FlightTaskManualAltitude.hpp

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/**
 * @file FlightManualAltitude.hpp
 *
 * Flight task for manual controlled altitude.
 */

#pragma once

#include "FlightTaskManual.hpp"
#include <uORB/topics/home_position.h>

class FlightTaskManualAltitude : public FlightTaskManual
{
public:
    FlightTaskManualAltitude() = default;
    virtual ~FlightTaskManualAltitude() = default;
    bool activate(vehicle_local_position_setpoint_s last_setpoint) override;
    bool updateInitialize() override;
    bool update() override;

protected:
    void _updateHeadingSetpoints(); /**< sets yaw or yaw speed */
    void _ekfResetHandlerHeading(float delta_psi) override; /**< adjust heading setpoint in case of EKF reset event */
    virtual void _updateSetpoints(); /**< updates all setpoints */
    virtual void _scaleSticks(); /**< scales sticks to velocity in z */
    bool _checkTakeoff() override;

    /**
     * rotates vector into local frame
     */
    void _rotateIntoHeadingFrame(matrix::Vector2f &vec);

    /**
     *  Check and sets for position lock.
     *  If sticks are at center position, the vehicle
     *  will exit velocity control and enter position control.
     */
    void _updateAltitudeLock();

    DEFINE_PARAMETERS_CUSTOM_PARENT(FlightTaskManual,
                    (ParamFloat<px4::params::MPC_HOLD_MAX_Z>) _param_mpc_hold_max_z,
                    (ParamInt<px4::params::MPC_ALT_MODE>) _param_mpc_alt_mode,
                    (ParamFloat<px4::params::MPC_HOLD_MAX_XY>) _param_mpc_hold_max_xy,
                    (ParamFloat<px4::params::MPC_Z_P>) _param_mpc_z_p, /**< position controller altitude propotional gain */
                    (ParamFloat<px4::params::MPC_MAN_Y_MAX>) _param_mpc_man_y_max, /**< scaling factor from stick to yaw rate */
                    (ParamFloat<px4::params::MPC_MAN_Y_TAU>) _param_mpc_man_y_tau,
                    (ParamFloat<px4::params::MPC_MAN_TILT_MAX>) _param_mpc_man_tilt_max, /**< maximum tilt allowed for manual flight */
                    (ParamFloat<px4::params::MPC_LAND_ALT1>) _param_mpc_land_alt1, /**< altitude at which to start downwards slowdown */
                    (ParamFloat<px4::params::MPC_LAND_ALT2>) _param_mpc_land_alt2, /**< altitude below wich to land with land speed */
                    (ParamFloat<px4::params::MPC_LAND_SPEED>)
                    _param_mpc_land_speed, /**< desired downwards speed when approaching the ground */
                    (ParamFloat<px4::params::MPC_TKO_SPEED>)
                    _param_mpc_tko_speed /**< desired upwards speed when still close to the ground */
                       )
private:
    bool _isYawInput();
    void _unlockYaw();
    void _lockYaw();

    /**
     * Filter between stick input and yaw setpoint
     *
     * @param yawspeed_target yaw setpoint desired by the stick
     * @return filtered value from independent filter state
     */
    float _applyYawspeedFilter(float yawspeed_target);

    /**
     * Terrain following.
     * During terrain following, the position setpoint is adjusted
     * such that the distance to ground is kept constant.
     * @param apply_brake is true if user wants to break
     * @param stopped is true if vehicle has stopped moving in D-direction
     */
    void _terrainFollowing(bool apply_brake, bool stopped);

    /**
     * Minimum Altitude during range sensor operation.
     * If a range sensor is used for altitude estimates, for
     * best operation a minimum altitude is required. The minimum
     * altitude is only enforced during altitude lock.
     */
    void _respectMinAltitude();

    void _respectMaxAltitude();

    /**
     * Sets downwards velocity constraint based on the distance to ground.
     * To ensure a slowdown to land speed before hitting the ground.
     */
    void _respectGroundSlowdown();

    uORB::SubscriptionData<home_position_s> _sub_home_position{ORB_ID(home_position)};

    float _yawspeed_filter_state{}; /**< state of low-pass filter in rad/s */
    uint8_t _reset_counter = 0; /**< counter for estimator resets in z-direction */
    float _max_speed_up = 10.0f;
    float _min_speed_down = 1.0f;
    bool _terrain_follow{false}; /**< true when the vehicle is following the terrain height */
    bool _terrain_hold{false}; /**< true when vehicle is controlling height above a static ground position */

    /**
     * Distance to ground during terrain following.
     * If user does not demand velocity change in D-direction and the vehcile
     * is in terrain-following mode, then height to ground will be locked to
     * _dist_to_ground_lock.
     */
    float _dist_to_ground_lock = NAN;
};