Michael Ernst Peter / Mbed OS PM2_Example_Line_Follower

Example project for the Line Follower robot.

Dependencies:   PM2_Libary Eigen

main.cpp@44:340cdc4b6e47, 2022-05-13 (annotated)

Committer:
pmic
Date:
Fri May 13 14:56:01 2022 +0200
Revision:
44:340cdc4b6e47
Parent:
43:5648b7083fe5
Child:
45:5e1dd4117ed2
Example with vector

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 44:340cdc4b6e47 3 #include <vector>
pmic 33:cff70742569d 4
pmic 17:c19b471f05cb 5 #include "PM2_Libary.h"
pmic 40:eb7f8dce5787 6 #include "Eigen/Dense.h"
pmic 6:e1fa1a2d7483 7
pmic 34:702246639f02 8 # define M_PI 3.14159265358979323846 // number pi
pmic 33:cff70742569d 9
pmic 24:86f1a63e35a0 10 // logical variable main task
pmic 24:86f1a63e35a0 11 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 12
pmic 24:86f1a63e35a0 13 // user button on nucleo board
pmic 24:86f1a63e35a0 14 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 15 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 16 void user_button_pressed_fcn(); // custom functions which gets executed when user button gets pressed and released, definition below
pmic 24:86f1a63e35a0 17 void user_button_released_fcn();
pmic 6:e1fa1a2d7483 18
pmic 24:86f1a63e35a0 19 // while loop gets executed every main_task_period_ms milliseconds
pmic 34:702246639f02 20 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 21 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 22
pmic 24:86f1a63e35a0 23 // led on nucleo board
pmic 24:86f1a63e35a0 24 DigitalOut user_led(LED1); // create DigitalOut object to command user led
pmic 17:c19b471f05cb 25
pmic 38:6d11788e14c0 26 // Sharp GP2Y0A41SK0F, 4-40 cm IR Sensor
pmic 38:6d11788e14c0 27 float ir_distance_mV = 0.0f; // define variable to store measurement
pmic 38:6d11788e14c0 28 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 29
pmic 38:6d11788e14c0 30 // 78:1, 100:1, ... Metal Gearmotor 20Dx44L mm 12V CB
pmic 38:6d11788e14c0 31 DigitalOut enable_motors(PB_15); // create DigitalOut object to enable dc motors
pmic 38:6d11788e14c0 32
pmic 38:6d11788e14c0 33 float pwm_period_s = 0.00005f; // define pwm period time in seconds and create FastPWM objects to command dc motors
pmic 38:6d11788e14c0 34 FastPWM pwm_M1(PB_13); // motor M1 is closed-loop speed controlled (angle velocity)
pmic 38:6d11788e14c0 35 FastPWM pwm_M2(PA_9); // motor M2 is closed-loop speed controlled (angle velocity)
pmic 38:6d11788e14c0 36
pmic 38:6d11788e14c0 37 EncoderCounter encoder_M1(PA_6, PC_7); // create encoder objects to read in the encoder counter values
pmic 38:6d11788e14c0 38 EncoderCounter encoder_M2(PB_6, PB_7);
pmic 38:6d11788e14c0 39
pmic 38:6d11788e14c0 40 // create SpeedController and PositionController objects, default parametrization is for 78.125:1 gear box
pmic 38:6d11788e14c0 41 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 42 float counts_per_turn = 20.0f * 78.125f; // define counts per turn at gearbox end: counts/turn * gearratio
pmic 38:6d11788e14c0 43 float kn = 180.0f / 12.0f; // define motor constant in rpm per V
pmic 38:6d11788e14c0 44 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 45 float kp = 0.1f; // define custom kp, this is the default speed controller gain for gear box 78.125:1
pmic 38:6d11788e14c0 46
pmic 44:340cdc4b6e47 47
pmic 44:340cdc4b6e47 48 //SpeedController speedController_M1(counts_per_turn, kn, max_voltage, pwm_M1, encoder_M1); // default 78.125:1 gear box with default contoller parameters
pmic 44:340cdc4b6e47 49 //SpeedController speedController_M2(counts_per_turn, kn, max_voltage, pwm_M2, encoder_M2); // default 78.125:1 gear box with default contoller parameters
pmic 43:5648b7083fe5 50 //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 51
pmic 44:340cdc4b6e47 52
pmic 44:340cdc4b6e47 53
pmic 38:6d11788e14c0 54 // sparkfun line follower array
pmic 33:cff70742569d 55 I2C i2c(PB_9, PB_8); // I2C (PinName sda, PinName scl)
pmic 33:cff70742569d 56 SensorBar sensor_bar(i2c, 0.1175f);
pmic 20:7e7325edcf5c 57
pmic 42:b54a4f294aa9 58 // transformations and stuff
pmic 38:6d11788e14c0 59 float r_wheel = 0.0358f / 2.0f;
pmic 38:6d11788e14c0 60 float L_wheel = 0.143f;
pmic 42:b54a4f294aa9 61 Eigen::Matrix<float, 2, 2> Cwheel2robot; // transform wheel to robot
pmic 42:b54a4f294aa9 62 Eigen::Matrix<float, 2, 2> Crobot2wheel; // transform robot to wheel
pmic 42:b54a4f294aa9 63 Eigen::Matrix<float, 2, 1> robot_coord; // contains v and w
pmic 42:b54a4f294aa9 64 Eigen::Matrix<float, 2, 1> wheel_speed; // w1 w2
pmic 41:d8067ab9def5 65
pmic 43:5648b7083fe5 66 float fcn_ang_cntrl(const float& Kp, const float& Kp_nl, const float& angle);
pmic 43:5648b7083fe5 67 float fcn_vel_cntrl_v1(const float& vel_max, const float& vel_min, const float& ang_max, const float& angle);
pmic 43:5648b7083fe5 68 float fcn_vel_cntrl_v2(float wheel_speed_max, float b, float robot_omega);
pmic 38:6d11788e14c0 69
pmic 1:93d997d6b232 70 int main()
pmic 44:340cdc4b6e47 71 {
pmic 44:340cdc4b6e47 72 //SpeedController* speedController_ptr[2];
pmic 44:340cdc4b6e47 73 //speedController_ptr[0] = new SpeedController(counts_per_turn, kn, max_voltage, pwm_M1, encoder_M1);
pmic 44:340cdc4b6e47 74 //speedController_ptr[1] = new SpeedController(counts_per_turn, kn, max_voltage, pwm_M2, encoder_M2);
pmic 44:340cdc4b6e47 75 std::vector<SpeedController*> speedController_ptr;
pmic 44:340cdc4b6e47 76 speedController_ptr.push_back( new SpeedController(counts_per_turn, kn, max_voltage, pwm_M1, encoder_M1) );
pmic 44:340cdc4b6e47 77 speedController_ptr.push_back( new SpeedController(counts_per_turn, kn, max_voltage, pwm_M2, encoder_M2) );
pmic 44:340cdc4b6e47 78
pmic 24:86f1a63e35a0 79 // attach button fall and rise functions to user button object
pmic 24:86f1a63e35a0 80 user_button.fall(&user_button_pressed_fcn);
pmic 24:86f1a63e35a0 81 user_button.rise(&user_button_released_fcn);
pmic 17:c19b471f05cb 82
pmic 29:d6f1ccf42a31 83 // start timer
pmic 24:86f1a63e35a0 84 main_task_timer.start();
pmic 6:e1fa1a2d7483 85
pmic 38:6d11788e14c0 86 // enable hardwaredriver dc motors: 0 -> disabled, 1 -> enabled
pmic 38:6d11788e14c0 87 enable_motors = 1;
pmic 6:e1fa1a2d7483 88
pmic 42:b54a4f294aa9 89 // initialise matrizes and vectros
pmic 42:b54a4f294aa9 90 Cwheel2robot << r_wheel / 2.0f , r_wheel / 2.0f ,
pmic 42:b54a4f294aa9 91 r_wheel / L_wheel, -r_wheel / L_wheel;
pmic 42:b54a4f294aa9 92 Crobot2wheel << 1.0f / r_wheel, L_wheel / (2.0f * r_wheel),
pmic 42:b54a4f294aa9 93 1.0f / r_wheel, -L_wheel / (2.0f * r_wheel);
pmic 42:b54a4f294aa9 94 robot_coord << 0.06f, 0.0f;
pmic 42:b54a4f294aa9 95 wheel_speed << 0.0f, 0.0f;
pmic 42:b54a4f294aa9 96
pmic 24:86f1a63e35a0 97 while (true) { // this loop will run forever
pmic 6:e1fa1a2d7483 98
pmic 24:86f1a63e35a0 99 main_task_timer.reset();
pmic 6:e1fa1a2d7483 100
pmic 24:86f1a63e35a0 101 if (do_execute_main_task) {
pmic 34:702246639f02 102
pmic 42:b54a4f294aa9 103 // read SensorBar
pmic 43:5648b7083fe5 104 static float sensor_bar_avgAngleRad = 0.0f; // by making this static it will not be overwritten (only fist time set to zero)
pmic 42:b54a4f294aa9 105 if (sensor_bar.isAnyLedActive()) {
pmic 42:b54a4f294aa9 106 sensor_bar_avgAngleRad = sensor_bar.getAvgAngleRad();
pmic 42:b54a4f294aa9 107 }
pmic 42:b54a4f294aa9 108
pmic 42:b54a4f294aa9 109 const static float Kp = 2.0f; //2.0f;
pmic 42:b54a4f294aa9 110 const static float Kp_nl = 17.0f; //10.0f; //5.0f;
pmic 42:b54a4f294aa9 111 robot_coord(1) = fcn_ang_cntrl(Kp, Kp_nl, sensor_bar_avgAngleRad);
pmic 42:b54a4f294aa9 112
pmic 43:5648b7083fe5 113 // nonlinear controllers version 1 (whatever came to my mind)
pmic 43:5648b7083fe5 114 /*
pmic 43:5648b7083fe5 115 const static float vel_max = 0.3374f; //0.10f;
pmic 43:5648b7083fe5 116 const static float vel_min = 0.00f; //0.02f;
pmic 43:5648b7083fe5 117 const static float ang_max = 27.0f * M_PI / 180.0f;
pmic 43:5648b7083fe5 118 robot_coord(0) = fcn_vel_cntrl_v1(vel_max, vel_min, ang_max, sensor_bar_avgAngleRad);
pmic 43:5648b7083fe5 119 */
pmic 43:5648b7083fe5 120
pmic 43:5648b7083fe5 121 // nonlinear controllers version 2 (one wheel always at full speed controller)
pmic 43:5648b7083fe5 122 ///*
pmic 43:5648b7083fe5 123 static float wheel_speed_max = max_voltage * kn / 60.0f * 2.0f * M_PI;
pmic 43:5648b7083fe5 124 static float b = L_wheel / (2.0f * r_wheel);
pmic 43:5648b7083fe5 125 robot_coord(0) = fcn_vel_cntrl_v2(wheel_speed_max, b, robot_coord(1));
pmic 43:5648b7083fe5 126 //*/
pmic 43:5648b7083fe5 127
pmic 42:b54a4f294aa9 128 // transform to robot coordinates
pmic 42:b54a4f294aa9 129 wheel_speed = Crobot2wheel * robot_coord;
pmic 42:b54a4f294aa9 130
pmic 38:6d11788e14c0 131 // read analog input
pmic 38:6d11788e14c0 132 ir_distance_mV = 1.0e3f * ir_analog_in.read() * 3.3f;
pmic 38:6d11788e14c0 133
pmic 44:340cdc4b6e47 134 speedController_ptr[0]->setDesiredSpeedRPS(wheel_speed(0) / (2.0f * M_PI)); // set a desired speed for speed controlled dc motors M1
pmic 44:340cdc4b6e47 135 speedController_ptr[1]->setDesiredSpeedRPS(wheel_speed(1) / (2.0f * M_PI)); // set a desired speed for speed controlled dc motors M2
pmic 38:6d11788e14c0 136
pmic 34:702246639f02 137 /*
pmic 34:702246639f02 138 uint8_t sensor_bar_raw_value = sensor_bar.getRaw();
pmic 34:702246639f02 139 for( int i = 7; i >= 0; i-- ) {
pmic 34:702246639f02 140 printf("%d", (sensor_bar_raw_value >> i) & 0x01);
pmic 34:702246639f02 141 }
pmic 34:702246639f02 142 printf(", ");
pmic 34:702246639f02 143 */
pmic 42:b54a4f294aa9 144
pmic 42:b54a4f294aa9 145 /*
pmic 34:702246639f02 146 int8_t sensor_bar_binaryPosition = sensor_bar.getBinaryPosition();
pmic 34:702246639f02 147 printf("%d, ", sensor_bar_binaryPosition);
pmic 34:702246639f02 148
pmic 34:702246639f02 149 uint8_t sensor_bar_nrOfLedsActive = sensor_bar.getNrOfLedsActive();
pmic 34:702246639f02 150 printf("%d, ", sensor_bar_nrOfLedsActive);
pmic 34:702246639f02 151
pmic 34:702246639f02 152 float sensor_bar_angleRad = 0.0f;
pmic 34:702246639f02 153 float sensor_bar_avgAngleRad = 0.0f;
pmic 34:702246639f02 154 if (sensor_bar.isAnyLedActive()) {
pmic 34:702246639f02 155 sensor_bar_angleRad = sensor_bar.getAngleRad();
pmic 34:702246639f02 156 sensor_bar_avgAngleRad = sensor_bar.getAvgAngleRad();
pmic 34:702246639f02 157 }
pmic 34:702246639f02 158 printf("%f, ", sensor_bar_angleRad * 180.0f / M_PI);
pmic 42:b54a4f294aa9 159 printf("%f, ", sensor_bar_avgAngleRad * 180.0f / M_PI);
pmic 42:b54a4f294aa9 160 */
pmic 42:b54a4f294aa9 161
pmic 42:b54a4f294aa9 162 printf("%f, %f\r\n", wheel_speed(0) / (2.0f * M_PI), wheel_speed(1) / (2.0f * M_PI));
pmic 34:702246639f02 163
pmic 1:93d997d6b232 164 } else {
pmic 6:e1fa1a2d7483 165
pmic 38:6d11788e14c0 166 ir_distance_mV = 0.0f;
pmic 38:6d11788e14c0 167
pmic 44:340cdc4b6e47 168 speedController_ptr[0]->setDesiredSpeedRPS(0.0f);
pmic 44:340cdc4b6e47 169 speedController_ptr[1]->setDesiredSpeedRPS(0.0f);
pmic 33:cff70742569d 170 }
pmic 6:e1fa1a2d7483 171
pmic 24:86f1a63e35a0 172 user_led = !user_led;
pmic 24:86f1a63e35a0 173
pmic 24:86f1a63e35a0 174 // do only output via serial what's really necessary (this makes your code slow)
pmic 33:cff70742569d 175 // printf("%d, %d\r\n", sensor_bar_raw_value_time_ms, sensor_bar_position_time_ms);
pmic 17:c19b471f05cb 176
pmic 24:86f1a63e35a0 177 // read timer and make the main thread sleep for the remaining time span (non blocking)
pmic 24:86f1a63e35a0 178 int main_task_elapsed_time_ms = std::chrono::duration_cast<std::chrono::milliseconds>(main_task_timer.elapsed_time()).count();
pmic 24:86f1a63e35a0 179 thread_sleep_for(main_task_period_ms - main_task_elapsed_time_ms);
pmic 1:93d997d6b232 180 }
pmic 1:93d997d6b232 181 }
pmic 6:e1fa1a2d7483 182
pmic 24:86f1a63e35a0 183 void user_button_pressed_fcn()
pmic 25:ea1d6e27c895 184 {
pmic 26:28693b369945 185 user_button_timer.start();
pmic 6:e1fa1a2d7483 186 user_button_timer.reset();
pmic 6:e1fa1a2d7483 187 }
pmic 6:e1fa1a2d7483 188
pmic 24:86f1a63e35a0 189 void user_button_released_fcn()
pmic 6:e1fa1a2d7483 190 {
pmic 24:86f1a63e35a0 191 // read timer and toggle do_execute_main_task if the button was pressed longer than the below specified time
pmic 24:86f1a63e35a0 192 int user_button_elapsed_time_ms = std::chrono::duration_cast<std::chrono::milliseconds>(user_button_timer.elapsed_time()).count();
pmic 6:e1fa1a2d7483 193 user_button_timer.stop();
pmic 24:86f1a63e35a0 194 if (user_button_elapsed_time_ms > 200) {
pmic 24:86f1a63e35a0 195 do_execute_main_task = !do_execute_main_task;
pmic 8:9bb806a7f585 196 }
pmic 42:b54a4f294aa9 197 }
pmic 42:b54a4f294aa9 198
pmic 43:5648b7083fe5 199 float fcn_ang_cntrl(const float& Kp, const float& Kp_nl, const float& angle)
pmic 43:5648b7083fe5 200 {
pmic 43:5648b7083fe5 201 float retval = 0.0f;
pmic 43:5648b7083fe5 202 if (angle > 0) {
pmic 43:5648b7083fe5 203 retval = Kp * angle + Kp_nl * angle * angle;
pmic 43:5648b7083fe5 204 } else if (angle < 0) {
pmic 43:5648b7083fe5 205 retval = Kp * angle - Kp_nl * angle * angle;
pmic 43:5648b7083fe5 206 }
pmic 43:5648b7083fe5 207 return retval;
pmic 43:5648b7083fe5 208 }
pmic 43:5648b7083fe5 209
pmic 43:5648b7083fe5 210 float fcn_vel_cntrl_v1(const float& vel_max, const float& vel_min, const float& ang_max, const float& angle)
pmic 42:b54a4f294aa9 211 {
pmic 42:b54a4f294aa9 212 const static float gain = (vel_min - vel_max) / ang_max;
pmic 42:b54a4f294aa9 213 const static float offset = vel_max;
pmic 43:5648b7083fe5 214 return gain * fabs(angle) + offset;
pmic 42:b54a4f294aa9 215 }
pmic 42:b54a4f294aa9 216
pmic 43:5648b7083fe5 217 float fcn_vel_cntrl_v2(float wheel_speed_max, float b, float robot_omega)
pmic 42:b54a4f294aa9 218 {
pmic 43:5648b7083fe5 219 static Eigen::Matrix<float, 2, 2> _wheel_speed;
pmic 43:5648b7083fe5 220 static Eigen::Matrix<float, 2, 2> _robot_coord;
pmic 43:5648b7083fe5 221 if (robot_omega > 0) {
pmic 43:5648b7083fe5 222 _wheel_speed(0) = wheel_speed_max;
pmic 43:5648b7083fe5 223 _wheel_speed(1) = wheel_speed_max - 2*b*robot_omega;
pmic 43:5648b7083fe5 224 } else {
pmic 43:5648b7083fe5 225 _wheel_speed(0) = wheel_speed_max + 2*b*robot_omega;
pmic 43:5648b7083fe5 226 _wheel_speed(1) = wheel_speed_max;
pmic 42:b54a4f294aa9 227 }
pmic 43:5648b7083fe5 228 _robot_coord = Cwheel2robot * _wheel_speed;
pmic 43:5648b7083fe5 229 return _robot_coord(0);
pmic 6:e1fa1a2d7483 230 }