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

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/**
* @file FailureDetector.hpp
* Base class for failure detection logic based on vehicle states
* for failsafe triggering.
*
* @author Mathieu Bresciani 	<brescianimathieu@gmail.com>
*
*/

#pragma once

#include <lib/hysteresis/hysteresis.h>
#include <lib/mathlib/mathlib.h>
#include <lib/mathlib/math/filter/AlphaFilter.hpp>
#include <matrix/matrix/math.hpp>
#include <px4_platform_common/module_params.h>

// subscriptions
#include <uORB/Subscription.hpp>
#include <uORB/Publication.hpp>
#include <uORB/topics/actuator_motors.h>
#include <uORB/topics/sensor_selection.h>
#include <uORB/topics/vehicle_attitude_setpoint.h>
#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_command.h>
#include <uORB/topics/vehicle_command_ack.h>
#include <uORB/topics/vehicle_control_mode.h>
#include <uORB/topics/vehicle_imu_status.h>
#include <uORB/topics/vehicle_status.h>
#include <uORB/topics/esc_status.h>
#include <uORB/topics/pwm_input.h>

union failure_detector_status_u {
	struct {
		uint16_t roll : 1;
		uint16_t pitch : 1;
		uint16_t alt : 1;
		uint16_t ext : 1;
		uint16_t arm_escs : 1;
		uint16_t battery : 1;
		uint16_t imbalanced_prop : 1;
		uint16_t motor : 1;
	} flags;
	uint16_t value {0};
};

using uORB::SubscriptionData;

class FailureInjector
{
public:
	void update();

	void manipulateEscStatus(esc_status_s &status);
private:
	uORB::Subscription _vehicle_command_sub{ORB_ID(vehicle_command)};
	uORB::Publication<vehicle_command_ack_s> _command_ack_pub{ORB_ID(vehicle_command_ack)};

	uint32_t _esc_blocked{};
	uint32_t _esc_wrong{};
};

class FailureDetector : public ModuleParams
{
public:
	FailureDetector(ModuleParams *parent);
	~FailureDetector() = default;

	bool update(const vehicle_status_s &vehicle_status, const vehicle_control_mode_s &vehicle_control_mode);
	const failure_detector_status_u &getStatus() const { return _status; }
	const decltype(failure_detector_status_u::flags) &getStatusFlags() const { return _status.flags; }
	float getImbalancedPropMetric() const { return _imbalanced_prop_lpf.getState(); }
	uint16_t getMotorFailures() const { return _motor_failure_esc_timed_out_mask | _motor_failure_esc_under_current_mask; }

private:
	void updateAttitudeStatus();
	void updateExternalAtsStatus();
	void updateEscsStatus(const vehicle_status_s &vehicle_status, const esc_status_s &esc_status);
	void updateMotorStatus(const vehicle_status_s &vehicle_status, const esc_status_s &esc_status);
	void updateImbalancedPropStatus();

	failure_detector_status_u _status{};

	systemlib::Hysteresis _roll_failure_hysteresis{false};
	systemlib::Hysteresis _pitch_failure_hysteresis{false};
	systemlib::Hysteresis _ext_ats_failure_hysteresis{false};
	systemlib::Hysteresis _esc_failure_hysteresis{false};

	static constexpr float _imbalanced_prop_lpf_time_constant{5.f};
	AlphaFilter<float> _imbalanced_prop_lpf{};
	uint32_t _selected_accel_device_id{0};
	hrt_abstime _imu_status_timestamp_prev{0};

	// Motor failure check
	uint8_t _motor_failure_esc_valid_current_mask{};  // ESC 1-8, true if ESC telemetry was valid at some point
	uint8_t _motor_failure_esc_timed_out_mask{};      // ESC telemetry no longer available -> failure
	uint8_t _motor_failure_esc_under_current_mask{};  // ESC drawing too little current -> failure
	bool _motor_failure_escs_have_current{false}; // true if some ESC had non-zero current (some don't support it)
	hrt_abstime _motor_failure_undercurrent_start_time[actuator_motors_s::NUM_CONTROLS] {};

	uORB::Subscription _vehicle_attitude_sub{ORB_ID(vehicle_attitude)};
	uORB::Subscription _esc_status_sub{ORB_ID(esc_status)}; // TODO: multi-instance
	uORB::Subscription _pwm_input_sub{ORB_ID(pwm_input)};
	uORB::Subscription _sensor_selection_sub{ORB_ID(sensor_selection)};
	uORB::Subscription _vehicle_imu_status_sub{ORB_ID(vehicle_imu_status)};
	uORB::Subscription _actuator_motors_sub{ORB_ID(actuator_motors)};

	FailureInjector _failure_injector;

	DEFINE_PARAMETERS(
		(ParamInt<px4::params::FD_FAIL_P>) _param_fd_fail_p,
		(ParamInt<px4::params::FD_FAIL_R>) _param_fd_fail_r,
		(ParamFloat<px4::params::FD_FAIL_R_TTRI>) _param_fd_fail_r_ttri,
		(ParamFloat<px4::params::FD_FAIL_P_TTRI>) _param_fd_fail_p_ttri,
		(ParamBool<px4::params::FD_EXT_ATS_EN>) _param_fd_ext_ats_en,
		(ParamInt<px4::params::FD_EXT_ATS_TRIG>) _param_fd_ext_ats_trig,
		(ParamInt<px4::params::FD_ESCS_EN>) _param_escs_en,
		(ParamInt<px4::params::FD_IMB_PROP_THR>) _param_fd_imb_prop_thr,

		// Actuator failure
		(ParamBool<px4::params::FD_ACT_EN>) _param_fd_actuator_en,
		(ParamFloat<px4::params::FD_ACT_MOT_THR>) _param_fd_motor_throttle_thres,
		(ParamFloat<px4::params::FD_ACT_MOT_C2T>) _param_fd_motor_current2throttle_thres,
		(ParamInt<px4::params::FD_ACT_MOT_TOUT>) _param_fd_motor_time_thres
	)
};