root / branches / simulator / projects / simulator / simulator / core / motion.c @ 1090
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1 | 1006 | bcoltin | #include <stdio.h> |
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2 | 1027 | chihsiuh | #include <stdlib.h> |
3 | 1006 | bcoltin | #include <math.h> |
4 | |||
5 | #include "motion.h" |
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6 | |||
7 | 1010 | bcoltin | #include "robot.h" |
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9 | 1027 | chihsiuh | #define CUTOFF 120 |
10 | #define TIME 1 /*sec*/ |
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11 | 1006 | bcoltin | #define ROBOT_WIDTH 131 /*mm*/ |
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13 | 1020 | bcoltin | #define MOTOR_CONVERSION_FACTOR 10.0 |
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15 | 1090 | bpoole | #define FUDGE 10 /* minimum rangefinder distance until collision */ |
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17 | 1027 | chihsiuh | /** move_robot will move a robot from its initial position, (x,y), and theta (in radians) to a new position given speed.
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18 | * (x,y) and theta will be updated by the move_robot function instead of returning a value
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19 | * (x,y) is some kind of absolute position in the "world", (0,0) is the top left of the "world"
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20 | * theta will an angle be between 0 and 2*Pi (0 being faces east and goes clockwise)
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21 | * speed is between 0 and 255, there is some magical cutoff point before the motors actually starts running
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22 | 1006 | bcoltin | * move will return 0 if successful
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23 | **/
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24 | 1010 | bcoltin | int move_robot(Robot* r)
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25 | { |
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26 | 1090 | bpoole | Pose old_pose = r->pose; |
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28 | 1010 | bcoltin | short speed1 = r->shared->motor1;
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29 | short speed2 = r->shared->motor2;
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30 | float theta = r->pose.theta;
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31 | 1075 | bjy | |
32 | 1010 | bcoltin | if (theta < 0 || theta > 2*M_PI) return 1; |
33 | 1075 | bjy | if (speed1 < -255 || speed1 > 255) return 1; |
34 | if (speed2 < -255 || speed2 > 255) return 1; |
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35 | 1006 | bcoltin | |
36 | 1010 | bcoltin | /* if speed is lower than the cut off, don't move */
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37 | 1027 | chihsiuh | if (abs(speed1) < CUTOFF) {
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38 | 1010 | bcoltin | speed1 = 0;
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39 | } |
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40 | 1027 | chihsiuh | if (abs(speed2) < CUTOFF) {
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41 | 1010 | bcoltin | speed2 = 0;
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42 | } |
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43 | 1046 | chihsiuh | |
44 | 1010 | bcoltin | double radius;
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45 | if (speed1 == speed2) {
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46 | 1027 | chihsiuh | /* go straight */
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47 | r->pose.x += cos(theta) * speed1 / MOTOR_CONVERSION_FACTOR; |
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48 | r->pose.y += sin(theta) * speed1 / MOTOR_CONVERSION_FACTOR; |
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49 | return 0; |
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50 | 1010 | bcoltin | } |
51 | radius = ROBOT_WIDTH * speed1 / (speed1 - speed2); |
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52 | |||
53 | 1020 | bcoltin | double t = speed1 / radius / MOTOR_CONVERSION_FACTOR;
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54 | 1006 | bcoltin | |
55 | 1020 | bcoltin | double newx = (radius * sin(t)) / MOTOR_CONVERSION_FACTOR;
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56 | double newy = (radius - radius * cos(t)) / MOTOR_CONVERSION_FACTOR;
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57 | 1019 | bcoltin | |
58 | 1010 | bcoltin | r->pose.x += newx * cos(theta); |
59 | r->pose.y += newx * sin(theta); |
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60 | 1006 | bcoltin | |
61 | 1010 | bcoltin | r->pose.x += newy * - sin(theta); |
62 | r->pose.y += newy * cos(theta); |
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63 | 1019 | bcoltin | |
64 | int divide = (t+r->pose.theta)/(2 * M_PI); |
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65 | r->pose.theta = (t+r->pose.theta) - (2 * M_PI * divide);
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66 | 1010 | bcoltin | if (r->pose.theta<0) r->pose.theta += 2 * M_PI; |
67 | |||
68 | 1090 | bpoole | /* XXX: this is a terrible hack */
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69 | update_rangefinders(r); |
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70 | for (divide = 0; divide < 5; divide++) { |
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71 | if (r->shared->ranges.d[divide] < FUDGE) {
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72 | r->pose = old_pose; |
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73 | return 0; |
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74 | } |
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75 | } |
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76 | /* XXX: should store values from before we alter rangefinders
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77 | * and restore here, but this is all temporary...right? */
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78 | update_rangefinders(r); |
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79 | |||
80 | 1010 | bcoltin | return 0; |
81 | 1006 | bcoltin | } |