root / trunk / code / projects / libdragonfly / move.c @ 483
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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 "dragonfly_lib.h" |
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#include "move.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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} |