root / trunk / code / projects / linefollowing / lineFollow.c @ 1951
History | View | Annotate | Download (8.67 KB)
1 |
/**
|
---|---|
2 |
* @file lineFollow.c
|
3 |
* @defgroup lineFollwing Line Following
|
4 |
*
|
5 |
* Takes care of following a line. Running this program is done by calling the
|
6 |
* init() function and then the lineFollow(speed) command. However, direct use
|
7 |
* of this class is discouraged as its behavior is used by lineDrive.c, which
|
8 |
* extends this class to provide behavior functionality.
|
9 |
*
|
10 |
* @author Dan Jacobs and the Colony Project
|
11 |
* @date 11-1-2010
|
12 |
*/
|
13 |
|
14 |
#include "lineFollow.h" |
15 |
|
16 |
//! The number of bits expected in a barcode
|
17 |
#define CODESIZE 5 |
18 |
#define LINE_COLOR 200 |
19 |
|
20 |
|
21 |
int countHi = 0; |
22 |
int countLo = 0; |
23 |
int maxAvg, avg;
|
24 |
int barCode[ CODESIZE ];
|
25 |
int barCodePosition=0; |
26 |
|
27 |
int duration = 0; |
28 |
int lastColor = 0; |
29 |
char isReset = 0; |
30 |
|
31 |
int turnDistance=0; |
32 |
//! Counts the number of full line readings before we determine an intersection
|
33 |
int intersectionFilter=0; |
34 |
int disableBarCode=0; |
35 |
|
36 |
//! Keeps track of where the encoder of one motor started, for use in turns.
|
37 |
int encoderStart = -1; |
38 |
int encoderReset = 0; // 0 if encoderStart has no value set |
39 |
|
40 |
|
41 |
void lineFollow_init()
|
42 |
{ |
43 |
analog_init(0);
|
44 |
lost = 0;
|
45 |
intersectionFilter=0;
|
46 |
disableBarCode=0;
|
47 |
} |
48 |
|
49 |
|
50 |
/**
|
51 |
* Follows a line at the given speed.
|
52 |
* @param speed The speed with which to follow the line.
|
53 |
*/
|
54 |
int lineFollow(int speed) |
55 |
{ |
56 |
int colors[5]; |
57 |
int position;
|
58 |
|
59 |
|
60 |
updateLine(colors); |
61 |
position = lineLocate(colors); |
62 |
|
63 |
//not on line
|
64 |
if(position == NOLINE)
|
65 |
{ |
66 |
if(lost++ > 20) |
67 |
{ |
68 |
orb2_set_color(GREEN); |
69 |
motors_off(); |
70 |
return LINELOST;
|
71 |
} |
72 |
} |
73 |
else if(position == FULL_LINE) |
74 |
{ |
75 |
if(intersectionFilter++ > 4) |
76 |
{ |
77 |
orb2_set_color(RED); |
78 |
barCodePosition=0;
|
79 |
disableBarCode=50;
|
80 |
} |
81 |
} |
82 |
//on line
|
83 |
else
|
84 |
{ |
85 |
position*=30;
|
86 |
orb2_set_color(ORB_OFF); |
87 |
motorLeft(min(speed+position, 255));
|
88 |
motorRight(min(speed-position, 255));
|
89 |
lost=0;
|
90 |
intersectionFilter=0;
|
91 |
} |
92 |
|
93 |
// If we're running over a line, stop reading barcodes for a sec
|
94 |
if(disableBarCode-- > 0) |
95 |
{ |
96 |
// Return intersection once we cross the line
|
97 |
if(disableBarCode) return NOBARCODE; |
98 |
return INTERSECTION;
|
99 |
} |
100 |
updateBarCode(); |
101 |
return getBarCode();
|
102 |
} |
103 |
|
104 |
|
105 |
/**
|
106 |
* Implements the left merge, assuming a line exists to the left. Works by
|
107 |
* turning off the line at an increasing angle and waiting to hit another line
|
108 |
* on the left.
|
109 |
*/
|
110 |
int mergeLeft()
|
111 |
{ |
112 |
motor_l_set(FORWARD, 200);
|
113 |
if(turnDistance!=21)motor_r_set(FORWARD, 230); |
114 |
else motor_r_set(FORWARD, 210); |
115 |
int colors[5]; |
116 |
updateLine(colors); |
117 |
int position = lineLocate(colors);
|
118 |
if(position>3 || position<-3)turnDistance++; |
119 |
|
120 |
if(turnDistance>20) |
121 |
{ |
122 |
turnDistance=21;
|
123 |
|
124 |
if(position<3 && position>-3) |
125 |
{ |
126 |
turnDistance = 0;
|
127 |
return 0; |
128 |
} |
129 |
} |
130 |
return 1; |
131 |
} |
132 |
|
133 |
|
134 |
/**
|
135 |
* Implements the right merge, assuming a line exists to the right. Works by
|
136 |
* turning off the line at an increasing angle and waiting to hit another line
|
137 |
* on the right.
|
138 |
*/
|
139 |
int mergeRight()
|
140 |
{ |
141 |
motor_r_set(FORWARD, 200);
|
142 |
if(turnDistance!=21)motor_l_set(FORWARD, 230); |
143 |
else motor_l_set(FORWARD, 210); |
144 |
int colors[5]; |
145 |
updateLine(colors); |
146 |
int position = lineLocate(colors);
|
147 |
if(position>3 || position<-3)turnDistance++; |
148 |
|
149 |
if(turnDistance>20) |
150 |
{ |
151 |
turnDistance=21;
|
152 |
|
153 |
if(position<3 && position>-3) |
154 |
{ |
155 |
turnDistance = 0;
|
156 |
return 0; |
157 |
} |
158 |
} |
159 |
return 1; |
160 |
} |
161 |
|
162 |
|
163 |
|
164 |
/**
|
165 |
* Turns left at a cross of two lines. Assumes that we are at lines in a cross
|
166 |
* pattern, and turns until it sets straight on the new line.
|
167 |
* @return 0 if turn finishes otherwise return 1
|
168 |
*/
|
169 |
int turnLeft()
|
170 |
{ |
171 |
/*motor_l_set(BACKWARD, 200);
|
172 |
motor_r_set(FORWARD, 200);
|
173 |
int colors[5];
|
174 |
updateLine(colors);
|
175 |
int position = lineLocate(colors);
|
176 |
if(position>2 || position<-2)turnDistance++;
|
177 |
if(turnDistance>1)
|
178 |
{
|
179 |
if(position<3 && position>-3)
|
180 |
{
|
181 |
turnDistance = 0;
|
182 |
return 0;
|
183 |
}
|
184 |
}
|
185 |
return 1;*/
|
186 |
|
187 |
motor_l_set(BACKWARD,200);
|
188 |
motor_r_set(FORWARD,200);
|
189 |
if(!encoderReset)
|
190 |
{ |
191 |
encoderStart = encoder_get_x(RIGHT); |
192 |
encoderReset = 1;
|
193 |
} |
194 |
|
195 |
if(encoder_get_x(RIGHT) < encoderStart)
|
196 |
{ |
197 |
encoderStart = 0;
|
198 |
// Temporary: display an "error message" in case of overflow.
|
199 |
// Using this for debugging, take it out soon!
|
200 |
motor_l_set(FORWARD,0);
|
201 |
motor_r_set(FORWARD,0);
|
202 |
orb_set_color(WHITE); |
203 |
delay_ms(2000);
|
204 |
} |
205 |
|
206 |
if(encoder_get_x(RIGHT) - encoderStart > 300) |
207 |
{ |
208 |
encoderReset = 0;
|
209 |
return 0; |
210 |
} |
211 |
return 1; |
212 |
} |
213 |
|
214 |
|
215 |
|
216 |
/**
|
217 |
* Turns right at a cross of two lines. Assumes that we are at lines in a cross
|
218 |
* pattern, and turns until it sets straight on the new line.
|
219 |
* @return 0 if the turn finishes otherwise return 1
|
220 |
*/
|
221 |
int turnRight()
|
222 |
{ |
223 |
motor_r_set(BACKWARD, 200);
|
224 |
motor_l_set(FORWARD, 200);
|
225 |
int colors[5]; |
226 |
updateLine(colors); |
227 |
int position = lineLocate(colors);
|
228 |
if(position>2 || position<-2)turnDistance++; |
229 |
if(turnDistance>1) |
230 |
{ |
231 |
if(position<3 && position>-3) |
232 |
{ |
233 |
turnDistance = 0;
|
234 |
return 0; |
235 |
} |
236 |
} |
237 |
return 1; |
238 |
} |
239 |
|
240 |
|
241 |
|
242 |
int getBarCode()
|
243 |
{ |
244 |
if(barCodePosition != CODESIZE)
|
245 |
return NOBARCODE ;
|
246 |
else
|
247 |
{ |
248 |
int temp = 0; |
249 |
for(int i=0; i<CODESIZE; i++) |
250 |
temp += (barCode[i] << i); |
251 |
barCodePosition = 0;
|
252 |
return temp;
|
253 |
} |
254 |
} |
255 |
|
256 |
|
257 |
|
258 |
void updateLine(int* values) |
259 |
{ |
260 |
for(int i = 0; i<5; i++) |
261 |
values[i] = (read_line(4-i) < LINE_COLOR ? LWHITE : LBLACK);
|
262 |
} |
263 |
|
264 |
|
265 |
|
266 |
int lineLocate(int* colors) |
267 |
{ |
268 |
int i;
|
269 |
int wsum = 0; |
270 |
int count=0; |
271 |
|
272 |
for(i = 0; i<5; i++) |
273 |
{ |
274 |
count += colors[i]/2;
|
275 |
wsum += (i)*colors[i]; |
276 |
} |
277 |
if(count==0) |
278 |
return NOLINE;
|
279 |
if(count==5) |
280 |
return FULL_LINE;
|
281 |
return (wsum/count)-4; // Subtract 4 to center the index around the center. |
282 |
} |
283 |
|
284 |
|
285 |
// new version by Alex
|
286 |
void updateBarCode()
|
287 |
{ |
288 |
// USING THESE GLOBAL VARIABLES
|
289 |
// global int duration = 0;
|
290 |
// global int lastColor = 0;
|
291 |
// global int barCodePosition = 0;
|
292 |
// global char isReset = 0;
|
293 |
|
294 |
// Average the readings of the last 2 sensors
|
295 |
if(read_line(6) - read_line(7) > 150 || read_line(6) - read_line(7) < -150) |
296 |
{ |
297 |
return;
|
298 |
} |
299 |
|
300 |
int curReading = (read_line(6) + read_line(7)) / 2; |
301 |
int curColor;
|
302 |
|
303 |
if(curReading > BLACK_THRESHOLD)
|
304 |
curColor = LBLACK; |
305 |
else if(curReading < GREY_THRESHOLD) |
306 |
curColor = LWHITE; |
307 |
else
|
308 |
curColor = LGREY; |
309 |
|
310 |
// Just an error check
|
311 |
if(barCodePosition > CODESIZE)
|
312 |
{ |
313 |
barCodePosition = 0;
|
314 |
} |
315 |
|
316 |
// We are only interested in consecutive color values
|
317 |
if(curColor == lastColor)
|
318 |
{ |
319 |
duration++; |
320 |
} |
321 |
else
|
322 |
{ |
323 |
duration = 0;
|
324 |
lastColor = curColor; |
325 |
} |
326 |
|
327 |
if(duration > MAX_DURATION)
|
328 |
{ |
329 |
// Now we assume our reading is significant - a bit, or a white space
|
330 |
|
331 |
// Only read a value if we have read 0 first (isReset == 1)
|
332 |
if(isReset && (curColor == LBLACK || curColor == LGREY) )
|
333 |
{ |
334 |
isReset = 0;
|
335 |
usb_puts("Read barcode bit: ");
|
336 |
usb_puti(barCodePosition); |
337 |
usb_puts(" = ");
|
338 |
usb_puti(curColor); |
339 |
usb_puts(", curReading = ");
|
340 |
usb_puti(curReading); |
341 |
usb_puts(".\n");
|
342 |
|
343 |
barCode[barCodePosition++] = (curColor == LBLACK) ? 1 : 0; |
344 |
} |
345 |
else if(curColor == LWHITE) |
346 |
{ |
347 |
isReset = 1;
|
348 |
} |
349 |
} |
350 |
if(duration > TIMEOUT_DURATION && barCodePosition != 0) |
351 |
{ |
352 |
usb_puts("TIMED OUT. BARCODE READER RESET.\n");
|
353 |
barCodePosition = 0;
|
354 |
duration = 0;
|
355 |
} |
356 |
} |
357 |
|
358 |
// Dan's version
|
359 |
/*void updateBarCode()
|
360 |
{
|
361 |
//! Note: currently only uses one of the barcode sensors.
|
362 |
|
363 |
//maps the sensors to the analog input ports
|
364 |
int ports[2] = {8,1};
|
365 |
int current[2];
|
366 |
// current[0] = analog_get10(ports[0]);
|
367 |
//current[1] = analog_get10(ports[1]);
|
368 |
current[1] = read_line(6);
|
369 |
|
370 |
if(current[1] > 150)
|
371 |
{
|
372 |
if(countHi++ == 0)
|
373 |
{
|
374 |
avg = 500;
|
375 |
maxAvg = 500;
|
376 |
}
|
377 |
else
|
378 |
{
|
379 |
avg = 3*avg + current[1];
|
380 |
avg/=4;
|
381 |
maxAvg = max(maxAvg, avg);
|
382 |
}
|
383 |
}
|
384 |
else if(countHi > 5)
|
385 |
{
|
386 |
if(countLo++ > 15)
|
387 |
{
|
388 |
countHi = countLo = 0;
|
389 |
if(maxAvg > 825)
|
390 |
orb1_set_color(RED);
|
391 |
else orb1_set_color(BLUE);
|
392 |
barCode[barCodePosition++] = maxAvg > 825 ? 1:0;
|
393 |
}
|
394 |
}
|
395 |
else countHi/=2;
|
396 |
if(countHi==0)countLo=0;
|
397 |
}*/
|
398 |
|
399 |
|
400 |
int min(int x, int y){return x>y ? y : x;} |
401 |
int max(int x, int y){return x<y ? y : x;} |
402 |
|
403 |
void motorLeft(int speed){ |
404 |
((speed-=127)>=0)?motor_l_set(FORWARD, 160+speed*95/128):motor_l_set(BACKWARD, 160-speed*95/127); |
405 |
} |
406 |
|
407 |
void motorRight(int speed){ |
408 |
((speed-=127)>=0)?motor_r_set(FORWARD, 160+speed*95/128):motor_r_set(BACKWARD, 160-speed*95/127); |
409 |
} |