299 lines
11 KiB
C++
299 lines
11 KiB
C++
#include <Arduino.h>
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//#include <DMXSerial.h>
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#include <PID_v1.h>
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#include <PWM.h>
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// Motor Driver: IBT-2 (BTS7960)
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#define LPWM_PIN 9 // LPWM for CCW motion (postive)
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#define RPWM_PIN 10 // RPWM for CW motion (negative)
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#define L_EN_PIN 11 // Both enable pins must be high to drive motor
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#define R_EN_PIN 12 // Both enable pins must be high to drive motor
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// Encoder p/n: e38s6g5-600b-g24n
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#define ENCODER_A 2
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#define ENCODER_B 3
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// LED indicators to follow motor pwm output
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#define LLED_PIN 5
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#define RLED_PIN 6
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#define ENCODER_PPR 6000 // pulses per revolution
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#define ENCODER_RATIO 1.0f // number of times encoder spins per revolution of wall
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#define MOTOR_RATIO 5.0f // number of time motor spins per revolution of wall
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#define MOTOR_MAX_RPM 330.0f // p/n MY1016Z3 rated 300 rpm @ 24VDC; enter measured value
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#define MOTOR_MIN_PWM 30 // enter value required for motor to start turning
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#define MAX_MOTOR_ACCELERATION (MOTOR_MAX_RPM / 5.0f) // (RPM/s): 0 to max in 0.5s
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#define MAX_WALL_ACCELERATION MAX_MOTOR_ACCELERATION / MOTOR_RATIO
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#define WALL_POSITION_TOLERANCE 0.00056 // acceptable error in wall position (2 degrees = 0.0056 rev)
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#define SAMPLE_RATE 100.0f // min time (ms) between velocity calculations
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#define LOOP_RATE 100.0f // min time (ms) between control adjustments. ** Must be >= SAMPLE_RATE **
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const int DMX_CHANNEL = 1;
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long encoderPosition = 0; // raw count from encoder
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double maxWallVelocity = MOTOR_MAX_RPM / MOTOR_RATIO;
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double currentPosition = 0; // wall (revolutions)
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double prevPosition = 0; // wall (revolutions)
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double targetPosition = 0; // wall (revolutions)
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double currentVelocity = 0; // wall velocity (rpm)
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double targetMotorVelocity = 0; // motor velocity (rpm)
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unsigned long prevSample = 0; // time tracker for sensor sampling rate
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unsigned long prevControl = 0; // time tracker for control loop
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double remainingDistance = 0; // wall distance from current to target (revolutions)
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double remainingTime = 0; // estimate of time to get from current position to target (s)
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double stopTime = 0; // estimate of time to decelerate to zero
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int motorPWM = 0; // motor PWM level to achieve target motor velocity (0-255)
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// Serial Input processor:
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const byte numChars = 32;
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char receivedChars[numChars]; // an array to store the received data
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boolean newData = false;
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// Function Prototypes:
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void updateEncoder(); // react to encoder pulse and update encoder count
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double encoderToPosition(long); // convert encoder count to wall position
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int Velocity_to_PWM(double); // function to convert motor velocity to PWM drive signal
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void recvWithEndMarker(); // read Serial input
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void showNewData(); // act on Serial input
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PID pid = PID(¤tPosition, &targetMotorVelocity, &targetPosition, 600, 0.25, 5.0, DIRECT);
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void setup() {
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Serial.begin(115200);
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// Configure DMX shield (MAX485 chipset)
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// DMXSerial.init(DMXReceiver);
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// DMXSerial.write(DMX_CHANNEL, 0);
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// Initialize GPIO pins:
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pinMode(RPWM_PIN, OUTPUT);
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pinMode(LPWM_PIN, OUTPUT);
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pinMode(L_EN_PIN, OUTPUT);
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pinMode(R_EN_PIN, OUTPUT);
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pinMode(LLED_PIN, OUTPUT);
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pinMode(RLED_PIN, OUTPUT);
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pinMode(ENCODER_A, INPUT_PULLUP);
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pinMode(ENCODER_B, INPUT_PULLUP);
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// Start encoder:
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attachInterrupt(digitalPinToInterrupt(ENCODER_A), updateEncoder, RISING);
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// Start the Motor Driver - Set Frequency, start both PWM low, Enable both sides:
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InitTimersSafe();
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SetPinFrequencySafe(9, 10000);
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digitalWrite(LPWM_PIN, LOW);
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digitalWrite(RPWM_PIN, LOW);
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digitalWrite(L_EN_PIN, HIGH);
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digitalWrite(R_EN_PIN, HIGH);
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pid.SetSampleTime(10);
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pid.SetMode(AUTOMATIC);
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pid.SetOutputLimits(-330, 330);
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// initialize loop timers
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prevSample = millis();
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prevControl = millis();
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}
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void loop() {
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if (millis() < prevControl) {
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// millis timer rolled over, so reset sample and control timers:
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prevSample = millis();
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prevControl = millis();
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currentPosition = encoderToPosition(encoderPosition);
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}
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if (millis() - prevSample >= SAMPLE_RATE) {
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// this happens faster than control loop so that TBD smoothing function can be added
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prevPosition = currentPosition;
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currentPosition = encoderToPosition(encoderPosition); // get wall position (revolutions) from encoder reading
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currentVelocity = 60000.0f * (currentPosition - prevPosition) / (float)(millis() - prevSample); // wall speed (rpm)
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prevSample = millis();
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}
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if (millis() - prevControl >= LOOP_RATE) {
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// targetMotorVelocity = currentVelocity * MOTOR_RATIO; // begin with assumption we are going the right speed
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double remainingDistance = targetPosition - currentPosition;
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// double remainingTime; // projected running time assuming velocity doesn't change
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// if (currentVelocity == 0) {
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// remainingTime = 1e6;
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// } else {
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// remainingTime = remainingDistance / currentVelocity;
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// }
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// if (abs(remainingDistance) < WALL_POSITION_TOLERANCE) {
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// // we are close enough, stop moving:
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// if (abs(targetMotorVelocity) < MAX_MOTOR_ACCELERATION * (float)LOOP_RATE/1000.0f) {
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// // we aren't going very fast so just command zero:
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// targetMotorVelocity = 0;
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// } else {
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// // correct by max allowable rate:
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// targetMotorVelocity =- (abs(targetMotorVelocity) / targetMotorVelocity) * MAX_MOTOR_ACCELERATION * (float)LOOP_RATE/1000.0f;
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// }
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// } else if (remainingTime < 0) {
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// // moving in the wrong direction, so course correct:
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// if (remainingDistance > 0) {
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// // need to go CCW, so target velocity is more positive than current velocity
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// // but if we are close enough, don't over accelerate; just calculate target speed
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// targetMotorVelocity = min(targetMotorVelocity + MAX_MOTOR_ACCELERATION * (float)LOOP_RATE/1000.0f, (0.5 * remainingDistance / ((float)LOOP_RATE/1000.0f)) * MOTOR_RATIO);
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// } else {
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// // need to go CW, so target velocity is more negative than current velocity
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// targetMotorVelocity = max(targetMotorVelocity - MAX_MOTOR_ACCELERATION * (float)LOOP_RATE/1000.0f, (0.5 * remainingDistance / ((float)LOOP_RATE/1000.0f)) * MOTOR_RATIO);
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// }
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// } else {
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// // moving in the correct direction, so check if we should start slowing down:
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// stopTime = abs(currentVelocity) / MAX_WALL_ACCELERATION;
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// if (stopTime > (remainingTime - 2*(float)LOOP_RATE/1000.0f)) {
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// // we need to be slowing down within the next two control loops, so start now:
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// if (remainingDistance > 0) {
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// // going CCW, so target should adjust in CW direction
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// targetMotorVelocity = targetMotorVelocity - MAX_MOTOR_ACCELERATION * (float)LOOP_RATE/1000.0f;
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// if (targetMotorVelocity < 0) {
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// targetMotorVelocity = 0;
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// }
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// } else {
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// // going CW, so target should adjust in CCW direction
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// targetMotorVelocity = targetMotorVelocity + MAX_MOTOR_ACCELERATION * (float)LOOP_RATE/1000.0f;
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// if (targetMotorVelocity > 0) {
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// targetMotorVelocity = 0;
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// }
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// }
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// } else {
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// // we still have a ways to go, so we can accelerate:
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// if (remainingDistance > 0) {
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// // going CCW, so target should adjust more CCW until MAX
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// targetMotorVelocity = min(MOTOR_MAX_RPM, targetMotorVelocity + MAX_MOTOR_ACCELERATION * LOOP_RATE/1000.0f);
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// } else {
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// // going CW, so target should adjust more CW until -MAX
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// targetMotorVelocity = max(-MOTOR_MAX_RPM, targetMotorVelocity - MAX_MOTOR_ACCELERATION * LOOP_RATE/1000.0f);
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// }
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// }
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// }
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// int motorPWM = Velocity_to_PWM(targetMotorVelocity);
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// targetMotorVelocity += min((remainingDistance * 0.5) - targetMotorVelocity, MAX_MOTOR_ACCELERATION / LOOP_RATE / 1000.0f);
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// if (abs(remainingDistance) > WALL_POSITION_TOLERANCE) {
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// if (((remainingDistance / 0.16 * 330) - targetMotorVelocity) > 0) {
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// targetMotorVelocity = currentVelocity + min((remainingDistance / 0.16 * 330) - currentVelocity, MAX_MOTOR_ACCELERATION * (LOOP_RATE / 1000.0f));
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// } else {
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// targetMotorVelocity = currentVelocity + max((remainingDistance / 0.16 * 330) - currentVelocity, - MAX_MOTOR_ACCELERATION * (LOOP_RATE / 1000.0f));
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// }
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// if (targetMotorVelocity > MOTOR_MAX_RPM) {
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// targetMotorVelocity = MOTOR_MAX_RPM;
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// }
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// if (targetMotorVelocity < - MOTOR_MAX_RPM) {
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// targetMotorVelocity = - MOTOR_MAX_RPM;
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// }
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// } else if (currentVelocity < 1){
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// targetMotorVelocity = 0;
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// }
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pid.Compute();
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int motorPWM = Velocity_to_PWM(targetMotorVelocity);
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if (targetMotorVelocity == 0) {
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digitalWrite(RPWM_PIN, LOW);
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digitalWrite(RLED_PIN, LOW);
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digitalWrite(LPWM_PIN, LOW);
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digitalWrite(LLED_PIN, LOW);
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} else if (targetMotorVelocity > 0) {
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digitalWrite(RPWM_PIN, LOW);
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digitalWrite(RLED_PIN, LOW);
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pwmWrite(LPWM_PIN, motorPWM);
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pwmWrite(LLED_PIN, motorPWM);
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} else {
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digitalWrite(LPWM_PIN, LOW);
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digitalWrite(LLED_PIN, LOW);
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pwmWrite(RPWM_PIN, motorPWM);
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pwmWrite(RLED_PIN, motorPWM);
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}
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prevControl = millis();
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Serial.print(">ePos: ");
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Serial.print(encoderPosition);
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Serial.print(", wPos: ");
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Serial.print(currentPosition);
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Serial.print(", wVel: ");
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Serial.print(currentVelocity);
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Serial.print(", rDist: ");
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Serial.print(remainingDistance);
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Serial.print(", rTime: ");
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Serial.print(remainingTime);
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Serial.print(", sTime:");
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Serial.print(stopTime);
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Serial.print(", tVel: ");
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Serial.print(targetMotorVelocity);
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Serial.print(", mPWM: ");
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Serial.println(motorPWM);
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}
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recvWithEndMarker();
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showNewData();
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// delay(5);
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// make sure DMX is still alive:
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// // } else {
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// // digitalWrite(R_EN_PIN, 0);
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// // digitalWrite(L_EN_PIN, 0);
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// // }
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}
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void updateEncoder() {
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if (digitalRead(ENCODER_B) == LOW) {
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encoderPosition--; // CCW
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} else {
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encoderPosition++; // CW
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}
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}
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double encoderToPosition(long encoderPosition) {
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return (encoderPosition / (float)ENCODER_PPR) / (float)ENCODER_RATIO;
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}
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int Velocity_to_PWM(double motorVelocity) {
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if (abs(motorVelocity) > 0) {
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return min(round(MOTOR_MIN_PWM + ((255 - MOTOR_MIN_PWM) / (float)MOTOR_MAX_RPM) * abs(motorVelocity)), 255);
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}
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return 0;
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}
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void recvWithEndMarker() {
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static byte ndx = 0;
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char endMarker = '\n';
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char rc;
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while (Serial.available() > 0 && newData == false) {
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rc = Serial.read();
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if (rc != endMarker) {
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receivedChars[ndx] = rc;
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ndx++;
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if (ndx >= numChars) {
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ndx = numChars - 1;
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}
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}
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else {
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receivedChars[ndx] = '\0'; // terminate the string
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ndx = 0;
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newData = true;
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}
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}
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}
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void showNewData() {
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if (newData == true) {
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Serial.print("This just in ... ");
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Serial.println(receivedChars);
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newData = false;
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}
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} |