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comparison python/prediction.py @ 271:bbd9c09e6869

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changed the names to prediction methods and predicted trajectories
author Nicolas Saunier <nicolas.saunier@polymtl.ca>
date Thu, 09 Aug 2012 15:18:20 -0400
parents python/extrapolation.py@05c9b0cb8202
children e56c34c1ebac
comparison
equal deleted inserted replaced
270:05c9b0cb8202 271:bbd9c09e6869
1 #! /usr/bin/env python
2 '''Library for motion prediction methods'''
3
4 import moving
5 import math
6 import random
7
8 class PredictedTrajectory:
9 '''Class for predicted trajectories with lazy evaluation
10 if the predicted position has not been already computed, compute it
11
12 it should also have a probability'''
13
14 def __init__(self):
15 self.probability = 0.
16 self.predictedPositions = {}
17 self.predictedSpeedOrientations = {}
18 self.collisionPoints = {}
19 self.crossingZones = {}
20
21 def predictPosition(self, nTimeSteps):
22 if nTimeSteps > 0 and not nTimeSteps in self.predictedPositions.keys():
23 self.predictPosition(nTimeSteps-1)
24 self.predictedPositions[nTimeSteps], self.predictedSpeedOrientations[nTimeSteps] = moving.predictPosition(self.predictedPositions[nTimeSteps-1], self.predictedSpeedOrientations[nTimeSteps-1], self.getControl(), self.maxSpeed)
25 return self.predictedPositions[nTimeSteps]
26
27 def getPredictedTrajectory(self):
28 return moving.Trajectory.fromPointList(self.predictedPositions.values())
29
30 def getPredictedSpeeds(self):
31 return [so.norm for so in self.predictedSpeedOrientations.values()]
32
33 def draw(self, options = '', withOrigin = False, timeStep = 1, **kwargs):
34 self.getPredictedTrajectory().draw(options, withOrigin, timeStep, **kwargs)
35
36 class PredictedTrajectoryConstant(PredictedTrajectory):
37 '''Predicted trajectory at constant speed or acceleration
38 TODO generalize by passing a series of velocities/accelerations'''
39
40 def __init__(self, initialPosition, initialVelocity, control = moving.NormAngle(0,0), probability = 1, maxSpeed = None):
41 self.control = control
42 self.maxSpeed = maxSpeed
43 self.probability = probability
44 self.predictedPositions = {0: initialPosition}
45 self.predictedSpeedOrientations = {0: moving.NormAngle.fromPoint(initialVelocity)}
46
47 def getControl(self):
48 return self.control
49
50 class PredictedTrajectoryNormalAdaptation(PredictedTrajectory):
51 '''Random small adaptation of vehicle control '''
52 def __init__(self, initialPosition, initialVelocity, accelerationDistribution, steeringDistribution, probability = 1, maxSpeed = None):
53 '''Constructor
54 accelerationDistribution and steeringDistribution are distributions
55 that return random numbers drawn from them'''
56 self.accelerationDistribution = accelerationDistribution
57 self.steeringDistribution = steeringDistribution
58 self.maxSpeed = maxSpeed
59 self.probability = probability
60 self.predictedPositions = {0: initialPosition}
61 self.predictedSpeedOrientations = {0: moving.NormAngle.fromPoint(initialVelocity)}
62
63 def getControl(self):
64 return moving.NormAngle(self.accelerationDistribution(),self.steeringDistribution())
65
66 class PredictionParameters:
67 def __init__(self, name, maxSpeed):
68 self.name = name
69 self.maxSpeed = maxSpeed
70
71 def __str__(self):
72 return '{0} {1}'.format(self.name, self.maxSpeed)
73
74 class ConstantPredictionParameters(PredictionParameters):
75 def __init__(self, maxSpeed):
76 PredictionParameters.__init__(self, 'constant velocity', maxSpeed)
77
78 def generatePredictedTrajectories(self, obj, instant):
79 return [PredictedTrajectoryConstant(obj.getPositionAtInstant(instant), obj.getVelocityAtInstant(instant),
80 maxSpeed = self.maxSpeed)]
81
82 class NormalAdaptationPredictionParameters(PredictionParameters):
83 def __init__(self, maxSpeed, nPredictedTrajectories, maxAcceleration, maxSteering):
84 PredictionParameters.__init__(self, 'normal adaptation', maxSpeed)
85 self.nPredictedTrajectories = nPredictedTrajectories
86 self.maxAcceleration = maxAcceleration
87 self.maxSteering = maxSteering
88 self.accelerationDistribution = lambda: random.triangular(-self.maxAcceleration,
89 self.maxAcceleration, 0.)
90 self.steeringDistribution = lambda: random.triangular(-self.maxSteering,
91 self.maxSteering, 0.)
92
93 def __str__(self):
94 return PredictionParameters.__str__(self)+' {0} {1} {2}'.format(self.nPredictedTrajectories,
95 self.maxAcceleration,
96 self.maxSteering)
97
98 def generatePredictedTrajectories(self, obj, instant):
99 predictedTrajectories = []
100 for i in xrange(self.nPredictedTrajectories):
101 predictedTrajectories.append(PredictedTrajectoryNormalAdaptation(obj.getPositionAtInstant(instant),
102 obj.getVelocityAtInstant(instant),
103 self.accelerationDistribution,
104 self.steeringDistribution,
105 maxSpeed = self.maxSpeed))
106 return predictedTrajectories
107
108 class PointSetPredictionParameters(PredictionParameters):
109 # todo generate several trajectories with normal adaptatoins from each position (feature)
110 def __init__(self, maxSpeed):
111 PredictionParameters.__init__(self, 'point set', maxSpeed)
112
113 def generatePredictedTrajectories(self, obj, instant):
114 predictedTrajectories = []
115 features = [f for f in obj.features if f.existsAtInstant(instant)]
116 positions = [f.getPositionAtInstant(instant) for f in features]
117 velocities = [f.getVelocityAtInstant(instant) for f in features]
118 for initialPosition,initialVelocity in zip(positions, velocities):
119 predictedTrajectories.append(PredictedTrajectoryConstant(initialPosition, initialVelocity,
120 maxSpeed = self.maxSpeed))
121 return predictedTrajectories
122
123 class EvasiveActionPredictionParameters(PredictionParameters):
124 def __init__(self, maxSpeed, nPredictedTrajectories, minAcceleration, maxAcceleration, maxSteering, useFeatures = False):
125 if useFeatures:
126 name = 'point set evasive action'
127 else:
128 name = 'evasive action'
129 PredictionParameters.__init__(self, name, maxSpeed)
130 self.nPredictedTrajectories = nPredictedTrajectories
131 self.minAcceleration = minAcceleration
132 self.maxAcceleration = maxAcceleration
133 self.maxSteering = maxSteering
134 self.useFeatures = useFeatures
135 self.accelerationDistribution = lambda: random.triangular(self.minAcceleration,
136 self.maxAcceleration, 0.)
137 self.steeringDistribution = lambda: random.triangular(-self.maxSteering,
138 self.maxSteering, 0.)
139
140 def __str__(self):
141 return PredictionParameters.__str__(self)+' {0} {1} {2} {3}'.format(self.nPredictedTrajectories, self.minAcceleration, self.maxAcceleration, self.maxSteering)
142
143 def generatePredictedTrajectories(self, obj, instant):
144 predictedTrajectories = []
145 if self.useFeatures:
146 features = [f for f in obj.features if f.existsAtInstant(instant)]
147 positions = [f.getPositionAtInstant(instant) for f in features]
148 velocities = [f.getVelocityAtInstant(instant) for f in features]
149 else:
150 positions = [obj.getPositionAtInstant(instant)]
151 velocities = [obj.getVelocityAtInstant(instant)]
152 for i in xrange(self.nPredictedTrajectories):
153 for initialPosition,initialVelocity in zip(positions, velocities):
154 predictedTrajectories.append(PredictedTrajectoryConstant(initialPosition,
155 initialVelocity,
156 moving.NormAngle(self.accelerationDistribution(),
157 self.steeringDistribution()),
158 maxSpeed = self.maxSpeed))
159 return predictedTrajectories
160
161 class SafetyPoint(moving.Point):
162 '''Can represent a collision point or crossing zone
163 with respective safety indicator, TTC or pPET'''
164 def __init__(self, p, probability = 1., indicator = -1):
165 self.x = p.x
166 self.y = p.y
167 self.probability = probability
168 self.indicator = indicator
169
170 @staticmethod
171 def save(out, points, objNum1, objNum2, instant):
172 for p in points:
173 out.write('{0} {1} {2} {3} {4} {5} {6}\n'.format(objNum1, objNum2, instant, p.x, p.y, p.probability, p.indicator))
174
175 def computeExpectedIndicator(points):
176 from numpy import sum
177 return sum([p.indicator*p.probability for p in points])/sum([p.probability for p in points])
178
179 def computeCollisionTime(predictedTrajectory1, predictedTrajectory2, collisionDistanceThreshold, timeHorizon):
180 t = 1
181 p1 = predictedTrajectory1.predictPosition(t)
182 p2 = predictedTrajectory2.predictPosition(t)
183 while t <= timeHorizon and (p1-p2).norm2() > collisionDistanceThreshold:
184 p1 = predictedTrajectory1.predictPosition(t)
185 p2 = predictedTrajectory2.predictPosition(t)
186 t += 1
187 return t, p1, p2
188
189 def computeCrossingsCollisionsAtInstant(i, obj1, obj2, predictionParameters, collisionDistanceThreshold, timeHorizon, debug = False):
190 '''returns the lists of collision points and crossing zones
191
192 Check: Predicting all the points together, as if they represent the whole vehicle'''
193 predictedTrajectories1 = predictionParameters.generatePredictedTrajectories(obj1, i)
194 predictedTrajectories2 = predictionParameters.generatePredictedTrajectories(obj2, i)
195
196 collisionPoints = []
197 crossingZones = []
198 for et1 in predictedTrajectories1:
199 for et2 in predictedTrajectories2:
200 t, p1, p2 = computeCollisionTime(et1, et2, collisionDistanceThreshold, timeHorizon)
201
202 if t <= timeHorizon:
203 collisionPoints.append(SafetyPoint((p1+p2).multiply(0.5), et1.probability*et2.probability, t))
204 else: # check if there is a crossing zone
205 # TODO? zone should be around the points at which the traj are the closest
206 # look for CZ at different times, otherwise it would be a collision
207 # an approximation would be to look for close points at different times, ie the complementary of collision points
208 cz = None
209 t1 = 0
210 while not cz and t1 < timeHorizon: # t1 <= timeHorizon-1
211 t2 = 0
212 while not cz and t2 < timeHorizon:
213 #if (et1.predictPosition(t1)-et2.predictPosition(t2)).norm2() < collisionDistanceThreshold:
214 # cz = (et1.predictPosition(t1)+et2.predictPosition(t2)).multiply(0.5)
215 cz = moving.segmentIntersection(et1.predictPosition(t1), et1.predictPosition(t1+1), et2.predictPosition(t2), et2.predictPosition(t2+1))
216 if cz:
217 crossingZones.append(SafetyPoint(cz, et1.probability*et2.probability, abs(t1-t2)))
218 t2 += 1
219 t1 += 1
220
221 if debug:
222 from matplotlib.pyplot import figure, axis, title
223 figure()
224 for et in predictedTrajectories1:
225 et.predictPosition(timeHorizon)
226 et.draw('rx')
227
228 for et in predictedTrajectories2:
229 et.predictPosition(timeHorizon)
230 et.draw('bx')
231 obj1.draw('r')
232 obj2.draw('b')
233 title('instant {0}'.format(i))
234 axis('equal')
235
236 return collisionPoints, crossingZones
237
238 def computeCrossingsCollisions(obj1, obj2, predictionParameters, collisionDistanceThreshold, timeHorizon, outCP, outCZ, debug = False, timeInterval = None):
239 collisionPoints={}
240 crossingZones={}
241 if timeInterval:
242 commonTimeInterval = timeInterval
243 else:
244 commonTimeInterval = obj1.commonTimeInterval(obj2)
245 for i in list(commonTimeInterval)[:-1]: # do not look at the 1 last position/velocities, often with errors
246 print(obj1.num, obj2.num, i)
247 collisionPoints[i], crossingZones[i] = computeCrossingsCollisionsAtInstant(i, obj1, obj2, predictionParameters, collisionDistanceThreshold, timeHorizon, debug)
248 SafetyPoint.save(outCP, collisionPoints[i], obj1.num, obj2.num, i)
249 SafetyPoint.save(outCZ, crossingZones[i], obj1.num, obj2.num, i)
250
251 return collisionPoints, crossingZones
252
253 def computeCollisionProbability(obj1, obj2, predictionParameters, collisionDistanceThreshold, timeHorizon, out, debug = False, timeInterval = None):
254 collisionProbabilities = {}
255 if timeInterval:
256 commonTimeInterval = timeInterval
257 else:
258 commonTimeInterval = obj1.commonTimeInterval(obj2)
259 for i in list(commonTimeInterval)[:-1]:
260 nCollisions = 0
261 print(obj1.num, obj2.num, i)
262 predictedTrajectories1 = predictionParameters.generatePredictedTrajectories(obj1, i)
263 predictedTrajectories2 = predictionParameters.generatePredictedTrajectories(obj2, i)
264 for et1 in predictedTrajectories1:
265 for et2 in predictedTrajectories2:
266 t, p1, p2 = computeCollisionTime(et1, et2, collisionDistanceThreshold, timeHorizon)
267 if t <= timeHorizon:
268 nCollisions += 1
269 # take into account probabilities ??
270 nSamples = float(len(predictedTrajectories1)*len(predictedTrajectories2))
271 collisionProbabilities[i] = float(nCollisions)/nSamples
272 out.write('{0} {1} {2} {3} {4}\n'.format(obj1.num, obj2.num, nSamples, i, collisionProbabilities[i]))
273
274 if debug:
275 from matplotlib.pyplot import figure, axis, title
276 figure()
277 for et in predictedTrajectories1:
278 et.predictPosition(timeHorizon)
279 et.draw('rx')
280
281 for et in predictedTrajectories2:
282 et.predictPosition(timeHorizon)
283 et.draw('bx')
284 obj1.draw('r')
285 obj2.draw('b')
286 title('instant {0}'.format(i))
287 axis('equal')
288
289 return collisionProbabilities
290
291
292 if __name__ == "__main__":
293 import doctest
294 import unittest
295 suite = doctest.DocFileSuite('tests/prediction.txt')
296 #suite = doctest.DocTestSuite()
297 unittest.TextTestRunner().run(suite)
298 #doctest.testmod()
299 #doctest.testfile("example.txt")
300