scan_to_angle.py
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00001 #! /usr/bin/python
00002 #***********************************************************
00003 # Software License Agreement (BSD License)
00004 #
00005 # Copyright (c) 2008, Willow Garage, Inc.
00006 # All rights reserved.
00007 #
00008 # Redistribution and use in source and binary forms, with or without
00009 # modification, are permitted provided that the following conditions
00010 # are met:
00011 #
00012 #  * Redistributions of source code must retain the above copyright
00013 #    notice, this list of conditions and the following disclaimer.
00014 #  * Redistributions in binary form must reproduce the above
00015 #    copyright notice, this list of conditions and the following
00016 #    disclaimer in the documentation and/or other materials provided
00017 #    with the distribution.
00018 #  * Neither the name of the Willow Garage nor the names of its
00019 #    contributors may be used to endorse or promote products derived
00020 #    from this software without specific prior written permission.
00021 #
00022 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00023 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00024 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00025 # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
00026 # COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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00028 # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
00029 # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00030 # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00031 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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00034 #
00035 
00036 # Author: Wim Meeussen
00037 
00038 from __future__ import with_statement
00039 
00040 import roslib; roslib.load_manifest('turtlebot_calibration')
00041 import yaml
00042 import rospy
00043 from sensor_msgs.msg import LaserScan
00044 from turtlebot_calibration.msg import ScanAngle
00045 from math import *
00046 
00047 
00048 class ScanToAngle:
00049     def __init__(self):
00050         self.min_angle = rospy.get_param('min_angle', -0.3)
00051         self.max_angle = rospy.get_param('max_angle', 0.3)
00052         self.pub = rospy.Publisher('scan_angle', ScanAngle)
00053         self.sub = rospy.Subscriber('scan', LaserScan, self.scan_cb)
00054 
00055 
00056     def scan_cb(self, msg):
00057         angle = msg.angle_min
00058         d_angle = msg.angle_increment
00059         sum_x = 0
00060         sum_y = 0
00061         sum_xx = 0
00062         sum_xy = 0
00063         num = 0
00064         for r in msg.ranges:
00065             if angle > self.min_angle and angle < self.max_angle and r < msg.range_max:
00066                 x = sin(angle) * r
00067                 y = cos(angle) * r
00068                 sum_x += x
00069                 sum_y += y
00070                 sum_xx += x*x
00071                 sum_xy += x*y
00072                 num += 1
00073             angle += d_angle
00074         if num > 0:
00075             angle=atan2((-sum_x*sum_y+num*sum_xy)/(num*sum_xx-sum_x*sum_x), 1)
00076             res = ScanAngle()
00077             res.header = msg.header
00078             res.scan_angle = angle
00079             self.pub.publish(res)
00080         else:
00081             rospy.logerr("Please point me at a wall.")
00082 
00083 def main():
00084     rospy.init_node('scan_to_angle')
00085     s = ScanToAngle()
00086     rospy.spin()
00087 
00088 
00089 if __name__ == '__main__':
00090     main()


turtlebot_calibration
Author(s): Wim Meeussen
autogenerated on Mon Oct 6 2014 08:07:14