Arcadie Cracan
/
dcMotorControl
PI DC motor control with encoder sensor
main.cpp@0:b6369e728067, 2014-11-03 (annotated)
- Committer:
- acracan
- Date:
- Mon Nov 03 15:50:59 2014 +0000
- Revision:
- 0:b6369e728067
First version of PI control...
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
acracan | 0:b6369e728067 | 1 | #include "mbed.h" |
acracan | 0:b6369e728067 | 2 | |
acracan | 0:b6369e728067 | 3 | //------------------------------------ |
acracan | 0:b6369e728067 | 4 | // Hyperterminal configuration |
acracan | 0:b6369e728067 | 5 | // 9600 bauds, 8-bit data, no parity |
acracan | 0:b6369e728067 | 6 | //------------------------------------ |
acracan | 0:b6369e728067 | 7 | |
acracan | 0:b6369e728067 | 8 | Serial pc(SERIAL_TX, SERIAL_RX); |
acracan | 0:b6369e728067 | 9 | |
acracan | 0:b6369e728067 | 10 | InterruptIn sig(D4); |
acracan | 0:b6369e728067 | 11 | Timer sigTimer; |
acracan | 0:b6369e728067 | 12 | PwmOut ctrl(D9); |
acracan | 0:b6369e728067 | 13 | DigitalIn A(D7); |
acracan | 0:b6369e728067 | 14 | DigitalIn B(D2); |
acracan | 0:b6369e728067 | 15 | |
acracan | 0:b6369e728067 | 16 | int sigPeriod = 0, refPeriod = 3000; |
acracan | 0:b6369e728067 | 17 | |
acracan | 0:b6369e728067 | 18 | double dutyCycle = 0.5, stepSize = 0.01; |
acracan | 0:b6369e728067 | 19 | |
acracan | 0:b6369e728067 | 20 | Timer displayTimer, controlTimer; |
acracan | 0:b6369e728067 | 21 | |
acracan | 0:b6369e728067 | 22 | void onRisingEdge(); |
acracan | 0:b6369e728067 | 23 | void displayRPM(int period); |
acracan | 0:b6369e728067 | 24 | void controlLoop(int period); |
acracan | 0:b6369e728067 | 25 | |
acracan | 0:b6369e728067 | 26 | void readEncoder(); |
acracan | 0:b6369e728067 | 27 | void encoderIncrement(); |
acracan | 0:b6369e728067 | 28 | void encoderDecrement(); |
acracan | 0:b6369e728067 | 29 | |
acracan | 0:b6369e728067 | 30 | |
acracan | 0:b6369e728067 | 31 | int main() { |
acracan | 0:b6369e728067 | 32 | pc.printf("Hello world\n\r"); |
acracan | 0:b6369e728067 | 33 | displayTimer.start(); |
acracan | 0:b6369e728067 | 34 | controlTimer.start(); |
acracan | 0:b6369e728067 | 35 | sig.mode(PullNone); |
acracan | 0:b6369e728067 | 36 | sig.rise(onRisingEdge); |
acracan | 0:b6369e728067 | 37 | sigTimer.start(); |
acracan | 0:b6369e728067 | 38 | ctrl.period_us(1000); |
acracan | 0:b6369e728067 | 39 | ctrl.write(0.5); |
acracan | 0:b6369e728067 | 40 | while(1) { |
acracan | 0:b6369e728067 | 41 | displayRPM(sigPeriod); |
acracan | 0:b6369e728067 | 42 | controlLoop(sigPeriod); |
acracan | 0:b6369e728067 | 43 | readEncoder(); |
acracan | 0:b6369e728067 | 44 | } |
acracan | 0:b6369e728067 | 45 | } |
acracan | 0:b6369e728067 | 46 | |
acracan | 0:b6369e728067 | 47 | void onRisingEdge() |
acracan | 0:b6369e728067 | 48 | { |
acracan | 0:b6369e728067 | 49 | static const int queueLength = 1; |
acracan | 0:b6369e728067 | 50 | static int queue[queueLength], queueStart = 0, queueEnd = 0; |
acracan | 0:b6369e728067 | 51 | static uint64_t sum = 0; |
acracan | 0:b6369e728067 | 52 | int time; |
acracan | 0:b6369e728067 | 53 | |
acracan | 0:b6369e728067 | 54 | time = sigTimer.read_us(); |
acracan | 0:b6369e728067 | 55 | if (time < 100) |
acracan | 0:b6369e728067 | 56 | return; |
acracan | 0:b6369e728067 | 57 | sigTimer.reset(); |
acracan | 0:b6369e728067 | 58 | if (queueStart == queueEnd && sum != 0) { |
acracan | 0:b6369e728067 | 59 | sum -= queue[queueStart]; |
acracan | 0:b6369e728067 | 60 | queueStart = (queueStart + 1) % queueLength; |
acracan | 0:b6369e728067 | 61 | } |
acracan | 0:b6369e728067 | 62 | sum += time; |
acracan | 0:b6369e728067 | 63 | queue[queueEnd] = time; |
acracan | 0:b6369e728067 | 64 | queueEnd = (queueEnd + 1) % queueLength; |
acracan | 0:b6369e728067 | 65 | |
acracan | 0:b6369e728067 | 66 | if (queueStart == queueEnd) |
acracan | 0:b6369e728067 | 67 | sigPeriod = sum / queueLength; |
acracan | 0:b6369e728067 | 68 | else |
acracan | 0:b6369e728067 | 69 | sigPeriod = sum / ((queueEnd + queueLength - queueStart) % queueLength); |
acracan | 0:b6369e728067 | 70 | } |
acracan | 0:b6369e728067 | 71 | |
acracan | 0:b6369e728067 | 72 | void displayRPM(int period) |
acracan | 0:b6369e728067 | 73 | { |
acracan | 0:b6369e728067 | 74 | if (displayTimer.read_ms() < 100) |
acracan | 0:b6369e728067 | 75 | return; |
acracan | 0:b6369e728067 | 76 | displayTimer.reset(); |
acracan | 0:b6369e728067 | 77 | pc.printf("period is %d, refPeriod is %d, dutyCycle is %f\n\r", period, refPeriod, dutyCycle); |
acracan | 0:b6369e728067 | 78 | } |
acracan | 0:b6369e728067 | 79 | |
acracan | 0:b6369e728067 | 80 | void controlLoop(int period) |
acracan | 0:b6369e728067 | 81 | { |
acracan | 0:b6369e728067 | 82 | if (controlTimer.read_ms() < 10) |
acracan | 0:b6369e728067 | 83 | return; |
acracan | 0:b6369e728067 | 84 | controlTimer.reset(); |
acracan | 0:b6369e728067 | 85 | |
acracan | 0:b6369e728067 | 86 | double input = period - refPeriod; |
acracan | 0:b6369e728067 | 87 | static const double intGain = 1.0e-7; |
acracan | 0:b6369e728067 | 88 | static const double propGain = 1.0e-6; |
acracan | 0:b6369e728067 | 89 | static double intState = 0.0; |
acracan | 0:b6369e728067 | 90 | |
acracan | 0:b6369e728067 | 91 | intState += intGain * input; |
acracan | 0:b6369e728067 | 92 | if (intState > 0.9) |
acracan | 0:b6369e728067 | 93 | intState = 0.9; |
acracan | 0:b6369e728067 | 94 | else if (intState < 0.1) |
acracan | 0:b6369e728067 | 95 | intState = 0.1; |
acracan | 0:b6369e728067 | 96 | dutyCycle = propGain * input + intState; |
acracan | 0:b6369e728067 | 97 | if (dutyCycle < 0.05) |
acracan | 0:b6369e728067 | 98 | dutyCycle = 0.05; |
acracan | 0:b6369e728067 | 99 | else if (dutyCycle > 0.95) |
acracan | 0:b6369e728067 | 100 | dutyCycle = 0.95; |
acracan | 0:b6369e728067 | 101 | ctrl.write(1.0 - dutyCycle); |
acracan | 0:b6369e728067 | 102 | } |
acracan | 0:b6369e728067 | 103 | |
acracan | 0:b6369e728067 | 104 | void readEncoder() |
acracan | 0:b6369e728067 | 105 | { |
acracan | 0:b6369e728067 | 106 | static int state = 0; |
acracan | 0:b6369e728067 | 107 | int currentState; |
acracan | 0:b6369e728067 | 108 | const int stateOrder[] = {0, 2, 3, 1}; |
acracan | 0:b6369e728067 | 109 | const int stateIndex[] = {0, 3, 1, 2}; |
acracan | 0:b6369e728067 | 110 | int ccwState, cwState; |
acracan | 0:b6369e728067 | 111 | |
acracan | 0:b6369e728067 | 112 | currentState = (A << 1) + B; |
acracan | 0:b6369e728067 | 113 | ccwState = stateOrder[(stateIndex[state] + 3) & 3]; |
acracan | 0:b6369e728067 | 114 | cwState = stateOrder[(stateIndex[state] + 1) & 3]; |
acracan | 0:b6369e728067 | 115 | if (currentState == cwState) |
acracan | 0:b6369e728067 | 116 | encoderIncrement(); |
acracan | 0:b6369e728067 | 117 | else if (currentState == ccwState) |
acracan | 0:b6369e728067 | 118 | encoderDecrement(); |
acracan | 0:b6369e728067 | 119 | state = currentState; |
acracan | 0:b6369e728067 | 120 | } |
acracan | 0:b6369e728067 | 121 | |
acracan | 0:b6369e728067 | 122 | void encoderIncrement() |
acracan | 0:b6369e728067 | 123 | { |
acracan | 0:b6369e728067 | 124 | refPeriod -= 1000; |
acracan | 0:b6369e728067 | 125 | } |
acracan | 0:b6369e728067 | 126 | |
acracan | 0:b6369e728067 | 127 | void encoderDecrement() |
acracan | 0:b6369e728067 | 128 | { |
acracan | 0:b6369e728067 | 129 | refPeriod += 1000; |
acracan | 0:b6369e728067 | 130 | } |