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00001 /* 00002 * Copyright (c) 2011, Ivan Dryanovski, William Morris 00003 * All rights reserved. 00004 * 00005 * Redistribution and use in source and binary forms, with or without 00006 * modification, are permitted provided that the following conditions are met: 00007 * 00008 * * Redistributions of source code must retain the above copyright 00009 * notice, this list of conditions and the following disclaimer. 00010 * * Redistributions in binary form must reproduce the above copyright 00011 * notice, this list of conditions and the following disclaimer in the 00012 * documentation and/or other materials provided with the distribution. 00013 * * Neither the name of the CCNY Robotics Lab nor the names of its 00014 * contributors may be used to endorse or promote products derived from 00015 * this software without specific prior written permission. 00016 * 00017 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 00018 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00019 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00020 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 00021 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 00022 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 00023 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00024 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00025 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 00026 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 00027 * POSSIBILITY OF SUCH DAMAGE. 00028 */ 00029 00030 #include "laser_scan_sparsifier/laser_scan_sparsifier.h" 00031 00032 namespace scan_tools { 00033 00034 LaserScanSparsifier::LaserScanSparsifier(ros::NodeHandle nh, ros::NodeHandle nh_private): 00035 nh_(nh), 00036 nh_private_(nh_private) 00037 { 00038 ROS_INFO ("Starting LaserScanSparsifier"); 00039 00040 // **** get paramters 00041 00042 if (!nh_private_.getParam ("step", step_)) 00043 step_ = 2; 00044 00045 ROS_ASSERT_MSG(step_ > 0, 00046 "step parameter is set to %, must be > 0", step_); 00047 00048 // **** advertise topics 00049 00050 scan_publisher_ = nh_.advertise<sensor_msgs::LaserScan>( 00051 "scan_sparse", 10); 00052 00053 // **** subscribe to laser scan messages 00054 00055 scan_subscriber_ = nh_.subscribe( 00056 "scan", 10, &LaserScanSparsifier::scanCallback, this); 00057 } 00058 00059 LaserScanSparsifier::~LaserScanSparsifier () 00060 { 00061 ROS_INFO ("Destroying LaserScanSparsifier"); 00062 } 00063 00064 void LaserScanSparsifier::scanCallback (const sensor_msgs::LaserScanConstPtr& scan_msg) 00065 { 00066 sensor_msgs::LaserScan::Ptr scan_sparse; 00067 scan_sparse = boost::make_shared<sensor_msgs::LaserScan>(); 00068 00069 // copy over equal fields 00070 00071 scan_sparse->header = scan_msg->header; 00072 scan_sparse->range_min = scan_msg->range_min; 00073 scan_sparse->range_max = scan_msg->range_max; 00074 scan_sparse->angle_min = scan_msg->angle_min; 00075 scan_sparse->angle_increment = scan_msg->angle_increment * step_; 00076 scan_sparse->time_increment = scan_msg->time_increment; 00077 scan_sparse->scan_time = scan_msg->scan_time; 00078 00079 // determine size of new scan 00080 00081 unsigned int size_sparse = scan_msg->ranges.size() / step_; 00082 scan_sparse->ranges.resize(size_sparse); 00083 00084 // determine new maximum angle 00085 00086 scan_sparse->angle_max = 00087 scan_sparse->angle_min + (scan_sparse->angle_increment * (size_sparse - 1)); 00088 00089 for (unsigned int i = 0; i < size_sparse; i++) 00090 { 00091 scan_sparse->ranges[i] = scan_msg->ranges[i * step_]; 00092 // TODO - also copy intensity values 00093 } 00094 00095 scan_publisher_.publish(scan_sparse); 00096 } 00097 00098 } //namespace scan_tools 00099