Create dynamic_rrt.py

Sampling-based Planning/rrt_2D/dynamic_rrt.py

@@ -0,0 +1,260 @@
+"""
+DYNAMIC_RRT_2D
+@author: huiming zhou
+"""
+
+import os
+import sys
+import math
+import numpy as np
+import matplotlib.pyplot as plt
+import matplotlib.patches as patches
+
+sys.path.append(os.path.dirname(os.path.abspath(__file__)) +
+                "/../../Sampling-based Planning/")
+
+from rrt_2D import env
+from rrt_2D import plotting
+from rrt_2D import utils
+
+
+class Node:
+    def __init__(self, n):
+        self.x = n[0]
+        self.y = n[1]
+        self.parent = None
+
+
+class Edge:
+    def __init__(self, n_p, n_c):
+        self.parent = n_p
+        self.child = n_c
+
+
+class DynamicRrt:
+    def __init__(self, s_start, s_goal, step_len, goal_sample_rate, waypoint_sample_rate, iter_max):
+        self.s_start = Node(s_start)
+        self.s_goal = Node(s_goal)
+        self.step_len = step_len
+        self.goal_sample_rate = goal_sample_rate
+        self.waypoint_sample_rate = waypoint_sample_rate
+        self.iter_max = iter_max
+        self.vertex = [self.s_start]
+        self.edges = set()
+
+        self.env = env.Env()
+        self.plotting = plotting.Plotting(s_start, s_goal)
+        self.utils = utils.Utils()
+        self.fig, self.ax = plt.subplots()
+
+        self.x_range = self.env.x_range
+        self.y_range = self.env.y_range
+        self.obs_circle = self.env.obs_circle
+        self.obs_rectangle = self.env.obs_rectangle
+        self.obs_boundary = self.env.obs_boundary
+
+        self.path = []
+        self.waypoint = []
+
+    def planning(self):
+        for i in range(self.iter_max):
+            node_rand = self.generate_random_node(self.goal_sample_rate)
+            node_near = self.nearest_neighbor(self.vertex, node_rand)
+            node_new = self.new_state(node_near, node_rand)
+
+            if node_new and not self.utils.is_collision(node_near, node_new):
+                self.vertex.append(node_new)
+                dist, _ = self.get_distance_and_angle(node_new, self.s_goal)
+
+                if dist <= self.step_len:
+                    self.new_state(node_new, self.s_goal)
+
+                    path = self.extract_path(node_new)
+                    self.plot_grid("Extended_RRT")
+                    self.plot_visited()
+                    self.plot_path(path)
+                    self.path = path
+                    self.waypoint = self.extract_waypoint(node_new)
+                    self.fig.canvas.mpl_connect('button_press_event', self.on_press)
+                    plt.show()
+
+                    return
+
+        return None
+
+    def on_press(self, event):
+        x, y = event.xdata, event.ydata
+        if x < 0 or x > 50 or y < 0 or y > 30:
+            print("Please choose right area!")
+        else:
+            x, y = int(x), int(y)
+            print("Add circle obstacle at: x =", x, ",", "y =", y)
+            self.obs_circle.append([x, y, 2])
+            self.utils.update_obs(self.obs_circle, self.obs_boundary, self.obs_rectangle)
+            path, waypoint = self.replanning()
+
+            plt.cla()
+            self.plot_grid("Extended_RRT")
+            self.plot_path(self.path, color='blue')
+            self.plot_visited()
+            self.plot_path(path)
+            self.path = path
+            self.waypoint = waypoint
+            self.fig.canvas.draw_idle()
+
+    def replanning(self):
+        self.vertex = [self.s_start]
+
+        for i in range(self.iter_max):
+            node_rand = self.generate_random_node_replanning(self.goal_sample_rate, self.waypoint_sample_rate)
+            node_near = self.nearest_neighbor(self.vertex, node_rand)
+            node_new = self.new_state(node_near, node_rand)
+
+            if node_new and not self.utils.is_collision(node_near, node_new):
+                self.vertex.append(node_new)
+                dist, _ = self.get_distance_and_angle(node_new, self.s_goal)
+
+                if dist <= self.step_len:
+                    self.new_state(node_new, self.s_goal)
+                    path = self.extract_path(node_new)
+                    waypoint = self.extract_waypoint(node_new)
+
+                    return path, waypoint
+
+        return None
+
+    def generate_random_node(self, goal_sample_rate):
+        delta = self.utils.delta
+
+        if np.random.random() > goal_sample_rate:
+            return Node((np.random.uniform(self.x_range[0] + delta, self.x_range[1] - delta),
+                         np.random.uniform(self.y_range[0] + delta, self.y_range[1] - delta)))
+
+        return self.s_goal
+
+    def generate_random_node_replanning(self, goal_sample_rate, waypoint_sample_rate):
+        delta = self.utils.delta
+        p = np.random.random()
+
+        if p < goal_sample_rate:
+            return self.s_goal
+        elif goal_sample_rate < p < goal_sample_rate + waypoint_sample_rate:
+            return self.waypoint[np.random.randint(0, len(self.path) - 1)]
+        else:
+            return Node((np.random.uniform(self.x_range[0] + delta, self.x_range[1] - delta),
+                         np.random.uniform(self.y_range[0] + delta, self.y_range[1] - delta)))
+
+
+    @staticmethod
+    def nearest_neighbor(node_list, n):
+        return node_list[int(np.argmin([math.hypot(nd.x - n.x, nd.y - n.y)
+                                        for nd in node_list]))]
+
+    def new_state(self, node_start, node_end):
+        dist, theta = self.get_distance_and_angle(node_start, node_end)
+
+        dist = min(self.step_len, dist)
+        node_new = Node((node_start.x + dist * math.cos(theta),
+                         node_start.y + dist * math.sin(theta)))
+        node_new.parent = node_start
+
+        return node_new
+
+    def extract_path(self, node_end):
+        path = [(self.s_goal.x, self.s_goal.y)]
+        node_now = node_end
+
+        while node_now.parent is not None:
+            node_now = node_now.parent
+            path.append((node_now.x, node_now.y))
+
+        return path
+
+    def extract_waypoint(self, node_end):
+        waypoint = [self.s_goal]
+        node_now = node_end
+
+        while node_now.parent is not None:
+            node_now = node_now.parent
+            waypoint.append(node_now)
+
+        return waypoint
+
+    @staticmethod
+    def get_distance_and_angle(node_start, node_end):
+        dx = node_end.x - node_start.x
+        dy = node_end.y - node_start.y
+        return math.hypot(dx, dy), math.atan2(dy, dx)
+
+    def plot_grid(self, name):
+
+        for (ox, oy, w, h) in self.obs_boundary:
+            self.ax.add_patch(
+                patches.Rectangle(
+                    (ox, oy), w, h,
+                    edgecolor='black',
+                    facecolor='black',
+                    fill=True
+                )
+            )
+
+        for (ox, oy, w, h) in self.obs_rectangle:
+            self.ax.add_patch(
+                patches.Rectangle(
+                    (ox, oy), w, h,
+                    edgecolor='black',
+                    facecolor='gray',
+                    fill=True
+                )
+            )
+
+        for (ox, oy, r) in self.obs_circle:
+            self.ax.add_patch(
+                patches.Circle(
+                    (ox, oy), r,
+                    edgecolor='black',
+                    facecolor='gray',
+                    fill=True
+                )
+            )
+
+        plt.plot(self.s_start.x, self.s_start.y, "bs", linewidth=3)
+        plt.plot(self.s_goal.x, self.s_goal.y, "gs", linewidth=3)
+
+        plt.title(name)
+        plt.axis("equal")
+
+    def plot_visited(self):
+        animation = True
+        if animation:
+            count = 0
+            for node in self.vertex:
+                count += 1
+                if node.parent:
+                    plt.plot([node.parent.x, node.x], [node.parent.y, node.y], "-g")
+                    plt.gcf().canvas.mpl_connect('key_release_event',
+                                                 lambda event:
+                                                 [exit(0) if event.key == 'escape' else None])
+                    if count % 10 == 0:
+                        plt.pause(0.001)
+        else:
+            for node in self.vertex:
+                if node.parent:
+                    plt.plot([node.parent.x, node.x], [node.parent.y, node.y], "-g")
+
+    @staticmethod
+    def plot_path(path, color='red'):
+        plt.plot([x[0] for x in path], [x[1] for x in path], linewidth=2, color=color)
+        plt.pause(0.01)
+
+
+def main():
+    x_start = (2, 2)  # Starting node
+    x_goal = (49, 24)  # Goal node
+
+    drrt = DynamicRrt(x_start, x_goal, 0.5, 0.1, 0.6, 5000)
+    drrt.planning()
+
+
+if __name__ == '__main__':
+    main()