Files
PathPlanning/Search-based Planning/Search_3D/DstarLite3D.py
T
zhm-real ffa911e80c update
2020-07-28 00:48:51 -07:00

219 lines
9.0 KiB
Python

import numpy as np
import matplotlib.pyplot as plt
import os
import sys
from collections import defaultdict
sys.path.append(os.path.dirname(os.path.abspath(__file__)) + "/../../Search-based Planning/")
from Search_3D.env3D import env
from Search_3D.utils3D import getDist, heuristic_fun, getNearest, isinbound, \
cost, children, StateSpace
from Search_3D.plot_util3D import visualization
from Search_3D import queue
import time
class D_star_Lite(object):
# Original version of the D*lite
def __init__(self, resolution = 1):
self.Alldirec = {(1, 0, 0): 1, (0, 1, 0): 1, (0, 0, 1): 1, \
(-1, 0, 0): 1, (0, -1, 0): 1, (0, 0, -1): 1, \
(1, 1, 0): np.sqrt(2), (1, 0, 1): np.sqrt(2), (0, 1, 1): np.sqrt(2), \
(-1, -1, 0): np.sqrt(2), (-1, 0, -1): np.sqrt(2), (0, -1, -1): np.sqrt(2), \
(1, -1, 0): np.sqrt(2), (-1, 1, 0): np.sqrt(2), (1, 0, -1): np.sqrt(2), \
(-1, 0, 1): np.sqrt(2), (0, 1, -1): np.sqrt(2), (0, -1, 1): np.sqrt(2), \
(1, 1, 1): np.sqrt(3), (-1, -1, -1) : np.sqrt(3), \
(1, -1, -1): np.sqrt(3), (-1, 1, -1): np.sqrt(3), (-1, -1, 1): np.sqrt(3), \
(1, 1, -1): np.sqrt(3), (1, -1, 1): np.sqrt(3), (-1, 1, 1): np.sqrt(3)}
self.env = env(resolution=resolution)
#self.X = StateSpace(self.env)
#self.x0, self.xt = getNearest(self.X, self.env.start), getNearest(self.X, self.env.goal)
self.settings = 'CollisionChecking' # for collision checking
self.x0, self.xt = tuple(self.env.start), tuple(self.env.goal)
# self.OPEN = queue.QueuePrior()
self.OPEN = queue.MinheapPQ()
self.km = 0
self.g = {} # all g initialized at inf
self.rhs = {self.xt:0} # rhs(x0) = 0
self.h = {}
self.OPEN.put(self.xt, self.CalculateKey(self.xt))
self.CLOSED = set()
# init children set:
self.CHILDREN = {}
# init Cost set
self.COST = defaultdict(lambda: defaultdict(dict))
# for visualization
self.V = set() # vertice in closed
self.ind = 0
self.Path = []
self.done = False
def updatecost(self, range_changed=None, new=None, old=None, mode=False):
# scan graph for changed Cost, if Cost is changed update it
CHANGED = set()
for xi in self.CLOSED:
if isinbound(old, xi, mode) or isinbound(new, xi, mode):
newchildren = set(children(self, xi)) # B
self.CHILDREN[xi] = newchildren
for xj in newchildren:
self.COST[xi][xj] = cost(self, xi, xj)
CHANGED.add(xi)
return CHANGED
def getcost(self, xi, xj):
# use a LUT for getting the costd
if xi not in self.COST:
for (xj,xjcost) in children(self, xi, settings=1):
self.COST[xi][xj] = cost(self, xi, xj, xjcost)
# this might happen when there is a node changed.
if xj not in self.COST[xi]:
self.COST[xi][xj] = cost(self, xi, xj)
return self.COST[xi][xj]
def getchildren(self, xi):
if xi not in self.CHILDREN:
allchild = children(self, xi)
self.CHILDREN[xi] = set(allchild)
return self.CHILDREN[xi]
def geth(self, xi):
# when the heurisitic is first calculated
if xi not in self.h:
self.h[xi] = heuristic_fun(self, xi, self.x0)
return self.h[xi]
def getg(self, xi):
if xi not in self.g:
self.g[xi] = np.inf
return self.g[xi]
def getrhs(self, xi):
if xi not in self.rhs:
self.rhs[xi] = np.inf
return self.rhs[xi]
#-------------main functions for D*Lite-------------
def CalculateKey(self, s, epsilion = 1):
return [min(self.getg(s), self.getrhs(s)) + epsilion * self.geth(s) + self.km, min(self.getg(s), self.getrhs(s))]
def UpdateVertex(self, u):
# if still in the hunt
if not getDist(self.xt, u) <= self.env.resolution: # originally: u != x_goal
if u in self.CHILDREN and len(self.CHILDREN[u]) == 0:
self.rhs[u] = np.inf
else:
self.rhs[u] = min([self.getcost(s, u) + self.getg(s) for s in self.getchildren(u)])
# if u is in OPEN, remove it
self.OPEN.check_remove(u)
# if rhs(u) not equal to g(u)
if self.getg(u) != self.getrhs(u):
self.OPEN.put(u, self.CalculateKey(u))
def ComputeShortestPath(self):
while self.OPEN.top_key() < self.CalculateKey(self.x0) or self.getrhs(self.x0) != self.getg(self.x0) :
kold = self.OPEN.top_key()
u = self.OPEN.get()
self.V.add(u)
self.CLOSED.add(u)
if not self.done: # first time running, we need to stop on this condition
if getDist(self.x0,u) < 1*self.env.resolution:
self.x0 = u
break
if kold < self.CalculateKey(u):
self.OPEN.put(u, self.CalculateKey(u))
if self.getg(u) > self.getrhs(u):
self.g[u] = self.rhs[u]
else:
self.g[u] = np.inf
self.UpdateVertex(u)
for s in self.getchildren(u):
self.UpdateVertex(s)
# visualization(self)
self.ind += 1
def main(self):
s_last = self.x0
print('first run ...')
self.ComputeShortestPath()
self.Path = self.path()
self.done = True
visualization(self)
plt.pause(0.5)
# plt.show()
print('running with map update ...')
t = 0 # count time
ischanged = False
self.V = set()
while getDist(self.x0, self.xt) > 2*self.env.resolution:
#---------------------------------- at specific times, the environment is changed and Cost is updated
if t % 2 == 0:
new0,old0 = self.env.move_block(a=[-0.1, 0, -0.2], s=0.5, block_to_move=1, mode='translation')
new1,old1 = self.env.move_block(a=[0, 0, -0.2], s=0.5, block_to_move=0, mode='translation')
new2,old2 = self.env.move_block(theta = [0,0,0.1*t], mode='rotation')
#new2,old2 = self.env.move_block(a=[-0.3, 0, -0.1], s=0.5, block_to_move=1, mode='translation')
ischanged = True
self.Path = []
#----------------------------------- traverse the route as originally planned
if t == 0:
children_new = [i for i in self.CLOSED if getDist(self.x0, i) <= self.env.resolution*np.sqrt(3)]
else:
children_new = list(children(self,self.x0))
self.x0 = children_new[np.argmin([self.getcost(self.x0,s_p) + self.getg(s_p) for s_p in children_new])]
# TODO add the moving robot position codes
self.env.start = self.x0
# ---------------------------------- if any Cost changed, update km, reset slast,
# for all directed edgees (u,v) with chaged edge costs,
# update the edge Cost c(u,v) and update vertex u. then replan
if ischanged:
self.km += heuristic_fun(self, self.x0, s_last)
s_last = self.x0
CHANGED = self.updatecost(True, new0, old0)
CHANGED1 = self.updatecost(True, new1, old1)
CHANGED2 = self.updatecost(True, new2, old2, mode='obb')
CHANGED = CHANGED.union(CHANGED1, CHANGED2)
# self.V = set()
for u in CHANGED:
self.UpdateVertex(u)
self.ComputeShortestPath()
ischanged = False
self.Path = self.path(self.x0)
visualization(self)
t += 1
plt.show()
def path(self, s_start=None):
'''After ComputeShortestPath()
returns, one can then follow a shortest path from x_start to
x_goal by always moving from the current vertex s, starting
at x_start. , to any successor s' that minimizes c(s,s') + g(s')
until x_goal is reached (ties can be broken arbitrarily).'''
path = []
s_goal = self.xt
if not s_start:
s = self.x0
else:
s= s_start
ind = 0
while s != s_goal:
if s == self.x0:
children = [i for i in self.CLOSED if getDist(s, i) <= self.env.resolution*np.sqrt(3)]
else:
children = list(self.CHILDREN[s])
snext = children[np.argmin([self.getcost(s,s_p) + self.getg(s_p) for s_p in children])]
path.append([s, snext])
s = snext
if ind > 100:
break
ind += 1
return path
if __name__ == '__main__':
D_lite = D_star_Lite(1)
a = time.time()
D_lite.main()
print('used time (s) is ' + str(time.time() - a))