PID motor controll for the biorobotics project.
Dependents: PID_example Motor_calibration Demo_mode Demo_mode ... more
motor.h
- Committer:
- brass_phoenix
- Date:
- 2018-10-31
- Revision:
- 12:2c65bcbebf8a
- Parent:
- 10:d50c4957a193
- Child:
- 13:9be1857401f8
File content as of revision 12:2c65bcbebf8a:
#pragma once #include "mbed.h" #include "FastPWM.h" #include "MODSERIAL.h" #include "QEI.h" #include "pid.h" // Amount of motor encoder pulses per rotation. When using X4 encoding. const int PULSES_PER_ROTATION = 6533; const double MOTOR_THRESHOLD_RPS = 0.1; // Rad/s under which we send 0 to the motor, to prevent it from jittering around. const double MOTOR_STALL_PWM = 0.45; // PWM fraction above which the motor starts to move. class Motor { /// Rotates a motor to a given angle using PID control. /// Sets the pwm frequency to 60 HZ. private: const float PI = 3.14159265359; Ticker motor_ticker; FastPWM pwm_out; DigitalOut dir_out; QEI encoder; PID pid; // Reduction ratio of an extra gear box. // On top of the gear box in the motor. double extra_reduction_ratio; // How much our rotation frame is turned with respect to the "0" value // of the encoder. double rotation_frame_offset; double target_angle; // Maximum pwm fraction that this motor is allowed to output. double max_pwm_fraction; // For debugging purposes; Serial* pc; bool serial_debugging; int printcount; float pid_period; public: // Initializes the motor with the two driver pins, and the two encoder pins. Motor(PinName pwm_pin, PinName dir_pin, PinName encoder_a, PinName encoder_b, Serial* pc); // Initialize the motor without serial output. Motor(PinName pwm_pin, PinName dir_pin, PinName encoder_a, PinName encoder_b); // Set the angle the motor needs to rotate to. In radians. void set_target_angle(double angle); void set_pid_k_values(double k_p, double k_i, double k_d); // Reduction ratio of an extra gear box. // On top of the gear box in the motor. void set_extra_reduction_ratio(double ratio); void set_max_pwm_fraction(double fraction) { max_pwm_fraction = fraction; }; // Starts the motor controller with the specified update period. void start(float period); // Stops the motor immediately. void stop(); // Defines the current angle to be the given amount of radians. void define_current_angle_as_x_radians(double radians); // Returns the current angle of the motor. double get_current_angle(); private: void update(); // Updates the motor with the given speed. // The speed can be both positive and negative, in the range [-1, 1]. void update_motor_speed(double speed); double encoder_pulses_to_radians(int pulses); // Converts radians/s values into PWM values for motor controll. // Both positive and negative values. double radians_per_second_to_pwm(double rps); };