mirror of
https://github.com/AtsushiSakai/PythonRobotics.git
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170 lines
4.5 KiB
Python
170 lines
4.5 KiB
Python
#!/usr/bin/python
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# -*- coding: utf-8 -*-
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u"""
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@brief: Path Planning Sample Code with Randamized Rapidly-Exploring Random Trees (RRT)
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@author: AtsushiSakai
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@license: MIT
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"""
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import random
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import math
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import copy
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class RRT():
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u"""
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Class for RRT Planning
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"""
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def __init__(self, start, goal, obstacleList,
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randArea, expandDis=1.0, goalSampleRate=5, maxIter=500):
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u"""
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Setting Parameter
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start:Start Position [x,y]
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goal:Goal Position [x,y]
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obstacleList:obstacle Positions [[x,y,size],...]
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randArea:Ramdom Samping Area [min,max]
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"""
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self.start = Node(start[0], start[1])
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self.end = Node(goal[0], goal[1])
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self.minrand = randArea[0]
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self.maxrand = randArea[1]
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self.expandDis = expandDis
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self.goalSampleRate = goalSampleRate
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self.maxIter = maxIter
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def Planning(self, animation=True):
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u"""
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Pathplanning
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animation: flag for animation on or off
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"""
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self.nodeList = [self.start]
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while True:
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# Random Sampling
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if random.randint(0, 100) > self.goalSampleRate:
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rnd = [random.uniform(self.minrand, self.maxrand), random.uniform(
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self.minrand, self.maxrand)]
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else:
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rnd = [self.end.x, self.end.y]
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# Find nearest node
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nind = self.GetNearestListIndex(self.nodeList, rnd)
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# print(nind)
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# expand tree
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nearestNode = self.nodeList[nind]
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theta = math.atan2(rnd[1] - nearestNode.y, rnd[0] - nearestNode.x)
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newNode = copy.deepcopy(nearestNode)
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newNode.x += self.expandDis * math.cos(theta)
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newNode.y += self.expandDis * math.sin(theta)
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newNode.parent = nind
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if not self.__CollisionCheck(newNode, obstacleList):
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continue
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self.nodeList.append(newNode)
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# check goal
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dx = newNode.x - self.end.x
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dy = newNode.y - self.end.y
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d = math.sqrt(dx * dx + dy * dy)
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if d <= self.expandDis:
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print("Goal!!")
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break
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if animation:
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self.DrawGraph(rnd)
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path = [[self.end.x, self.end.y]]
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lastIndex = len(self.nodeList) - 1
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while self.nodeList[lastIndex].parent is not None:
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node = self.nodeList[lastIndex]
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path.append([node.x, node.y])
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lastIndex = node.parent
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path.append([self.start.x, self.start.y])
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return path
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def DrawGraph(self, rnd=None):
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u"""
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Draw Graph
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"""
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import matplotlib.pyplot as plt
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plt.clf()
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if rnd is not None:
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plt.plot(rnd[0], rnd[1], "^k")
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for node in self.nodeList:
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if node.parent is not None:
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plt.plot([node.x, self.nodeList[node.parent].x], [
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node.y, self.nodeList[node.parent].y], "-g")
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for (ox, oy, size) in obstacleList:
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plt.plot(ox, oy, "ok", ms=30 * size)
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plt.plot(self.start.x, self.start.y, "xr")
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plt.plot(self.end.x, self.end.y, "xr")
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plt.axis([-2, 15, -2, 15])
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plt.grid(True)
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plt.pause(0.01)
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def GetNearestListIndex(self, nodeList, rnd):
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dlist = [(node.x - rnd[0]) ** 2 + (node.y - rnd[1])
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** 2 for node in nodeList]
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minind = dlist.index(min(dlist))
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return minind
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def __CollisionCheck(self, node, obstacleList):
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for (ox, oy, size) in obstacleList:
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dx = ox - node.x
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dy = oy - node.y
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d = math.sqrt(dx * dx + dy * dy)
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if d <= size:
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return False # collision
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return True # safe
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class Node():
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u"""
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RRT Node
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"""
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def __init__(self, x, y):
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self.x = x
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self.y = y
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self.parent = None
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if __name__ == '__main__':
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import matplotlib.pyplot as plt
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# ====Search Path with RRT====
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obstacleList = [
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(5, 5, 1),
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(3, 6, 2),
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(3, 8, 2),
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(3, 10, 2),
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(7, 5, 2),
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(9, 5, 2)
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] # [x,y,size]
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# Set Initial parameters
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rrt = RRT(start=[0, 0], goal=[5, 10],
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randArea=[-2, 15], obstacleList=obstacleList)
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path = rrt.Planning(animation=True)
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# Draw final path
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rrt.DrawGraph()
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plt.plot([x for (x, y) in path], [y for (x, y) in path], '-r')
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plt.grid(True)
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plt.pause(0.01) # Need for Mac
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plt.show()
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