Files
PathPlanning/Sampling-based Planning/rrt_2D/rrt.py
T
2020-06-24 12:55:13 -07:00

117 lines
3.5 KiB
Python

from rrt_2D import env
from rrt_2D import plotting
import numpy as np
import math
class Node:
def __init__(self, n):
self.x = n[0]
self.y = n[1]
self.parent = None
class Rrt:
def __init__(self, x_start, x_goal, expand_len, goal_sample_rate, iter_limit):
self.xI = Node(x_start)
self.xG = Node(x_goal)
self.expand_len = expand_len
self.goal_sample_rate = goal_sample_rate
self.iter_limit = iter_limit
self.vertex = [self.xI]
self.env = env.Env()
self.plotting = plotting.Plotting(x_start, x_goal)
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_limit):
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.check_collision(node_new):
self.vertex.append(node_new)
dist, _ = self.get_distance_and_angle(node_new, self.xG)
if dist <= self.expand_len:
self.new_state(node_new, self.xG)
return self.extract_path(node_new)
return None
def random_state(self, goal_sample_rate):
if np.random.random() > goal_sample_rate:
return Node((np.random.uniform(self.x_range[0], self.x_range[1]),
np.random.uniform(self.y_range[0], self.y_range[1])))
return self.xG
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):
node_new = Node((node_start.x, node_start.y))
dist, theta = self.get_distance_and_angle(node_new, node_end)
dist = min(self.expand_len, dist)
node_new.x += dist * math.cos(theta)
node_new.y += dist * math.sin(theta)
node_new.parent = node_start
return node_new
def extract_path(self, node_end):
path = [(self.xG.x, self.xG.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 check_collision(self, node_end):
for (ox, oy, r) in self.obs_circle:
if math.hypot(node_end.x - ox, node_end.y - oy) <= r:
return True
for (ox, oy, w, h) in self.obs_rectangle:
if 0 <= (node_end.x - ox) <= w and 0 <= (node_end.y - oy) <= h:
return True
for (ox, oy, w, h) in self.obs_boundary:
if 0 <= (node_end.x - ox) <= w and 0 <= (node_end.y - oy) <= h:
return True
return False
@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, 28) # Goal node
rrt = Rrt(x_start, x_goal, 0.4, 0.05, 2000)
path = rrt.planning()
if path:
rrt.plotting.animation(rrt.vertex, path)
else:
print("No Path Found!")
if __name__ == '__main__':
main()