File content as of revision 0:1a0321f1ffbc:

/*
 * TaskMoveToWaypoint.cpp
 * Copyright (c) 2018, ZHAW
 * All rights reserved.
 */

#include <cmath>
#include "TaskMoveToWaypoint.h"

using namespace std;

const float TaskMoveToWaypoint::DEFAULT_VELOCITY = 0.2f;    // default velocity value, given in [m/s]
const float TaskMoveToWaypoint::PI = 3.14159265f;           // the constant PI
const float TaskMoveToWaypoint::K = 2.0f;                   // controller gain parameter

/**
 * Creates a task object that moves the robot to a given waypoint.
 * @param conroller a reference to the controller object of the robot.
 * @param x the x coordinate of the waypoint position, given in [m].
 * @param y the y coordinate of the waypoint position, given in [m].
 */
TaskMoveToWaypoint::TaskMoveToWaypoint(Controller& controller, float x, float y) : controller(controller) {
    
    this->x = x;
    this->y = y;
    this->velocity = DEFAULT_VELOCITY;
    this->initialDistance = 0.0f;
}

/**
 * Creates a task object that moves the robot to a given waypoint.
 * @param conroller a reference to the controller object of the robot.
 * @param x the x coordinate of the target position, given in [m].
 * @param y the y coordinate of the target position, given in [m].
 * @param velocity the maximum translational velocity, given in [m/s].
 */
TaskMoveToWaypoint::TaskMoveToWaypoint(Controller& controller, float x, float y, float velocity) : controller(controller) {
    
    this->x = x;
    this->y = y;
    this->velocity = velocity;
    this->initialDistance = 0.0f;
}

/**
 * Deletes the task object.
 */
TaskMoveToWaypoint::~TaskMoveToWaypoint() {}

/**
 * This method is called periodically by a task sequencer.
 * @param period the period of the task sequencer, given in [s].
 * @return the status of this task, i.e. RUNNING or DONE.
 */
int TaskMoveToWaypoint::run(float period) {
    
    float translationalVelocity = 0.0f;
    float rotationalVelocity = 0.0f;
    
    float x = controller.getX();
    float y = controller.getY();
    float alpha = controller.getAlpha();
    
    float rho = sqrt((this->x-x)*(this->x-x)+(this->y-y)*(this->y-y));
    float gamma = atan2(this->y-y, this->x-x)-alpha;
    
    while (gamma < -PI) gamma += 2.0f*PI;
    while (gamma > PI) gamma -= 2.0f*PI;
    
    if (initialDistance == 0.0f) initialDistance = rho;
    
    translationalVelocity = velocity;
    rotationalVelocity = (rho < initialDistance/2.0f) ? 0.0f : K*gamma;
    
    controller.setTranslationalVelocity(translationalVelocity);
    controller.setRotationalVelocity(rotationalVelocity);
    
    return (rho < initialDistance/2.0f) && ((gamma < -PI/2.0f) || (gamma > PI/2.0f)) ? DONE : RUNNING;
}