PM2_Lib

Dependencies:   LSM9DS1 RangeFinder FastPWM

PositionController.cpp

Committer:
pmic
Date:
2021-08-31
Revision:
9:583dbd17e0ba
Parent:
8:6b747ad59ff5
Child:
10:fe74e8909d3f

File content as of revision 9:583dbd17e0ba:

#include "PositionController.h"

using namespace std;

const float PositionController::TS = 0.001f;                       // period of 1 ms
const float PositionController::LOWPASS_FILTER_FREQUENCY = 100.0f; // given in [rad/s]
const float PositionController::MIN_DUTY_CYCLE = 0.02f;            // minimum duty-cycle
const float PositionController::MAX_DUTY_CYCLE = 0.98f;            // maximum duty-cycle

PositionController::PositionController(float counts_per_turn, float kn, float max_voltage, FastPWM& pwm, EncoderCounter& encoderCounter) : pwm(pwm), encoderCounter(encoderCounter), thread(osPriorityHigh, 4096)
{
    this->counts_per_turn = counts_per_turn;
    this->kn = kn;
    this->kp = 0.1f;
    this->max_voltage = max_voltage;
    this->max_speed   = kn*max_voltage;
    this->p  = 1300.0f;

    // Initialisieren der PWM Ausgaenge
    pwm.period(0.00005); // PWM Periode von 50 us
    pwm.write(0.5);      // Duty-Cycle von 50%

    // Initialisieren von lokalen Variabeln
    previousValueCounter = encoderCounter.read();
    speedFilter.setPeriod(TS);
    speedFilter.setFrequency(LOWPASS_FILTER_FREQUENCY);
    desiredSpeed = 0.0f;
    actualSpeed = 0.0f;
    float initialRotation = (float)encoderCounter.read()/counts_per_turn;
    this->initialRotation = initialRotation;
    actualRotation  = initialRotation;
    desiredRotation = initialRotation;

    // Starten des periodischen Tasks
    thread.start(callback(this, &PositionController::run));
    ticker.attach(callback(this, &PositionController::sendThreadFlag), TS);
}

PositionController::PositionController(float counts_per_turn, float kn, float kp, float p, float max_voltage, FastPWM& pwm, EncoderCounter& encoderCounter) : pwm(pwm), encoderCounter(encoderCounter), thread(osPriorityHigh, 4096)
{
    this->counts_per_turn = counts_per_turn;
    this->kn = kn;
    this->kp = kp;
    this->max_voltage = max_voltage;
    this->max_speed   = kn*max_voltage;
    this->p  = p;

    // Initialisieren der PWM Ausgaenge
    pwm.period(0.00005); // PWM Periode von 50 us
    pwm.write(0.5);      // Duty-Cycle von 50%

    // Initialisieren von lokalen Variabeln
    previousValueCounter = encoderCounter.read();
    speedFilter.setPeriod(TS);
    speedFilter.setFrequency(LOWPASS_FILTER_FREQUENCY);
    desiredSpeed = 0.0f;
    actualSpeed  = 0.0f;
    float initialRotation = (float)encoderCounter.read()/counts_per_turn;
    this->initialRotation = initialRotation;
    actualRotation  = initialRotation;
    desiredRotation = initialRotation;

    // Starten des periodischen Tasks
    thread.start(callback(this, &PositionController::run));
    ticker.attach(callback(this, &PositionController::sendThreadFlag), TS);
}

PositionController::~PositionController()
{
    ticker.detach(); // Stoppt den periodischen Task
}

float PositionController::getSpeedRPM()
{
    return actualSpeed;
}

float PositionController::getSpeedRPS()
{
    return actualSpeed/60.0f;
}

void PositionController::setDesiredRotation(float desiredRotation)
{
    this->desiredRotation = initialRotation + desiredRotation;
}

void PositionController::setDesiredRotation(float desiredRotation, float maxSpeedRPS)
{
    this->max_speed = maxSpeedRPS*60.0f;
    this->desiredRotation = initialRotation + desiredRotation;
}

float PositionController::getRotation()
{
    return actualRotation - initialRotation;
}

void PositionController::run()
{
    while(true) {

        // wait for the periodic signal
        ThisThread::flags_wait_any(threadFlag);

        // calculate actual speed of motors in [rpm]
        short valueCounter = encoderCounter.read();
        short countsInPastPeriod = valueCounter - previousValueCounter;
        previousValueCounter = valueCounter;
        actualSpeed = speedFilter.filter((float)countsInPastPeriod/counts_per_turn/TS*60.0f);
        actualRotation = actualRotation + actualSpeed/60.0f*TS;

        // calculate motor phase voltages
        desiredSpeed  = p*(desiredRotation - actualRotation);
        if (desiredSpeed < -max_speed) desiredSpeed = -max_speed;
        else if (desiredSpeed > max_speed) desiredSpeed = max_speed;
        float voltage = kp*(desiredSpeed - actualSpeed) + desiredSpeed/kn;
        // calculate, limit and set duty cycles
        float dutyCycle = 0.5f + 0.5f*voltage/max_voltage;
        if (dutyCycle < MIN_DUTY_CYCLE) dutyCycle = MIN_DUTY_CYCLE;
        else if (dutyCycle > MAX_DUTY_CYCLE) dutyCycle = MAX_DUTY_CYCLE;
        pwm.write(static_cast<double>(dutyCycle));

    }
}

void PositionController::sendThreadFlag()
{
    thread.flags_set(threadFlag);
}