ardupilot/libraries/AP_Motors/AP_MotorsHeli_Single.h

/// @file	AP_MotorsHeli_Single.h
/// @brief	Motor control class for traditional heli
#pragma once

#include <AP_Common/AP_Common.h>
#include <AP_Math/AP_Math.h>            // ArduPilot Mega Vector/Matrix math Library
#include <RC_Channel/RC_Channel.h>      // RC Channel Library
#include "AP_MotorsHeli.h"
#include "AP_MotorsHeli_RSC.h"

// rsc and aux function output channels
#define AP_MOTORS_HELI_SINGLE_RSC                              CH_8
#define AP_MOTORS_HELI_SINGLE_AUX                              CH_7

// servo position defaults
#define AP_MOTORS_HELI_SINGLE_SERVO1_POS                       -60
#define AP_MOTORS_HELI_SINGLE_SERVO2_POS                       60
#define AP_MOTORS_HELI_SINGLE_SERVO3_POS                       180

// swash type definitions
#define AP_MOTORS_HELI_SINGLE_SWASH_CCPM                       0
#define AP_MOTORS_HELI_SINGLE_SWASH_H1                         1

// tail types
#define AP_MOTORS_HELI_SINGLE_TAILTYPE_SERVO                   0
#define AP_MOTORS_HELI_SINGLE_TAILTYPE_SERVO_EXTGYRO           1
#define AP_MOTORS_HELI_SINGLE_TAILTYPE_DIRECTDRIVE_VARPITCH    2
#define AP_MOTORS_HELI_SINGLE_TAILTYPE_DIRECTDRIVE_FIXEDPITCH  3

// default direct-drive variable pitch tail defaults
#define AP_MOTORS_HELI_SINGLE_DDVPT_SPEED_DEFAULT              500
#define AP_MOTORS_HELI_SINGLE_DDVPT_RAMP_TIME                  2
#define AP_MOTORS_HELI_SINGLE_DDVPT_RUNUP_TIME                 3

// default external gyro gain
#define AP_MOTORS_HELI_SINGLE_EXT_GYRO_GAIN                    350

// COLYAW parameter min and max values
#define AP_MOTORS_HELI_SINGLE_COLYAW_RANGE             10.0f

/// @class      AP_MotorsHeli_Single
class AP_MotorsHeli_Single : public AP_MotorsHeli {
public:
    // constructor
    AP_MotorsHeli_Single(RC_Channel&    servo_aux,
                         uint16_t       loop_rate,
                         uint16_t       speed_hz = AP_MOTORS_HELI_SPEED_DEFAULT) :
        AP_MotorsHeli(loop_rate, speed_hz),
        _servo_aux(servo_aux),
        _main_rotor(RC_Channel_aux::k_heli_rsc, AP_MOTORS_HELI_SINGLE_RSC),
        _tail_rotor(RC_Channel_aux::k_heli_tail_rsc, AP_MOTORS_HELI_SINGLE_AUX),
        _swash_servo_1(CH_NONE), _swash_servo_2(CH_NONE), _swash_servo_3(CH_NONE), _yaw_servo(CH_NONE)
    {
        AP_Param::setup_object_defaults(this, var_info);
    };

    // set update rate to motors - a value in hertz
    // you must have setup_motors before calling this
    void set_update_rate(uint16_t speed_hz);

    // enable - starts allowing signals to be sent to motors and servos
    void enable();

    // output_test - spin a motor at the pwm value specified
    //  motor_seq is the motor's sequence number from 1 to the number of motors on the frame
    //  pwm value is an actual pwm value that will be output, normally in the range of 1000 ~ 2000
    void output_test(uint8_t motor_seq, int16_t pwm);

    // set_desired_rotor_speed - sets target rotor speed as a number from 0 ~ 1
    void set_desired_rotor_speed(float desired_speed);

    // get_main_rotor_speed - gets estimated or measured main rotor speed
    float get_main_rotor_speed() const { return _main_rotor.get_rotor_speed(); }

    // get_desired_rotor_speed - gets target rotor speed as a number from 0 ~ 1
    float get_desired_rotor_speed() const { return _main_rotor.get_desired_speed(); }

    // rotor_speed_above_critical - return true if rotor speed is above that critical for flight
    bool rotor_speed_above_critical() const { return _main_rotor.get_rotor_speed() > _main_rotor.get_critical_speed(); }

    // calculate_scalars - recalculates various scalars used
    void calculate_scalars();

    // calculate_armed_scalars - recalculates scalars that can change while armed
    void calculate_armed_scalars();
    
    // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
    //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
    uint16_t get_motor_mask();

    // ext_gyro_gain - set external gyro gain in range 0 ~ 1
    void ext_gyro_gain(float gain) { _ext_gyro_gain_std = gain * 1000.0f; }

    // has_flybar - returns true if we have a mechical flybar
    bool has_flybar() const { return _flybar_mode; }

    // supports_yaw_passthrought - returns true if we support yaw passthrough
    bool supports_yaw_passthrough() const { return _tail_type == AP_MOTORS_HELI_SINGLE_TAILTYPE_SERVO_EXTGYRO; }

    void set_acro_tail(bool set) { _acro_tail = set; }

    // parameter_check - returns true if helicopter specific parameters are sensible, used for pre-arm check
    bool parameter_check(bool display_msg) const;
    
    // var_info
    static const struct AP_Param::GroupInfo var_info[];

protected:

    // init_outputs - initialise Servo/PWM ranges and endpoints
    void init_outputs();

    // update_motor_controls - sends commands to motor controllers
    void update_motor_control(RotorControlState state);

    // calculate_roll_pitch_collective_factors - calculate factors based on swash type and servo position
    void calculate_roll_pitch_collective_factors();

    // heli_move_actuators - moves swash plate and tail rotor
    void move_actuators(float roll_out, float pitch_out, float coll_in, float yaw_out);

    // move_yaw - moves the yaw servo
    void move_yaw(float yaw_out);

    // write_aux - converts servo_out parameter value (0 to 1 range) to pwm and outputs to aux channel (ch7)
    void write_aux(float servo_out);

    // servo_test - move servos through full range of movement
    void servo_test();

    // external objects we depend upon
    RC_Channel&     _servo_aux;                 // output to ext gyro gain and tail direct drive esc (ch7)
    AP_MotorsHeli_RSC   _main_rotor;            // main rotor
    AP_MotorsHeli_RSC   _tail_rotor;            // tail rotor

    // internal variables
    float _oscillate_angle = 0.0f;              // cyclic oscillation angle, used by servo_test function
    float _servo_test_cycle_time = 0.0f;        // cycle time tracker, used by servo_test function
    float _collective_test = 0.0f;              // over-ride for collective output, used by servo_test function
    float _roll_test = 0.0f;                    // over-ride for roll output, used by servo_test function
    float _pitch_test = 0.0f;                   // over-ride for pitch output, used by servo_test function
    float _yaw_test = 0.0f;                     // over-ride for yaw output, used by servo_test function

    // parameters
    AP_Int16        _servo1_pos;                // Angular location of swash servo #1
    AP_Int16        _servo2_pos;                // Angular location of swash servo #2
    AP_Int16        _servo3_pos;                // Angular location of swash servo #3    
    AP_Int16        _tail_type;                 // Tail type used: Servo, Servo with external gyro, direct drive variable pitch or direct drive fixed pitch
    AP_Int8         _swash_type;                // Swash Type Setting - either 3-servo CCPM or H1 Mechanical Mixing
    AP_Int16        _ext_gyro_gain_std;         // PWM sent to external gyro on ch7 when tail type is Servo w/ ExtGyro
    AP_Int16        _ext_gyro_gain_acro;        // PWM sent to external gyro on ch7 when tail type is Servo w/ ExtGyro in ACRO
    AP_Int16        _phase_angle;               // Phase angle correction for rotor head.  If pitching the swash forward induces a roll, this can be correct the problem
    AP_Float        _collective_yaw_effect;     // Feed-forward compensation to automatically add rudder input when collective pitch is increased. Can be positive or negative depending on mechanics.
    AP_Int8         _flybar_mode;               // Flybar present or not.  Affects attitude controller used during ACRO flight mode
    AP_Int16        _direct_drive_tailspeed;    // Direct Drive VarPitch Tail ESC speed (0 ~ 1000)
    RC_Channel      _swash_servo_1;             // swash plate servo #1
    RC_Channel      _swash_servo_2;             // swash plate servo #2
    RC_Channel      _swash_servo_3;             // swash plate servo #3
    RC_Channel      _yaw_servo;                 // tail servo

    bool            _acro_tail = false;
};