PX4-Autopilot/src/lib/flight_tasks/tasks/AutoMapper/FlightTaskAutoMapper.cpp

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/**
 * @file FlightAutoMapper.cpp
 */

#include "FlightTaskAutoMapper.hpp"
#include <mathlib/mathlib.h>

using namespace matrix;

bool FlightTaskAutoMapper::activate(vehicle_local_position_setpoint_s last_setpoint)
{
	bool ret = FlightTaskAuto::activate(last_setpoint);
	_reset();
	return ret;
}

bool FlightTaskAutoMapper::update()
{
	// always reset constraints because they might change depending on the type
	_setDefaultConstraints();

	// The only time a thrust set-point is sent out is during
	// idle. Hence, reset thrust set-point to NAN in case the
	// vehicle exits idle.

	if (_type_previous == WaypointType::idle) {
		_thrust_setpoint.setNaN();
	}

	// during mission and reposition, raise the landing gears but only
	// if altitude is high enough
	if (_highEnoughForLandingGear()) {
		_gear.landing_gear = landing_gear_s::GEAR_UP;
	}

	switch (_type) {
	case WaypointType::idle:
		_prepareIdleSetpoints();
		break;

	case WaypointType::land:
		_prepareLandSetpoints();
		break;

	case WaypointType::loiter:

	/* fallthrought */
	case WaypointType::position:
		_preparePositionSetpoints();
		break;

	case WaypointType::takeoff:
		_prepareTakeoffSetpoints();
		break;

	case WaypointType::velocity:
		_prepareVelocitySetpoints();
		break;

	default:
		_preparePositionSetpoints();
		break;
	}

	if (_param_com_obs_avoid.get()) {
		_obstacle_avoidance.updateAvoidanceDesiredSetpoints(_position_setpoint, _velocity_setpoint, (int)_type);
		_obstacle_avoidance.injectAvoidanceSetpoints(_position_setpoint, _velocity_setpoint, _yaw_setpoint,
				_yawspeed_setpoint);
	}


	_generateSetpoints();

	// update previous type
	_type_previous = _type;

	return true;
}

void FlightTaskAutoMapper::_reset()
{
	// Set setpoints equal current state.
	_velocity_setpoint = _velocity;
	_position_setpoint = _position;
}

void FlightTaskAutoMapper::_prepareIdleSetpoints()
{
	// Send zero thrust setpoint
	_position_setpoint.setNaN(); // Don't require any position/velocity setpoints
	_velocity_setpoint.setNaN();
	_thrust_setpoint.zero();
}

void FlightTaskAutoMapper::_prepareLandSetpoints()
{
	float land_speed = _getLandSpeed();

	// Keep xy-position and go down with landspeed
	_position_setpoint = Vector3f(_target(0), _target(1), NAN);
	_velocity_setpoint = Vector3f(Vector3f(NAN, NAN, land_speed));

	// set constraints
	_constraints.tilt = math::radians(_param_mpc_tiltmax_lnd.get());
	_gear.landing_gear = landing_gear_s::GEAR_DOWN;
}

void FlightTaskAutoMapper::_prepareTakeoffSetpoints()
{
	// Takeoff is completely defined by target position
	_position_setpoint = _target;
	const float speed_tko = (_dist_to_ground > _param_mpc_land_alt1.get()) ? _constraints.speed_up :
				_param_mpc_tko_speed.get();
	_velocity_setpoint = Vector3f(NAN, NAN, -speed_tko); // Limit the maximum vertical speed

	_gear.landing_gear = landing_gear_s::GEAR_DOWN;
}

void FlightTaskAutoMapper::_prepareVelocitySetpoints()
{
	// XY Velocity waypoint
	// TODO : Rewiew that. What is the expected behavior?
	_position_setpoint = Vector3f(NAN, NAN, _position(2));
	Vector2f vel_sp_xy = Vector2f(_velocity).unit_or_zero() * _mc_cruise_speed;
	_velocity_setpoint = Vector3f(vel_sp_xy(0), vel_sp_xy(1), NAN);
}

void FlightTaskAutoMapper::_preparePositionSetpoints()
{
	// Simple waypoint navigation: go to xyz target, with standard limitations
	_position_setpoint = _target;
	_velocity_setpoint.setNaN(); // No special velocity limitations
}

void FlightTaskAutoMapper::updateParams()
{
	FlightTaskAuto::updateParams();

	// make sure that alt1 is above alt2
	_param_mpc_land_alt1.set(math::max(_param_mpc_land_alt1.get(), _param_mpc_land_alt2.get()));
}

bool FlightTaskAutoMapper::_highEnoughForLandingGear()
{
	// return true if altitude is above two meters
	return _dist_to_ground > 2.0f;
}

float FlightTaskAutoMapper::_getLandSpeed()
{
	bool rc_assist_enabled = _param_mpc_land_rc_help.get();
	bool rc_is_valid = !_sub_vehicle_status.get().rc_signal_lost;

	float throttle = 0.5f;

	if (rc_is_valid && rc_assist_enabled) {
		throttle = _sub_manual_control_setpoint.get().z;
	}

	float speed = 0;

	if (_dist_to_ground > _param_mpc_land_alt1.get()) {
		speed = _constraints.speed_down;

	} else {
		const float land_speed = math::gradual(_dist_to_ground,
						       _param_mpc_land_alt2.get(), _param_mpc_land_alt1.get(),
						       _param_mpc_land_speed.get(), _constraints.speed_down);
		const float head_room = _constraints.speed_down - land_speed;

		speed = land_speed + 2 * (0.5f - throttle) * head_room;

		// Allow minimum assisted land speed to be half of parameter
		if (speed < land_speed * 0.5f) {
			speed = land_speed * 0.5f;
		}
	}

	return speed;
}