Example project for the Line Follower robot.
Dependencies: PM2_Libary Eigen
main.cpp
- Committer:
- pmic
- Date:
- 23 months ago
- Revision:
- 53:155c309f7d75
- Parent:
- 52:60a710ecc162
File content as of revision 53:155c309f7d75:
#include <mbed.h> #include <math.h> #include "PM2_Libary.h" #include "Eigen/Dense.h" #define NEW_PES_BOARD_VERSION #ifdef NEW_PES_BOARD_VERSION #define PN_enable_Motors PB_15 #define PN_pwm_M1 PB_13 #define PN_pwm_M2 PA_9 #define PN_encoder_M1_A PA_6 #define PN_encoder_M1_B PC_7 #define PN_encoder_M2_A PB_6 #define PN_encoder_M2_B PB_7 #else #define PN_enable_Motors PB_2 #define PN_pwm_M1 PA_8 #define PN_pwm_M2 PA_9 #define PN_encoder_M1_A PB_6 #define PN_encoder_M1_B PB_7 #define PN_encoder_M2_A PA_6 #define PN_encoder_M2_B PC_7 #endif #define M_PI 3.14159265358979323846 // number pi // logical variable main task bool do_execute_main_task = false; // this variable will be toggled via the user button (blue button) to or not to execute the main task // user button on nucleo board Timer user_button_timer; // create Timer object which we use to check if user button was pressed for a certain time (robust against signal bouncing) InterruptIn user_button(PC_13); // create InterruptIn interface object to evaluate user button falling and rising edge (no blocking code in ISR) void user_button_pressed_fcn(); // custom functions which gets executed when user button gets pressed and released, definition below void user_button_released_fcn(); // controller functions float ang_cntrl_fcn(const float& Kp, const float& Kp_nl, const float& angle); float vel_cntrl_v1_fcn(const float& vel_max, const float& vel_min, const float& ang_max, const float& angle); float vel_cntrl_v2_fcn(const float& wheel_speed_max, const float& b, const float& robot_omega, const Eigen::Matrix2f& Cwheel2robot); int main() { // while loop gets executed every main_task_period_ms milliseconds const int main_task_period_ms = 10; // define main task period time in ms e.g. 50 ms -> main task runns 20 times per second Timer main_task_timer; // create Timer object which we use to run the main task every main task period time in ms // led on nucleo board DigitalOut user_led(LED1); // create DigitalOut object to command user led // Sharp GP2Y0A41SK0F, 4-40 cm IR Sensor float ir_distance_mV = 0.0f; // define variable to store measurement AnalogIn ir_analog_in(PC_2); // create AnalogIn object to read in infrared distance sensor, 0...3.3V are mapped to 0...1 // 78:1, 100:1, ... Metal Gearmotor 20Dx44L mm 12V CB DigitalOut enable_motors(PN_enable_Motors); // create DigitalOut object to enable dc motors // create SpeedController objects FastPWM pwm_M1(PN_pwm_M1); // motor M1 is closed-loop speed controlled (angle velocity) FastPWM pwm_M2(PN_pwm_M2); // motor M2 is closed-loop speed controlled (angle velocity) EncoderCounter encoder_M1(PN_encoder_M1_A, PN_encoder_M1_B); // create encoder objects to read in the encoder counter values EncoderCounter encoder_M2(PN_encoder_M2_A, PN_encoder_M2_B); const float max_voltage = 12.0f; // define maximum voltage of battery packs, adjust this to 6.0f V if you only use one batterypack const float counts_per_turn = 20.0f * 78.125f; // define counts per turn at gearbox end: counts/turn * gearratio const float kn = 180.0f / 12.0f; // define motor constant in rpm per V // create SpeedController objects SpeedController* speedControllers[2]; speedControllers[0] = new SpeedController(counts_per_turn, kn, max_voltage, pwm_M1, encoder_M1); speedControllers[1] = new SpeedController(counts_per_turn, kn, max_voltage, pwm_M2, encoder_M2); //speedControllers[0]->setMaxAccelerationRPS(999.0f); // big number, so it is no doing anything //speedControllers[1]->setMaxAccelerationRPS(999.0f); // big number, so it is no doing anything // create SensorBar object for sparkfun line follower array I2C i2c(PB_9, PB_8); SensorBar sensor_bar(i2c, 0.1175f); // second input argument is distance from bar to wheel axis // robot kinematics const float r_wheel = 0.0358f / 2.0f; // wheel radius const float L_wheel = 0.143f; // distance from wheel to wheel Eigen::Matrix2f Cwheel2robot; // transform wheel to robot //Eigen::Matrix2f Crobot2wheel; // transform robot to wheel Cwheel2robot << r_wheel / 2.0f , r_wheel / 2.0f , r_wheel / L_wheel, -r_wheel / L_wheel; //Crobot2wheel << 1.0f / r_wheel, L_wheel / (2.0f * r_wheel), // 1.0f / r_wheel, -L_wheel / (2.0f * r_wheel); Eigen::Vector2f robot_coord; // contains v and w (robot translational and rotational velocities) Eigen::Vector2f wheel_speed; // w1 w2 (wheel speed) robot_coord.setZero(); wheel_speed.setZero(); // attach button fall and rise functions to user button object user_button.fall(&user_button_pressed_fcn); user_button.rise(&user_button_released_fcn); // start timer main_task_timer.start(); while (true) { // this loop will run forever main_task_timer.reset(); if (do_execute_main_task) { // enable hardwaredriver dc motors: 0 -> disabled, 1 -> enabled enable_motors = 1; // read SensorBar static float sensor_bar_avgAngleRad = 0.0f; // by making this static it will not be overwritten (only fist time set to zero) if (sensor_bar.isAnyLedActive()) { sensor_bar_avgAngleRad = sensor_bar.getAvgAngleRad(); } const static float Kp = 2.0f; // by making this const static it will not be overwritten and only initiliazed once const static float Kp_nl = 17.0f; robot_coord(1) = ang_cntrl_fcn(Kp, Kp_nl, sensor_bar_avgAngleRad); // nonlinear controllers version 1 (whatever came to my mind) /* const static float vel_max = 0.3374f; //0.10f; const static float vel_min = 0.00f; //0.02f; const static float ang_max = 27.0f * M_PI / 180.0f; robot_coord(0) = vel_cntrl_v1_fcn(vel_max, vel_min, ang_max, sensor_bar_avgAngleRad); */ // nonlinear controllers version 2 (one wheel always at full speed controller) ///* const static float wheel_speed_max = max_voltage * kn / 60.0f * 2.0f * M_PI; const static float b = L_wheel / (2.0f * r_wheel); robot_coord(0) = vel_cntrl_v2_fcn(wheel_speed_max, b, robot_coord(1), Cwheel2robot); //*/ // transform robot coordinates to wheel speed wheel_speed = Cwheel2robot.inverse() * robot_coord; // read analog input ir_distance_mV = 1.0e3f * ir_analog_in.read() * 3.3f; // command speedController objects speedControllers[0]->setDesiredSpeedRPS(wheel_speed(0) / (2.0f * M_PI)); // set a desired speed for speed controlled dc motors M1 speedControllers[1]->setDesiredSpeedRPS(wheel_speed(1) / (2.0f * M_PI)); // set a desired speed for speed controlled dc motors M2 } else { enable_motors = 0; ir_distance_mV = 0.0f; speedControllers[0]->setDesiredSpeedRPS(0.0f); speedControllers[1]->setDesiredSpeedRPS(0.0f); } user_led = !user_led; // do only output via serial what's really necessary (this makes your code slow) printf("%f, %f, %f\r\n", speedControllers[0]->getSpeedRPS(), speedControllers[1]->getSpeedRPS(), sensor_bar.getAvgAngleRad() * 180.0f / M_PI); // read timer and make the main thread sleep for the remaining time span (non blocking) int main_task_elapsed_time_ms = std::chrono::duration_cast<std::chrono::milliseconds>(main_task_timer.elapsed_time()).count(); thread_sleep_for(main_task_period_ms - main_task_elapsed_time_ms); } } void user_button_pressed_fcn() { user_button_timer.start(); user_button_timer.reset(); } void user_button_released_fcn() { // read timer and toggle do_execute_main_task if the button was pressed longer than the below specified time int user_button_elapsed_time_ms = std::chrono::duration_cast<std::chrono::milliseconds>(user_button_timer.elapsed_time()).count(); user_button_timer.stop(); if (user_button_elapsed_time_ms > 200) { do_execute_main_task = !do_execute_main_task; } } float ang_cntrl_fcn(const float& Kp, const float& Kp_nl, const float& angle) { static float retval = 0.0f; if (angle > 0) { retval = Kp * angle + Kp_nl * angle * angle; } else if (angle <= 0) { retval = Kp * angle - Kp_nl * angle * angle; } return retval; } float vel_cntrl_v1_fcn(const float& vel_max, const float& vel_min, const float& ang_max, const float& angle) { const static float gain = (vel_min - vel_max) / ang_max; const static float offset = vel_max; return gain * fabs(angle) + offset; } float vel_cntrl_v2_fcn(const float& wheel_speed_max, const float& b, const float& robot_omega, const Eigen::Matrix2f& Cwheel2robot) { static Eigen::Matrix<float, 2, 2> _wheel_speed; static Eigen::Matrix<float, 2, 2> _robot_coord; if (robot_omega > 0) { _wheel_speed(0) = wheel_speed_max; _wheel_speed(1) = wheel_speed_max - 2*b*robot_omega; } else { _wheel_speed(0) = wheel_speed_max + 2*b*robot_omega; _wheel_speed(1) = wheel_speed_max; } _robot_coord = Cwheel2robot * _wheel_speed; return _robot_coord(0); }