root / trunk / code / projects / libdragonfly / move.c @ 1546
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1 | 241 | bcoltin | /**
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2 | * Copyright (c) 2007 Colony Project
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3 | *
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4 | * Permission is hereby granted, free of charge, to any person
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5 | * obtaining a copy of this software and associated documentation
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6 | * files (the "Software"), to deal in the Software without
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7 | * restriction, including without limitation the rights to use,
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8 | * copy, modify, merge, publish, distribute, sublicense, and/or sell
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9 | * copies of the Software, and to permit persons to whom the
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10 | * Software is furnished to do so, subject to the following
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11 | * conditions:
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12 | *
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13 | * The above copyright notice and this permission notice shall be
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14 | * included in all copies or substantial portions of the Software.
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15 | *
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16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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17 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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18 | * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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19 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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20 | * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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21 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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22 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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23 | * OTHER DEALINGS IN THE SOFTWARE.
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24 | **/
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25 | |||
26 | |||
27 | /**
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28 | * @file move.c
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29 | * @brief Functions for moving
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30 | *
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31 | * Implementation of functions for moving the robot.
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32 | *
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33 | * @author Colony Project, CMU Robotics Club
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34 | **/
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35 | |||
36 | 8 | bcoltin | #include "move.h" |
37 | 1452 | dsschult | #include "motor.h" |
38 | 8 | bcoltin | #include "rangefinder.h" |
39 | |||
40 | |||
41 | // Internal prototypes
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42 | void translateAngulartoLinear (int velocity, int omega, int* vl, int* vr); |
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43 | |||
44 | // global varaibles for move_avoid
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45 | 380 | jknichel | int d1, d2, d3, d4, d5;
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46 | /**
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47 | 8 | bcoltin | * @defgroup move Movement
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48 | * @brief Functions fo controlling robot motion
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49 | * Higher level functions to control the movement of robots.
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50 | *
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51 | * @{
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52 | **/
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53 | |||
54 | |||
55 | /**
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56 | * Causes the robot to move with the given translation and rotational velocities.
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57 | * motors_init must be called before this function can be used.
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58 | *
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59 | * @param velocity the translational velocity of the robot, in the range -255 to 255.
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60 | * A positive value indicates forward motion, while a negative value indicates
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61 | * backwards motion.
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62 | *
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63 | * @param omega the rotational velocity of the robot, in the range -255 to 255.
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64 | * A positive value indicates a counterclockwise velocity, while a negative
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65 | * value indicates a clockwise velocity.
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66 | *
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67 | * @see motors_init, motor1_set, motor2_set
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68 | **/
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69 | void move (int velocity, int omega) { |
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70 | int vl = 0; |
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71 | int vr = 0; |
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72 | translateAngulartoLinear(velocity, omega, &vl , &vr ); |
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73 | //
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74 | |||
75 | if (vl < 0) { |
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76 | motor1_set(BACKWARD, -vl); |
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77 | } else {
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78 | motor1_set(FORWARD, vl); |
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79 | } |
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80 | if (vr < 0) { |
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81 | motor2_set(BACKWARD, -vr); |
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82 | } else {
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83 | motor2_set(FORWARD, vr); |
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84 | } |
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85 | } |
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86 | |||
87 | |||
88 | /**
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89 | * Moves the robot with the given translational and angular velocities
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90 | * while avoiding obstacles. To be effective, this function must be
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91 | * called repeatedly throughout the motion. It relies on the IR
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92 | * rangefinders to detect obstacles. Before calling this function,
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93 | * motors_init and range_init must be called.
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94 | *
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95 | * @param velocity the translational velocity of the robot, in the
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96 | * range -255 to 255. A positive value indicates forward motion.
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97 | *
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98 | * @param omega the rotational velocity of the robot, in the range
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99 | * -255 to 255. A positive value indicates a counterclockwise velocity.
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100 | *
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101 | * @param strength the strength of the avoid behavior, in the range
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102 | * 0 to 100.
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103 | *
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104 | * @see motors_init, range_init, move
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105 | **/
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106 | 380 | jknichel | void move_avoid(int velocity, int omega, int strength) { |
107 | 8 | bcoltin | int pControl;
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108 | int vl = 0; |
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109 | int vr = 0; |
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110 | int temp;
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111 | |||
112 | temp=range_read_distance(IR1); |
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113 | d1 = (temp == -1) ? d1 : temp;
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114 | |||
115 | temp=range_read_distance(IR2); |
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116 | d2=(temp == -1) ? d2 : temp;
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117 | |||
118 | temp=range_read_distance(IR3); |
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119 | d3=(temp == -1) ? d3 : temp;
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120 | |||
121 | temp=range_read_distance(IR4); |
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122 | d4=(temp == -1) ? d4 : temp;
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123 | |||
124 | temp=range_read_distance(IR5); |
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125 | d5=(temp == -1) ? d5 : temp;
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126 | |||
127 | /* Avoid obstacles ahead
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128 | 380 | jknichel | if(d2>170)
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129 | v*=-1;
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130 | 8 | bcoltin | |
131 | 380 | jknichel | Naturally slow down if there is something in the way.
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132 | if(d2>150 || d1>180 || d3>180){
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133 | v>>=1;
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134 | 8 | bcoltin | */
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135 | |||
136 | //pControl= (((d3-d1) + (d4-d5))*strength)/100;
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137 | pControl= (((d5-d4))*strength)/100;
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138 | omega = (omega*(100-strength))/100 + pControl; |
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139 | translateAngulartoLinear(velocity, omega, &vl , &vr ); |
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140 | |||
141 | if (vl < 0) { |
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142 | motor1_set(BACKWARD, -vl); |
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143 | } else {
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144 | motor1_set(FORWARD, vl); |
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145 | } |
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146 | if (vr < 0) { |
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147 | motor2_set(BACKWARD, -vr); |
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148 | } else {
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149 | motor2_set(FORWARD, vr); |
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150 | } |
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151 | } |
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152 | |||
153 | /**@}**///end the motion group |
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154 | |||
155 | void translateAngulartoLinear (int velocity, int omega, int* vl, int* vr) { |
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156 | 380 | jknichel | //omega: angle measure, positive couter-clockwise from front.
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157 | // -180 <= omega <= 180
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158 | //velocity: -255 <= velocity <= 255
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159 | 8 | bcoltin | |
160 | long int vltemp, vrtemp; |
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161 | |||
162 | //make sure values are in bounds
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163 | if (velocity < -255 || velocity >255 || omega < -255 || omega > 255) return; |
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164 | |||
165 | //compute
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166 | 380 | jknichel | vrtemp = velocity + omega * 3;
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167 | vltemp = velocity - omega * 3;
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168 | 8 | bcoltin | |
169 | 380 | jknichel | //check to see if max linear velocities have been exceeded.
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170 | 8 | bcoltin | if (vrtemp > 255) { |
171 | vltemp = 255 * vltemp / vrtemp;
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172 | vrtemp = 255;
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173 | } |
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174 | if (vltemp > 255) { |
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175 | 380 | jknichel | vrtemp = 255 * vrtemp / vltemp;
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176 | vltemp = 255;
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177 | 8 | bcoltin | } |
178 | if (vrtemp < -255) { |
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179 | vltemp = -255 * vltemp / vrtemp;
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180 | vrtemp = -255;
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181 | } |
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182 | if (vltemp < -255) { |
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183 | vrtemp = -255 * vrtemp / vltemp;
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184 | vltemp = -255;
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185 | } |
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186 | |||
187 | *vr = (int)vrtemp;
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188 | *vl = (int)vltemp;
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189 | } |