PX4-Autopilot/src/modules/navigator/gpsfailure.cpp

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/**
 * @file gpsfailure.cpp
 * Helper class for gpsfailure mode according to the OBC rules
 *
 * @author Thomas Gubler <thomasgubler@gmail.com>
 */

#include "gpsfailure.h"
#include "navigator.h"

#include <systemlib/mavlink_log.h>
#include <geo/geo.h>
#include <navigator/navigation.h>
#include <uORB/uORB.h>
#include <uORB/topics/mission.h>
#include <uORB/topics/home_position.h>
#include <mathlib/mathlib.h>

using matrix::Eulerf;
using matrix::Quatf;

static constexpr float DELAY_SIGMA = 0.01f;

GpsFailure::GpsFailure(Navigator *navigator, const char *name) :
	MissionBlock(navigator, name),
	_param_loitertime(this, "LT"),
	_param_openlooploiter_roll(this, "R"),
	_param_openlooploiter_pitch(this, "P"),
	_param_openlooploiter_thrust(this, "TR"),
	_gpsf_state(GPSF_STATE_NONE),
	_timestamp_activation(0)
{
	/* load initial params */
	updateParams();

	/* initial reset */
	on_inactive();
}

void
GpsFailure::on_inactive()
{
	/* reset GPSF state only if setpoint moved */
	if (!_navigator->get_can_loiter_at_sp()) {
		_gpsf_state = GPSF_STATE_NONE;
	}
}

void
GpsFailure::on_activation()
{
	_gpsf_state = GPSF_STATE_NONE;
	_timestamp_activation = hrt_absolute_time();
	advance_gpsf();
	set_gpsf_item();
}

void
GpsFailure::on_active()
{
	switch (_gpsf_state) {
	case GPSF_STATE_LOITER: {
			/* Position controller does not run in this mode:
			 * navigator has to publish an attitude setpoint */
			vehicle_attitude_setpoint_s att_sp = {};
			att_sp.timestamp = hrt_absolute_time();
			att_sp.roll_body = math::radians(_param_openlooploiter_roll.get());
			att_sp.pitch_body = math::radians(_param_openlooploiter_pitch.get());
			att_sp.thrust = _param_openlooploiter_thrust.get();

			Quatf q(Eulerf(att_sp.roll_body, att_sp.pitch_body, 0.0f));
			q.copyTo(att_sp.q_d);
			att_sp.q_d_valid = true;

			if (_att_sp_pub != nullptr) {
				/* publish att sp*/
				orb_publish(ORB_ID(vehicle_attitude_setpoint), _att_sp_pub, &att_sp);

			} else {
				/* advertise and publish */
				_att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &att_sp);
			}

			/* Measure time */
			if ((_param_loitertime.get() > FLT_EPSILON) &&
			    (hrt_elapsed_time(&_timestamp_activation) > _param_loitertime.get() * 1e6f)) {
				/* no recovery, advance the state machine */
				PX4_WARN("GPS not recovered, switching to next failure state");
				advance_gpsf();
			}

			break;
		}

	case GPSF_STATE_TERMINATE:
		set_gpsf_item();
		advance_gpsf();
		break;

	default:
		break;
	}
}

void
GpsFailure::set_gpsf_item()
{
	struct position_setpoint_triplet_s *pos_sp_triplet = _navigator->get_position_setpoint_triplet();

	/* Set pos sp triplet to invalid to stop pos controller */
	pos_sp_triplet->previous.valid = false;
	pos_sp_triplet->current.valid = false;
	pos_sp_triplet->next.valid = false;

	switch (_gpsf_state) {
	case GPSF_STATE_TERMINATE: {
			/* Request flight termination from commander */
			_navigator->get_mission_result()->flight_termination = true;
			_navigator->set_mission_result_updated();
			PX4_WARN("GPS failure: request flight termination");
		}
		break;

	default:
		break;
	}

	_navigator->set_position_setpoint_triplet_updated();
}

void
GpsFailure::advance_gpsf()
{
	switch (_gpsf_state) {
	case GPSF_STATE_NONE:
		_gpsf_state = GPSF_STATE_LOITER;
		mavlink_log_critical(_navigator->get_mavlink_log_pub(), "Global position failure: fixed bank loiter");
		break;

	case GPSF_STATE_LOITER:
		_gpsf_state = GPSF_STATE_TERMINATE;
		mavlink_log_emergency(_navigator->get_mavlink_log_pub(), "no GPS recovery, terminating flight");
		break;

	case GPSF_STATE_TERMINATE:
		PX4_WARN("terminate");
		_gpsf_state = GPSF_STATE_END;
		break;

	default:
		break;
	}
}