text
stringlengths 0
715
|
---|
//core of the PID loop here, calculate the necessary motor power |
motorPower = kP * error + kI * integral + kD * derivative; |
///keep motor power variable in proper range, 0-1 |
if (motorPower > 1) motorPower = 1; |
if (motorPower < 0) motorPower = 0; |
//control the slew rate (dampen voltage differences), limits harsh acceleration |
float slewRate = 0.05f; |
if (motorPower > prevMotorPower + slewRate) { |
motorPower = prevMotorPower + slewRate; |
} |
if (motorPower < prevMotorPower - slewRate) { |
motorPower = prevMotorPower - slewRate; |
} |
//apply motor voltages |
LeftMotors.spin(forward, 12 * motorPower, volt); |
RightMotors.spin(reverse, 12 * motorPower, volt); |
//update final variables |
prevMotorPower = motorPower; |
prevError = error; |
//don't hog CPU |
wait(20, msec); |
} |
return 0; |
} |
int drivePID() { |
//drive straightforward with driveDistance as the distance, in degrees (for now) |
//forward PID constants: |
float kP1 = 0.0048;//.003 and 0 for other two |
float kI1 = 0.00003; |
float kD1 = 0.013; |
//turning PID constants: |
float kP2 = 0.001; |
float kI2 = 0.00; |
float kD2 = 0.00; |
//other variables for forward PID |
float error1 = 0; |
float integral1 = 0; |
float derivative1 = 0; |
float prevError1 = 0; |
//other variables for turn PID |
float error2 = 0; |
float integral2 = 0; |
float derivative2 = 0; |
float prevError2 = 0; |
//motor power variables |
float motorPower = 0; |
float prevMotorPower = 0; |
//lists |
std::vector<int> errorHistory; //keep track of error over time |
std::vector<float> powerHistory; //keep track of motor power over time |
int time = 0; |
float currentDist = 0; //the distance the robot is from its starting point |
RightMotors.setPosition(0, degrees); |
LeftMotors.setPosition(0, degrees); |
while(true) { |
currentDist = (RightMotors.position(degrees) + LeftMotors.position(degrees)) / 2; |
//calculate error / integral / derivative, of error vs time graph |
error1 = driveDistance - currentDist; |
if (std::abs(error1) < 200) { |
//weigh the integral double when error < 50 |
if (std::abs(error1) < 50) { |
integral1 += error1 * 2; |
} else { |
integral1 += error1; |
} |
} |
derivative1 = error1 - prevError1; |
error2 = RightMotors.position(degrees) - RightMotors.position(degrees); |
integral2 += error2; |
derivative2 = error2 - prevError2; |
//core of the PID loop here, calculate the necessary motor power, combine both PID loops |
motorPower = (kP1 * error1 + kI1 * integral1 + kD1 * derivative1); |
///keep motor power variable in proper range, -1 to 1 |
if (motorPower > 1) motorPower = 1; |
if (motorPower < -1) motorPower = -1; |
//control the slew rate (dampen voltage differences), limits harsh acceleration |
float slewRate = 0.08f; |
if (motorPower > prevMotorPower + slewRate) { |
motorPower = prevMotorPower + slewRate; |
} |
if (motorPower < prevMotorPower - slewRate) { |
motorPower = prevMotorPower - slewRate; |
} |
//apply motor voltages |
LeftMotors.spin(forward, 11 * motorPower * speedPID, volt); |
RightMotors.spin(forward, 11 * motorPower * speedPID, volt); |
//update final variables |
prevMotorPower = motorPower; |
prevError1 = error1; |
prevError2 = error2; |
//update histories |
errorHistory.push_back(error1); |
powerHistory.push_back(std::abs(motorPower)); |
time += 20; |
//break out of the loop if we have reached the target or B is pressed |
//we have reached the target if the error is less than 5 and the previous error is similar |
if (Controller1.ButtonB.pressing() || ((std::abs(error1) < 5) && std::abs(error1 - prevError1) < 2)) { |
break; |
} |
//don't hog CPU |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.