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PathPlanning/Search_based_Planning/Search_2D/Anytime_D_star.py
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zhm-real 5f06989837 reformat
2020-07-30 10:02:26 -07:00

310 lines
9.8 KiB
Python

"""
Anytime_D_star 2D
@author: huiming zhou
"""
import os
import sys
import math
import matplotlib.pyplot as plt
sys.path.append(os.path.dirname(os.path.abspath(__file__)) +
"/../../Search_based_Planning/")
from Search_2D import plotting
from Search_2D import env
class ADStar:
def __init__(self, s_start, s_goal, eps, heuristic_type):
self.s_start, self.s_goal = s_start, s_goal
self.heuristic_type = heuristic_type
self.Env = env.Env() # class Env
self.Plot = plotting.Plotting(s_start, s_goal)
self.u_set = self.Env.motions # feasible input set
self.obs = self.Env.obs # position of obstacles
self.x = self.Env.x_range
self.y = self.Env.y_range
self.g, self.rhs, self.OPEN = {}, {}, {}
for i in range(1, self.Env.x_range - 1):
for j in range(1, self.Env.y_range - 1):
self.rhs[(i, j)] = float("inf")
self.g[(i, j)] = float("inf")
self.rhs[self.s_goal] = 0.0
self.eps = eps
self.OPEN[self.s_goal] = self.Key(self.s_goal)
self.CLOSED, self.INCONS = set(), dict()
self.visited = set()
self.count = 0
self.count_env_change = 0
self.obs_add = set()
self.obs_remove = set()
self.title = "Anytime D*: Small changes" # significant changes
self.fig = plt.figure()
def run(self):
self.Plot.plot_grid(self.title)
self.ComputeOrImprovePath()
self.plot_visited()
self.plot_path(self.extract_path())
self.visited = set()
while True:
if self.eps <= 1.0:
break
self.eps -= 0.5
self.OPEN.update(self.INCONS)
for s in self.OPEN:
self.OPEN[s] = self.Key(s)
self.CLOSED = set()
self.ComputeOrImprovePath()
self.plot_visited()
self.plot_path(self.extract_path())
self.visited = set()
plt.pause(0.5)
self.fig.canvas.mpl_connect('button_press_event', self.on_press)
plt.show()
def on_press(self, event):
x, y = event.xdata, event.ydata
if x < 0 or x > self.x - 1 or y < 0 or y > self.y - 1:
print("Please choose right area!")
else:
self.count_env_change += 1
x, y = int(x), int(y)
print("Change position: x =", x, ",", "y =", y)
# for small changes
if self.title == "Anytime D*: Small changes":
if (x, y) not in self.obs:
self.obs.add((x, y))
plt.plot(x, y, 'sk')
self.g[(x, y)] = float("inf")
self.rhs[(x, y)] = float("inf")
else:
self.obs.remove((x, y))
plt.plot(x, y, marker='s', color='white')
self.UpdateState((x, y))
for sn in self.get_neighbor((x, y)):
self.UpdateState(sn)
while True:
if len(self.INCONS) == 0:
break
self.OPEN.update(self.INCONS)
for s in self.OPEN:
self.OPEN[s] = self.Key(s)
self.CLOSED = set()
self.ComputeOrImprovePath()
self.plot_visited()
self.plot_path(self.extract_path())
# plt.plot(self.title)
self.visited = set()
if self.eps <= 1.0:
break
else:
if (x, y) not in self.obs:
self.obs.add((x, y))
self.obs_add.add((x, y))
plt.plot(x, y, 'sk')
if (x, y) in self.obs_remove:
self.obs_remove.remove((x, y))
else:
self.obs.remove((x, y))
self.obs_remove.add((x, y))
plt.plot(x, y, marker='s', color='white')
if (x, y) in self.obs_add:
self.obs_add.remove((x, y))
if self.count_env_change >= 15:
self.count_env_change = 0
self.eps += 2.0
for s in self.obs_add:
self.g[(x, y)] = float("inf")
self.rhs[(x, y)] = float("inf")
for sn in self.get_neighbor(s):
self.UpdateState(sn)
for s in self.obs_remove:
for sn in self.get_neighbor(s):
self.UpdateState(sn)
self.UpdateState(s)
while True:
if self.eps <= 1.0:
break
self.eps -= 0.5
self.OPEN.update(self.INCONS)
for s in self.OPEN:
self.OPEN[s] = self.Key(s)
self.CLOSED = set()
self.ComputeOrImprovePath()
self.plot_visited()
self.plot_path(self.extract_path())
plt.title(self.title)
self.visited = set()
plt.pause(0.5)
self.fig.canvas.draw_idle()
def ComputeOrImprovePath(self):
while True:
s, v = self.TopKey()
if v >= self.Key(self.s_start) and \
self.rhs[self.s_start] == self.g[self.s_start]:
break
self.OPEN.pop(s)
self.visited.add(s)
if self.g[s] > self.rhs[s]:
self.g[s] = self.rhs[s]
self.CLOSED.add(s)
for sn in self.get_neighbor(s):
self.UpdateState(sn)
else:
self.g[s] = float("inf")
for sn in self.get_neighbor(s):
self.UpdateState(sn)
self.UpdateState(s)
def UpdateState(self, s):
if s != self.s_goal:
self.rhs[s] = float("inf")
for x in self.get_neighbor(s):
self.rhs[s] = min(self.rhs[s], self.g[x] + self.cost(s, x))
if s in self.OPEN:
self.OPEN.pop(s)
if self.g[s] != self.rhs[s]:
if s not in self.CLOSED:
self.OPEN[s] = self.Key(s)
else:
self.INCONS[s] = 0
def Key(self, s):
if self.g[s] > self.rhs[s]:
return [self.rhs[s] + self.eps * self.h(self.s_start, s), self.rhs[s]]
else:
return [self.g[s] + self.h(self.s_start, s), self.g[s]]
def TopKey(self):
"""
:return: return the min key and its value.
"""
s = min(self.OPEN, key=self.OPEN.get)
return s, self.OPEN[s]
def h(self, s_start, s_goal):
heuristic_type = self.heuristic_type # heuristic type
if heuristic_type == "manhattan":
return abs(s_goal[0] - s_start[0]) + abs(s_goal[1] - s_start[1])
else:
return math.hypot(s_goal[0] - s_start[0], s_goal[1] - s_start[1])
def cost(self, s_start, s_goal):
"""
Calculate Cost for this motion
:param s_start: starting node
:param s_goal: end node
:return: Cost for this motion
:note: Cost function could be more complicate!
"""
if self.is_collision(s_start, s_goal):
return float("inf")
return math.hypot(s_goal[0] - s_start[0], s_goal[1] - s_start[1])
def is_collision(self, s_start, s_end):
if s_start in self.obs or s_end in self.obs:
return True
if s_start[0] != s_end[0] and s_start[1] != s_end[1]:
if s_end[0] - s_start[0] == s_start[1] - s_end[1]:
s1 = (min(s_start[0], s_end[0]), min(s_start[1], s_end[1]))
s2 = (max(s_start[0], s_end[0]), max(s_start[1], s_end[1]))
else:
s1 = (min(s_start[0], s_end[0]), max(s_start[1], s_end[1]))
s2 = (max(s_start[0], s_end[0]), min(s_start[1], s_end[1]))
if s1 in self.obs or s2 in self.obs:
return True
return False
def get_neighbor(self, s):
nei_list = set()
for u in self.u_set:
s_next = tuple([s[i] + u[i] for i in range(2)])
if s_next not in self.obs:
nei_list.add(s_next)
return nei_list
def extract_path(self):
"""
Extract the path based on the PARENT set.
:return: The planning path
"""
path = [self.s_start]
s = self.s_start
for k in range(100):
g_list = {}
for x in self.get_neighbor(s):
if not self.is_collision(s, x):
g_list[x] = self.g[x]
s = min(g_list, key=g_list.get)
path.append(s)
if s == self.s_goal:
break
return list(path)
def plot_path(self, path):
px = [x[0] for x in path]
py = [x[1] for x in path]
plt.plot(px, py, linewidth=2)
plt.plot(self.s_start[0], self.s_start[1], "bs")
plt.plot(self.s_goal[0], self.s_goal[1], "gs")
def plot_visited(self):
self.count += 1
color = ['gainsboro', 'lightgray', 'silver', 'darkgray',
'bisque', 'navajowhite', 'moccasin', 'wheat',
'powderblue', 'skyblue', 'lightskyblue', 'cornflowerblue']
if self.count >= len(color) - 1:
self.count = 0
for x in self.visited:
plt.plot(x[0], x[1], marker='s', color=color[self.count])
def main():
s_start = (5, 5)
s_goal = (45, 25)
dstar = ADStar(s_start, s_goal, 2.5, "euclidean")
dstar.run()
if __name__ == '__main__':
main()