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/**
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 * Copyright (c) 2007 Colony Project
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 * 
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 * Permission is hereby granted, free of charge, to any person
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 * obtaining a copy of this software and associated documentation
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 * files (the "Software"), to deal in the Software without
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 * restriction, including without limitation the rights to use,
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 * copy, modify, merge, publish, distribute, sublicense, and/or sell
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 * copies of the Software, and to permit persons to whom the
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 * Software is furnished to do so, subject to the following
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 * conditions:
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 * 
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 * The above copyright notice and this permission notice shall be
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 * included in all copies or substantial portions of the Software.
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 * 
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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 * OTHER DEALINGS IN THE SOFTWARE.
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 **/
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/**
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 * @file move.c
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 * @brief Functions for moving
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 *
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 * Implementation of functions for moving the robot.
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 *
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 * @author Colony Project, CMU Robotics Club
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 **/
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#include "move.h"
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#include "motor.h"
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#include "rangefinder.h"
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// Internal prototypes
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void translateAngulartoLinear (int velocity, int omega, int* vl, int* vr);
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// global varaibles for move_avoid
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int d1, d2, d3, d4, d5; 
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/**
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 * @defgroup move Movement
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 * @brief Functions fo controlling robot motion
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 * Higher level functions to control the movement of robots.
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 * 
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 * @{
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 **/
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/**
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 * Causes the robot to move with the given translation and rotational velocities.
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 * motors_init must be called before this function can be used.
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 *
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 * @param velocity the translational velocity of the robot, in the range -255 to 255.
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 * A positive value indicates forward motion, while a negative value indicates
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 * backwards motion.
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 * 
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 * @param omega the rotational velocity of the robot, in the range -255 to 255.
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 * A positive value indicates a counterclockwise velocity, while a negative
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 * value indicates a clockwise velocity.
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 *
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 * @see motors_init, motor1_set, motor2_set
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 **/
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void move (int velocity, int omega) {
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  int vl = 0;
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  int vr = 0;
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  translateAngulartoLinear(velocity, omega, &vl , &vr );
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  //
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  if (vl < 0) {
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    motor1_set(BACKWARD, -vl);
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  } else {
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    motor1_set(FORWARD, vl);
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  }
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  if (vr < 0) {
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    motor2_set(BACKWARD, -vr);
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  } else {
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    motor2_set(FORWARD, vr);
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  }
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}
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/**
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 * Moves the robot with the given translational and angular velocities
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 * while avoiding obstacles. To be effective, this function must be
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 * called repeatedly throughout the motion. It relies on the IR
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 * rangefinders to detect obstacles. Before calling this function,
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 * motors_init and range_init must be called.
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 *
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 * @param velocity the translational velocity of the robot, in the
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 * range -255 to 255. A positive value indicates forward motion.
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 *
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 * @param omega the rotational velocity of the robot, in the range
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 * -255 to 255. A positive value indicates a counterclockwise velocity.
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 *
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 * @param strength the strength of the avoid behavior, in the range
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 * 0 to 100.
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 *
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 * @see motors_init, range_init, move
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 **/
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void move_avoid(int velocity, int omega, int strength) {
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  int pControl;
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  int vl = 0;
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  int vr = 0;
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  int temp;
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  temp=range_read_distance(IR1);
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  d1 = (temp == -1) ? d1 : temp;
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  temp=range_read_distance(IR2);
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  d2=(temp == -1) ? d2 : temp;
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  temp=range_read_distance(IR3);
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  d3=(temp == -1) ? d3 : temp;
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  temp=range_read_distance(IR4);
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  d4=(temp == -1) ? d4 : temp;
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  temp=range_read_distance(IR5);
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  d5=(temp == -1) ? d5 : temp;
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  /* Avoid obstacles ahead
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     if(d2>170)
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     v*=-1;
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     Naturally slow down if there is something in the way.
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     if(d2>150 || d1>180 || d3>180){
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     v>>=1;
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  */
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  //pControl= (((d3-d1) + (d4-d5))*strength)/100;
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  pControl= (((d5-d4))*strength)/100;
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  omega = (omega*(100-strength))/100 + pControl;
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  translateAngulartoLinear(velocity, omega, &vl , &vr );
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  if (vl < 0) {
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    motor1_set(BACKWARD, -vl);
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  } else {
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    motor1_set(FORWARD, vl);
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  }
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  if (vr < 0) {
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    motor2_set(BACKWARD, -vr);
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  } else {
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    motor2_set(FORWARD, vr);
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  }
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}
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/**@}**///end the motion group
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void translateAngulartoLinear (int velocity, int omega, int* vl, int* vr) {
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  //omega: angle measure, positive couter-clockwise from front.
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  // -180 <= omega <= 180
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  //velocity: -255 <= velocity <= 255
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  long int vltemp, vrtemp;
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  //make sure values are in bounds
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  if (velocity < -255 || velocity >255 || omega < -255 || omega > 255) return;
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  //compute
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  vrtemp = velocity + omega * 3;
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  vltemp = velocity - omega * 3;
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  //check to see if max linear velocities have been exceeded.
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  if (vrtemp > 255) {
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    vltemp = 255 * vltemp / vrtemp;
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    vrtemp = 255;
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  }
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  if (vltemp > 255) {           
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    vrtemp = 255 * vrtemp / vltemp;    
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    vltemp = 255;  
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  }
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  if (vrtemp < -255) {
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    vltemp = -255 * vltemp / vrtemp;
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    vrtemp = -255;
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  }
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  if (vltemp < -255) {
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    vrtemp = -255 * vrtemp / vltemp;
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    vltemp = -255;
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  }
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  *vr = (int)vrtemp;
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  *vl = (int)vltemp;
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}