Landingslope.hpp

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/*
 * @file landingslope.h
 *
 * @author Thomas Gubler <thomasgubler@gmail.com>
 */

#ifndef LANDINGSLOPE_H_
#define LANDINGSLOPE_H_

#include <math.h>

class Landingslope
{
private:
    /* see Documentation/fw_landing.png for a plot of the landing slope */
    float _landing_slope_angle_rad{0.0f};       /**< phi in the plot */
    float _flare_relative_alt{0.0f};        /**< h_flare,rel in the plot */
    float _motor_lim_relative_alt{0.0f};
    float _H1_virt{0.0f};               /**< H1 in the plot */
    float _H0{0.0f};                /**< h_flare,rel + H1 in the plot */
    float _d1{0.0f};                /**< d1 in the plot */
    float _flare_constant{0.0f};
    float _flare_length{0.0f};          /**< d1 + delta d in the plot */
    float _horizontal_slope_displacement{0.0f}; /**< delta d in the plot */

    void calculateSlopeValues();

public:
    Landingslope() = default;
    ~Landingslope() = default;

    /**
     *
     * @return relative altitude of point on landing slope at distance to landing waypoint=wp_landing_distance
     */
    float getLandingSlopeRelativeAltitude(float wp_landing_distance);

    /**
     *
     * @return relative altitude of point on landing slope at distance to landing waypoint=wp_landing_distance
     * Performs check if aircraft is in front of waypoint to avoid climbout
     */
    float getLandingSlopeRelativeAltitudeSave(float wp_landing_distance, float bearing_lastwp_currwp,
            float bearing_airplane_currwp);

    /**
     *
     * @return Relative altitude of point on landing slope at distance to landing waypoint=wp_landing_distance
     */
    static float getLandingSlopeRelativeAltitude(float wp_landing_distance, float horizontal_slope_displacement,
            float landing_slope_angle_rad);

    /**
     *
     * @return Absolute altitude of point on landing slope at distance to landing waypoint=wp_landing_distance
     */
    static float getLandingSlopeAbsoluteAltitude(float wp_landing_distance, float wp_landing_altitude,
            float horizontal_slope_displacement, float landing_slope_angle_rad);

    /**
     *
     * @return distance to landing waypoint of point on landing slope at altitude=slope_altitude
     */
    static float getLandingSlopeWPDistance(float slope_altitude, float wp_landing_altitude,
                           float horizontal_slope_displacement, float landing_slope_angle_rad);

    float getFlareCurveRelativeAltitudeSave(float wp_landing_distance, float bearing_lastwp_currwp,
                        float bearing_airplane_currwp);

    void update(float landing_slope_angle_rad_new,
            float flare_relative_alt_new,
            float motor_lim_relative_alt_new,
            float H1_virt_new);


    float landing_slope_angle_rad() { return _landing_slope_angle_rad; }
    float flare_relative_alt() { return _flare_relative_alt; }
    float motor_lim_relative_alt() { return _motor_lim_relative_alt; }
    float flare_length() { return _flare_length; }
    float horizontal_slope_displacement() { return _horizontal_slope_displacement; }

};


#endif /* LANDINGSLOPE_H_ */