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PythonRobotics/PathPlanning/LatticePlanner/model_predictive_trajectory_generator.py
Atsushi Sakai ff63950ffe commit test
2017-07-14 16:34:50 -07:00

175 lines
4.2 KiB
Python

"""
Model trajectory generator
author: Atsushi Sakai
"""
import numpy as np
import matplotlib.pyplot as plt
import math
import motion_model
from matplotrecorder import matplotrecorder
# optimization parameter
maxiter = 1000
h = np.matrix([0.1, 0.002, 0.002]).T # parameter sampling distanse
matplotrecorder.donothing = True
def plot_arrow(x, y, yaw, length=1.0, width=0.5, fc="r", ec="k"):
u"""
Plot arrow
"""
plt.arrow(x, y, length * math.cos(yaw), length * math.sin(yaw),
fc=fc, ec=ec, head_width=width, head_length=width)
plt.plot(x, y)
plt.plot(0, 0)
def calc_diff(target, x, y, yaw):
d = np.array([target.x - x[-1],
target.y - y[-1],
motion_model.pi_2_pi(target.yaw - yaw[-1])])
return d
def calc_J(target, p, h, k0):
xp, yp, yawp = motion_model.generate_last_state(
p[0, 0] + h[0, 0], p[1, 0], p[2, 0], k0)
dp = calc_diff(target, [xp], [yp], [yawp])
xn, yn, yawn = motion_model.generate_last_state(
p[0, 0] - h[0, 0], p[1, 0], p[2, 0], k0)
dn = calc_diff(target, [xn], [yn], [yawn])
d1 = np.matrix((dp - dn) / (2.0 * h[1, 0])).T
xp, yp, yawp = motion_model.generate_last_state(
p[0, 0], p[1, 0] + h[1, 0], p[2, 0], k0)
dp = calc_diff(target, [xp], [yp], [yawp])
xn, yn, yawn = motion_model.generate_last_state(
p[0, 0], p[1, 0] - h[1, 0], p[2, 0], k0)
dn = calc_diff(target, [xn], [yn], [yawn])
d2 = np.matrix((dp - dn) / (2.0 * h[2, 0])).T
xp, yp, yawp = motion_model.generate_last_state(
p[0, 0], p[1, 0], p[2, 0] + h[2, 0], k0)
dp = calc_diff(target, [xp], [yp], [yawp])
xn, yn, yawn = motion_model.generate_last_state(
p[0, 0], p[1, 0], p[2, 0] - h[2, 0], k0)
dn = calc_diff(target, [xn], [yn], [yawn])
d3 = np.matrix((dp - dn) / (2.0 * h[2, 0])).T
J = np.hstack((d1, d2, d3))
return J
def selection_learning_param(dp, p, k0, target):
mincost = float("inf")
mina = 1.0
maxa = 5.0
da = 0.5
for a in np.arange(mina, maxa, da):
tp = p[:, :] + a * dp
xc, yc, yawc = motion_model.generate_last_state(
tp[0], tp[1], tp[2], k0)
dc = np.matrix(calc_diff(target, [xc], [yc], [yawc])).T
cost = np.linalg.norm(dc)
if cost <= mincost and a != 0.0:
mina = a
mincost = cost
# print(mincost, mina)
# input()
return mina
def show_trajectory(target, xc, yc):
plt.clf()
plot_arrow(target.x, target.y, target.yaw)
plt.plot(xc, yc, "-r")
plt.axis("equal")
plt.grid(True)
plt.pause(0.1)
matplotrecorder.save_frame()
def optimize_trajectory(target, k0, p):
for i in range(maxiter):
xc, yc, yawc = motion_model.generate_trajectory(p[0], p[1], p[2], k0)
dc = np.matrix(calc_diff(target, xc, yc, yawc)).T
# print(dc.T)
cost = np.linalg.norm(dc)
print("cost is:" + str(cost))
if cost <= 0.05:
print("cost is:" + str(cost))
print(p)
break
J = calc_J(target, p, h, k0)
dp = - np.linalg.inv(J) * dc
alpha = selection_learning_param(dp, p, k0, target)
p += alpha * np.array(dp)
# print(p.T)
show_trajectory(target, xc, yc)
show_trajectory(target, xc, yc)
print("done")
def test_optimize_trajectory():
# target = motion_model.State(x=5.0, y=2.0, yaw=math.radians(00.0))
target = motion_model.State(x=5.0, y=2.0, yaw=math.radians(90.0))
k0 = 0.0
init_p = np.matrix([6.0, 0.0, 0.0]).T
optimize_trajectory(target, k0, init_p)
matplotrecorder.save_movie("animation.gif", 0.1)
# plt.plot(x, y, "-r")
plot_arrow(target.x, target.y, target.yaw)
plt.axis("equal")
plt.grid(True)
plt.show()
def test_trajectory_generate():
s = 5.0 # [m]
k0 = 0.0
km = math.radians(30.0)
kf = math.radians(-30.0)
# plt.plot(xk, yk, "xr")
# plt.plot(t, kp)
# plt.show()
x, y = motion_model.generate_trajectory(s, km, kf, k0)
plt.plot(x, y, "-r")
plt.axis("equal")
plt.grid(True)
plt.show()
def main():
print(__file__ + " start!!")
# test_trajectory_generate()
test_optimize_trajectory()
if __name__ == '__main__':
main()