/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
*/
/*
simple electric motor simulation class
*/
#pragma once
#include
#include
namespace SITL {
/*
class to describe a motor position
*/
class Motor {
public:
float angle;
float yaw_factor;
uint8_t servo;
uint8_t display_order;
// support for tilting motors
int8_t roll_servo = -1;
float roll_min, roll_max;
int8_t pitch_servo = -1;
float pitch_min, pitch_max;
// support for servo slew rate
enum {SERVO_NORMAL, SERVO_RETRACT} servo_type;
float servo_rate = 0.24; // seconds per 60 degrees
uint64_t last_change_usec;
float last_roll_value, last_pitch_value;
Motor(uint8_t _servo, float _angle, float _yaw_factor, uint8_t _display_order) :
angle(_angle), // angle in degrees from front
yaw_factor(_yaw_factor), // positive is clockwise
servo(_servo), // what servo output drives this motor
display_order(_display_order) // order for clockwise display
{
position.x = cosf(radians(angle));
position.y = sinf(radians(angle));
position.z = 0;
thrust_vector.x = 0;
thrust_vector.y = 0;
thrust_vector.z = -1;
}
/*
alternative constructor for tiltable motors
*/
Motor(uint8_t _servo, float _angle, float _yaw_factor, uint8_t _display_order,
int8_t _roll_servo, float _roll_min, float _roll_max,
int8_t _pitch_servo, float _pitch_min, float _pitch_max) :
angle(_angle), // angle in degrees from front
yaw_factor(_yaw_factor), // positive is clockwise
servo(_servo), // what servo output drives this motor
display_order(_display_order), // order for clockwise display
roll_servo(_roll_servo),
roll_min(_roll_min),
roll_max(_roll_max),
pitch_servo(_pitch_servo),
pitch_min(_pitch_min),
pitch_max(_pitch_max)
{
position.x = cosf(radians(angle));
position.y = sinf(radians(angle));
position.z = 0;
thrust_vector.x = 0;
thrust_vector.y = 0;
thrust_vector.z = -1;
}
void calculate_forces(const struct sitl_input &input,
uint8_t motor_offset,
Vector3f &torque, // Newton meters
Vector3f &thrust, // Z is down, Newtons
const Vector3f &velocity_air_bf,
const Vector3f &gyro, // rad/sec
float air_density,
float voltage,
bool use_drag);
uint16_t update_servo(uint16_t demand, uint64_t time_usec, float &last_value) const;
// get current
float get_current(void) const;
// convert a PWM value to a thrust demand from 0 to 1
float pwm_to_command(float pwm) const;
// setup motor key parameters
void setup_params(uint16_t _pwm_min, uint16_t _pwm_max, float _spin_min, float _spin_max, float _expo, float _slew_max,
float _diagonal_size, float _power_factor, float _voltage_max, float _effective_prop_area,
float _velocity_max, Vector3f _position, Vector3f _thrust_vector, float _yaw_factor,
float _true_prop_area, float _momentum_drag_coefficient);
// override slew limit
void set_slew_max(float _slew_max) {
slew_max = _slew_max;
}
float get_command(void) const {
return last_command;
}
// calculate thrust of motor
float calc_thrust(float command, float air_density, float velocity_in, float voltage_scale) const;
private:
float mot_pwm_min;
float mot_pwm_max;
float mot_spin_min;
float mot_spin_max;
float mot_expo;
float slew_max;
float current;
float power_factor;
float voltage_max;
float effective_prop_area;
float max_outflow_velocity;
float true_prop_area;
float momentum_drag_coefficient;
float diagonal_size;
float last_command;
uint64_t last_calc_us;
Vector3f position;
Vector3f thrust_vector;
};
}