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PythonRobotics/PathPlanning/RRT/rrt_with_pathsmoothing.py
2023-01-26 21:56:42 +09:00

146 lines
3.2 KiB
Python

"""
Path planning Sample Code with RRT with path smoothing
@author: AtsushiSakai(@Atsushi_twi)
"""
import math
import random
import matplotlib.pyplot as plt
import sys
import pathlib
sys.path.append(str(pathlib.Path(__file__).parent))
from rrt import RRT
show_animation = True
def get_path_length(path):
le = 0
for i in range(len(path) - 1):
dx = path[i + 1][0] - path[i][0]
dy = path[i + 1][1] - path[i][1]
d = math.hypot(dx, dy)
le += d
return le
def get_target_point(path, targetL):
le = 0
ti = 0
lastPairLen = 0
for i in range(len(path) - 1):
dx = path[i + 1][0] - path[i][0]
dy = path[i + 1][1] - path[i][1]
d = math.hypot(dx, dy)
le += d
if le >= targetL:
ti = i - 1
lastPairLen = d
break
partRatio = (le - targetL) / lastPairLen
x = path[ti][0] + (path[ti + 1][0] - path[ti][0]) * partRatio
y = path[ti][1] + (path[ti + 1][1] - path[ti][1]) * partRatio
return [x, y, ti]
def line_collision_check(first, second, obstacleList):
# Line Equation
x1 = first[0]
y1 = first[1]
x2 = second[0]
y2 = second[1]
try:
a = y2 - y1
b = -(x2 - x1)
c = y2 * (x2 - x1) - x2 * (y2 - y1)
except ZeroDivisionError:
return False
for (ox, oy, size) in obstacleList:
d = abs(a * ox + b * oy + c) / (math.hypot(a, b))
if d <= size:
return False
return True # OK
def path_smoothing(path, max_iter, obstacle_list):
le = get_path_length(path)
for i in range(max_iter):
# Sample two points
pickPoints = [random.uniform(0, le), random.uniform(0, le)]
pickPoints.sort()
first = get_target_point(path, pickPoints[0])
second = get_target_point(path, pickPoints[1])
if first[2] <= 0 or second[2] <= 0:
continue
if (second[2] + 1) > len(path):
continue
if second[2] == first[2]:
continue
# collision check
if not line_collision_check(first, second, obstacle_list):
continue
# Create New path
newPath = []
newPath.extend(path[:first[2] + 1])
newPath.append([first[0], first[1]])
newPath.append([second[0], second[1]])
newPath.extend(path[second[2] + 1:])
path = newPath
le = get_path_length(path)
return path
def main():
# ====Search Path with RRT====
# Parameter
obstacleList = [
(5, 5, 1),
(3, 6, 2),
(3, 8, 2),
(3, 10, 2),
(7, 5, 2),
(9, 5, 2)
] # [x,y,size]
rrt = RRT(start=[0, 0], goal=[6, 10],
rand_area=[-2, 15], obstacle_list=obstacleList)
path = rrt.planning(animation=show_animation)
# Path smoothing
maxIter = 1000
smoothedPath = path_smoothing(path, maxIter, obstacleList)
# Draw final path
if show_animation:
rrt.draw_graph()
plt.plot([x for (x, y) in path], [y for (x, y) in path], '-r')
plt.plot([x for (x, y) in smoothedPath], [
y for (x, y) in smoothedPath], '-c')
plt.grid(True)
plt.pause(0.01) # Need for Mac
plt.show()
if __name__ == '__main__':
main()