rrt star first release

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AtsushiSakai
2017-05-05 23:23:15 -07:00
parent bbceb55fbe
commit ee91694c8e
2 changed files with 95 additions and 58 deletions

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@@ -3,18 +3,16 @@
u"""
@brief: Path Planning Sample Code with Randamized Rapidly-Exploring Random Trees (RRT)
@author: AtsushiSakai
@author: AtsushiSakai(@Atsushi_twi)
@license: MIT
"""
import random
import math
import copy
import numpy as np
from numba import jit
class RRT():
@@ -23,7 +21,7 @@ class RRT():
"""
def __init__(self, start, goal, obstacleList, randArea,
expandDis=0.5, goalSampleRate=50, maxIter=10000):
expandDis=0.5, goalSampleRate=20, maxIter=5000):
u"""
Setting Parameter
@@ -51,42 +49,17 @@ class RRT():
self.nodeList = [self.start]
for i in range(self.maxIter):
# Random Sampling
if random.randint(0, 100) > self.goalSampleRate:
rnd = [random.uniform(self.minrand, self.maxrand),
random.uniform(self.minrand, self.maxrand)]
else:
rnd = [self.end.x, self.end.y]
# Find nearest node
rnd = self.get_random_point()
nind = self.GetNearestListIndex(self.nodeList, rnd)
# expand tree
nearestNode = self.nodeList[nind]
theta = math.atan2(rnd[1] - nearestNode.y, rnd[0] - nearestNode.x)
newNode = copy.deepcopy(nearestNode)
newNode.x += self.expandDis * math.cos(theta)
newNode.y += self.expandDis * math.sin(theta)
newNode.cost += self.expandDis + \
self.calc_dist_to_goal(newNode.x, newNode.y)
newNode.parent = nind
newNode = self.steer(rnd, nind)
# print(newNode.cost)
if not self.__CollisionCheck(newNode, obstacleList):
continue
self.nodeList.append(newNode)
# check goal
dx = newNode.x - self.end.x
dy = newNode.y - self.end.y
d = math.sqrt(dx * dx + dy * dy)
if d <= self.expandDis:
print("Goal!!")
# break
self.rewire(newNode)
if self.__CollisionCheck(newNode, obstacleList):
nearinds = self.find_near_nodes(newNode)
newNode = self.choose_parent(newNode, nearinds)
self.nodeList.append(newNode)
self.rewire(newNode, nearinds)
if animation:
self.DrawGraph(rnd)
@@ -96,6 +69,56 @@ class RRT():
path = self.gen_final_course(lastIndex)
return path
def choose_parent(self, newNode, nearinds):
if len(nearinds) == 0:
return newNode
dlist = []
for i in nearinds:
dx = newNode.x - self.nodeList[i].x
dy = newNode.y - self.nodeList[i].y
d = math.sqrt(dx ** 2 + dy ** 2)
theta = math.atan2(dy, dx)
if self.check_collision_extend(self.nodeList[i], theta, d):
dlist.append(self.nodeList[i].cost + d)
else:
dlist.append(float("inf"))
mincost = min(dlist)
minind = nearinds[dlist.index(mincost)]
if mincost == float("inf"):
print("mincost is inf")
return newNode
newNode.cost = mincost
newNode.parent = minind
return newNode
def steer(self, rnd, nind):
# expand tree
nearestNode = self.nodeList[nind]
theta = math.atan2(rnd[1] - nearestNode.y, rnd[0] - nearestNode.x)
newNode = copy.deepcopy(nearestNode)
newNode.x += self.expandDis * math.cos(theta)
newNode.y += self.expandDis * math.sin(theta)
newNode.cost += self.expandDis
newNode.parent = nind
return newNode
def get_random_point(self):
if random.randint(0, 100) > self.goalSampleRate:
rnd = [random.uniform(self.minrand, self.maxrand),
random.uniform(self.minrand, self.maxrand)]
else: # goal point sampling
rnd = [self.end.x, self.end.y]
return rnd
def get_best_last_index(self):
disglist = [self.calc_dist_to_goal(
@@ -122,30 +145,43 @@ class RRT():
def calc_dist_to_goal(self, x, y):
return np.linalg.norm([x - self.end.x, y - self.end.y])
def rewire(self, newNode):
# print("rewire")
def find_near_nodes(self, newNode):
nnode = len(self.nodeList)
# r = 50.0 * math.sqrt((math.log(nnode) / nnode))
r = self.expandDis * 2.0
dlist = [math.sqrt((node.x - newNode.x) ** 2 +
(node.y - newNode.y) ** 2) for node in self.nodeList]
nearinds = [dlist.index(i) for i in dlist if i <= r]
r = 50.0 * math.sqrt((math.log(nnode) / nnode))
# r = self.expandDis * 5.0
dlist = [(node.x - newNode.x) ** 2 +
(node.y - newNode.y) ** 2 for node in self.nodeList]
nearinds = [dlist.index(i) for i in dlist if i <= r ** 2]
return nearinds
def rewire(self, newNode, nearinds):
nnode = len(self.nodeList)
for i in nearinds:
nearNode = self.nodeList[i]
dx = nearNode.x - newNode.x
dy = nearNode.y - newNode.y
dx = newNode.x - nearNode.x
dy = newNode.y - nearNode.y
d = math.sqrt(dx ** 2 + dy ** 2)
scost = newNode.cost + \
math.sqrt(dx ** 2 + dy ** 2) + \
self.calc_dist_to_goal(nearNode.x, nearNode.y)
scost = newNode.cost + d
if nearNode.cost > scost:
# print("rewire")
nearNode.parent = nnode - 1
nearNode.cost = scost
# input()
theta = math.atan2(dy, dx)
if self.check_collision_extend(nearNode, theta, d):
nearNode.parent = nnode - 1
nearNode.cost = scost
def check_collision_extend(self, nearNode, theta, d):
tmpNode = copy.deepcopy(nearNode)
for i in range(int(d / self.expandDis)):
tmpNode.x += self.expandDis * math.cos(theta)
tmpNode.y += self.expandDis * math.sin(theta)
if not self.__CollisionCheck(tmpNode, obstacleList):
return False
return True
def DrawGraph(self, rnd=None):
u"""
@@ -160,8 +196,9 @@ class RRT():
plt.plot([node.x, self.nodeList[node.parent].x], [
node.y, self.nodeList[node.parent].y], "-g")
plt.plot([ox for (ox, oy, size) in obstacleList], [
oy for (ox, oy, size) in obstacleList], "ok", ms=20)
for (ox, oy, size) in obstacleList:
plt.plot(ox, oy, "ok", ms=30 * size)
plt.plot(self.start.x, self.start.y, "xr")
plt.plot(self.end.x, self.end.y, "xr")
plt.axis([-2, 15, -2, 15])
@@ -176,12 +213,11 @@ class RRT():
return minind
def __CollisionCheck(self, node, obstacleList):
for (ox, oy, size) in obstacleList:
dx = ox - node.x
dy = oy - node.y
d = math.sqrt(dx * dx + dy * dy)
if d <= size:
d = dx * dx + dy * dy
if d <= size ** 2:
return False # collision
return True # safe
@@ -200,6 +236,7 @@ class Node():
if __name__ == '__main__':
print("Start rrt start planning")
import matplotlib.pyplot as plt
# ====Search Path with RRT====
obstacleList = [
@@ -209,7 +246,7 @@ if __name__ == '__main__':
(3, 10, 2),
(7, 5, 2),
(9, 5, 2)
] # [x,y,size]
] # [x,y,size(radius)]
# Set Initial parameters
rrt = RRT(start=[0, 0], goal=[5, 10],