Mercurial Hosting > traffic-intelligence
comparison scripts/timeToCollision.py @ 461:cb41f9a4652b
TTC tested and updatet!
author | Sohail Zangenehpour <sohail.zangenehpour@mail.mcgill.ca> |
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date | Mon, 03 Feb 2014 15:39:12 -0500 |
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441:ea907ae19d8c | 461:cb41f9a4652b |
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1 def timeToCollision(obj1,obj2,collisionDistanceThreshold,frameNum,framePerSecond): | |
2 | |
3 import numpy as np | |
4 | |
5 x1 = obj1.getPositionAtInstant(frameNum).x | |
6 y1 = obj1.getPositionAtInstant(frameNum).y | |
7 x2 = obj2.getPositionAtInstant(frameNum).x | |
8 y2 = obj2.getPositionAtInstant(frameNum).y | |
9 v1x = obj1.getVelocityAtInstant(frameNum).x * framePerSecond | |
10 v1y = obj1.getVelocityAtInstant(frameNum).y * framePerSecond | |
11 v2x = obj2.getVelocityAtInstant(frameNum).x * framePerSecond | |
12 v2y = obj2.getVelocityAtInstant(frameNum).y * framePerSecond | |
13 l = collisionDistanceThreshold | |
14 | |
15 a = pow(v1x-v2x,2) + pow(v1y-v2y,2) | |
16 b = 2 * ((x1-x2) * (v1x-v2x) + (y1-y2) * (v1y-v2y)) | |
17 c = pow(x1-x2,2) + pow(y1-y2,2) - pow(l,2) | |
18 | |
19 if pow(b,2) >= 4*a*c: | |
20 ttc1 = (-b + np.sqrt(pow(b,2) - 4*a*c)) / (2*a) | |
21 ttc2 = (-b - np.sqrt(pow(b,2) - 4*a*c)) / (2*a) | |
22 if ttc1 >= 0 and ttc2 >= 0: | |
23 ttc = min(ttc1,ttc2) | |
24 else: | |
25 if ttc1 < 0: | |
26 ttc = ttc2 | |
27 if ttc2 < 0: | |
28 ttc = ttc1 | |
29 if ttc1 < 0 and ttc2 < 0: | |
30 ttc = [] | |
31 else: | |
32 ttc = [] | |
33 | |
34 return ttc |