED) {
		esc_status_s esc_status;

		if (_esc_status_sub.update(&esc_status)) {
			int all_escs_armed = (1 << esc_status.esc_count) - 1;

			_esc_failure_hysteresis.set_hysteresis_time_from(false, 300_ms);
			_esc_failure_hysteresis.set_state_and_update(all_escs_armed != esc_status.esc_armed_flags, time_now);

			if (_esc_failure_hysteresis.get_state()) {
				_status |= FAILURE_ARM_ESCS;
			}
		}

	} else {
		// reset ESC bitfield
		_esc_failure_hysteresis.set_state_and_update(false, time_now);
		_status &= ~FAILURE_ARM_ESCS;
	}
}