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@@ -0,0 +1,200 @@
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+import env
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+import plotting
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+
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+import numpy as np
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+import math
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+
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+
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+class Node:
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+ def __init__(self, n):
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+ self.x = n[0]
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+ self.y = n[1]
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+ self.cost = 0.0
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+ self.parent = None
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+
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+
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+class RRT:
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+ def __init__(self, xI, xG):
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+ self.xI = Node(xI)
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+ self.xG = Node(xG)
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+ self.expand_len = 1
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+ self.goal_sample_rate = 0.05
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+ self.connect_dist = 10
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+ self.iterations = 5000
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+ self.node_list = [self.xI]
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+
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+ self.env = env.Env()
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+ self.plotting = plotting.Plotting(xI, xG)
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+
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+ self.x_range = self.env.x_range
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+ self.y_range = self.env.y_range
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+ self.obs_circle = self.env.obs_circle
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+ self.obs_rectangle = self.env.obs_rectangle
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+ self.obs_boundary = self.env.obs_boundary
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+
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+ self.path = self.planning()
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+ self.plotting.animation(self.node_list, self.path, False)
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+
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+ def planning(self):
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+ for k in range(self.iterations):
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+ node_rand = self.random_state()
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+ node_near = self.nearest_neighbor(self.node_list, node_rand)
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+ node_new = self.new_state(node_near, node_rand)
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+
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+ if not self.check_collision(node_new):
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+ neighbor_index = self.find_near_neighbor(node_new)
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+ node_new = self.choose_parent(node_new, neighbor_index)
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+ if node_new:
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+ self.node_list.append(node_new)
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+ self.rewire(node_new, neighbor_index)
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+
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+ # if self.dis_to_goal(self.node_list[-1]) <= self.expand_len:
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+ # self.new_state(self.node_list[-1], self.xG)
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+ # return self.extract_path()
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+
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+ index = self.search_best_goal_node()
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+ self.xG.parent = self.node_list[index]
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+ return self.extract_path()
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+
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+ def random_state(self):
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+ if np.random.random() > self.goal_sample_rate:
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+ return Node((np.random.uniform(self.x_range[0], self.x_range[1]),
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+ np.random.uniform(self.y_range[0], self.y_range[1])))
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+ return self.xG
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+
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+ def nearest_neighbor(self, node_list, n):
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+ return self.node_list[int(np.argmin([math.hypot(nd.x - n.x, nd.y - n.y)
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+ for nd in node_list]))]
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+
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+ def new_state(self, node_start, node_goal):
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+ node_new = Node((node_start.x, node_start.y))
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+ dist, theta = self.get_distance_and_angle(node_new, node_goal)
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+ dist = min(self.expand_len, dist)
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+
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+ node_new.x += dist * math.cos(theta)
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+ node_new.y += dist * math.sin(theta)
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+ node_new.parent = node_start
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+
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+ return node_new
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+
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+ def find_near_neighbor(self, node_new):
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+ n = len(self.node_list) + 1
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+ r = min(self.connect_dist * math.sqrt((math.log(n) / n)), self.expand_len)
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+
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+ dist_table = [math.hypot(nd.x - node_new.x, nd.y - node_new.y) for nd in self.node_list]
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+ node_index = [dist_table.index(d) for d in dist_table if d <= r]
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+
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+ return node_index
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+
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+ def choose_parent(self, node_new, neighbor_index):
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+ if not neighbor_index:
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+ return None
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+
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+ cost = []
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+
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+ for i in neighbor_index:
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+ node_near = self.node_list[i]
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+ node_mid = self.new_state(node_near, node_new)
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+
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+ if node_mid and not self.check_collision(node_mid):
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+ cost.append(self.update_cost(node_near, node_mid))
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+ else:
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+ cost.append(float("inf"))
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+
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+ if min(cost) != float('inf'):
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+ index = int(np.argmin(cost))
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+ neighbor_min = neighbor_index[index]
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+ node_new = self.new_state(self.node_list[neighbor_min], node_new)
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+ node_new.cost = min(cost)
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+ return node_new
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+
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+ return None
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+
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+ def search_best_goal_node(self):
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+ dist_to_goal_list = [self.dis_to_goal(n) for n in self.node_list]
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+ goal_inds = [dist_to_goal_list.index(i) for i in dist_to_goal_list if i <= self.expand_len]
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+
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+ return goal_inds[0]
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+ # safe_goal_inds = []
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+ # for goal_ind in goal_inds:
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+ # t_node = self.new_state(self.node_list[goal_ind], self.xG)
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+ # if self.check_collision(t_node):
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+ # safe_goal_inds.append(goal_ind)
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+ #
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+ # if not safe_goal_inds:
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+ # print('hahhah')
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+ # return None
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+ #
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+ # min_cost = min([self.node_list[i].cost for i in safe_goal_inds])
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+ # for i in safe_goal_inds:
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+ # if self.node_list[i].cost == min_cost:
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+ # self.xG.parent = self.node_list[i]
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+
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+ def rewire(self, node_new, neighbor_index):
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+ for i in neighbor_index:
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+ node_near = self.node_list[i]
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+ node_edge = self.new_state(node_new, node_near)
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+ if not node_edge:
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+ continue
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+
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+ node_edge.cost = self.update_cost(node_new, node_near)
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+ collision = self.check_collision(node_edge)
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+ improved_cost = node_near.cost > node_edge.cost
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+
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+ if not collision and improved_cost:
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+ self.node_list[i] = node_edge
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+ self.propagate_cost_to_leaves(node_new)
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+
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+ def update_cost(self, node_start, node_end):
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+ dist, theta = self.get_distance_and_angle(node_start, node_end)
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+ return node_start.cost + dist
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+
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+ def propagate_cost_to_leaves(self, parent_node):
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+ for node in self.node_list:
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+ if node.parent == parent_node:
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+ node.cost = self.update_cost(parent_node, node)
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+ self.propagate_cost_to_leaves(node)
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+
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+ def extract_path(self):
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+ path = [[self.xG.x, self.xG.y]]
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+ node = self.xG
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+ while node.parent is not None:
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+ path.append([node.x, node.y])
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+ node = node.parent
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+ path.append([node.x, node.y])
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+
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+ return path
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+
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+ def dis_to_goal(self, node_cal):
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+ return math.hypot(node_cal.x - self.xG.x, node_cal.y - self.xG.y)
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+
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+ def check_collision(self, node_end):
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+ if node_end is None:
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+ return True
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+
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+ for (ox, oy, r) in self.obs_circle:
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+ if math.hypot(node_end.x - ox, node_end.y - oy) <= r:
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+ return True
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+
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+ for (ox, oy, w, h) in self.obs_rectangle:
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+ if 0 <= (node_end.x - ox) <= w and 0 <= (node_end.y - oy) <= h:
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+ return True
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+
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+ for (ox, oy, w, h) in self.obs_boundary:
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+ if 0 <= (node_end.x - ox) <= w and 0 <= (node_end.y - oy) <= h:
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+ return True
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+
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+ return False
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+
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+ @staticmethod
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+ def get_distance_and_angle(node_start, node_end):
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+ dx = node_end.x - node_start.x
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+ dy = node_end.y - node_start.y
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+ return math.hypot(dx, dy), math.atan2(dy, dx)
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+
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+
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+if __name__ == '__main__':
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+ x_Start = (2, 2) # Starting node
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+ x_Goal = (49, 28) # Goal node
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+
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+ rrt = RRT(x_Start, x_Goal)
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