mirror of
https://github.com/zhm-real/PathPlanning.git
synced 2026-08-29 08:34:46 +08:00
yue qi
120 lines
4.4 KiB
Python
120 lines
4.4 KiB
Python
# this is the three dimensional A* algo
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# !/usr/bin/env python3
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# -*- coding: utf-8 -*-
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"""
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@author: yue qi
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"""
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import numpy as np
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import matplotlib.pyplot as plt
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import os
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import sys
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sys.path.append(os.path.dirname(os.path.abspath(__file__)) + "/../../Search-based Planning/")
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from Search_3D.env3D import env
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from Search_3D.utils3D import getDist, getRay, g_Space, Heuristic, getNearest, isCollide, \
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cost, children, StateSpace, heuristic_fun
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from Search_3D.plot_util3D import visualization
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import queue
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import time
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class Weighted_A_star(object):
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def __init__(self, resolution=0.5):
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self.Alldirec = {(1, 0, 0): 1, (0, 1, 0): 1, (0, 0, 1): 1, \
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(-1, 0, 0): 1, (0, -1, 0): 1, (0, 0, -1): 1, \
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(1, 1, 0): np.sqrt(2), (1, 0, 1): np.sqrt(2), (0, 1, 1): np.sqrt(2), \
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(-1, -1, 0): np.sqrt(2), (-1, 0, -1): np.sqrt(2), (0, -1, -1): np.sqrt(2), \
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(1, -1, 0): np.sqrt(2), (-1, 1, 0): np.sqrt(2), (1, 0, -1): np.sqrt(2), \
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(-1, 0, 1): np.sqrt(2), (0, 1, -1): np.sqrt(2), (0, -1, 1): np.sqrt(2), \
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(1, 1, 1): np.sqrt(3), (-1, -1, -1) : np.sqrt(3), \
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(1, -1, -1): np.sqrt(3), (-1, 1, -1): np.sqrt(3), (-1, -1, 1): np.sqrt(3), \
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(1, 1, -1): np.sqrt(3), (1, -1, 1): np.sqrt(3), (-1, 1, 1): np.sqrt(3)}
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self.settings = 'NonCollisionChecking'
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self.env = env(resolution=resolution)
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self.start, self.goal = tuple(self.env.start), tuple(self.env.goal)
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self.g = {self.start:0,self.goal:np.inf}
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self.Parent = {}
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self.CLOSED = set()
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self.V = []
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self.done = False
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self.Path = []
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self.ind = 0
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self.x0, self.xt = self.start, self.goal
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self.OPEN = queue.MinheapPQ() # store [point,priority]
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self.OPEN.put(self.x0, self.g[self.x0] + heuristic_fun(self,self.x0)) # item, priority = g + h
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self.lastpoint = self.x0
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def run(self, N=None):
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xt = self.xt
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xi = self.x0
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while self.OPEN: # while xt not reached and open is not empty
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xi = self.OPEN.get()
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if xi not in self.CLOSED:
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self.V.append(np.array(xi))
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self.CLOSED.add(xi) # add the point in CLOSED set
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if getDist(xi,xt) < self.env.resolution:
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break
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# visualization(self)
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for xj in children(self,xi):
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# if xj not in self.CLOSED:
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if xj not in self.g:
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self.g[xj] = np.inf
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else:
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pass
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a = self.g[xi] + cost(self, xi, xj)
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if a < self.g[xj]:
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self.g[xj] = a
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self.Parent[xj] = xi
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# if (a, xj) in self.OPEN.enumerate():
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# update priority of xj
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self.OPEN.put(xj, a + 1 * heuristic_fun(self, xj))
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# else:
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# add xj in to OPEN set
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# self.OPEN.put(xj, a + 1 * heuristic_fun(self, xj))
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# For specified expanded nodes, used primarily in LRTA*
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if N:
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if len(self.CLOSED) % N == 0:
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break
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if self.ind % 100 == 0: print('number node expanded = ' + str(len(self.V)))
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self.ind += 1
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self.lastpoint = xi
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# if the path finding is finished
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if self.lastpoint in self.CLOSED:
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self.done = True
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self.Path = self.path()
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if N is None:
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visualization(self)
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plt.show()
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return True
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return False
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def path(self):
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path = []
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x = self.lastpoint
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start = self.x0
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while x != start:
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path.append([x, self.Parent[x]])
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x = self.Parent[x]
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# path = np.flip(path, axis=0)
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return path
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# utility used in LRTA*
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def reset(self, xj):
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self.g = g_Space(self) # key is the point, store g value
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self.start = xj
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self.g[getNearest(self.g, self.start)] = 0 # set g(x0) = 0
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self.x0 = xj
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self.OPEN.put(self.x0, self.g[self.x0] + heuristic_fun(self,self.x0)) # item, priority = g + h
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self.CLOSED = set()
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# self.h = h(self.Space, self.goal)
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if __name__ == '__main__':
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Astar = Weighted_A_star(0.5)
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sta = time.time()
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Astar.run()
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print(time.time() - sta) |