Kalman-and-Bayesian-Filters.../experiments/bicycle.py
Roger Labbe 54bce9d7a0 Added EKF robot localization example.
Still needs a lot of explanation; mostly the implementation is there
for now.
2015-05-30 14:44:49 -07:00

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Python

# -*- coding: utf-8 -*-
"""
Created on Tue Apr 28 08:19:21 2015
@author: Roger
"""
from math import *
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.patches import Polygon
wheelbase = 100 #inches
vel = 20 *12 # fps to inches per sec
steering_angle = radians(1)
t = 1 # second
orientation = 0. # radians
pos = np.array([0., 0.]
for i in range(100):
#if abs(steering_angle) > 1.e-8:
turn_radius = tan(steering_angle)
radius = wheelbase / tan(steering_angle)
dist = vel*t
arc_len = dist / (2*pi*radius)
turn_angle = 2*pi * arc_len
cx = pos[0] - radius * sin(orientation)
cy = pos[1] + radius * cos(orientation)
orientation = (orientation + turn_angle) % (2.0 * pi)
pos[0] = cx + (sin(orientation) * radius)
pos[1] = cy - (cos(orientation) * radius)
plt.scatter(pos[0], pos[1])
plt.axis('equal')