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https://github.com/zhm-real/PathPlanning.git
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zhm-real
60 lines
2.3 KiB
Python
60 lines
2.3 KiB
Python
#!/usr/bin/env python3
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# -*- coding: utf-8 -*-
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"""
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@author: huiming zhou
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"""
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import queue
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import environment
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import tools
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class DFS:
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"""
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DFS -> Depth-first Searching
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"""
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def __init__(self, Start_State, Goal_State, n, m):
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self.xI = Start_State
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self.xG = Goal_State
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self.u_set = environment.motions # feasible input set
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self.obs_map = environment.map_obs() # position of obstacles
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self.n = n
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self.m = m
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def searching(self):
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"""
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Searching using DFS.
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:return: planning path, action in each node, visited nodes in the planning process
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"""
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q_dfs = queue.QueueLIFO() # last-in-first-out queue
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q_dfs.put(self.xI)
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parent = {self.xI: self.xI} # record parents of nodes
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actions = {self.xI: (0, 0)} # record actions of nodes
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visited = []
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while not q_dfs.empty():
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x_current = q_dfs.get()
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visited.append(x_current) # record visited nodes
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if x_current == self.xG: # stop condition
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break
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for u_next in self.u_set: # explore neighborhoods of current node
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x_next = tuple([x_current[i] + u_next[i] for i in range(len(x_current))]) # neighbor node
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# if neighbor node is not in obstacles and has not been visited -> ...
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if 0 <= x_next[0] < self.n and 0 <= x_next[1] < self.m \
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and x_next not in parent \
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and not tools.obs_detect(x_current, u_next, self.obs_map):
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q_dfs.put(x_next)
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parent[x_next] = x_current
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actions[x_next] = u_next
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[path_dfs, actions_dfs] = tools.extract_path(self.xI, self.xG, parent, actions)
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return path_dfs, actions_dfs, visited
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if __name__ == '__main__':
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x_Start = (15, 10) # Starting node
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x_Goal = (48, 15) # Goal node
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dfs = DFS(x_Start, x_Goal, environment.col, environment.row)
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[path_dfs, actions_dfs, visited_dfs] = dfs.searching()
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tools.showPath(x_Start, x_Goal, path_dfs, visited_dfs, 'depth_first_searching') # Plot path and visited nodes |