ManualSmoothingXY.hpp

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/**
 * @file SmoothingXY.hpp
 *
 * This Class is used for smoothing the velocity setpoint in XY-direction.
 * The velocity setpoint is smoothed by applying a velocity change limit, which
 * we call acceleration. Depending on the user intention, the acceleration limit
 * will differ.
 * In manual mode we consider four states with different acceleration handling:
 * 1. user wants to stop
 * 2. user wants to quickly change direction
 * 3. user wants to accelerate
 * 4. user wants to decelerate
 */

#pragma once

#include <px4_platform_common/module_params.h>
#include <matrix/matrix/math.hpp>

class ManualSmoothingXY : public ModuleParams
{
public:
    ManualSmoothingXY(ModuleParams *parent, const matrix::Vector2f &vel);
    ~ManualSmoothingXY() = default;

    /**
     * Maximum velocity is required to detect user intention.
     * Maximum velocity depends on flight-task.
     * In order to deduce user intention from velocity, the maximum
     * allowed velocity has to be updated.
     * @param vel_max corresponds to vehicle constraint
     */
    void updateMaxVelocity(const float &vel_max) {_vel_max = vel_max;};

    /**
     * Smoothing of velocity setpoint horizontally based
     * on flight direction.
     * @param vel_sp: velocity setpoint in xy
     * @param dt: time delta in seconds
     */
    void smoothVelocity(matrix::Vector2f &vel_sp, const matrix::Vector2f &vel,  const float &yaw,
                const float &yawrate_sp, const float dt);

    /*
     * User intention.
     * - brake when user demands a brake
     * - acceleration when vehicle keeps speed or accelerates in the same direction
     * - deceleration when vehicle slows down in the same direction
     * - direction_change whne vehcile demands an abrupt direction change
     */
    enum class Intention {
        brake,
        acceleration,
        deceleration,
        direction_change
    };
    /**
     * Get user intention.
     * @see Intention
     */
    Intention getIntention() { return _intention; }

    /**
     *  Overwrite methods:
     *  Needed if different parameter values than default required.
     */
    void overwriteHoverAcceleration(float acc) { _param_mpc_acc_hor_max.set(acc); }
    void overwriteMaxAcceleration(float acc) { _param_mpc_acc_hor.set(acc); }
    void overwriteDecelerationMin(float dec) { _param_mpc_dec_hor_slow.set(dec); }
    void overwriteJerkMax(float jerk) { _param_mpc_jerk_max.set(jerk); }
    void overwriteJerkMin(float jerk) { _param_mpc_jerk_min.set(jerk); }

private:
    /**
     * Sets velocity change limits (=acceleration).
     * Depending on the user intention, the acceleration differs.
     * @param vel_sp is desired velocity setpoint before slewrate.
     * @param vel is current velocity in horizontal direction
     * @param yaw is vehicle yaw
     * @param yawrate_sp is desired yawspeed
     * @param dt is delta-time
     */
    void _updateAcceleration(matrix::Vector2f &vel_sp, const matrix::Vector2f &vel, const float &yaw,
                 const float &yawrate_sp, const float dt);

    /**
     * Gets user intention.
     * The intention is deduced from desired velocity setpoint.
     * @param vel_sp is desired velocity setpoint before slewrate.
     * @param vel is vehicle velocity in xy-direction.
     * @param yaw is vehicle yaw
     * @param yawrate_sp is the desired yaw-speed
     */
    Intention _getIntention(const matrix::Vector2f &vel_sp, const matrix::Vector2f &vel, const float &yaw,
                const float &yawrate_sp);

    /**
     * Set acceleration depending on Intention.
     * @param vel_sp is desired velocity septoint in xy-direction
     * @param vel is vehicle velociy in xy-direction
     * @param intention is the user intention during flight
     * @param dt is delta-time
     */
    void _setStateAcceleration(const matrix::Vector2f &vel_sp, const matrix::Vector2f &vel, const Intention &intention,
                   const float dt);

    /**
     * Limits the velocity setpoint change.
     * @param vel_sp that gets limited based on acceleration and previous velocity setpoint
     * @param dt is delta-time
     */
    void _velocitySlewRate(matrix::Vector2f &vel_sp, const float dt);

    /**
     * Rotate vector from local frame into heading frame.
     * @param vec is an arbitrary vector in local frame
     * @param yaw is the vehicle heading
     */
    matrix::Vector2f _getWorldToHeadingFrame(const matrix::Vector2f &vec, const float &yaw);

    /**
     * Rotate vector from heading frame to local frame.
     * @param vec is an arbitrary vector in heading frame
     * @param yaw is the vehicle yaw
     */
    matrix::Vector2f _getHeadingToWorldFrame(const matrix::Vector2f &vec, const float &yaw);

    Intention _intention{Intention::acceleration}; /**< user intention */
    float _acc_state_dependent; /**< velocity change limit that depends on Intention */
    float _jerk_state_dependent; /**< acceleration change limit during brake */
    float _vel_max{10.0f}; /**< maximum horizontal speed allowed */
    matrix::Vector2f _vel_sp_prev; /**< previous velocity setpoint */

    DEFINE_PARAMETERS(
        (ParamFloat<px4::params::MPC_ACC_HOR_MAX>) _param_mpc_acc_hor_max, /**< acceleration in hover */
        (ParamFloat<px4::params::MPC_ACC_HOR>) _param_mpc_acc_hor, /**< acceleration in flight */
        (ParamFloat<px4::params::MPC_DEC_HOR_SLOW>) _param_mpc_dec_hor_slow, /**< deceleration in flight */
        (ParamFloat<px4::params::MPC_JERK_MIN>) _param_mpc_jerk_min, /**< jerk min during brake */
        (ParamFloat<px4::params::MPC_JERK_MAX>) _param_mpc_jerk_max, /**< jerk max during brake */
        (ParamFloat<px4::params::MPC_VEL_MANUAL>) _param_mpc_vel_manual /**< maximum velocity in manual controlled mode */
    )
};