Files
PathPlanning/Sampling-based Planning/rrt_2D/rrt.py
T
2020-07-02 21:51:22 -07:00

116 lines
3.3 KiB
Python

"""
RRT_2D
@author: huiming zhou
"""
import math
import numpy as np
import os
import sys
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 Rrt:
def __init__(self, s_start, s_goal, step_len, goal_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.iter_max = iter_max
self.vertex = [self.s_start]
self.env = env.Env()
self.plotting = plotting.Plotting(s_start, s_goal)
self.utils = utils.Utils()
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
def planning(self):
for i in range(self.iter_max):
node_rand = self.random_state(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)
return self.extract_path(node_new)
return None
def random_state(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 nearest_neighbor(self, node_list, n):
return self.vertex[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
@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 main():
x_start = (2, 2) # Starting node
x_goal = (49, 24) # Goal node
rrt = Rrt(x_start, x_goal, 0.5, 0.03, 5000)
path = rrt.planning()
if path:
rrt.plotting.animation(rrt.vertex, path, "RRT", True)
else:
print("No Path Found!")
if __name__ == '__main__':
main()