Fix RRT Star algorithm

This commit is contained in:
Atsushi Sakai
2019-07-15 08:31:46 +09:00
parent 3c6833210b
commit 80d0be2baf
5 changed files with 289 additions and 286 deletions

2
.gitignore vendored
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@@ -68,3 +68,5 @@ target/
#Ipython Notebook
.ipynb_checkpoints
matplotrecorder/*

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@@ -0,0 +1,286 @@
"""
Path planning Sample Code with RRT*
author: Atsushi Sakai(@Atsushi_twi)
"""
import copy
import math
import random
import matplotlib.pyplot as plt
import numpy as np
show_animation = True
class RRTStar:
"""
Class for RRT planning
"""
class Node:
def __init__(self, x, y):
self.x = x
self.y = y
self.cost = 0.0
self.parent = None
def __init__(self, start, goal, obstacle_list, rand_area,
expand_dis=0.5,
goal_sample_rate=20,
max_iter=500,
connect_circle_dist=50.0
):
"""
Setting Parameter
start:Start Position [x,y]
goal:Goal Position [x,y]
obstacleList:obstacle Positions [[x,y,size],...]
randArea:Random Sampling Area [min,max]
"""
self.connect_circle_dist = connect_circle_dist
self.start = self.Node(start[0], start[1])
self.end = self.Node(goal[0], goal[1])
self.min_rand = rand_area[0]
self.max_rand = rand_area[1]
self.expandDis = expand_dis
self.goalSampleRate = goal_sample_rate
self.maxIter = max_iter
self.obstacleList = obstacle_list
self.node_list = []
def planning(self, animation=True, search_until_maxiter=True):
"""
rrt path planning
animation: flag for animation on or off
search_until_maxiter: search until max iteration for path improving or not
"""
self.node_list = [self.start]
for i in range(self.maxIter):
rnd = self.get_random_point()
nearest_ind = self.get_nearest_list_index(self.node_list, rnd)
new_node = self.steer(rnd, self.node_list[nearest_ind])
if self.check_collision(new_node, self.obstacleList):
near_inds = self.find_near_nodes(new_node)
new_node = self.choose_parent(new_node, near_inds)
if new_node:
self.node_list.append(new_node)
self.rewire(new_node, near_inds)
if animation and i % 5 == 0:
self.draw_graph(rnd)
if not search_until_maxiter: # check reaching the goal
d, _ = self.calc_distance_and_angle(new_node, self.end)
if d <= self.expandDis:
return self.gen_final_course(len(self.node_list) - 1)
print("reached max iteration")
last_index = self.search_best_goal_node()
if last_index:
return self.gen_final_course(last_index)
return None
def choose_parent(self, new_node, near_inds):
if not near_inds:
return None
# search nearest cost in near_inds
costs = []
for i in near_inds:
d, theta = self.calc_distance_and_angle(self.node_list[i], new_node)
if self.check_collision_extend(self.node_list[i], theta, d):
costs.append(self.node_list[i].cost + d)
else:
costs.append(float("inf")) # the cost of collision node
min_cost = min(costs)
if min_cost == float("inf"):
print("There is no good path.(min_cost is inf)")
return None
new_node.cost = min_cost
min_ind = near_inds[costs.index(min_cost)]
new_node.parent = self.node_list[min_ind]
return new_node
def steer(self, rnd, nearest_node):
new_node = self.Node(rnd[0], rnd[1])
d, theta = self.calc_distance_and_angle(nearest_node, new_node)
if d > self.expandDis:
new_node.x = nearest_node.x + self.expandDis * math.cos(theta)
new_node.y = nearest_node.y + self.expandDis * math.sin(theta)
new_node.cost = float("inf")
return new_node
def get_random_point(self):
if random.randint(0, 100) > self.goalSampleRate:
rnd = [random.uniform(self.min_rand, self.max_rand),
random.uniform(self.min_rand, self.max_rand)]
else: # goal point sampling
rnd = [self.end.x, self.end.y]
return rnd
def search_best_goal_node(self):
dist_to_goal_list = [self.calc_dist_to_goal(n.x, n.y) for n in self.node_list]
goal_inds = [dist_to_goal_list.index(i) for i in dist_to_goal_list if i <= self.expandDis]
if not goal_inds:
return None
min_cost = min([self.node_list[i].cost for i in goal_inds])
for i in goal_inds:
if self.node_list[i].cost == min_cost:
return i
return None
def gen_final_course(self, goal_ind):
path = [[self.end.x, self.end.y]]
node = self.node_list[goal_ind]
while node.parent is not None:
path.append([node.x, node.y])
node = node.parent
path.append([node.x, node.y])
return path
def calc_dist_to_goal(self, x, y):
return np.linalg.norm([x - self.end.x, y - self.end.y])
def find_near_nodes(self, new_node):
nnode = len(self.node_list) + 1
r = self.connect_circle_dist * math.sqrt((math.log(nnode) / nnode))
dist_list = [(node.x - new_node.x) ** 2 +
(node.y - new_node.y) ** 2 for node in self.node_list]
near_inds = [dist_list.index(i) for i in dist_list if i <= r ** 2]
return near_inds
def rewire(self, new_node, near_inds):
for i in near_inds:
near_node = self.node_list[i]
d, theta = self.calc_distance_and_angle(near_node, new_node)
new_cost = new_node.cost + d
if near_node.cost > new_cost:
if self.check_collision_extend(near_node, theta, d):
near_node.parent = new_node
near_node.cost = new_cost
self.propagate_cost_to_leaves(new_node)
def propagate_cost_to_leaves(self, parent_node):
for node in self.node_list:
if node.parent == parent_node:
d, _ = self.calc_distance_and_angle(parent_node, node)
node.cost = parent_node.cost + d
self.propagate_cost_to_leaves(node)
def check_collision_extend(self, near_node, theta, d):
tmp_node = copy.deepcopy(near_node)
for i in range(int(d / self.expandDis)):
tmp_node.x += self.expandDis * math.cos(theta)
tmp_node.y += self.expandDis * math.sin(theta)
if not self.check_collision(tmp_node, self.obstacleList):
return False
return True
def draw_graph(self, rnd=None):
plt.clf()
if rnd is not None:
plt.plot(rnd[0], rnd[1], "^k")
for node in self.node_list:
if node.parent is not None:
plt.plot([node.x, node.parent.x],
[node.y, node.parent.y],
"-g")
for (ox, oy, size) in self.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])
plt.grid(True)
plt.pause(0.01)
@staticmethod
def get_nearest_list_index(node_list, rnd):
dlist = [(node.x - rnd[0]) ** 2 + (node.y - rnd[1])
** 2 for node in node_list]
minind = dlist.index(min(dlist))
return minind
@staticmethod
def check_collision(node, obstacleList):
for (ox, oy, size) in obstacleList:
dx = ox - node.x
dy = oy - node.y
d = dx * dx + dy * dy
if d <= size ** 2:
return False # collision
return True # safe
@staticmethod
def calc_distance_and_angle(from_node, to_node):
dx = to_node.x - from_node.x
dy = to_node.y - from_node.y
d = math.sqrt(dx ** 2 + dy ** 2)
theta = math.atan2(dy, dx)
return d, theta
def main():
print("Start " + __file__)
# ====Search Path with RRT====
obstacle_list = [
(5, 5, 1),
(3, 6, 2),
(3, 8, 2),
(3, 10, 2),
(7, 5, 2),
(9, 5, 2)
] # [x,y,size(radius)]
# Set Initial parameters
rrt = RRTStar(start=[0, 0],
goal=[10, 10],
rand_area=[-2, 15],
obstacle_list=obstacle_list)
path = rrt.planning(animation=show_animation, search_until_maxiter=False)
if path is None:
print("Cannot find path")
else:
print("found path!!")
# Draw final path
if show_animation:
rrt.draw_graph()
plt.plot([x for (x, y) in path], [y for (x, y) in path], '-r')
plt.grid(True)
plt.pause(0.01) # Need for Mac
plt.show()
if __name__ == '__main__':
main()

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@@ -1,285 +0,0 @@
"""
Path Planning Sample Code with RRT*
author: AtsushiSakai(@Atsushi_twi)
"""
import random
import math
import copy
import numpy as np
import matplotlib.pyplot as plt
show_animation = True
class Node():
def __init__(self, x, y):
self.x = x
self.y = y
self.cost = 0.0
self.parent = None
class RRT():
"""
Class for RRT Planning
"""
def __init__(self, start, goal, obstacleList, randArea,
expandDis=0.5, goalSampleRate=20, maxIter=500):
"""
Setting Parameter
start:Start Position [x,y]
goal:Goal Position [x,y]
obstacleList:obstacle Positions [[x,y,size],...]
randArea:Ramdom Samping Area [min,max]
"""
self.start = Node(start[0], start[1])
self.end = Node(goal[0], goal[1])
self.minrand = randArea[0]
self.maxrand = randArea[1]
self.expandDis = expandDis
self.goalSampleRate = goalSampleRate
self.maxIter = maxIter
self.obstacleList = obstacleList
def Planning(self, animation=True, search_until_maxiter=True):
"""
rrt path planning
animation: flag for animation on or off
search_until_maxiter: search until max iteration for path improving or not
"""
self.nodeList = [self.start]
for i in range(self.maxIter):
rnd = self.get_random_point()
nind = self.GetNearestListIndex(self.nodeList, rnd)
new_node = self.steer(rnd, nind)
if self.__CollisionCheck(new_node, self.obstacleList):
nearinds = self.find_near_nodes(new_node)
new_node = self.choose_parent(new_node, nearinds)
self.nodeList.append(new_node)
self.rewire(new_node, nearinds)
if animation and i % 5 == 0:
self.DrawGraph(rnd)
# generate course
if not search_until_maxiter:
lastIndex = self.get_best_last_index()
if lastIndex:
return self.gen_final_course(lastIndex)
print("reached max iteration")
lastIndex = self.get_best_last_index()
if lastIndex:
return self.gen_final_course(lastIndex)
return None
def choose_parent(self, new_node, nearinds):
if not nearinds:
return new_node
dlist = []
for i in nearinds:
dx = new_node.x - self.nodeList[i].x
dy = new_node.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 new_node
new_node.cost = mincost
new_node.parent = minind
return new_node
def steer(self, rnd, nind):
# expand tree
nearest_node = self.nodeList[nind]
theta = math.atan2(rnd[1] - nearest_node.y, rnd[0] - nearest_node.x)
new_node = Node(rnd[0], rnd[1])
currentDistance = math.sqrt(
(rnd[1] - nearest_node.y) ** 2 + (rnd[0] - nearest_node.x) ** 2)
# Find a point within expandDis of nind, and closest to rnd
if currentDistance <= self.expandDis:
pass
else:
new_node.x = nearest_node.x + self.expandDis * math.cos(theta)
new_node.y = nearest_node.y + self.expandDis * math.sin(theta)
new_node.cost = float("inf")
new_node.parent = None
return new_node
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(
node.x, node.y) for node in self.nodeList]
goalinds = [disglist.index(i) for i in disglist if i <= self.expandDis]
if not goalinds:
return None
mincost = min([self.nodeList[i].cost for i in goalinds])
for i in goalinds:
if self.nodeList[i].cost == mincost:
return i
return None
def gen_final_course(self, goalind):
path = [[self.end.x, self.end.y]]
while self.nodeList[goalind].parent is not None:
node = self.nodeList[goalind]
path.append([node.x, node.y])
goalind = node.parent
path.append([self.start.x, self.start.y])
return path
def calc_dist_to_goal(self, x, y):
return np.linalg.norm([x - self.end.x, y - self.end.y])
def find_near_nodes(self, new_node):
nnode = len(self.nodeList)
r = 50.0 * math.sqrt((math.log(nnode) / nnode))
dlist = [(node.x - new_node.x) ** 2 +
(node.y - new_node.y) ** 2 for node in self.nodeList]
nearinds = [dlist.index(i) for i in dlist if i <= r ** 2]
return nearinds
def rewire(self, new_node, nearinds):
nnode = len(self.nodeList)
for i in nearinds:
nearNode = self.nodeList[i]
dx = new_node.x - nearNode.x
dy = new_node.y - nearNode.y
d = math.sqrt(dx ** 2 + dy ** 2)
scost = new_node.cost + d
if nearNode.cost > scost:
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, self.obstacleList):
return False
return True
def DrawGraph(self, rnd=None):
"""
Draw Graph
"""
plt.clf()
if rnd is not None:
plt.plot(rnd[0], rnd[1], "^k")
for node in self.nodeList:
if node.parent is not None:
plt.plot([node.x, self.nodeList[node.parent].x], [
node.y, self.nodeList[node.parent].y], "-g")
for (ox, oy, size) in self.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])
plt.grid(True)
plt.pause(0.01)
def GetNearestListIndex(self, nodeList, rnd):
dlist = [(node.x - rnd[0]) ** 2 + (node.y - rnd[1])
** 2 for node in nodeList]
minind = dlist.index(min(dlist))
return minind
def __CollisionCheck(self, node, obstacleList):
for (ox, oy, size) in obstacleList:
dx = ox - node.x
dy = oy - node.y
d = dx * dx + dy * dy
if d <= size ** 2:
return False # collision
return True # safe
def main():
print("Start " + __file__)
# ====Search Path with RRT====
obstacleList = [
(5, 5, 1),
(3, 6, 2),
(3, 8, 2),
(3, 10, 2),
(7, 5, 2),
(9, 5, 2)
] # [x,y,size(radius)]
# Set Initial parameters
rrt = RRT(start=[0, 0], goal=[10, 10],
randArea=[-2, 15], obstacleList=obstacleList)
path = rrt.Planning(animation=show_animation, search_until_maxiter=False)
if path is None:
print("Cannot find path")
else:
print("found path!!")
# Draw final path
if show_animation:
rrt.DrawGraph()
plt.plot([x for (x, y) in path], [y for (x, y) in path], '-r')
plt.grid(True)
plt.pause(0.01) # Need for Mac
plt.show()
if __name__ == '__main__':
main()

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@@ -3,7 +3,7 @@ import sys
from unittest import TestCase
sys.path.append(os.path.dirname(os.path.abspath(__file__)) +
"/../PathPlanning/RRTstar/")
"/../PathPlanning/RRTStar/")
try:
import rrt_star as m