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https://github.com/zhm-real/PathPlanning.git
synced 2026-08-29 08:34:46 +08:00
BITstar
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@@ -25,7 +25,7 @@ import sys
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sys.path.append(os.path.dirname(os.path.abspath(__file__)) + "/../../Sampling_based_Planning/")
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from rrt_3D.env3D import env
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from rrt_3D.utils3D import getDist, sampleFree, nearest, steer, isCollide, isinside
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from rrt_3D.utils3D import getDist, sampleFree, nearest, steer, isCollide, isinside, isinbound
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from rrt_3D.plot_util3D import make_get_proj, draw_block_list, draw_Spheres, draw_obb, draw_line, make_transparent
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from rrt_3D.queue import MinheapPQ
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@@ -53,63 +53,84 @@ class BIT_star:
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self.env = env()
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self.xstart, self.xgoal = tuple(self.env.start), tuple(self.env.goal)
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self.x0, self.xt = tuple(self.env.start), tuple(self.env.goal)
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self.maxiter = 3000 # used for determining how many batches needed
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# radius calc
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self.eta = 20 # bigger or equal to 1
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self.maxiter = 5000 # used for determining how many batches needed
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# radius calc parameter:
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# larger value makes better 1-time-performance, but longer time trade off
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self.eta = 7 # bigger or equal to 1
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# sampling
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self.m = 1000 # number of samples for one time sample
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self.d = 3 # dimension we work with
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self.Path = []
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self.edgeCost = {} # corresponding to c
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self.heuristic_edgeCost = {} # correspoinding to c_hat
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# instance of the cost to come gT
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self.g = {self.xstart:0, self.xgoal:np.inf}
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# draw ellipse
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self.show_ellipse = show_ellipse
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# denote if the path is found
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self.done = False
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self.Path = []
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def run(self):
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self.V = {self.xstart}
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self.E = set()
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self.Parent = {}
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self.T = (self.V, self.E) # tree
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self.Xsamples = {self.xgoal}
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self.QE = set()
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self.QV = set()
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self.r = np.inf
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self.V = {self.xstart} # node expanded
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self.E = set() # edge set
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self.Parent = {} # Parent relation
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# self.T = (self.V, self.E) # tree
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self.Xsamples = {self.xgoal} # sampled set
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self.QE = set() # edges in queue
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self.QV = set() # nodes in queue
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self.r = np.inf # radius for evaluation
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self.ind = 0
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while True:
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# for the first round
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print(self.ind)
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print(self.r)
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print('round '+str(self.ind))
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self.visualization()
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# print(len(self.V))
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if len(self.QE) == 0 and len(self.QV) == 0:
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self.Prune(self.g_T(self.xgoal))
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self.Xsamples = self.Sample(self.m, self.g_T(self.xgoal)) # sample function
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self.Vold = copy.deepcopy(self.V)
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self.QV = copy.deepcopy(self.V)
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self.r = self.radius(len(self.V) + len(self.Xsamples))
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self.Xsamples.add(self.xgoal) # adding goal into the sample
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self.Vold = {v for v in self.V}
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self.QV = {v for v in self.V}
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# setting the radius
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if self.done:
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self.r = 1
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else:
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self.r = self.radius(len(self.V) + len(self.Xsamples))
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while self.BestQueueValue(self.QV, mode = 'QV') <= self.BestQueueValue(self.QE, mode = 'QE'):
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self.ExpandVertex(self.BestInQueue(self.QV, mode = 'QV'))
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(vm, xm) = self.BestInQueue(self.QE, mode = 'QE')
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self.QE.difference_update({(vm, xm)})
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self.QE.remove((vm, xm))
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if self.g_T(vm) + self.c_hat(vm, xm) + self.h_hat(xm) < self.g_T(self.xgoal):
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if self.g_hat(vm) + self.c(vm, xm) + self.h_hat(xm) < self.g_T(self.xgoal):
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if self.g_T(vm) + self.c(vm, xm) < self.g_T(xm):
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cost = self.c(vm, xm)
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if self.g_hat(vm) + cost + self.h_hat(xm) < self.g_T(self.xgoal):
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if self.g_T(vm) + cost < self.g_T(xm):
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if xm in self.V:
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self.E.difference_update({(v, x) for (v, x) in self.E if x == xm})
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else:
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self.Xsamples.difference_update({xm})
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self.Xsamples.remove(xm)
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self.V.add(xm)
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self.QV.add(xm)
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self.g[xm] = self.g[vm] + cost
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self.E.add((vm, xm))
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self.Parent[vm] = xm # add parent or update parent
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self.QE.difference_update({(v, x) for (v, x) in self.QE if x == xm and self.g_T(v) + self.c_hat(v, x) >= self.g_T(x)})
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self.Parent[xm] = vm # add parent or update parent
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self.QE.difference_update({(v, x) for (v, x) in self.QE if x == xm and (self.g_T(v) + self.c_hat(v, xm)) >= self.g_T(xm)})
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# reinitializing sampling
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else:
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self.QE = set()
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self.QV = set()
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self.ind += 1
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# if the goal is reached
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if self.xgoal in self.Parent:
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print('locating path...')
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self.done = True
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self.Path = self.path()
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# if the iteration is bigger
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if self.ind > self.maxiter:
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break
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return self.T
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@@ -133,7 +154,7 @@ class BIT_star:
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self.C = C # save to global var
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self.xcenter = xcenter
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self.L = L
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x2 = set(map(tuple, x[np.array([not isinside(self, state) for state in x])])) # intersection with the state space
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x2 = set(map(tuple, x[np.array([not isinside(self, state) and isinbound(self.env.boundary, state) for state in x])])) # intersection with the state space
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xrand.update(x2)
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# if there are samples inside obstacle: recursion
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if len(x2) < m:
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@@ -166,12 +187,12 @@ class BIT_star:
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#----------BIT_star particular
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def ExpandVertex(self, v):
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self.QV.difference_update({v})
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self.QV.remove(v)
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Xnear = {x for x in self.Xsamples if getDist(x, v) <= self.r}
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self.QE.update({(v, x) for v in self.V for x in Xnear if self.g_hat(v) + self.c_hat(v, x) + self.h_hat(x) < self.g_T(self.xgoal)})
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self.QE.update({(v, x) for x in Xnear if self.g_hat(v) + self.c_hat(v, x) + self.h_hat(x) < self.g_T(self.xgoal)})
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if v not in self.Vold:
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Vnear = {w for w in self.V if getDist(w, v) <= self.r}
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self.QE.update({(v,w) for v in self.V for w in Vnear if \
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self.QE.update({(v,w) for w in Vnear if \
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((v,w) not in self.E) and \
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(self.g_hat(v) + self.c_hat(v, w) + self.h_hat(w) < self.g_T(self.xgoal)) and \
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(self.g_T(v) + self.c_hat(v, w) < self.g_T(w))})
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@@ -207,26 +228,26 @@ class BIT_star:
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def BestInQueue(self, inputset, mode):
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# returns the best vertex in the vertex queue given this ordering
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# mode = 'QE' or 'QV'
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_, best_state = self.find_best(inputset, mode)
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return best_state
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if mode == 'QV':
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V = {state: self.g_T(state) + self.h_hat(state) for state in self.QV}
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if mode == 'QE':
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V = {state: self.g_T(state[0]) + self.c_hat(state[0], state[1]) + self.h_hat(state[1]) for state in self.QE}
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if len(V) == 0:
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print(mode + 'empty')
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return None
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return min(V, key = V.get)
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def BestQueueValue(self, inputset, mode):
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# returns the best value in the vertex queue given this ordering
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# mode = 'QE' or 'QV'
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best_val, _ = self.find_best(inputset, mode)
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return best_val
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if mode == 'QV':
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V = {self.g_T(state) + self.h_hat(state) for state in self.QV}
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if mode == 'QE':
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V = {self.g_T(state[0]) + self.c_hat(state[0], state[1]) + self.h_hat(state[1]) for state in self.QE}
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if len(V) == 0:
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return np.inf
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return min(V)
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def find_best(self, inputset, mode):
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min_val, min_state = np.inf, None
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for state in inputset:
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if mode == 'QE':
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curr_val = self.g_T(state[0]) + self.c_hat(state[0], state[1]) + self.h_hat(state[1])
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elif mode == 'QV':
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curr_val = self.g_T(state) + self.h_hat(state)
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if curr_val < min_val:
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min_val, min_state = curr_val, state
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return min_val, min_state
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def g_hat(self, v):
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return getDist(self.xstart, v)
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@@ -239,42 +260,40 @@ class BIT_star:
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def c(self, v, w):
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# admissible estimate of the cost of an edge between state v, w
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if (v,w) in self.edgeCost:
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pass
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else:
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collide, dist = isCollide(self, v, w)
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if collide:
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self.edgeCost[(v,w)] = np.inf
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else:
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self.edgeCost[(v,w)] = dist
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return self.edgeCost[(v,w)]
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collide, dist = isCollide(self, v, w)
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if collide:
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return np.inf
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else:
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return dist
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def c_hat(self, v, w):
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# c_hat < c < np.inf
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# heuristic estimate of the edge cost, since c is expensive
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if (v,w) in self.heuristic_edgeCost:
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pass
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else:
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self.heuristic_edgeCost[(v,w)] = getDist(v, w)
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return self.heuristic_edgeCost[(v,w)]
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return getDist(v, w)
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def g_T(self, v):
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# represent cost-to-come from the start in the tree,
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# if the state is not in tree, or unreachable, return inf
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if v in self.Parent:
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cost_to_come = 0
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while v != self.xstart:
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cost_to_come += self.c(v, self.Parent[v])
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v = self.Parent[v]
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return cost_to_come
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elif v == self.xstart:
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return 0
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else:
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return np.inf
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if v not in self.g:
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self.g[v] = np.inf
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return self.g[v]
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def path(self):
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path = []
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s = self.xgoal
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i = 0
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while s != self.xstart:
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path.append((s, self.Parent[s]))
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s = self.Parent[s]
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if i > self.m:
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break
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i += 1
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return path
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def visualization(self):
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if self.ind % 20 == 0:
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V = np.array(list(self.V))
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Xsample = np.array(list(self.Xsamples))
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edges = list(map(list, self.E))
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Path = np.array(self.Path)
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start = self.env.start
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@@ -305,6 +324,8 @@ class BIT_star:
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draw_ellipsoid(ax, self.C, self.L, self.xcenter) # beware, depending on start and goal position, this might be bad for vis
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if len(V) > 0:
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ax.scatter3D(V[:, 0], V[:, 1], V[:, 2], s=2, color='g', )
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if len(Xsample) > 0: # plot the sampled points
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ax.scatter3D(Xsample[:, 0], Xsample[:, 1], Xsample[:, 2], s=2, color='b', )
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ax.plot(start[0:1], start[1:2], start[2:], 'go', markersize=7, markeredgecolor='k')
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ax.plot(goal[0:1], goal[1:2], goal[2:], 'ro', markersize=7, markeredgecolor='k')
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# adjust the aspect ratio
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