Revision 4c9fb6ba scout/libscout/src/test_behaviors/smart_runaround.cpp

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scout/libscout/src/test_behaviors/smart_runaround.cpp
59 59
    return pixels/200.0;
60 60
}
61 61

  
62
// meters to pixels
63
int m_to_idx(float meters)
62
// millimeters to pixels
63
int mm_to_idx(float meters)
64 64
{
65
    float pixels = meters*200.0;
65
    // 200 pixels per meter, and 1000 millimeters per meter
66
    float pixels = meters*0.2;
66 67
    float idx = pixels/BLOCK_LENGTH;
67 68
    return floor(idx+0.5);
68 69
}
69 70

  
70
/* return a direction (if any) where adjacent block
71
 * is labeled "info" on map. Searches clockwise
72
 * starting at up. Returns -1 if no direction valid.
73
 */
74
int smart_runaround::choose_direc(int row, int col, int info)
71
float *matrix_mult(float inputs[2], float matrix[2][2])
75 72
{
76
    if (map[row-1][col] == info)
77
	return UP;
78
    else if (map[row][col+1] == info)
79
	return RIGHT;
80
    else if (map[row+1][col] == info)
81
	return DOWN;
82
    else if (map[row][col-1] == info)
83
	return LEFT;
84
    return -1;
73
    float newX = matrix[0][0]*inputs[0]+matrix[0][1]*inputs[1];
74
    float newY = matrix[1][0]*inputs[0]+matrix[1][1]*inputs[1];
75
    float output[2] = {newX, newY};
76
    return output;
85 77
}
86 78

  
87 79
// TODO This is bad! It's defined globally across all behaviors. Please fix this. -Alex
......
117 109

  
118 110

  
119 111
    int dir = RIGHT; // current direction
120
    int new_dir = RIGHT; // direction in which to turn after a scan
112
    //int new_dir = RIGHT; // direction in which to turn after a scan
121 113
    bool success = false; // true when maze solved
122 114
    while(ok())
123 115
    {
124
	// Look left, right, and forward
125 116
	look_around(row, col, dir);
126 117
	// Try moving in each direction
127
	new_dir = choose_direc(row, col, UNSEEN);
118
	/*new_dir = choose_direc(row, col, UNSEEN);
128 119
	if(new_dir < 0)
129 120
	    new_dir = choose_direc(row, col, SEEN);
130 121
	if(new_dir >= 0) {
131 122
	    turn_from_to(dir, new_dir);
132 123
	    dir = new_dir;
133
	}
124
	}*/
134 125
    }
135 126

  
136 127
    // Check and report final condition.
......
140 131
        ROS_INFO("NO! The maze is unsolvable");
141 132
}
142 133

  
143
// NOT CURRENTLY USED!!!
144
bool smart_runaround::solve(int row, int col, int dir)
134
/* return a direction (if any) where adjacent block
135
 * is labeled "info" on map. Searches clockwise
136
 * starting at up. Returns -1 if no direction valid.
137
 */
138
int smart_runaround::choose_direc(int row, int col, int info)
145 139
{
146
    int initial_dir = dir;
147

  
148
    ROS_INFO("I am at direction %d", dir);
149

  
150
    // use backtracking to solve the maze
151
    if (at_destination())
152
        return true;
153

  
154
    // Wait for sonar to update.
155
    sonar_update_time2.sleep();
156

  
157
    // this function should fill the adjacent cells around me with
158
    // wall's or paths
159
    while(!look_around(row, col, dir) && ok())
160
    {
161
        spinOnce();
162
    }
163

  
164
    /* try go up */
165
    if (map[row-1][col] != WALL && initial_dir != UP)
166
    {
167
    ROS_INFO("GOING UP!");
168
        // Turn up.
169
        turn_from_to(dir, UP);
170
        follow_line();
171
        // Solve recursively.
172
        bool solved = solve(row-1, col, DOWN);
173
        if (solved)
174
        {
175
            return solved;
176
        }
177
        else
178
        {
179
            //Update where we are.
180
            dir = UP;
181
        }
182
    }
183
    /* try right */
184
    if (map[row][col+1] != WALL && initial_dir != RIGHT)
185
    {
186
    ROS_INFO("GOING RIGHT!");
187
        // Turn right.
188
        turn_from_to(dir, RIGHT);
189
        follow_line();
190
        // Solve recursively.
191
        bool solved = solve(row, col+1, LEFT);
192
        if (solved)
193
        {
194
            return solved;
195
        }
196
        else
197
        {
198
            //Update where we are.
199
            dir = RIGHT;
200
        }
201
    }
202
    /* try down */
203
    if (map[row+1][col] != WALL && initial_dir != DOWN)
204
    {
205
    ROS_INFO("GOING DOWN!");
206
        // Turn down.
207
        turn_from_to(dir, DOWN);
208
        follow_line();
209
        // Solve recursively.
210
        bool solved = solve(row+1, col, UP);
211
        if (solved)
212
        {
213
            return solved;
214
        }
215
        else
216
        {
217
            //Update where we are.
218
            dir = DOWN;
219
        }
220
    }
221
    /* try left */
222
    if (map[row][col-1] != WALL && initial_dir != LEFT)
223
    {
224
    ROS_INFO("GOING LEFT!");
225
        // Turn down.
226
        turn_from_to(dir, LEFT);
227
        follow_line();
228
        // Solve recursively.
229
        bool solved = solve(row, col-1, RIGHT);
230
        if (solved)
231
        {
232
            return solved;
233
        }
234
        else
235
        {
236
            //Update where we are.
237
            dir = LEFT;
238
        }
239
    }
240

  
241
    ROS_INFO("DEAD END FOUND, TURNING BACK.");
242
    // we have exhausted all the options. This path is clearly a
243
    // dead end. go back to where we come from and return false.
244
    turn_from_to(dir, initial_dir);
245
    follow_line();
246
    return false;
140
    if (map[row-1][col] == info)
141
	return UP;
142
    else if (map[row][col+1] == info)
143
	return RIGHT;
144
    else if (map[row+1][col] == info)
145
	return DOWN;
146
    else if (map[row][col-1] == info)
147
	return LEFT;
148
    return -1;
247 149
}
248 150

  
249 151
/* this function takes in the current direction,
......
267 169
    }
268 170
}
269 171

  
172
/* Purpose: look front, left, and right using sonar, and update
173
 * map accordingly. Returns true if and only if sonar is initialized.
174
 */
270 175
bool smart_runaround::look_around(int row, int col, int dir)
271 176
{
272
    // look around current place using sonar
273
    // store whether or not
274
    // there is a wall into the map
275
    // stores at row col 2 if point is critical, 1 otherwise
276
    
277 177
    int* readings = sonar->get_sonar_readings();
278 178
    spinOnce();
279 179

  
280 180
    // Assumption: readings are given in millimeters - Zane
281 181

  
282
    // distances with respect to robot, NOT map
283
    // Look to the left.
284
    float left_distance = readings[0]/1000.0;
285
    int left_idx = m_to_idx(left_distance);
286
    // Look to the front.
287
    float front_distance = readings[36]/1000.0;
288
    int front_idx = m_to_idx(front_distance);
289
    // Look to the right.
290
    float right_distance = readings[24]/1000.0;
291
    int right_idx = m_to_idx(right_distance);
292

  
293
    ROS_INFO("front: %d  left: %d  right: %d", front_distance, left_distance, right_distance);
294
    if (right_distance == 0 || front_distance == 0 || left_distance == 0)
295
      return false;
296

  
297
    // determine relative distances on map, based on robot position
298
    int up_d, right_d, down_d, left_d;
299
    // determine upward distance
300
    switch (dir)
301
    {
302
	case UP:
303
	    up_d = front_idx;
304
	    right_d = right_idx;
305
	    down_d = 0; // unknown
306
	    left_d = left_idx;
307
	    break;
308
	case RIGHT:
309
	    up_d = left_idx;
310
	    right_d = front_idx;
311
	    down_d = right_idx;
312
	    left_d = 0; // unknown
313
	    break;
314
	case DOWN:
315
	    up_d = 0; // unknown
316
	    right_d = left_idx;
317
	    down_d = front_idx;
318
	    left_d = right_idx;
319
	    break;
320
	case LEFT:
321
	    up_d = right_idx;
322
	    right_d = 0; // unknown
323
	    down_d = left_idx;
324
	    left_d = front_idx;
325
	    break;
326
    }
327

  
328
    // change map until wall index, or until reading < 500
329
    // reading < 500 <=> left_idx < 8 (approx.)
330

  
331
    // map blocks above robot (on map)
332
    for(int u = 0; u < 8; u++)
333
    {
334
	if(u = up_d) {
335
	    map[row-u][col] = (up_d)?WALL:SEEN;
336
            break;
337
	}
338
	map[row-u][col] = SEEN;
339
    }
340

  
341
    // map blocks to right of robot
342
    for(int r = 0; r < 8; r++)
343
    {
344
	if(r = right_d) {
345
	    map[row][col+r] = (right_d)?WALL:SEEN;
346
            break;
347
	}
348
	map[row][col+r] = SEEN;
349
    }
350

  
351
    // map blocks under robot (on map)
352
    for(int d = 0; d < 8; d++)
353
    {
354
	if(d = down_d) {
355
	    map[row+d][col] = (down_d)?WALL:SEEN;
356
            break;
357
	}
358
	map[row+d][col] = SEEN;
359
    }
360

  
361
    // map blocks to left of robot
362
    for(int l = 0; l < 8; l++)
363
    {
364
	if(l = left_d) {
365
	    map[row][col-l] = (left_d)?WALL:SEEN;
366
            break;
367
	}
368
	map[row][col-l] = SEEN;
182
    // matrices for going from robot's frame to base frame
183
    float rightMat[2][2] = {{0, 1}, {-1, 0}};
184
    float downMat[2][2] = {{-1, 0}, {0, -1}};
185
    float leftMat[2][2] = {{0, 1}, {1, 0}};
186

  
187
    // Look to the left (and update map).
188
    float left_distance = readings[0]; // w.r.t. robot
189
    if(left_distance == 0)
190
        return false;
191
    int left_idx = -mm_to_idx(left_distance); // w.r.t. map
192
    // plot to map if indices are valid
193
    if (0 <= left_idx && left_idx < MAP_LENGTH)
194
        map[row][col+left_idx] = SEEN;
195

  
196
    // Look in the other directions (and update map).
197
    for (int i = 24; i < 48; i++) {
198
        float distance = readings[i]; // w.r.t. robot
199
        if(distance == 0)
200
            return false;
201
        if(distance >= 500)
202
            break; // too far to be accurate
203
        float theta = (M_PI/24)*i - M_PI;
204
        float xDist = distance*cos(theta); // w.r.t. robot
205
        float yDist = distance*sin(theta); // w.r.t. robot
206
        float inputs[2] = {xDist, yDist};
207
        float *ans;
208

  
209
        // re-orient x and y distances based on direction
210
        switch(dir) {
211
            case UP:
212
                ans[0] = xDist;
213
                ans[1] = yDist;
214
                break;
215
            case RIGHT:
216
                ans = matrix_mult(inputs, rightMat);
217
                break;
218
            case DOWN:
219
                ans = matrix_mult(inputs, downMat);
220
                break;
221
            case LEFT:
222
                ans = matrix_mult(inputs, leftMat);
223
                break;
224
        }
225
        // indices into the map
226
        int pixDistX = row + mm_to_idx(ans[0]);
227
        int pixDistY = col + mm_to_idx(ans[1]);
228
        // plot to map if indices are valid
229
        if (0 <= pixDistX && pixDistX < MAP_LENGTH
230
            && 0 <= pixDistY && pixDistY < MAP_LENGTH)
231
                map[pixDistX][pixDistY] = SEEN;
369 232
    }
370

  
371 233
    return true;
372 234
}
373 235

  

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