self-balancing-robot
Dependencies: mbed mbed-rtos Motor
Revision 41:b9c8d527dd2b, committed 2020-04-27
- Comitter:
- pandirimukund
- Date:
- Mon Apr 27 16:57:40 2020 +0000
- Parent:
- 39:80b565a355f3
- Commit message:
- added comments and cleaned up code
Changed in this revision
main.cpp | Show annotated file Show diff for this revision Revisions of this file |
--- a/main.cpp Mon Apr 27 16:28:16 2020 +0000 +++ b/main.cpp Mon Apr 27 16:57:40 2020 +0000 @@ -7,44 +7,52 @@ /////////////////////////////////////////////////////////////////////////////// ///////////////////////////// Variable Initialization////////////////////////// /////////////////////////////////////////////////////////////////////////////// -Ticker bluetooth; -Serial pc(USBTX, USBRX); +Serial pc(USBTX, USBRX); // serial setup for debug +// Setup mutexes for the parameters and the angle values Mutex parametersmutex; Mutex angleMutex; -Serial blue(p28, p27); + -LSM9DS1 imu(p9, p10, 0xD6, 0x3C); +Serial blue(p28, p27); // setup bluetooth device + +LSM9DS1 imu(p9, p10, 0xD6, 0x3C); // setup IMU /////////////////////////////////////////////////////////////////////////////// ///////////////////////////// Control System Variables///////////////////////// /////////////////////////////////////////////////////////////////////////////// -float rp = 50; -float rd = 60; -float ri = 20; -float desired_angle = 0; -volatile float speed = 0; -volatile float turnSpeed = 0; +// parameters for control system +float rp = 50; // proportion parameter +float rd = 60; // derivative parameter +float ri = 20; // integral parameter +float desired_angle = 0; // the angle the bot should lean at + +volatile float speed = 0; // speed of the robot +volatile float turnSpeed = 0; // turn speed when turning -float pAngle = 0; -float dAngle = 0; -float iAngle = 0; +float pAngle = 0; // angle error +float dAngle = 0; // change in angle error +float iAngle = 0; // integral of angle error -int time_segment = 5; //Update the speed every 5 milliseconds -void get_current_angle(); +float angleBias = 0; // the angle bias set during calibration -float angleBias = 0; - -Motor leftWheel(p21, p24, p23); // pwm, fwd, rev leftWheel(p21); -Motor rightWheel(p22, p25, p26); // pwm, fwd, rev rightWheel(p22); +Motor leftWheel(p21, p24, p23); // pwm, fwd, rev leftWheel(p21); +Motor rightWheel(p22, p25, p26); // pwm, fwd, rev rightWheel(p22); bool isTurning = false; + +/////////////////////////////////////////////////////////////////////////////// +///////////////////////////// Defining Function /////////////////////////////// +/////////////////////////////////////////////////////////////////////////////// +void get_current_angle(); + + /////////////////////////////////////////////////////////////////////////////// ///////////////////////////// Bluetooth Section /////////////////////////////// /////////////////////////////////////////////////////////////////////////////// @@ -55,57 +63,56 @@ if (blue.getc() == '!') { if (blue.getc() == 'B') { //button data packet bnum = blue.getc(); //button number - //pc.printf("%d",bnum); bhit = blue.getc(); //1=hit, 0=release - parametersmutex.lock(); + parametersmutex.lock(); // set mutex since parameters are being updated if (blue.getc() == char(~('!' + 'B' + bnum + bhit))) { //checksum OK? switch (bnum) { case '1': //number button 1 if (bhit == '1') { - rd += 1; + rd += 10; } else { //add release code here } break; case '2': //number button 2 if (bhit == '1') { - ri += 1; + ri += 10; } else { //add release code here } break; case '3': //number button 3 if (bhit == '1') { - rd -= 1; + rd -= 10; } else { //add release code here } break; case '4': //number button 4 if (bhit == '1') { - ri -= 1; + ri -= 10; } else { //add release code here } break; case '5': //button 5 up arrow if (bhit == '1') { - rp += 1; + rp += 10; } else { //add release code here } break; case '6': //button 6 down arrow if (bhit == '1') { - rp -= 1; + rp -= 10; } else { //add release code here } break; case '7': //button 7 left arrow if (bhit == '1') { -// desired_angle -= 1; - turnSpeed = .3; +// desired_angle -= 2; //uncomment to change desired angle on press + turnSpeed = .3; // comment to turn off turning isTurning = !isTurning; } else { //add release code here @@ -113,8 +120,8 @@ break; case '8': //button 8 right arrow if (bhit == '1') { -// desired_angle += 1; - turnSpeed = .3; +// desired_angle += 2; //uncomment to change desired angle on press + turnSpeed = .3; // comment to turn off turning isTurning = !isTurning; } else { //add release code here @@ -124,10 +131,10 @@ break; } } - parametersmutex.unlock(); + parametersmutex.unlock(); // unlocking parameters mutex } } - Thread::wait(100); + Thread::wait(100); // read bluetooth every tenth of a second } } @@ -135,10 +142,10 @@ ///////////////////////////// update motor speeds/////////////////////////// /////////////////////////////////////////////////////////////////////////////// void set_wheel_speed(float speed) { - if (isTurning) { + if (isTurning) { // set bot to turning if enabled leftWheel.speed(turnSpeed*(1)); rightWheel.speed(turnSpeed*(-1)); - } else { + } else { // otherwise set the wheel speeds to the current speeds and max out at 1 (library requirements) if(speed > 1) speed = 1; if (speed < -1) speed = -1; leftWheel.speed(speed*(-1)); @@ -154,15 +161,14 @@ //make the calls to IMU here and this should be another thread void update_system() { while(1){ - get_current_angle(); + get_current_angle(); // get the current angle from function - angleMutex.lock(); - speed = -1*(rp*pAngle + ri*iAngle + rd*dAngle)/(70 * 150 * 3); - set_wheel_speed(speed); - angleMutex.unlock(); + angleMutex.lock(); // going to update angle values so lock mutex + speed = -1*(rp*pAngle + ri*iAngle + rd*dAngle)/(70 * 150 * 3); //set the speed based on angle error values + set_wheel_speed(speed); // set the actual wheel speed + angleMutex.unlock(); // unlock the mutex - //pc.printf("this is running 100"); - Thread::wait(10); + Thread::wait(10); // update the sysetem every one hundreth of a second } } @@ -170,6 +176,8 @@ /////////////////////////////////////////////////////////////////////////////// ///////////////////////////// IMU STUFF//////////////////////////////////////// /////////////////////////////////////////////////////////////////////////////// + +//used to find the angle bias void calibrate_imu() { for(int i = 0; i < 500; i++){ imu.readGyro(); @@ -178,22 +186,23 @@ angleBias /= 500; } + + void get_current_angle() { -// return; - imu.readGyro(); - int gyro = -(imu.gy-angleBias) * .01; + imu.readGyro(); // read the gyro to get velocity of angle + int gyro = -(imu.gy-angleBias) * .01; // multiply by time to get the change in angle from before //pc.printf("gyro:%f",gyro); - angleMutex.lock(); - dAngle = pAngle; + angleMutex.lock(); // lock angle mutex + dAngle = pAngle; // save the old angle to be used later - pAngle += 1*gyro; //+ 0.02*acc; - pAngle -= desired_angle*70; + pAngle += 1*gyro; //+ 0.02*acc; //update the proportion error based on gyro + pAngle -= desired_angle*70; // get error based on the desired angle - 70 just random constant that worked well - dAngle = pAngle - dAngle; + dAngle = pAngle - dAngle; // get the change in angle error - iAngle += pAngle * 0.01; + iAngle += pAngle * 0.01; // update the integral of the angle error - angleMutex.unlock(); + angleMutex.unlock(); // unlock the mutex } @@ -204,23 +213,22 @@ /////////////////////////////////////////////////////////////////////////////// int main() { - pc.printf("this is running"); - + + // create the threads Thread bluetooth; Thread system_update; + // start and calibrate imu imu.begin(); calibrate_imu(); + + // start the threads bluetooth.start(bluetooth_update); system_update.start(update_system); - //bluetooth.attach(&bluetooth_update, 0.1); while (1) { - //bluetooth_update(); - //parametersmutex.lock(); -// pc.printf("rp: %f, rd: %f, ri: %f, desired_angle: %f\n", rp, rd, ri, desired_angle); -// parametersmutex.unlock(); + // print out values to debug angleMutex.lock(); pc.printf("pAngle: %f", pAngle/70); pc.printf(" speed: %f", speed); @@ -230,10 +238,8 @@ angleMutex.unlock(); - //get_current_angle(); - - Thread::wait(100); + Thread::wait(100); //print out 10 times a second } }