Michael Ernst Peter / Mbed OS PM2_Example_Line_Follower

Example project for the Line Follower robot.

Dependencies:   PM2_Libary Eigen

main.cpp@42:b54a4f294aa9, 2022-05-06 (annotated)

Committer:
pmic
Date:
Fri May 06 10:33:36 2022 +0200
Revision:
42:b54a4f294aa9
Parent:
41:d8067ab9def5
Child:
43:5648b7083fe5
Running pretty fast and neat :-)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
pmic 33:cff70742569d 1 #include <mbed.h>
pmic 33:cff70742569d 2 #include <math.h>
pmic 33:cff70742569d 3
pmic 17:c19b471f05cb 4 #include "PM2_Libary.h"
pmic 40:eb7f8dce5787 5 #include "Eigen/Dense.h"
pmic 6:e1fa1a2d7483 6
pmic 34:702246639f02 7 # define M_PI 3.14159265358979323846 // number pi
pmic 33:cff70742569d 8
pmic 24:86f1a63e35a0 9 // logical variable main task
pmic 24:86f1a63e35a0 10 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
pmic 17:c19b471f05cb 11
pmic 24:86f1a63e35a0 12 // user button on nucleo board
pmic 24:86f1a63e35a0 13 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)
pmic 24:86f1a63e35a0 14 InterruptIn user_button(PC_13); // create InterruptIn interface object to evaluate user button falling and rising edge (no blocking code in ISR)
pmic 24:86f1a63e35a0 15 void user_button_pressed_fcn(); // custom functions which gets executed when user button gets pressed and released, definition below
pmic 24:86f1a63e35a0 16 void user_button_released_fcn();
pmic 6:e1fa1a2d7483 17
pmic 24:86f1a63e35a0 18 // while loop gets executed every main_task_period_ms milliseconds
pmic 34:702246639f02 19 int main_task_period_ms = 10; // define main task period time in ms e.g. 50 ms -> main task runns 20 times per second
pmic 24:86f1a63e35a0 20 Timer main_task_timer; // create Timer object which we use to run the main task every main task period time in ms
pmic 6:e1fa1a2d7483 21
pmic 24:86f1a63e35a0 22 // led on nucleo board
pmic 24:86f1a63e35a0 23 DigitalOut user_led(LED1); // create DigitalOut object to command user led
pmic 17:c19b471f05cb 24
pmic 38:6d11788e14c0 25 // Sharp GP2Y0A41SK0F, 4-40 cm IR Sensor
pmic 38:6d11788e14c0 26 float ir_distance_mV = 0.0f; // define variable to store measurement
pmic 38:6d11788e14c0 27 AnalogIn ir_analog_in(PC_2); // create AnalogIn object to read in infrared distance sensor, 0...3.3V are mapped to 0...1
pmic 38:6d11788e14c0 28
pmic 38:6d11788e14c0 29 // 78:1, 100:1, ... Metal Gearmotor 20Dx44L mm 12V CB
pmic 38:6d11788e14c0 30 DigitalOut enable_motors(PB_15); // create DigitalOut object to enable dc motors
pmic 38:6d11788e14c0 31
pmic 38:6d11788e14c0 32 float pwm_period_s = 0.00005f; // define pwm period time in seconds and create FastPWM objects to command dc motors
pmic 38:6d11788e14c0 33 FastPWM pwm_M1(PB_13); // motor M1 is closed-loop speed controlled (angle velocity)
pmic 38:6d11788e14c0 34 FastPWM pwm_M2(PA_9); // motor M2 is closed-loop speed controlled (angle velocity)
pmic 38:6d11788e14c0 35
pmic 38:6d11788e14c0 36 EncoderCounter encoder_M1(PA_6, PC_7); // create encoder objects to read in the encoder counter values
pmic 38:6d11788e14c0 37 EncoderCounter encoder_M2(PB_6, PB_7);
pmic 38:6d11788e14c0 38
pmic 38:6d11788e14c0 39 // create SpeedController and PositionController objects, default parametrization is for 78.125:1 gear box
pmic 38:6d11788e14c0 40 float max_voltage = 12.0f; // define maximum voltage of battery packs, adjust this to 6.0f V if you only use one batterypack
pmic 38:6d11788e14c0 41 float counts_per_turn = 20.0f * 78.125f; // define counts per turn at gearbox end: counts/turn * gearratio
pmic 38:6d11788e14c0 42 float kn = 180.0f / 12.0f; // define motor constant in rpm per V
pmic 38:6d11788e14c0 43 float k_gear = 100.0f / 78.125f; // define additional ratio in case you are using a dc motor with a different gear box, e.g. 100:1
pmic 38:6d11788e14c0 44 float kp = 0.1f; // define custom kp, this is the default speed controller gain for gear box 78.125:1
pmic 38:6d11788e14c0 45
pmic 38:6d11788e14c0 46 SpeedController speedController_M1(counts_per_turn, kn, max_voltage, pwm_M1, encoder_M1); // default 78.125:1 gear box with default contoller parameters
pmic 38:6d11788e14c0 47 SpeedController speedController_M2(counts_per_turn, kn, max_voltage, pwm_M2, encoder_M2); // default 78.125:1 gear box with default contoller parameters
pmic 38:6d11788e14c0 48 // SpeedController speedController_M2(counts_per_turn * k_gear, kn / k_gear, max_voltage, pwm_M2, encoder_M2); // parameters adjusted to 100:1 gear
pmic 38:6d11788e14c0 49
pmic 38:6d11788e14c0 50 // sparkfun line follower array
pmic 33:cff70742569d 51 I2C i2c(PB_9, PB_8); // I2C (PinName sda, PinName scl)
pmic 33:cff70742569d 52 SensorBar sensor_bar(i2c, 0.1175f);
pmic 20:7e7325edcf5c 53
pmic 42:b54a4f294aa9 54 // transformations and stuff
pmic 38:6d11788e14c0 55 float r_wheel = 0.0358f / 2.0f;
pmic 38:6d11788e14c0 56 float L_wheel = 0.143f;
pmic 42:b54a4f294aa9 57 Eigen::Matrix<float, 2, 2> Cwheel2robot; // transform wheel to robot
pmic 42:b54a4f294aa9 58 Eigen::Matrix<float, 2, 2> Crobot2wheel; // transform robot to wheel
pmic 42:b54a4f294aa9 59 Eigen::Matrix<float, 2, 1> robot_coord; // contains v and w
pmic 42:b54a4f294aa9 60 Eigen::Matrix<float, 2, 1> wheel_speed; // w1 w2
pmic 41:d8067ab9def5 61
pmic 42:b54a4f294aa9 62 float fcn_vel_cntrl(const float& vel_max, const float& vel_min, const float& ang_max, const float& ang);
pmic 42:b54a4f294aa9 63 float fcn_ang_cntrl(const float& Kp, const float& Kp_nl, const float& ang);
pmic 38:6d11788e14c0 64
pmic 1:93d997d6b232 65 int main()
pmic 41:d8067ab9def5 66 {
pmic 24:86f1a63e35a0 67 // attach button fall and rise functions to user button object
pmic 24:86f1a63e35a0 68 user_button.fall(&user_button_pressed_fcn);
pmic 24:86f1a63e35a0 69 user_button.rise(&user_button_released_fcn);
pmic 17:c19b471f05cb 70
pmic 29:d6f1ccf42a31 71 // start timer
pmic 24:86f1a63e35a0 72 main_task_timer.start();
pmic 6:e1fa1a2d7483 73
pmic 38:6d11788e14c0 74 // enable hardwaredriver dc motors: 0 -> disabled, 1 -> enabled
pmic 38:6d11788e14c0 75 enable_motors = 1;
pmic 6:e1fa1a2d7483 76
pmic 42:b54a4f294aa9 77 // initialise matrizes and vectros
pmic 42:b54a4f294aa9 78 Cwheel2robot << r_wheel / 2.0f , r_wheel / 2.0f ,
pmic 42:b54a4f294aa9 79 r_wheel / L_wheel, -r_wheel / L_wheel;
pmic 42:b54a4f294aa9 80 Crobot2wheel << 1.0f / r_wheel, L_wheel / (2.0f * r_wheel),
pmic 42:b54a4f294aa9 81 1.0f / r_wheel, -L_wheel / (2.0f * r_wheel);
pmic 42:b54a4f294aa9 82 robot_coord << 0.06f, 0.0f;
pmic 42:b54a4f294aa9 83 wheel_speed << 0.0f, 0.0f;
pmic 42:b54a4f294aa9 84
pmic 24:86f1a63e35a0 85 while (true) { // this loop will run forever
pmic 6:e1fa1a2d7483 86
pmic 24:86f1a63e35a0 87 main_task_timer.reset();
pmic 6:e1fa1a2d7483 88
pmic 24:86f1a63e35a0 89 if (do_execute_main_task) {
pmic 34:702246639f02 90
pmic 42:b54a4f294aa9 91 // read SensorBar
pmic 42:b54a4f294aa9 92 float sensor_bar_avgAngleRad = 0.0f;
pmic 42:b54a4f294aa9 93 if (sensor_bar.isAnyLedActive()) {
pmic 42:b54a4f294aa9 94 sensor_bar_avgAngleRad = sensor_bar.getAvgAngleRad();
pmic 42:b54a4f294aa9 95 }
pmic 42:b54a4f294aa9 96
pmic 42:b54a4f294aa9 97 // proportional controller for angle
pmic 42:b54a4f294aa9 98 //robot_coord(1) = 3.0f * sensor_bar_avgAngleRad;
pmic 42:b54a4f294aa9 99 // robot_coord(0) = fcn_vel_cntrl(0.10f, 0.02f, 27.0f * M_PI / 180.0f, sensor_bar_avgAngleRad);
pmic 42:b54a4f294aa9 100 // robot_coord(1) = fcn_ang_cntrl(2.0f, 5.0f, sensor_bar_avgAngleRad);
pmic 42:b54a4f294aa9 101 const static float vel_max = 0.30f; //0.10f;
pmic 42:b54a4f294aa9 102 const static float vel_min = 0.02f; //0.02f;
pmic 42:b54a4f294aa9 103 const static float ang_max = 27.0f * M_PI / 180.0f;
pmic 42:b54a4f294aa9 104 robot_coord(0) = fcn_vel_cntrl(vel_max, vel_min, ang_max, sensor_bar_avgAngleRad);
pmic 42:b54a4f294aa9 105 const static float Kp = 2.0f; //2.0f;
pmic 42:b54a4f294aa9 106 const static float Kp_nl = 17.0f; //10.0f; //5.0f;
pmic 42:b54a4f294aa9 107 robot_coord(1) = fcn_ang_cntrl(Kp, Kp_nl, sensor_bar_avgAngleRad);
pmic 42:b54a4f294aa9 108
pmic 42:b54a4f294aa9 109 // transform to robot coordinates
pmic 42:b54a4f294aa9 110 wheel_speed = Crobot2wheel * robot_coord;
pmic 42:b54a4f294aa9 111
pmic 38:6d11788e14c0 112 // read analog input
pmic 38:6d11788e14c0 113 ir_distance_mV = 1.0e3f * ir_analog_in.read() * 3.3f;
pmic 38:6d11788e14c0 114
pmic 42:b54a4f294aa9 115 //speedController_M1.setDesiredSpeedRPS(1.0f); // set a desired speed for speed controlled dc motors M1
pmic 42:b54a4f294aa9 116 //speedController_M2.setDesiredSpeedRPS(1.0f); // set a desired speed for speed controlled dc motors M2
pmic 42:b54a4f294aa9 117 speedController_M1.setDesiredSpeedRPS(wheel_speed(0) / (2.0f * M_PI)); // set a desired speed for speed controlled dc motors M1
pmic 42:b54a4f294aa9 118 speedController_M2.setDesiredSpeedRPS(wheel_speed(1) / (2.0f * M_PI)); // set a desired speed for speed controlled dc motors M2
pmic 38:6d11788e14c0 119
pmic 34:702246639f02 120 /*
pmic 34:702246639f02 121 uint8_t sensor_bar_raw_value = sensor_bar.getRaw();
pmic 34:702246639f02 122 for( int i = 7; i >= 0; i-- ) {
pmic 34:702246639f02 123 printf("%d", (sensor_bar_raw_value >> i) & 0x01);
pmic 34:702246639f02 124 }
pmic 34:702246639f02 125 printf(", ");
pmic 34:702246639f02 126 */
pmic 42:b54a4f294aa9 127
pmic 42:b54a4f294aa9 128 /*
pmic 34:702246639f02 129 int8_t sensor_bar_binaryPosition = sensor_bar.getBinaryPosition();
pmic 34:702246639f02 130 printf("%d, ", sensor_bar_binaryPosition);
pmic 34:702246639f02 131
pmic 34:702246639f02 132 uint8_t sensor_bar_nrOfLedsActive = sensor_bar.getNrOfLedsActive();
pmic 34:702246639f02 133 printf("%d, ", sensor_bar_nrOfLedsActive);
pmic 34:702246639f02 134
pmic 34:702246639f02 135 float sensor_bar_angleRad = 0.0f;
pmic 34:702246639f02 136 float sensor_bar_avgAngleRad = 0.0f;
pmic 34:702246639f02 137 if (sensor_bar.isAnyLedActive()) {
pmic 34:702246639f02 138 sensor_bar_angleRad = sensor_bar.getAngleRad();
pmic 34:702246639f02 139 sensor_bar_avgAngleRad = sensor_bar.getAvgAngleRad();
pmic 34:702246639f02 140 }
pmic 34:702246639f02 141 printf("%f, ", sensor_bar_angleRad * 180.0f / M_PI);
pmic 42:b54a4f294aa9 142 printf("%f, ", sensor_bar_avgAngleRad * 180.0f / M_PI);
pmic 42:b54a4f294aa9 143 */
pmic 42:b54a4f294aa9 144
pmic 42:b54a4f294aa9 145 printf("%f, %f\r\n", wheel_speed(0) / (2.0f * M_PI), wheel_speed(1) / (2.0f * M_PI));
pmic 34:702246639f02 146
pmic 1:93d997d6b232 147 } else {
pmic 6:e1fa1a2d7483 148
pmic 38:6d11788e14c0 149 ir_distance_mV = 0.0f;
pmic 38:6d11788e14c0 150
pmic 38:6d11788e14c0 151 speedController_M1.setDesiredSpeedRPS(0.0f);
pmic 38:6d11788e14c0 152 speedController_M2.setDesiredSpeedRPS(0.0f);
pmic 33:cff70742569d 153 }
pmic 6:e1fa1a2d7483 154
pmic 24:86f1a63e35a0 155 user_led = !user_led;
pmic 24:86f1a63e35a0 156
pmic 24:86f1a63e35a0 157 // do only output via serial what's really necessary (this makes your code slow)
pmic 33:cff70742569d 158 // printf("%d, %d\r\n", sensor_bar_raw_value_time_ms, sensor_bar_position_time_ms);
pmic 17:c19b471f05cb 159
pmic 24:86f1a63e35a0 160 // read timer and make the main thread sleep for the remaining time span (non blocking)
pmic 24:86f1a63e35a0 161 int main_task_elapsed_time_ms = std::chrono::duration_cast<std::chrono::milliseconds>(main_task_timer.elapsed_time()).count();
pmic 24:86f1a63e35a0 162 thread_sleep_for(main_task_period_ms - main_task_elapsed_time_ms);
pmic 1:93d997d6b232 163 }
pmic 1:93d997d6b232 164 }
pmic 6:e1fa1a2d7483 165
pmic 24:86f1a63e35a0 166 void user_button_pressed_fcn()
pmic 25:ea1d6e27c895 167 {
pmic 26:28693b369945 168 user_button_timer.start();
pmic 6:e1fa1a2d7483 169 user_button_timer.reset();
pmic 6:e1fa1a2d7483 170 }
pmic 6:e1fa1a2d7483 171
pmic 24:86f1a63e35a0 172 void user_button_released_fcn()
pmic 6:e1fa1a2d7483 173 {
pmic 24:86f1a63e35a0 174 // read timer and toggle do_execute_main_task if the button was pressed longer than the below specified time
pmic 24:86f1a63e35a0 175 int user_button_elapsed_time_ms = std::chrono::duration_cast<std::chrono::milliseconds>(user_button_timer.elapsed_time()).count();
pmic 6:e1fa1a2d7483 176 user_button_timer.stop();
pmic 24:86f1a63e35a0 177 if (user_button_elapsed_time_ms > 200) {
pmic 24:86f1a63e35a0 178 do_execute_main_task = !do_execute_main_task;
pmic 8:9bb806a7f585 179 }
pmic 42:b54a4f294aa9 180 }
pmic 42:b54a4f294aa9 181
pmic 42:b54a4f294aa9 182 float fcn_vel_cntrl(const float& vel_max, const float& vel_min, const float& ang_max, const float& ang)
pmic 42:b54a4f294aa9 183 {
pmic 42:b54a4f294aa9 184 const static float gain = (vel_min - vel_max) / ang_max;
pmic 42:b54a4f294aa9 185 const static float offset = vel_max;
pmic 42:b54a4f294aa9 186 return gain * fabs(ang) + offset;
pmic 42:b54a4f294aa9 187 }
pmic 42:b54a4f294aa9 188
pmic 42:b54a4f294aa9 189 float fcn_ang_cntrl(const float& Kp, const float& Kp_nl, const float& ang)
pmic 42:b54a4f294aa9 190 {
pmic 42:b54a4f294aa9 191 float retval = 0.0f;
pmic 42:b54a4f294aa9 192 if (ang > 0) {
pmic 42:b54a4f294aa9 193 retval = Kp * ang + Kp_nl * ang * ang;
pmic 42:b54a4f294aa9 194 } else if (ang < 0) {
pmic 42:b54a4f294aa9 195 retval = Kp * ang - Kp_nl * ang * ang;
pmic 42:b54a4f294aa9 196 }
pmic 42:b54a4f294aa9 197 return retval;
pmic 6:e1fa1a2d7483 198 }