add rrt_star sample code

scripts/PathPlanning/RRTstar/rrt_star.py

@@ -0,0 +1,196 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+u"""
+@brief: Path Planning Sample Code with Randamized Rapidly-Exploring Random Trees (RRT)
+
+@author: AtsushiSakai
+
+@license: MIT
+
+"""
+
+
+import random
+import math
+import copy
+
+
+class RRT():
+    u"""
+    Class for RRT Planning
+    """
+
+    def __init__(self, start, goal, obstacleList, randArea,
+                 expandDis=0.5, goalSampleRate=5, maxIter=500):
+        u"""
+        Setting Parameter
+
+        start:Start Position [x,y]
+        goal:Goal Position [x,y]
+        obstacleList:obstacle Positions [[x,y,size],...]
+        randArea:Ramdom Samping Area [min,max]
+
+        """
+        self.start = Node(start[0], start[1])
+        self.end = Node(goal[0], goal[1])
+        self.minrand = randArea[0]
+        self.maxrand = randArea[1]
+        self.expandDis = expandDis
+        self.goalSampleRate = goalSampleRate
+        self.maxIter = maxIter
+
+    def Planning(self, animation=True):
+        u"""
+        Pathplanning
+
+        animation: flag for animation on or off
+        """
+
+        self.nodeList = [self.start]
+        while True:
+            # Random Sampling
+            if random.randint(0, 100) > self.goalSampleRate:
+                rnd = [random.uniform(self.minrand, self.maxrand),
+                       random.uniform(self.minrand, self.maxrand)]
+            else:
+                rnd = [self.end.x, self.end.y]
+
+            # Find nearest node
+            nind = self.GetNearestListIndex(self.nodeList, rnd)
+
+            # expand tree
+            nearestNode = self.nodeList[nind]
+            theta = math.atan2(rnd[1] - nearestNode.y, rnd[0] - nearestNode.x)
+
+            newNode = copy.deepcopy(nearestNode)
+            newNode.x += self.expandDis * math.cos(theta)
+            newNode.y += self.expandDis * math.sin(theta)
+            newNode.cost += self.expandDis
+            newNode.parent = nind
+            #  print(newNode.cost)
+
+            if not self.__CollisionCheck(newNode, obstacleList):
+                continue
+
+            self.nodeList.append(newNode)
+
+            # check goal
+            dx = newNode.x - self.end.x
+            dy = newNode.y - self.end.y
+            d = math.sqrt(dx * dx + dy * dy)
+            if d <= self.expandDis:
+                print("Goal!!")
+                break
+
+            self.rewire(newNode)
+
+            if animation:
+                self.DrawGraph(rnd)
+
+        # generate coruse
+        path = [[self.end.x, self.end.y]]
+        lastIndex = len(self.nodeList) - 1
+        while self.nodeList[lastIndex].parent is not None:
+            node = self.nodeList[lastIndex]
+            path.append([node.x, node.y])
+            lastIndex = node.parent
+        path.append([self.start.x, self.start.y])
+
+        return path
+
+    def rewire(self, newNode):
+        #  print("rewire")
+        r = 5
+        dlist = [math.sqrt((node.x - newNode.x) ** 2 +
+                           (node.y - newNode.y) ** 2) for node in self.nodeList]
+        nearinds = [dlist.index(i) for i in dlist if i <= r]
+
+        for i in nearinds:
+            nearNode = self.nodeList[i]
+
+            dx = nearNode.x - newNode.x
+            dy = nearNode.y - newNode.y
+
+            scost = newNode.cost + math.sqrt(dx ** 2 + dy ** 2)
+
+            if nearNode.cost > scost:
+                #  print("rewire")
+                nearNode.parent = len(self.nodeList) - 1
+                nearNode.cost = scost
+                #  print(nearNode)
+
+    def DrawGraph(self, rnd=None):
+        u"""
+        Draw Graph
+        """
+        import matplotlib.pyplot as plt
+        plt.clf()
+        if rnd is not None:
+            plt.plot(rnd[0], rnd[1], "^k")
+        for node in self.nodeList:
+            if node.parent is not None:
+                plt.plot([node.x, self.nodeList[node.parent].x], [
+                         node.y, self.nodeList[node.parent].y], "-g")
+
+        plt.plot([ox for (ox, oy, size) in obstacleList], [
+                 oy for (ox, oy, size) in obstacleList], "ok", ms=20)
+        plt.plot(self.start.x, self.start.y, "xr")
+        plt.plot(self.end.x, self.end.y, "xr")
+        plt.axis([-2, 15, -2, 15])
+        plt.grid(True)
+        plt.pause(0.01)
+
+    def GetNearestListIndex(self, nodeList, rnd):
+        dlist = [(node.x - rnd[0]) ** 2 + (node.y - rnd[1])
+                 ** 2 for node in nodeList]
+        minind = dlist.index(min(dlist))
+
+        return minind
+
+    def __CollisionCheck(self, node, obstacleList):
+
+        for (ox, oy, size) in obstacleList:
+            dx = ox - node.x
+            dy = oy - node.y
+            d = math.sqrt(dx * dx + dy * dy)
+            if d <= size:
+                return False  # collision
+
+        return True  # safe
+
+
+class Node():
+    u"""
+    RRT Node
+    """
+
+    def __init__(self, x, y):
+        self.x = x
+        self.y = y
+        self.cost = 0.0
+        self.parent = None
+
+
+if __name__ == '__main__':
+    import matplotlib.pyplot as plt
+    # ====Search Path with RRT====
+    obstacleList = [
+        (5, 5, 1),
+        (3, 6, 2),
+        (3, 8, 2),
+        (3, 10, 2),
+        (7, 5, 2),
+        (9, 5, 2)
+    ]  # [x,y,size]
+
+    # Set Initial parameters
+    rrt = RRT(start=[0, 0], goal=[5, 10],
+              randArea=[-2, 15], obstacleList=obstacleList)
+    path = rrt.Planning(animation=True)
+
+    # Draw final path
+    rrt.DrawGraph()
+    plt.plot([x for (x, y) in path], [y for (x, y) in path], '-r')
+    plt.grid(True)
+    plt.pause(0.01)  # Need for Mac
+    plt.show()