/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- #ifndef AC_POSCONTROL_H #define AC_POSCONTROL_H #include #include #include #include // PID library #include // PID library (2-axis) #include // P library #include // Inertial Navigation library #include "AC_AttitudeControl.h" // Attitude control library #include // motors library #include // common vehicle parameters // position controller default definitions #define POSCONTROL_THROTTLE_HOVER 500.0f // default throttle required to maintain hover #define POSCONTROL_ACCELERATION_MIN 50.0f // minimum horizontal acceleration in cm/s/s - used for sanity checking acceleration in leash length calculation #define POSCONTROL_ACCEL_XY 100.0f // default horizontal acceleration in cm/s/s. This is overwritten by waypoint and loiter controllers #define POSCONTROL_ACCEL_XY_MAX 980.0f // max horizontal acceleration in cm/s/s that the position velocity controller will ask from the lower accel controller #define POSCONTROL_STOPPING_DIST_Z_MAX 200.0f // max stopping distance vertically // should be 1.5 times larger than POSCONTROL_ACCELERATION. // max acceleration = max lean angle * 980 * pi / 180. i.e. 23deg * 980 * 3.141 / 180 = 393 cm/s/s #define POSCONTROL_JERK_LIMIT_CMSSS 1700.0f // default jerk limit on horizontal acceleration (unit: m/s/s/s) #define POSCONTROL_SPEED 500.0f // default horizontal speed in cm/s #define POSCONTROL_SPEED_DOWN -150.0f // default descent rate in cm/s #define POSCONTROL_SPEED_UP 250.0f // default climb rate in cm/s #define POSCONTROL_VEL_XY_MAX_FROM_POS_ERR 200.0f // max speed output from pos_to_vel controller when feed forward is used #define POSCONTROL_ACCEL_Z 250.0f // default vertical acceleration in cm/s/s. #define POSCONTROL_LEASH_LENGTH_MIN 100.0f // minimum leash lengths in cm #define POSCONTROL_DT_50HZ 0.02f // time difference in seconds for 50hz update rate #define POSCONTROL_DT_400HZ 0.0025f // time difference in seconds for 400hz update rate #define POSCONTROL_ACTIVE_TIMEOUT_MS 200 // position controller is considered active if it has been called within the past 0.2 seconds #define POSCONTROL_VEL_ERROR_CUTOFF_FREQ 4.0f // low-pass filter on velocity error (unit: hz) #define POSCONTROL_THROTTLE_CUTOFF_FREQ 2.0f // low-pass filter on accel error (unit: hz) #define POSCONTROL_ACCEL_FILTER_HZ 2.0f // low-pass filter on acceleration (unit: hz) #define POSCONTROL_JERK_RATIO 1.0f // Defines the time it takes to reach the requested acceleration #define POSCONTROL_OVERSPEED_GAIN_Z 2.0f // gain controlling rate at which z-axis speed is brought back within SPEED_UP and SPEED_DOWN range class AC_PosControl { public: /// Constructor AC_PosControl(const AP_AHRS& ahrs, const AP_InertialNav& inav, const AP_Motors& motors, AC_AttitudeControl& attitude_control, AC_P& p_pos_z, AC_P& p_vel_z, AC_PID& pid_accel_z, AC_P& p_pos_xy, AC_PI_2D& pi_vel_xy); // xy_mode - specifies behavior of xy position controller enum xy_mode { XY_MODE_POS_ONLY = 0, // position correction only (i.e. no velocity feed-forward) XY_MODE_POS_LIMITED_AND_VEL_FF, // for loiter - rate-limiting the position correction, velocity feed-forward XY_MODE_POS_AND_VEL_FF // for velocity controller - unlimied position correction, velocity feed-forward }; /// /// initialisation functions /// /// set_dt - sets time delta in seconds for all controllers (i.e. 100hz = 0.01, 400hz = 0.0025) /// updates z axis accel controller's D term filter void set_dt(float delta_sec); float get_dt() const { return _dt; } /// set_dt_xy - sets time delta in seconds for horizontal controller (i.e. 50hz = 0.02) void set_dt_xy(float dt_xy); float get_dt_xy() const { return _dt_xy; } /// /// z position controller /// /// set_alt_max - sets maximum altitude above home in cm /// only enforced when set_alt_target_from_climb_rate is used /// set to zero to disable limit void set_alt_max(float alt) { _alt_max = alt; } /// set_speed_z - sets maximum climb and descent rates /// speed_down can be positive or negative but will always be interpreted as a descent speed /// leash length will be recalculated the next time update_z_controller() is called void set_speed_z(float speed_down, float speed_up); /// get_speed_up - accessor for current up speed in cm/s float get_speed_up() const { return _speed_up_cms; } /// get_speed_down - accessors for current down speed in cm/s. Will be a negative number float get_speed_down() const { return _speed_down_cms; } /// get_vel_target_z - returns current vertical speed in cm/s float get_vel_target_z() const { return _vel_target.z; } /// set_accel_z - set vertical acceleration in cm/s/s /// leash length will be recalculated the next time update_z_controller() is called void set_accel_z(float accel_cmss); /// get_accel_z - returns current vertical acceleration in cm/s/s float get_accel_z() const { return _accel_z_cms; } /// calc_leash_length - calculates the vertical leash lengths from maximum speed, acceleration /// called by pos_to_rate_z if z-axis speed or accelerations are changed void calc_leash_length_z(); /// set_throttle_hover - update estimated throttle required to maintain hover void set_throttle_hover(float throttle) { _throttle_hover = throttle; } /// set_alt_target - set altitude target in cm above home void set_alt_target(float alt_cm) { _pos_target.z = alt_cm; } /// set_alt_target_with_slew - adjusts target towards a final altitude target /// should be called continuously (with dt set to be the expected time between calls) /// actual position target will be moved no faster than the speed_down and speed_up /// target will also be stopped if the motors hit their limits or leash length is exceeded void set_alt_target_with_slew(float alt_cm, float dt); /// set_alt_target_from_climb_rate - adjusts target up or down using a climb rate in cm/s /// should be called continuously (with dt set to be the expected time between calls) /// actual position target will be moved no faster than the speed_down and speed_up /// target will also be stopped if the motors hit their limits or leash length is exceeded /// set force_descend to true during landing to allow target to move low enough to slow the motors void set_alt_target_from_climb_rate(float climb_rate_cms, float dt, bool force_descend); /// set_alt_target_from_climb_rate_ff - adjusts target up or down using a climb rate in cm/s using feed-forward /// should be called continuously (with dt set to be the expected time between calls) /// actual position target will be moved no faster than the speed_down and speed_up /// target will also be stopped if the motors hit their limits or leash length is exceeded /// set force_descend to true during landing to allow target to move low enough to slow the motors void set_alt_target_from_climb_rate_ff(float climb_rate_cms, float dt, bool force_descend); /// add_takeoff_climb_rate - adjusts alt target up or down using a climb rate in cm/s /// should be called continuously (with dt set to be the expected time between calls) /// almost no checks are performed on the input void add_takeoff_climb_rate(float climb_rate_cms, float dt); /// set_alt_target_to_current_alt - set altitude target to current altitude void set_alt_target_to_current_alt() { _pos_target.z = _inav.get_altitude(); } /// relax_alt_hold_controllers - set all desired and targets to measured void relax_alt_hold_controllers(float throttle_setting); /// get_alt_target, get_desired_alt - get desired altitude (in cm above home) from loiter or wp controller which should be fed into throttle controller /// To-Do: remove one of the two functions below float get_alt_target() const { return _pos_target.z; } /// get_alt_error - returns altitude error in cm float get_alt_error() const; /// set_target_to_stopping_point_z - sets altitude target to reasonable stopping altitude in cm above home void set_target_to_stopping_point_z(); /// get_stopping_point_z - calculates stopping point based on current position, velocity, vehicle acceleration void get_stopping_point_z(Vector3f& stopping_point) const; /// init_takeoff - initialises target altitude if we are taking off void init_takeoff(); // is_active - returns true if the z-axis position controller has been run very recently bool is_active_z() const; /// update_z_controller - fly to altitude in cm above home void update_z_controller(); // get_leash_down_z, get_leash_up_z - returns vertical leash lengths in cm float get_leash_down_z() const { return _leash_down_z; } float get_leash_up_z() const { return _leash_up_z; } /// /// xy position controller /// /// init_xy_controller - initialise the xy controller /// sets target roll angle, pitch angle and I terms based on vehicle current lean angles /// should be called once whenever significant changes to the position target are made /// this does not update the xy target void init_xy_controller(bool reset_I = true); /// set_accel_xy - set horizontal acceleration in cm/s/s /// leash length will be recalculated the next time update_xy_controller() is called void set_accel_xy(float accel_cmss); float get_accel_xy() const { return _accel_cms; } /// set_speed_xy - set horizontal speed maximum in cm/s /// leash length will be recalculated the next time update_xy_controller() is called void set_speed_xy(float speed_cms); float get_speed_xy() const { return _speed_cms; } /// set_jerk_xy - set max horizontal jerk in cm/s/s/s void set_jerk_xy(float jerk_cmsss) { _jerk_cmsss = jerk_cmsss; } void set_jerk_xy_to_default() { _jerk_cmsss = POSCONTROL_JERK_LIMIT_CMSSS; } /// calc_leash_length - calculates the horizontal leash length given a maximum speed, acceleration /// should be called whenever the speed, acceleration or position kP is modified void calc_leash_length_xy(); /// get_pos_target - get target as position vector (from home in cm) const Vector3f& get_pos_target() const { return _pos_target; } /// set_pos_target in cm from home void set_pos_target(const Vector3f& position); /// set_xy_target in cm from home void set_xy_target(float x, float y); /// shift position target target in x, y axis void shift_pos_xy_target(float x_cm, float y_cm); /// get_desired_velocity - returns xy desired velocity (i.e. feed forward) in cm/s in lat and lon direction const Vector3f& get_desired_velocity() { return _vel_desired; } /// set_desired_velocity_z - sets desired velocity in cm/s in z axis void set_desired_velocity_z(float vel_z_cms) {_vel_desired.z = vel_z_cms;} /// set_desired_velocity_xy - sets desired velocity in cm/s in lat and lon directions /// when update_xy_controller is next called the position target is moved based on the desired velocity and /// the desired velocities are fed forward into the rate_to_accel step void set_desired_velocity_xy(float vel_lat_cms, float vel_lon_cms) {_vel_desired.x = vel_lat_cms; _vel_desired.y = vel_lon_cms; } /// set_desired_velocity - sets desired velocity in cm/s in all 3 axis /// when update_vel_controller_xyz is next called the position target is moved based on the desired velocity void set_desired_velocity(const Vector3f &des_vel) { _vel_desired = des_vel; freeze_ff_xy(); } /// freeze_ff_z - used to stop the feed forward being calculated during a known discontinuity void freeze_ff_z() { _flags.freeze_ff_z = true; } /// freeze_ff_xy - used to stop the feed forward being calculated during a known discontinuity void freeze_ff_xy() { _flags.freeze_ff_xy = true; } // is_active_xy - returns true if the xy position controller has been run very recently bool is_active_xy() const; /// update_xy_controller - run the horizontal position controller - should be called at 100hz or higher /// when use_desired_velocity is true the desired velocity (i.e. feed forward) is incorporated at the pos_to_rate step void update_xy_controller(xy_mode mode, float ekfNavVelGainScaler, bool use_althold_lean_angle); /// set_target_to_stopping_point_xy - sets horizontal target to reasonable stopping position in cm from home void set_target_to_stopping_point_xy(); /// get_stopping_point_xy - calculates stopping point based on current position, velocity, vehicle acceleration /// distance_max allows limiting distance to stopping point /// results placed in stopping_position vector /// set_accel_xy() should be called before this method to set vehicle acceleration /// set_leash_length() should have been called before this method void get_stopping_point_xy(Vector3f &stopping_point) const; /// get_distance_to_target - get horizontal distance to position target in cm (used for reporting) float get_distance_to_target() const; /// xyz velocity controller /// init_vel_controller_xyz - initialise the velocity controller - should be called once before the caller attempts to use the controller void init_vel_controller_xyz(); /// update_velocity_controller_xyz - run the velocity controller - should be called at 100hz or higher /// velocity targets should we set using set_desired_velocity_xyz() method /// callers should use get_roll() and get_pitch() methods and sent to the attitude controller /// throttle targets will be sent directly to the motors void update_vel_controller_xyz(float ekfNavVelGainScaler); /// get desired roll, pitch which should be fed into stabilize controllers float get_roll() const { return _roll_target; } float get_pitch() const { return _pitch_target; } // get_leash_xy - returns horizontal leash length in cm float get_leash_xy() const { return _leash; } /// get_pos_xy_kP - returns xy position controller's kP gain float get_pos_xy_kP() const { return _p_pos_xy.kP(); } /// accessors for reporting const Vector3f& get_vel_target() const { return _vel_target; } const Vector3f& get_accel_target() const { return _accel_target; } // lean_angles_to_accel - convert roll, pitch lean angles to lat/lon frame accelerations in cm/s/s void lean_angles_to_accel(float& accel_x_cmss, float& accel_y_cmss) const; // time_since_last_xy_update - returns time in seconds since the horizontal position controller was last run float time_since_last_xy_update() const; static const struct AP_Param::GroupInfo var_info[]; private: // general purpose flags struct poscontrol_flags { uint16_t recalc_leash_z : 1; // 1 if we should recalculate the z axis leash length uint16_t recalc_leash_xy : 1; // 1 if we should recalculate the xy axis leash length uint16_t reset_desired_vel_to_pos : 1; // 1 if we should reset the rate_to_accel_xy step uint16_t reset_rate_to_accel_xy : 1; // 1 if we should reset the rate_to_accel_xy step uint16_t reset_accel_to_lean_xy : 1; // 1 if we should reset the accel to lean angle step uint16_t reset_rate_to_accel_z : 1; // 1 if we should reset the rate_to_accel_z step uint16_t reset_accel_to_throttle : 1; // 1 if we should reset the accel_to_throttle step of the z-axis controller uint16_t freeze_ff_xy : 1; // 1 use to freeze feed forward during step updates uint16_t freeze_ff_z : 1; // 1 used to freeze velocity to accel feed forward for one iteration uint16_t use_desvel_ff_z : 1; // 1 to use z-axis desired velocity as feed forward into velocity step } _flags; // limit flags structure struct poscontrol_limit_flags { uint8_t pos_up : 1; // 1 if we have hit the vertical position leash limit while going up uint8_t pos_down : 1; // 1 if we have hit the vertical position leash limit while going down uint8_t vel_up : 1; // 1 if we have hit the vertical velocity limit going up uint8_t vel_down : 1; // 1 if we have hit the vertical velocity limit going down uint8_t accel_xy : 1; // 1 if we have hit the horizontal accel limit } _limit; /// /// z controller private methods /// // pos_to_rate_z - position to rate controller for Z axis // target altitude should be placed into _pos_target.z using or set with one of these functions // set_alt_target // set_target_to_stopping_point_z // init_takeoff void pos_to_rate_z(); // rate_to_accel_z - calculates desired accel required to achieve the velocity target void rate_to_accel_z(); // accel_to_throttle - alt hold's acceleration controller void accel_to_throttle(float accel_target_z); /// /// xy controller private methods /// /// desired_vel_to_pos - move position target using desired velocities void desired_vel_to_pos(float nav_dt); /// pos_to_rate_xy - horizontal position error to velocity controller /// converts position (_pos_target) to target velocity (_vel_target) /// when use_desired_rate is set to true: /// desired velocity (_vel_desired) is combined into final target velocity and /// velocity due to position error is reduce to a maximum of 1m/s void pos_to_rate_xy(xy_mode mode, float dt, float ekfNavVelGainScaler); /// rate_to_accel_xy - horizontal desired rate to desired acceleration /// converts desired velocities in lat/lon directions to accelerations in lat/lon frame void rate_to_accel_xy(float dt, float ekfNavVelGainScaler); /// accel_to_lean_angles - horizontal desired acceleration to lean angles /// converts desired accelerations provided in lat/lon frame to roll/pitch angles void accel_to_lean_angles(float dt_xy, float ekfNavVelGainScaler, bool use_althold_lean_angle); /// calc_leash_length - calculates the horizontal leash length given a maximum speed, acceleration and position kP gain float calc_leash_length(float speed_cms, float accel_cms, float kP) const; // references to inertial nav and ahrs libraries const AP_AHRS& _ahrs; const AP_InertialNav& _inav; const AP_Motors& _motors; AC_AttitudeControl& _attitude_control; // references to pid controllers AC_P& _p_pos_z; AC_P& _p_vel_z; AC_PID& _pid_accel_z; AC_P& _p_pos_xy; AC_PI_2D& _pi_vel_xy; // parameters AP_Float _accel_xy_filt_hz; // XY acceleration filter cutoff frequency // internal variables float _dt; // time difference (in seconds) between calls from the main program float _dt_xy; // time difference (in seconds) between update_xy_controller and update_vel_controller_xyz calls uint32_t _last_update_xy_ms; // system time of last update_xy_controller call uint32_t _last_update_z_ms; // system time of last update_z_controller call float _throttle_hover; // estimated throttle required to maintain a level hover float _speed_down_cms; // max descent rate in cm/s float _speed_up_cms; // max climb rate in cm/s float _speed_cms; // max horizontal speed in cm/s float _accel_z_cms; // max vertical acceleration in cm/s/s float _accel_last_z_cms; // max vertical acceleration in cm/s/s float _accel_cms; // max horizontal acceleration in cm/s/s float _jerk_cmsss; // max horizontal jerk in cm/s/s/s float _leash; // horizontal leash length in cm. target will never be further than this distance from the vehicle float _leash_down_z; // vertical leash down in cm. target will never be further than this distance below the vehicle float _leash_up_z; // vertical leash up in cm. target will never be further than this distance above the vehicle // output from controller float _roll_target; // desired roll angle in centi-degrees calculated by position controller float _pitch_target; // desired roll pitch in centi-degrees calculated by position controller // position controller internal variables Vector3f _pos_target; // target location in cm from home Vector3f _pos_error; // error between desired and actual position in cm Vector3f _vel_desired; // desired velocity in cm/s Vector3f _vel_target; // velocity target in cm/s calculated by pos_to_rate step Vector3f _vel_error; // error between desired and actual acceleration in cm/s Vector3f _vel_last; // previous iterations velocity in cm/s Vector3f _accel_target; // desired acceleration in cm/s/s // To-Do: are xy actually required? Vector3f _accel_error; // desired acceleration in cm/s/s // To-Do: are xy actually required? Vector3f _accel_feedforward; // feedforward acceleration in cm/s/s float _alt_max; // max altitude - should be updated from the main code with altitude limit from fence float _distance_to_target; // distance to position target - for reporting only LowPassFilterFloat _vel_error_filter; // low-pass-filter on z-axis velocity error Vector2f _accel_target_jerk_limited; // acceleration target jerk limited to 100deg/s/s LowPassFilterVector2f _accel_target_filter; // acceleration target filter }; #endif // AC_POSCONTROL_H