This commit is contained in:
yue qi
2020-08-12 21:08:04 -07:00
parent d84e8d9baf
commit 1f06667394
5 changed files with 91 additions and 70 deletions
+91 -70
View File
@@ -25,7 +25,7 @@ import sys
sys.path.append(os.path.dirname(os.path.abspath(__file__)) + "/../../Sampling_based_Planning/")
from rrt_3D.env3D import env
from rrt_3D.utils3D import getDist, sampleFree, nearest, steer, isCollide, isinside
from rrt_3D.utils3D import getDist, sampleFree, nearest, steer, isCollide, isinside, isinbound
from rrt_3D.plot_util3D import make_get_proj, draw_block_list, draw_Spheres, draw_obb, draw_line, make_transparent
from rrt_3D.queue import MinheapPQ
@@ -53,63 +53,84 @@ class BIT_star:
self.env = env()
self.xstart, self.xgoal = tuple(self.env.start), tuple(self.env.goal)
self.x0, self.xt = tuple(self.env.start), tuple(self.env.goal)
self.maxiter = 3000 # used for determining how many batches needed
# radius calc
self.eta = 20 # bigger or equal to 1
self.maxiter = 5000 # used for determining how many batches needed
# radius calc parameter:
# larger value makes better 1-time-performance, but longer time trade off
self.eta = 7 # bigger or equal to 1
# sampling
self.m = 1000 # number of samples for one time sample
self.d = 3 # dimension we work with
self.Path = []
self.edgeCost = {} # corresponding to c
self.heuristic_edgeCost = {} # correspoinding to c_hat
# instance of the cost to come gT
self.g = {self.xstart:0, self.xgoal:np.inf}
# draw ellipse
self.show_ellipse = show_ellipse
# denote if the path is found
self.done = False
self.Path = []
def run(self):
self.V = {self.xstart}
self.E = set()
self.Parent = {}
self.T = (self.V, self.E) # tree
self.Xsamples = {self.xgoal}
self.QE = set()
self.QV = set()
self.r = np.inf
self.V = {self.xstart} # node expanded
self.E = set() # edge set
self.Parent = {} # Parent relation
# self.T = (self.V, self.E) # tree
self.Xsamples = {self.xgoal} # sampled set
self.QE = set() # edges in queue
self.QV = set() # nodes in queue
self.r = np.inf # radius for evaluation
self.ind = 0
while True:
# for the first round
print(self.ind)
print(self.r)
print('round '+str(self.ind))
self.visualization()
# print(len(self.V))
if len(self.QE) == 0 and len(self.QV) == 0:
self.Prune(self.g_T(self.xgoal))
self.Xsamples = self.Sample(self.m, self.g_T(self.xgoal)) # sample function
self.Vold = copy.deepcopy(self.V)
self.QV = copy.deepcopy(self.V)
self.r = self.radius(len(self.V) + len(self.Xsamples))
self.Xsamples.add(self.xgoal) # adding goal into the sample
self.Vold = {v for v in self.V}
self.QV = {v for v in self.V}
# setting the radius
if self.done:
self.r = 1
else:
self.r = self.radius(len(self.V) + len(self.Xsamples))
while self.BestQueueValue(self.QV, mode = 'QV') <= self.BestQueueValue(self.QE, mode = 'QE'):
self.ExpandVertex(self.BestInQueue(self.QV, mode = 'QV'))
(vm, xm) = self.BestInQueue(self.QE, mode = 'QE')
self.QE.difference_update({(vm, xm)})
self.QE.remove((vm, xm))
if self.g_T(vm) + self.c_hat(vm, xm) + self.h_hat(xm) < self.g_T(self.xgoal):
if self.g_hat(vm) + self.c(vm, xm) + self.h_hat(xm) < self.g_T(self.xgoal):
if self.g_T(vm) + self.c(vm, xm) < self.g_T(xm):
cost = self.c(vm, xm)
if self.g_hat(vm) + cost + self.h_hat(xm) < self.g_T(self.xgoal):
if self.g_T(vm) + cost < self.g_T(xm):
if xm in self.V:
self.E.difference_update({(v, x) for (v, x) in self.E if x == xm})
else:
self.Xsamples.difference_update({xm})
self.Xsamples.remove(xm)
self.V.add(xm)
self.QV.add(xm)
self.g[xm] = self.g[vm] + cost
self.E.add((vm, xm))
self.Parent[vm] = xm # add parent or update parent
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)})
self.Parent[xm] = vm # add parent or update parent
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)})
# reinitializing sampling
else:
self.QE = set()
self.QV = set()
self.ind += 1
# if the goal is reached
if self.xgoal in self.Parent:
print('locating path...')
self.done = True
self.Path = self.path()
# if the iteration is bigger
if self.ind > self.maxiter:
break
return self.T
@@ -133,7 +154,7 @@ class BIT_star:
self.C = C # save to global var
self.xcenter = xcenter
self.L = L
x2 = set(map(tuple, x[np.array([not isinside(self, state) for state in x])])) # intersection with the state space
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
xrand.update(x2)
# if there are samples inside obstacle: recursion
if len(x2) < m:
@@ -166,12 +187,12 @@ class BIT_star:
#----------BIT_star particular
def ExpandVertex(self, v):
self.QV.difference_update({v})
self.QV.remove(v)
Xnear = {x for x in self.Xsamples if getDist(x, v) <= self.r}
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)})
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)})
if v not in self.Vold:
Vnear = {w for w in self.V if getDist(w, v) <= self.r}
self.QE.update({(v,w) for v in self.V for w in Vnear if \
self.QE.update({(v,w) for w in Vnear if \
((v,w) not in self.E) and \
(self.g_hat(v) + self.c_hat(v, w) + self.h_hat(w) < self.g_T(self.xgoal)) and \
(self.g_T(v) + self.c_hat(v, w) < self.g_T(w))})
@@ -207,26 +228,26 @@ class BIT_star:
def BestInQueue(self, inputset, mode):
# returns the best vertex in the vertex queue given this ordering
# mode = 'QE' or 'QV'
_, best_state = self.find_best(inputset, mode)
return best_state
if mode == 'QV':
V = {state: self.g_T(state) + self.h_hat(state) for state in self.QV}
if mode == 'QE':
V = {state: self.g_T(state[0]) + self.c_hat(state[0], state[1]) + self.h_hat(state[1]) for state in self.QE}
if len(V) == 0:
print(mode + 'empty')
return None
return min(V, key = V.get)
def BestQueueValue(self, inputset, mode):
# returns the best value in the vertex queue given this ordering
# mode = 'QE' or 'QV'
best_val, _ = self.find_best(inputset, mode)
return best_val
if mode == 'QV':
V = {self.g_T(state) + self.h_hat(state) for state in self.QV}
if mode == 'QE':
V = {self.g_T(state[0]) + self.c_hat(state[0], state[1]) + self.h_hat(state[1]) for state in self.QE}
if len(V) == 0:
return np.inf
return min(V)
def find_best(self, inputset, mode):
min_val, min_state = np.inf, None
for state in inputset:
if mode == 'QE':
curr_val = self.g_T(state[0]) + self.c_hat(state[0], state[1]) + self.h_hat(state[1])
elif mode == 'QV':
curr_val = self.g_T(state) + self.h_hat(state)
if curr_val < min_val:
min_val, min_state = curr_val, state
return min_val, min_state
def g_hat(self, v):
return getDist(self.xstart, v)
@@ -239,42 +260,40 @@ class BIT_star:
def c(self, v, w):
# admissible estimate of the cost of an edge between state v, w
if (v,w) in self.edgeCost:
pass
else:
collide, dist = isCollide(self, v, w)
if collide:
self.edgeCost[(v,w)] = np.inf
else:
self.edgeCost[(v,w)] = dist
return self.edgeCost[(v,w)]
collide, dist = isCollide(self, v, w)
if collide:
return np.inf
else:
return dist
def c_hat(self, v, w):
# c_hat < c < np.inf
# heuristic estimate of the edge cost, since c is expensive
if (v,w) in self.heuristic_edgeCost:
pass
else:
self.heuristic_edgeCost[(v,w)] = getDist(v, w)
return self.heuristic_edgeCost[(v,w)]
return getDist(v, w)
def g_T(self, v):
# represent cost-to-come from the start in the tree,
# if the state is not in tree, or unreachable, return inf
if v in self.Parent:
cost_to_come = 0
while v != self.xstart:
cost_to_come += self.c(v, self.Parent[v])
v = self.Parent[v]
return cost_to_come
elif v == self.xstart:
return 0
else:
return np.inf
if v not in self.g:
self.g[v] = np.inf
return self.g[v]
def path(self):
path = []
s = self.xgoal
i = 0
while s != self.xstart:
path.append((s, self.Parent[s]))
s = self.Parent[s]
if i > self.m:
break
i += 1
return path
def visualization(self):
if self.ind % 20 == 0:
V = np.array(list(self.V))
Xsample = np.array(list(self.Xsamples))
edges = list(map(list, self.E))
Path = np.array(self.Path)
start = self.env.start
@@ -305,6 +324,8 @@ class BIT_star:
draw_ellipsoid(ax, self.C, self.L, self.xcenter) # beware, depending on start and goal position, this might be bad for vis
if len(V) > 0:
ax.scatter3D(V[:, 0], V[:, 1], V[:, 2], s=2, color='g', )
if len(Xsample) > 0: # plot the sampled points
ax.scatter3D(Xsample[:, 0], Xsample[:, 1], Xsample[:, 2], s=2, color='b', )
ax.plot(start[0:1], start[1:2], start[2:], 'go', markersize=7, markeredgecolor='k')
ax.plot(goal[0:1], goal[1:2], goal[2:], 'ro', markersize=7, markeredgecolor='k')
# adjust the aspect ratio