eeet-427-lab/lab6/Lab6Code/Lab6Code.ino

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18 KiB
C++

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// File: Lab6_Pos_PI_PZ_DEV
// Written: Sept 21, 2020 Clark Hochgraf
// Revised:
// Desc:
// Closed loop P+I control of motor speed.
// Assumes fixed 5v 2amp power supply on Motor Driver
volatile byte quadratureCode, oldquadratureCode;
volatile float quadPos = 0.0;
volatile bool isEncoderChange = false;
float lastquadPos = 0;
bool isModuleEn = false, prevModuleEn = false, isPrinting = false;
bool isProfileEn = false, oldProfileEn = false, isShowStats = false;
const byte TSAMP_MSEC = 20;
int TIC_MSEC = TSAMP_MSEC;
long timeElapsedTicks = 0;
const float TSAMP = 0.001 * TSAMP_MSEC;
volatile float adcReading = 0;
const int ENC2 = A2; // d16, PC2 PCINT10 (green wire)
const int ENC3 = A3; // d17, PC3 PCINT11 (blue wire
const int PWM_M1A_PIN = 3; // d3, PD3 PCINT19 digital output OCR2B (green wire)
const int PWM_M1B_PIN = 11; // d11, PB4 digital output OCR2A (blue wire)
const float VOLTS_PER_PWM = 5. / 255.0; // motor drive voltage per pwm command
const float PWM_PER_VOLT = 1 / VOLTS_PER_PWM; // pwm value to achieve 1 volt output
float Vctl, Varm;
float mtrVel = 0.0, mtrPos = 0.0, errVel = 0.0, errPos = 0.0;
float refAcc = 0.0, refVel = 0.0, refPos = 0.0;
unsigned int tick = 0;
float dir = 1.0;
float disp_rad = 0;
float specAcc = 0.0, specVel, specDisp_rad, specVdist;
float trapAcc = 0.0, trapVel = 0.0, trapDisp_rad = 0.0;
int dwellStartT, accT, platT, dwellEndT;
int T0, T1, T2, T3, T4, T5, T6, T7, T8;
int D0, D1, D2, D3, D4, D5, D6, D7, D8;
float dD1, dD2, dD3, dD4, dD5, dD6, dD7, dD8;
boolean isTrapezoid = true;
//---------------------------------------------------------------------
// Motor constants: DF robot motor with encoder model FIT0458
const float K_EMF = 0.00285; //(V/(160*120))*60.0/TWO_PI; // V/rad/sec from V/1000RPM
const float K_TRQ = 0.008 / 2.8; // N-m/Amp
const float R_ARM = 2.14; // ohms
const float D_DRAG = 0*1.117e-6;
const float SYS_A = 1795;//1795; //2040//1717
const float SYS_B = 6.21;
boolean isFrictionCompensated = true; boolean isVff = true;
const float V_FRICTION = 0.20;
float Vffwd = 0;
float Vdist = 0;
static float lastmicroseconds=0;
void setup()
{
Serial.begin(115200);//Initialize the serial port ** Set Serial Monitor to same 115200
Serial.println(F("Lab6_Pos_PI_PZ_DEV"));
displayMenu();
initMotorPins();
initEncoderInterrupts();
initPWMtimer2();
}
// ##################################################################
void loop()
{ manageMenu();
syncSample();
lastmicroseconds=micros();
isProfileEn = isModuleEn;
if (isModuleEn) {
isTrapezoid=false;
if (isTrapezoid) { // Choose speed reference
trapRefVel(700.0, 600.0, 1500.0); //displacement (radians), veloc (rad/sec), acceler (rad/sec/sec)
// good values for trapRefVel are 700, 600, 1500
} else {
stepRefPos(50);
}
// Choose which control method to use by uncommenting it below
calculateError(); // location of function call for efficient software execution
//delayMicroseconds(20000); // To model delay of digital controller, add delay here
//closedLoopVelPI(isFrictionCompensated, isVff, 0.004, 0.01); // friction enabled? Vff enabled? Kp gain
closedLoopPosPI(isFrictionCompensated, isVff, 0.16, 0.1); // friction enabled? Vff enabled? Kp gain
//closedLoopPosPI_PZ(isFrictionCompensated, isVff, 0.16,0.1,5,20); // friction enabled? Vff enabled? Kp,Ki,CompC,CompD
//calculateError(); // if the calculateError() is called here system stability is severely degraded.
}
else { // stop motor by sending zero voltage command to pwm
OCR2B = 0; OCR2A = 0;
timeElapsedTicks=0;
quadPos=0;
lastquadPos = quadPos;
}
if (isModuleEn && (timeElapsedTicks * TSAMP_MSEC) <= 4000) //stop print after 4 seconds
{
//isModuleEn = false;
printResults();
}
if (isPrinting) printResults();
//lastmicroseconds=micros();
//Serial.println(micros()-lastmicroseconds);
if (isModuleEn) timeElapsedTicks++;
prevModuleEn = isModuleEn;
} // End main loop
// ##################################################################
//**************************************************************
float PD_compensate(float x, float c, float d)
{
// Proportional plus Derivative compensator
// Cancel pole at -c, replace with a pole at -d.
// Implement (s+c)/(s+d) as 1 + (c-d)/(s+d).
// and post scale by d/c to get unity gain at DC.
// PD section
static float yd = 0.0;
yd += ((c - d) * x - d * yd) * TSAMP;
float ypd = x + yd;
ypd = ypd * d / c; // correct scaling to unity gain at DC.
return ypd;
}
//********************************************************************
float VfrictionVelocity(float Vcmd)
{ // calculates voltage required to overcome friction.
// direction of voltage depends on commanded direction of velocity
float frictionV = 0.0;
//Coulomb friction
if (Vcmd > 0.001) frictionV = V_FRICTION;
if (Vcmd < -0.001) frictionV = -V_FRICTION;
//static friction
if ((mtrVel < 1) && (mtrVel > -1) && (Vcmd > 0.001)) frictionV += 0.4;
if ((mtrVel < 1) && (mtrVel > -1) && (Vcmd < -0.001)) frictionV -= 0.4;
return frictionV;
}
//********************************************************************
void calculateError(void)
{
mtrVel = (quadPos - lastquadPos) / (TSAMP_MSEC * 0.001); // radians per time interval (rad/sec)
lastquadPos = quadPos;
mtrPos = quadPos;
errVel = refVel - mtrVel;
errPos = refPos - mtrPos;
}
//********************************************************************
void printResults(void)
{ if (isModuleEn != prevModuleEn)
{
//print header
Serial.print("time (msec): ");
Serial.print("\tmotorspeed: (rad/sec)");
Serial.print("\tquadPos: (rad)");
Serial.print("\t errVel: (rad/sec)");
Serial.print("\t Vctrl (V)");
Serial.print("\t Wref (rad/sec)");
Serial.print("\t Posref (rad)");
Serial.println();
//lastquadPos = quadPos;
}
Serial.print(timeElapsedTicks * TSAMP_MSEC); Serial.print("\t");
Serial.print(mtrVel); Serial.print("\t");
Serial.print(quadPos); Serial.print("\t");
Serial.print(errVel); Serial.print("\t");
Serial.print(Vctl); Serial.print("\t");
Serial.print(refVel); Serial.print("\t");
Serial.print(refPos);
Serial.println();
}
//********************************************************************
void initEncoderInterrupts(void)
{
// Position encoder ISR setup
// PCINT1_vect ISR triggered for enabled bit changes on PCMSK1
cli(); // disable global interrupts
PCMSK1 = 0b00001100; // ENC3,2,1,0 -> A3,A2,A1,A0 -> d17,16,15,14
PCICR = (1 << PCIE1); // enable pin change interrupts 8..14
sei(); // enable global interrupts
}
//********************************************************************
void initPWMtimer2(void)
{
//-----------------------------------------------------------------
// Use Timer 2 for direct motor drive PWM generation.
// Prescale = 1, FAST PWM, 8-bit (Mode 3) -> 62.5 kHz PWM
// Output pins OC2B (d3~) and OC2A (d11~) driven by counter hardware.
cli();
TCCR2B = 0;
TCCR2A = 0;
TCCR2B = (0 << WGM22); // start FAST PWM mode 3 setup
TCCR2A = (1 << WGM21) | (1 << WGM20); // finish FAST PWM setup
TCCR2B |= (0 << CS22) | (0 << CS21) | (1 << CS20); // clock prescale = 1
TCCR2A |= (1 << COM2B1) | (0 << COM2B0); // OCR2B pin (d3~) noninverting PWM
TCCR2A |= (1 << COM2A1) | (0 << COM2A0); // OCR2A pin (d11~) noninverting PWM
OCR2B = 1; OCR2A = 1;
sei();
}
//********************************************************************
ISR(PCINT1_vect) // vector to quadrature decoder
{
//digitalWrite(ALED,!digitalRead(ALED));
isEncoderChange = true;
decodeEncoder32();
}
//********************************************************************
void decodeEncoder32(void) // 2 bit quad decoder
{
const float MTR_RAD_PER_TICK = TWO_PI / 32;
static byte oldquadratureCode = 0;
oldquadratureCode = quadratureCode;
quadratureCode = (PINC & 0b00001100); // inner tracks
// Quadrature sequence: 0,8,12,4 (update ?CW facing end)
switch (quadratureCode)
{
case 0:
if (oldquadratureCode == 4) quadPos += MTR_RAD_PER_TICK;
if (oldquadratureCode == 8) quadPos -= MTR_RAD_PER_TICK;
break;
case 8:
if (oldquadratureCode == 0) quadPos += MTR_RAD_PER_TICK;
if (oldquadratureCode == 12) quadPos -= MTR_RAD_PER_TICK;
break;
case 12:
if (oldquadratureCode == 8) quadPos += MTR_RAD_PER_TICK;
if (oldquadratureCode == 4) quadPos -= MTR_RAD_PER_TICK;
break;
case 4:
if (oldquadratureCode == 12) quadPos += MTR_RAD_PER_TICK;
if (oldquadratureCode == 0) quadPos -= MTR_RAD_PER_TICK;
break;
}
} // decodeEncoder32( )
//********************************************************************
void syncSample() // set the sample rate for ADC and therefore for the main loop
{ // sample interval time is set by TIC_MSEC
const unsigned long TIC_USEC = TIC_MSEC * 1000UL;
const byte ADCSRA_ISR = 0b11101111; // auto ISR, clkdiv = 128
static unsigned long tic, stake = 0;
static boolean first_run = true;
if (first_run) {
stake = micros(); // only runs first time to set stake
first_run = false;
}
while ((tic - stake) < TIC_USEC) tic = micros(); // wait here until
stake = tic;
ADCSRA = ADCSRA_ISR; // start oversample-average series
}
//********************************************************************
ISR (ADC_vect)
{
const byte N_ADC_AVE = 80;
const float INV_N_ADC = 1.0 / N_ADC_AVE;
static byte nConv = 0;
static unsigned int loAccum = 0, hiAccum = 0;
//SET_TP0_HI;
loAccum += ADCL; // lower 8 bits: must read before ADCH per Atmel
hiAccum += ADCH; // upper 2 bits
if (++nConv >= N_ADC_AVE)
{
//SET_TP1_HI;
adcReading = INV_N_ADC * (256UL * hiAccum + loAccum);
hiAccum = 0; loAccum = 0;
nConv = 0;
ADCSRA &= ~bit(ADIE); // stop auto conversions
//SET_TP1_LO;
}
//SET_TP0_LO;
} // end of ADC_vect
//********************************************************************
void displayMenu()
{
Serial.println("\nEnter 'e' to toggle module enable.");
//Serial.println("Enter 'g' to go.");
}
//********************************************************************
void manageMenu()
{
char inChar = Serial.read();
if (inChar == 'e')
{
isModuleEn = !isModuleEn;
//digitalWrite(PWMVAL_PIN, isModuleEn); // PWM disable low
if (isModuleEn) {
Serial.println(F("Module ENABLED"));
timeElapsedTicks = 0;
oldProfileEn=false; isProfileEn=true;
}
else {
Serial.println(F("Module DISABLED"));
quadPos=0;
lastquadPos=quadPos;
}
}
else if (inChar == 'g')
{
timeElapsedTicks = 0;
dir = 1.0;
isProfileEn = true;
}
else if (inChar == 'p')
{
isPrinting = !isPrinting;
}
else if (inChar == 'f')
{
isFrictionCompensated = !isFrictionCompensated;
if (isFrictionCompensated) Serial.println(F("Stiction Comp Enabled"));
}
else if (inChar == 't')
{
isTrapezoid = !isTrapezoid;
if (isTrapezoid) {
Serial.println(F("Trapezoidal Reference"));
}
else {
Serial.println(F("Step Reference"));
}
}
}
//********************************************************************
void initMotorPins()
{ // configure pins as input or output
pinMode(ENC2, INPUT); // Encoder A
pinMode(ENC3, INPUT); // Encoder B
pinMode(PWM_M1A_PIN, OUTPUT); // set motor PWM signal to output
pinMode(PWM_M1B_PIN, OUTPUT); // set motor direction pin to output
}
//*********************************************************************
void stepRefPos(float pos_rad) // step input velocity reference levels
{
static float refPos_last_time = 0;
oldProfileEn = isProfileEn;
if (timeElapsedTicks < 0) refVel = 0.0;
else if (timeElapsedTicks < 40000) refPos = pos_rad;
else if (timeElapsedTicks < 80) refPos = -pos_rad;
else if (timeElapsedTicks < 100) refPos = 0.0;
else isProfileEn = false;
//refPos += refVel_last_time * TSAMP;
//refVel_last_time = refVel;
isShowStats = (oldProfileEn && !isProfileEn);
}
//*********************************************************************
void trapRefVel(float specDisp_rad, float specVel, float specAcc) // trap velocity profile
{
if (!oldProfileEn && isProfileEn)
{
//specDisp_rad = 300.0; specVel = 150.0; specAcc = 800.0;
trapBuildSymAcc(specDisp_rad, specVel, specAcc);
dwellStartT = 10; dwellEndT = 10; specVdist = 0.0;
//specDisp_rad = 300.0, specVel = 100.0, specAcc = 200.0;
//trapBuildSymAcc(specDisp_rad, specVel, specAcc);
//dwellStartT = 50, dwellEndT = 200; specVdist = 2.0;
//specDisp_rad = 206.9, specVel = 110.0, specAcc = 180.0;
//trapBuildSymAcc(specDisp_rad, specVel, specAcc);
//dwellGoT = 300, dwellUpT = 500, dwellEndT = 200; specVdist = abs(V_DIST);
// Times when speed changes
T0 = dwellStartT;
T1 = T0 + accT; T2 = T1 + platT; T3 = T2 + accT; T4 = T3 + dwellEndT;
T5 = T4 + accT; T6 = T5 + platT; T7 = T6 + accT; T8 = T7 + dwellEndT;
//T0 = dwellGoT;
//T1 = T0 + accT, T2 = T1 + platT, T3 = T2 + accT, T4 = T3 + dwellUpT;
//T5 = T4 + accT, T6 = T5 + platT, T7 = T6 + accT, T8 = T7 + dwellEndT;
// Times when disturbances are applied and values
D1 = T3 + 100; D2 = D1 + 200;
dD1 = specVdist; dD2 = -specVdist;
//simJumpOn_simJumpOff();
//simJumpOn_simFileOff();
//weightOn_simJumpOff();
//weightOn_simFileOff();
}
tick = timeElapsedTicks;
// ---- Command profile -------------------------------------
oldProfileEn = isProfileEn;
if (tick < T0) refAcc = 0.0;
else if (tick < T1) refAcc = dir * trapAcc;
else if (tick < T2) refAcc = 0.0;
else if (tick < T3) refAcc = -dir * trapAcc;
else if (tick < T4) refAcc = 0.0;
//else if (tick == T4) isProfileEn = false;
else if (tick < T5) refAcc = -dir * trapAcc;
else if (tick < T6) refAcc = 0.0;
else if (tick < T7) refAcc = dir * trapAcc;
else if (tick < T8) refAcc = 0.0;
else if (tick == T8) isProfileEn = false;
//---- Disturbance profile -----------------------------------
if (tick < D1) Vdist = 0.0;
else if (tick == D1) Vdist += dD1 * specVdist; // module, sim load
else if (tick == D2) Vdist += dD2 * specVdist;
else if (tick == D3) Vdist += dD3 * specVdist;
else if (tick == D4) Vdist += dD4 * specVdist;
else if (tick == D5) Vdist += dD5 * specVdist;
else if (tick == D6) Vdist += dD6 * specVdist;
else if (tick == D7) Vdist += dD7 * specVdist;
else if (tick == D8) Vdist += dD8 * specVdist;
//---- Profile integration -----------------------------------
if (isProfileEn) {
refVel += refAcc * TSAMP;
refPos += refVel * TSAMP;
}
else {
refAcc = 0.0;
refVel = 0.0;
}
isShowStats = (oldProfileEn && !isProfileEn);
}
//**************************************************************
void trapBuildSymAcc(float Disp_rad, float Vplat, float Acc)
{
float tAcc = Vplat / Acc;
float dAcc = Vplat * tAcc;
float dPlat = Disp_rad - dAcc;
float tPlat = dPlat / Vplat;
trapAcc = Acc; // acceleration rate
accT = int(round(tAcc / TSAMP)); // time duration of acceleration
platT = int(round(tPlat / TSAMP)); // time duration of constant speed
float dTrap = (accT + platT) * TSAMP * Vplat; // total displacement during trapezoid profile
// Serial.println();
// Serial.print("tAcc = "); Serial.println(tAcc);
// Serial.print("dAcc = "); Serial.println(dAcc);
// Serial.print("dPlat = "); Serial.println(dPlat);
// Serial.print("tPlat = "); Serial.println(tPlat);
// Serial.print("accT = "); Serial.println(accT);
// Serial.print("platT = "); Serial.println(platT);
// Serial.print("dTrap = "); Serial.println(dTrap);
}
//********************************************************************
void closedLoopVelPI(boolean isFrictionCompensated, boolean isVff, float KpGain, float KiGain)
{
float Kp = KpGain;
float Ki = KiGain;
Vffwd = ((SYS_B / SYS_A) * refVel + (1.0 / SYS_A) * refAcc);
Vctl = PI_compensate(errVel, Kp, Ki); // PI control
if (isFrictionCompensated) {
Vctl += VfrictionVelocity(refVel);
}
if (isVff) {
Vctl += Vffwd;
}
Varm = Vctl;
if (isModuleEn) driveMotor(Varm, mtrVel, mtrPos);
}
//********************************************************************
void closedLoopPosPI(boolean isFrictionCompensated, boolean isVff, float KpGain, float KiGain)
{
float Kp = KpGain;
float Ki = KiGain;
Vffwd = ((SYS_B / SYS_A) * refVel + (1.0 / SYS_A) * refAcc);
Vctl = PI_compensate(errPos, Kp, Ki); // PI control
if (isFrictionCompensated) {
Vctl += VfrictionVelocity(refVel);
}
if (isVff) {
Vctl += Vffwd;
}
Varm = Vctl;
if (isModuleEn) driveMotor(Varm, mtrVel, mtrPos);
}
//********************************************************************
void closedLoopPosPI_PZ(boolean isFrictionCompensated, boolean isVff, float KpGain, float KiGain, float CompC, float CompD)
{
float Kp = KpGain;
float Ki = KiGain;
Vffwd = ((SYS_B / SYS_A) * refVel + (1.0 / SYS_A) * refAcc);
Vctl = PI_compensate(errPos, Kp, Ki); // PI control
Vctl = PD_compensate(Vctl, CompC, CompD); // PD control, signal, CompC, CompD)
if (isFrictionCompensated) {
Vctl += VfrictionVelocity(refVel);
}
if (isVff) {
Vctl += Vffwd;
}
Varm = Vctl;
if (isModuleEn) driveMotor(Varm, mtrVel, mtrPos);
//Serial.println(micros()-lastmicroseconds);
}
//**************************************************************
float PI_compensate(float x, float Kp, float Ki)
{
// Implement (Kp s+Ki)/s as Kp + Ki/s.
static float Integralx = 0.0;
Integralx += x * TSAMP;
float ypi = Kp * x + Ki * Integralx;
// Apply integral compensator windup clipping.
return ypi;
}
//********************************************************************
void driveMotor(float Varm, float &vel, float &disp_rad)
{
// 8 bit PWM, ~5 volt rail
// note: reversed sign of Varm to get positive speed for positive volts
float pwm_command = -Varm * PWM_PER_VOLT;
if (pwm_command < 0) { // negative case -- set direction CW
pwm_command = - int(pwm_command);
OCR2A = 0;
OCR2B = constrain(pwm_command, 0, 255);
//Serial.println(OCR2B);
}
else
{ //positive case -- set direction CW
pwm_command = int(pwm_command);
OCR2B = 0;
OCR2A = constrain(pwm_command, 0, 255);
//Serial.println(OCR2A);
}
}