root / trunk / code / behaviors / lemmings / smart_run_around_fsm.c @ 1345
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1 | 700 | dsschult | /**
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2 | */
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3 | |||
4 | #include <string.h> |
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5 | #include "dragonfly_lib.h" |
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6 | #include "smart_run_around_fsm.h" |
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7 | |||
8 | /*A simple behavior for navigating in an environment, i.e. avoiding walls and getting stuck.
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9 | Could be better at not getting stuck.
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10 | |||
11 | Latest revision only has two accessible states: move and reverse.
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12 | */
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13 | |||
14 | // FSM states
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15 | #define MOVING 12 //Move strait. |
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16 | #define BACKWARDS 15 //Move backwards. (Front close to wall.) |
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17 | #define STOP 16 //Stop. The default state, (Something broke). |
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18 | #define CRAZY 40 //Erratic behavior that occurs more often when the robot is frequently trying to turn. (i.e. may be stuck.) |
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19 | |||
20 | #define LEFT 37 //Left |
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21 | #define RIGHT 39 //Right |
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22 | |||
23 | #define BACKUP_MAX 20 |
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24 | #define CRAZY_MAX 200 //The number of counts between "crazy moments" |
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25 | #define STRAIT_SPEED 185 //The speed when going strait or backing up. |
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26 | #define TURN_CONSTANT 2 |
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27 | #define PCONTROL_CRAZY_LIMIT 80 |
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28 | |||
29 | // Globals
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30 | int avoid_state; /*State machine variable.*/ |
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31 | int crazy_count; /*Counter for a 'get unstuck' behavior.*/ |
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32 | |||
33 | int backup_count; /*Counter for backup duration.*/ |
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34 | int pControl; /*Proportional control variable, determines turn direction.*/ |
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35 | |||
36 | #define NUM_IR_SENSORS 5 |
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37 | int dist[NUM_IR_SENSORS];
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38 | |||
39 | static void evaluate_state(void); |
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40 | |||
41 | void run_around_init(void) { |
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42 | /* range_init(); */
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43 | /* analog_init(); */
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44 | /* motors_init(); */
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45 | /* orb_init(); */
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46 | /* orb_enable(); */
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47 | /* usb_init(); */
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48 | |||
49 | avoid_state = MOVING; |
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50 | |||
51 | /*Set timers to their maximum values.*/
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52 | crazy_count = CRAZY_MAX; |
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53 | backup_count = 0;
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54 | pControl = 0;
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55 | |||
56 | /*Initialize distances to zero.*/
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57 | memset(dist, 0, NUM_IR_SENSORS * sizeof(int)); |
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58 | } |
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59 | |||
60 | /*The main function, call this to update states as frequently as possible.*/
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61 | void run_around_FSM(void) { |
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62 | /*Default to moving.*/
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63 | avoid_state=MOVING; |
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64 | |||
65 | /*The following lines ensure that undefined (-1) values
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66 | will not update the distances.*/
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67 | int temp;
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68 | |||
69 | temp = range_read_distance(IR1); |
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70 | dist[0] = (temp == -1) ? dist[0] : temp; |
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71 | |||
72 | temp=range_read_distance(IR2); |
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73 | dist[1] = (temp == -1) ? dist[1] : temp; |
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74 | |||
75 | temp=range_read_distance(IR3); |
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76 | dist[2] = (temp == -1) ? dist[2] : temp; |
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77 | |||
78 | temp=range_read_distance(IR4); |
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79 | dist[3] = (temp == -1) ? dist[3] : temp; |
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80 | |||
81 | temp=range_read_distance(IR5); |
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82 | dist[4] = (temp == -1) ? dist[4] : temp; |
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83 | |||
84 | /*If the crazy count is in it's >>3 range, it acts crazy.*/
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85 | if (crazy_count <= (CRAZY_MAX>>3)) { |
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86 | avoid_state=CRAZY; |
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87 | crazy_count--; |
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88 | |||
89 | if (crazy_count < 0) { |
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90 | crazy_count=CRAZY_MAX; |
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91 | } |
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92 | |||
93 | evaluate_state(); |
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94 | return;
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95 | } |
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96 | |||
97 | //Checks the forward distance to see if it should back up, if so...state backwards.
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98 | if ((dist[1] != -1) && (dist[1] < 150)){ |
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99 | backup_count=BACKUP_MAX; |
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100 | avoid_state=BACKWARDS; |
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101 | evaluate_state(); |
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102 | return;
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103 | } |
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104 | |||
105 | /*
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106 | if(dist[0] < 120 || dist[2] < 120) {
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107 | avoid_state = BACKWARDS;
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108 | backup_count = BACKUP_MAX;
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109 | evaluate_state();
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110 | return;
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111 | }
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112 | */
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113 | |||
114 | if(backup_count<BACKUP_MAX){
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115 | avoid_state=BACKWARDS; |
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116 | if (backup_count<0) { |
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117 | backup_count = BACKUP_MAX; |
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118 | } |
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119 | |||
120 | evaluate_state(); |
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121 | return;
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122 | } |
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123 | |||
124 | /*Should evaluate an expression from -255 to 255 to pass to move.*/
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125 | pControl= ((dist[2]-dist[0]) + (dist[3]-dist[4])) >> TURN_CONSTANT; |
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126 | |||
127 | if(pControl>PCONTROL_CRAZY_LIMIT || pControl<-PCONTROL_CRAZY_LIMIT) crazy_count--;
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128 | /*i.e. if you really want to turn for an extended period of time...you're probably stuck.*/
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129 | |||
130 | /*Debug stuff:*/
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131 | /*usb_puts("pControl evaluating: ");
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132 | usb_puti(pControl);
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133 | usb_puts("\n\r");
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134 | usb_puts("IR1: ");
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135 | usb_puti(dist[0]);
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136 | usb_puts(" IR2: ");
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137 | usb_puti(dist[1]);
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138 | usb_puts(" IR3: ");
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139 | usb_puti(dist[2]);
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140 | usb_puts(" IR4: ");
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141 | usb_puti(dist[3]);
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142 | usb_puts(" IR5: ");
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143 | usb_puti(dist[4]);
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144 | usb_puts("\n\r");*/
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145 | |||
146 | evaluate_state(); |
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147 | } |
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148 | |||
149 | //Acts on state change.
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150 | static void evaluate_state(){ |
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151 | switch(avoid_state){
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152 | case(MOVING): orb_set_color(GREEN);
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153 | move(STRAIT_SPEED,-pControl); |
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154 | break;
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155 | |||
156 | case(BACKWARDS): orb_set_color(ORANGE);
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157 | move(-STRAIT_SPEED,0);
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158 | break;
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159 | |||
160 | case(CRAZY): orb_set_color(RED);
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161 | /*TODO: Implement a crazy state.*/
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162 | move(STRAIT_SPEED,-pControl); |
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163 | break;
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164 | |||
165 | default:
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166 | /*Should never get here, go strait.*/
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167 | move(100,0); orb_set_color(BLUE); |
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168 | break;
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169 | } |
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170 | } |