hello
Dependencies: AVEncoder QEI mbed-src-AV
main.cpp
- Committer:
- aduriseti
- Date:
- 2015-11-14
- Revision:
- 5:f9837617817b
- Parent:
- 4:453d534b1c1d
- Child:
- 6:32d9b855b90f
File content as of revision 5:f9837617817b:
//Micromouse code #include "mbed.h" #include "AVEncoder.h" // set things Serial pc(SERIAL_TX, SERIAL_RX); Ticker Systicker; Timer timer; PwmOut motor1_forward(PB_10); PwmOut motor1_reverse(PA_6); PwmOut motor2_forward(PA_7); PwmOut motor2_reverse(PB_6); // TODO: change our encoder pins from AnalogIn into: // otherwise, we can also use the AVEncoder thing as well. AVEncoder l_enco(PA_15, PB_3); AVEncoder r_enco(PA_1, PA_10); // gyro AnalogIn _gyro(PA_0); // AnalogIn gyro_cal(PC_1) ?? currently this isn't connected. //Left Front IR DigitalOut eLF(PC_3); AnalogIn rLF(PC_0); //PC_4 is an ADC //Left Side IR DigitalOut eLS(PC_2); AnalogIn rLS(PC_1); //Right Front IR DigitalOut eRF(PC_12); AnalogIn rRF(PA_4); //Right Side IR DigitalOut eRS(PC_15); AnalogIn rRS(PB_0); DigitalOut myled(LED1); // global variables. volatile float gyro_offset = 0; volatile float line_speed = 1; // currently is in terms of encoder pulses / ms. volatile float angl_speed = 0; // should not turn while moving forward. volatile float line_prevError = 0; volatile int enco_prevError = 0; volatile float gyro_prevError = 0; volatile float line_accumulator = 0; volatile float line_decayFactor = 1.5; volatile float enco_accumulator = 0; volatile float enco_decayFactor = 1.5; volatile float gyro_accumulator = 0; volatile float gyro_decayFactor = 1.5; volatile float left_speed = 0; volatile float right_speed = 0; volatile unsigned long l_pulses = 0; volatile unsigned long r_pulses = 0; // pid constants. these need to be tuned. but i set them as a default val for now. // line refers to the translational speed. // enco and gyro will be used primarily for angular speed. // (we can change the names later, // i added line in after i realized that i already had the angular code) const float line_propo = 1; const float line_integ = 0; const float line_deriv = 0; const float gyro_propo = 1; const float gyro_integ = 0; const float gyro_deriv = 0; const float enco_propo = 1; const float enco_integ = 0; const float enco_deriv = 0; const float spin_enco_weight = 0.5; const float spin_gyro_weight = 1 - spin_enco_weight; // this is just so that we can maintain what state our mouse is in. // currently this has no real use, but it may in the future. // or we could just remove this entirely. typedef enum { STOPPED, FORWARD, TURNING, UNKNOWN } STATE; STATE mouse_state; // helper functions void reset(); void offsetCalc(); void stop(); void moveForward(); void turn(); // interrupt stuff. void incLENC() { l_pulses++; } void incRENC() { r_pulses++; } // PID Control // this contains the simplistic PID control for the most part. // we do have to calibrate constants though. void systick() { pc.printf("systick ran\r\n"); if ( mouse_state == STOPPED || mouse_state == UNKNOWN ) { // do nothing? // reset? reset(); offsetCalc(); return; } pc.printf("systick ran while state is FORWARD \r\n"); int dt = timer.read_us(); // should be around 1 ms. timer.reset(); float line_error = line_speed * dt - 0.5 * ( l_enco.getPulses() - r_enco.getPulses()); int enco_error = l_enco.getPulses() - r_enco.getPulses(); float gyro_error = _gyro.read() - gyro_offset; line_accumulator += line_error; enco_accumulator += enco_error; gyro_accumulator += gyro_error; float line_pid = 0; line_pid += line_propo * line_error; line_pid += line_integ * line_accumulator; line_pid += line_deriv * (line_error - line_prevError)/dt; float enco_pid = 0; enco_pid += enco_propo * enco_error; enco_pid += enco_integ * enco_accumulator; enco_pid += enco_deriv * (enco_error - enco_prevError)/dt; float gyro_pid = 0; gyro_pid += gyro_propo * gyro_error; gyro_pid += gyro_integ * gyro_accumulator; gyro_pid += gyro_deriv * (gyro_error - gyro_prevError)/dt; // forward moving pid control. if ( mouse_state == FORWARD ) { float x_error = line_pid; float w_error = spin_enco_weight * enco_pid + spin_gyro_weight * gyro_pid; left_speed += x_error + w_error; right_speed += x_error - w_error; pc.printf("left_speed: %f, right_speed: %f\r\n", left_speed, right_speed); moveForward(); // offsetCalc(); } if ( mouse_state == TURNING ) { // nothing for now. if we turn in place, we assume no pid control. // this may have to change when we try curve turns. } line_prevError = line_error; enco_prevError = enco_error; gyro_prevError = gyro_error; line_accumulator /= line_decayFactor; enco_accumulator /= enco_decayFactor; gyro_accumulator /= gyro_decayFactor; reset(); } // setup stuff. void setup() { pc.printf("Hello World\r\n"); mouse_state = STOPPED; eRS = 0; eRF = 0; eLS = 0; eLF = 0; myled = 1; // repeat this for some time frame. for ( int i = 0; i < 200; i++ ) offsetCalc(); Systicker.attach_us(&systick, 1000); } void reset() { l_enco.reset(); r_enco.reset(); } // computes gyro_offset // uses a "weighted" average. // idea is that the current gyro offset is weighted more than previous ones. // uses the following y(n) = 1/2 * y(n-1) + 1/2 * x(n). // (therefore y(n) = sum of x(i)/2^i from i from 0 to n.) // this maintains that there will be some influence from previous factors, but keeps the current value at a higher weight. // currently this is only in the setup function. we can run this when the mouse is running in a line // when we figure out good line running pid. void offsetCalc() { gyro_offset = gyro_offset / 2 + _gyro.read() / 2; } int main() { setup(); mouse_state = FORWARD; wait(1.5); stop(); pc.printf("DONE\r\n"); //while(1) // { // pc.printf("The left motor is going at speed: %d\r\n", left_speed); // pc.printf("The left motor is going at speed: %d\r\n", right_speed); // wait(1); // } } // movement functions. void moveForward() { mouse_state = FORWARD; if ( left_speed > 0 ) // which should be always. { motor1_forward = left_speed; motor1_reverse = 0; } else { motor1_forward = 0; motor1_reverse = -left_speed; } if ( right_speed > 0 ) // which again should be always. { motor2_forward = right_speed; motor2_reverse = 0; } else { motor2_forward = 0; motor2_reverse = -right_speed; } } void stop() { mouse_state = STOPPED; motor1_forward = 1.0; motor1_reverse = 1.0; motor2_forward = 1.0; motor2_reverse = 1.0; } void turn()// maybe split this into two functions? { mouse_state = TURNING; float angle = 0; while (angle < 0.9) { float gyro_val = _gyro.read() - gyro_offset; angle += gyro_val; pc.printf("%f\r\n", angle); motor1_forward = 0.5; motor1_reverse = 0; motor2_forward = 0; motor2_reverse = 0.5; } }