/// @file AP_MotorsMulticopter.h
/// @brief Motor control class for Multicopters
#pragma once
#include "AP_Motors_Class.h"
#ifndef AP_MOTORS_DENSITY_COMP
#define AP_MOTORS_DENSITY_COMP 1
#endif
#define AP_MOTORS_DEFAULT_MID_THROTTLE 500
#define AP_MOTORS_SPIN_WHEN_ARMED 70 // spin motors at this PWM value when armed
#define AP_MOTORS_YAW_HEADROOM_DEFAULT 200
#define AP_MOTORS_THST_EXPO_DEFAULT 0.65f // set to 0 for linear and 1 for second order approximation
#define AP_MOTORS_THST_HOVER_DEFAULT 0.35f // the estimated hover throttle, 0 ~ 1
#define AP_MOTORS_THST_HOVER_TC 10.0f // time constant used to update estimated hover throttle, 0 ~ 1
#define AP_MOTORS_THST_HOVER_MIN 0.125f // minimum possible hover throttle
#define AP_MOTORS_THST_HOVER_MAX 0.6875f // maximum possible hover throttle
#define AP_MOTORS_SPIN_MIN_DEFAULT 0.15f // throttle out ratio which produces the minimum thrust. (i.e. 0 ~ 1 ) of the full throttle range
#define AP_MOTORS_SPIN_MAX_DEFAULT 0.95f // throttle out ratio which produces the maximum thrust. (i.e. 0 ~ 1 ) of the full throttle range
#define AP_MOTORS_SPIN_ARM_DEFAULT 0.10f // throttle out ratio which produces the armed spin rate. (i.e. 0 ~ 1 ) of the full throttle range
#define AP_MOTORS_BAT_VOLT_MAX_DEFAULT 0.0f // voltage limiting max default
#define AP_MOTORS_BAT_VOLT_MIN_DEFAULT 0.0f // voltage limiting min default (voltage dropping below this level will have no effect)
#define AP_MOTORS_BAT_CURR_MAX_DEFAULT 0.0f // current limiting max default
#define AP_MOTORS_BAT_CURR_TC_DEFAULT 5.0f // Time constant used to limit the maximum current
#define AP_MOTORS_BATT_VOLT_FILT_HZ 0.5f // battery voltage filtered at 0.5hz
// spool definition
#define AP_MOTORS_SPOOL_UP_TIME_DEFAULT 0.5f // time (in seconds) for throttle to increase from zero to min throttle, and min throttle to full throttle.
/// @class AP_MotorsMulticopter
class AP_MotorsMulticopter : public AP_Motors {
public:
// Constructor
AP_MotorsMulticopter(uint16_t loop_rate, uint16_t speed_hz = AP_MOTORS_SPEED_DEFAULT);
// output - sends commands to the motors
virtual void output();
// output_min - sends minimum values out to the motors
void output_min();
// set_yaw_headroom - set yaw headroom (yaw is given at least this amount of pwm)
void set_yaw_headroom(int16_t pwm) { _yaw_headroom = pwm; }
// set_throttle_range - sets the minimum throttle that will be sent to the engines when they're not off (i.e. to prevents issues with some motors spinning and some not at very low throttle)
// also sets minimum and maximum pwm values that will be sent to the motors
void set_throttle_range(int16_t radio_min, int16_t radio_max);
// update estimated throttle required to hover
void update_throttle_hover(float dt);
virtual float get_throttle_hover() const { return _throttle_hover; }
// spool up states
enum spool_up_down_mode {
SHUT_DOWN = 0, // all motors stop
SPIN_WHEN_ARMED = 1, // all motors at spin when armed
SPOOL_UP = 2, // increasing maximum throttle while stabilizing
THROTTLE_UNLIMITED = 3, // throttle is no longer constrained by start up procedure
SPOOL_DOWN = 4, // decreasing maximum throttle while stabilizing
};
// passes throttle directly to all motors for ESC calibration.
// throttle_input is in the range of 0 ~ 1 where 0 will send get_pwm_output_min() and 1 will send get_pwm_output_max()
void set_throttle_passthrough_for_esc_calibration(float throttle_input);
// get_lift_max - get maximum lift ratio - for logging purposes only
float get_lift_max() { return _lift_max; }
// get_batt_voltage_filt - get battery voltage ratio - for logging purposes only
float get_batt_voltage_filt() const { return _batt_voltage_filt.get(); }
// get_batt_resistance - get battery resistance approximation - for logging purposes only
float get_batt_resistance() const { return _batt_resistance; }
// get throttle limit imposed by battery current limiting. This is a number from 0 ~ 1 where 0 means hover throttle, 1 means full throttle (i.e. not limited)
float get_throttle_limit() const { return _throttle_limit; }
// returns maximum thrust in the range 0 to 1
float get_throttle_thrust_max() const { return _throttle_thrust_max; }
// return true if spool up is complete
bool spool_up_complete() const { return _spool_mode == THROTTLE_UNLIMITED; }
// output a thrust to all motors that match a given motor
// mask. This is used to control tiltrotor motors in forward
// flight. Thrust is in the range 0 to 1
void output_motor_mask(float thrust, uint8_t mask);
// get minimum or maximum pwm value that can be output to motors
int16_t get_pwm_output_min() const;
int16_t get_pwm_output_max() const;
// set thrust compensation callback
FUNCTOR_TYPEDEF(thrust_compensation_fn_t, void, float *, uint8_t);
void set_thrust_compensation_callback(thrust_compensation_fn_t callback) {
_thrust_compensation_callback = callback;
}
// var_info for holding Parameter information
static const struct AP_Param::GroupInfo var_info[];
protected:
// run spool logic
void output_logic();
// output_to_motors - sends commands to the motors
virtual void output_to_motors() = 0;
// update the throttle input filter
virtual void update_throttle_filter();
// return current_limit as a number from 0 ~ 1 in the range throttle_min to throttle_max
float get_current_limit_max_throttle();
// apply_thrust_curve_and_volt_scaling - returns throttle in the range 0 ~ 1
float apply_thrust_curve_and_volt_scaling(float thrust) const;
// update_lift_max_from_batt_voltage - used for voltage compensation
void update_lift_max_from_batt_voltage();
// update_battery_resistance - calculate battery resistance when throttle is above hover_out
void update_battery_resistance();
// return gain scheduling gain based on voltage and air density
float get_compensation_gain() const;
// convert thrust (0~1) range back to pwm range
int16_t calc_thrust_to_pwm(float thrust_in) const;
// calculate spin up to pwm range
int16_t calc_spin_up_to_pwm() const;
// apply any thrust compensation for the frame
virtual void thrust_compensation(void) {}
// save parameters as part of disarming
void save_params_on_disarm();
// enum values for HOVER_LEARN parameter
enum HoverLearn {
HOVER_LEARN_DISABLED = 0,
HOVER_LEARN_ONLY = 1,
HOVER_LEARN_AND_SAVE = 2
};
// parameters
AP_Int16 _yaw_headroom; // yaw control is given at least this pwm range
AP_Float _thrust_curve_expo; // curve used to linearize pwm to thrust conversion. set to 0 for linear and 1 for second order approximation
AP_Float _spin_min; // throttle out ratio which produces the minimum thrust. (i.e. 0 ~ 1 ) of the full throttle range
AP_Float _spin_max; // throttle out ratio which produces the maximum thrust. (i.e. 0 ~ 1 ) of the full throttle range
AP_Float _spin_arm; // throttle out ratio which produces the armed spin rate. (i.e. 0 ~ 1 ) of the full throttle range
AP_Float _batt_voltage_max; // maximum voltage used to scale lift
AP_Float _batt_voltage_min; // minimum voltage used to scale lift
AP_Float _batt_current_max; // current over which maximum throttle is limited
AP_Float _batt_current_time_constant; // Time constant used to limit the maximum current
AP_Int16 _pwm_min; // minimum PWM value that will ever be output to the motors (if 0, vehicle's throttle input channel's min pwm used)
AP_Int16 _pwm_max; // maximum PWM value that will ever be output to the motors (if 0, vehicle's throttle input channel's max pwm used)
AP_Float _throttle_hover; // estimated throttle required to hover throttle in the range 0 ~ 1
AP_Int8 _throttle_hover_learn; // enable/disabled hover thrust learning
AP_Int8 _disarm_disable_pwm; // disable PWM output while disarmed
// Maximum lean angle of yaw servo in degrees. This is specific to tricopter
AP_Float _yaw_servo_angle_max_deg;
// time to spool motors to min throttle
AP_Float _spool_up_time;
// motor output variables
bool motor_enabled[AP_MOTORS_MAX_NUM_MOTORS]; // true if motor is enabled
int16_t _throttle_radio_min; // minimum PWM from RC input's throttle channel (i.e. minimum PWM input from receiver, RC3_MIN)
int16_t _throttle_radio_max; // maximum PWM from RC input's throttle channel (i.e. maximum PWM input from receiver, RC3_MAX)
// spool variables
spool_up_down_mode _spool_mode; // motor's current spool mode
float _spin_up_ratio; // throttle percentage (0 ~ 1) between zero and throttle_min
// battery voltage, current and air pressure compensation variables
float _batt_voltage_resting; // battery voltage reading at minimum throttle
LowPassFilterFloat _batt_voltage_filt; // filtered battery voltage expressed as a percentage (0 ~ 1.0) of batt_voltage_max
float _batt_current_resting; // battery's current when motors at minimum
float _batt_resistance; // battery's resistance calculated by comparing resting voltage vs in flight voltage
int16_t _batt_timer; // timer used in battery resistance calcs
float _lift_max; // maximum lift ratio from battery voltage
float _throttle_limit; // ratio of throttle limit between hover and maximum
float _throttle_thrust_max; // the maximum allowed throttle thrust 0.0 to 1.0 in the range throttle_min to throttle_max
uint16_t _disarm_safety_timer;
// vehicle supplied callback for thrust compensation. Used for tiltrotors and tiltwings
thrust_compensation_fn_t _thrust_compensation_callback;
};