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00001 /********************************************************************* 00002 * Software License Agreement (BSD License) 00003 * 00004 * Copyright (c) 2008, Willow Garage, Inc. 00005 * All rights reserved. 00006 * 00007 * Redistribution and use in source and binary forms, with or without 00008 * modification, are permitted provided that the following conditions 00009 * are met: 00010 * 00011 * * Redistributions of source code must retain the above copyright 00012 * notice, this list of conditions and the following disclaimer. 00013 * * Redistributions in binary form must reproduce the above 00014 * copyright notice, this list of conditions and the following 00015 * disclaimer in the documentation and/or other materials provided 00016 * with the distribution. 00017 * * Neither the name of the Willow Garage nor the names of its 00018 * contributors may be used to endorse or promote products derived 00019 * from this software without specific prior written permission. 00020 * 00021 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 00022 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 00023 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 00024 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 00025 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 00026 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 00027 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00028 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 00029 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00030 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 00031 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 00032 * POSSIBILITY OF SUCH DAMAGE. 00033 *********************************************************************/ 00034 00035 /* Author: Wim Meeussen */ 00036 00037 #include <kdl/tree.hpp> 00038 #include <ros/ros.h> 00039 #include "robot_state_chain_publisher/robot_state_publisher.h" 00040 #include "robot_state_chain_publisher/joint_state_listener.h" 00041 00042 using namespace std; 00043 using namespace ros; 00044 using namespace KDL; 00045 using namespace robot_state_chain_publisher; 00046 00047 00048 JointStateListener::JointStateListener(const KDL::Tree& tree) 00049 : n_tilde_("~"), state_publisher_(tree) 00050 { 00051 // set publish frequency 00052 double publish_freq, min_publish_freq; 00053 n_tilde_.param("publish_frequency", publish_freq, 50.0); 00054 n_tilde_.param("min_publish_frequency", min_publish_freq, 1.0); 00055 publish_delay_ = Duration(1/publish_freq); 00056 max_publish_delay_ = Duration(1/min_publish_freq); 00057 //Time::waitForValid(); // new method which was introduced later? 00058 last_publish_time_ = Time::now(); 00059 // subscribe to mechanism state 00060 joint_state_sub_ = n_.subscribe("joint_states", 10, &JointStateListener::callbackJointState, this); 00061 00062 timer_ = n_tilde_.createTimer(max_publish_delay_, &JointStateListener::timerCallback, this); 00063 }; 00064 00065 00066 JointStateListener::~JointStateListener() 00067 {}; 00068 00069 00070 void JointStateListener::timerCallback(const ros::TimerEvent& e) 00071 { 00072 Time now = Time::now(); 00073 if( now >= last_publish_time_ + max_publish_delay_*0.9 ) 00074 { 00075 // time to publish something, with or without joint states 00076 state_publisher_.publishTransforms(joint_positions, now, (now - max_publish_delay_)); 00077 00078 if( last_publish_time_ - now > max_publish_delay_*2 || last_publish_time_ - now < max_publish_delay_*2) 00079 last_publish_time_ = now; 00080 else 00081 last_publish_time_ += max_publish_delay_; 00082 } 00083 } 00084 00085 void JointStateListener::callbackJointState(const JointStateConstPtr& state) 00086 { 00087 if (state->name.size() == 0){ 00088 ROS_ERROR("Robot state publisher received an empty joint state vector"); 00089 return; 00090 } 00091 00092 if (state->name.size() != state->position.size()){ 00093 ROS_ERROR("Robot state publisher received an invalid joint state vector"); 00094 return; 00095 } 00096 00097 // early-simtime bug - if we compute a negative time, ros throws an exception 00098 if(last_publish_time_.toSec() <= max_publish_delay_.toSec()) { 00099 last_publish_time_ = Time::now(); 00100 return; 00101 } 00102 00103 // get joint positions from state message 00104 for (unsigned int i=0; i<state->name.size(); i++) { 00105 RobotStatePublisher::JointState s; 00106 s.pos = state->position[i]; 00107 s.time = state->header.stamp; 00108 s.published = false; 00109 joint_positions[state->name[i]] = s; 00110 00111 } 00112 00113 Time now = Time::now(); 00114 if( now >= last_publish_time_ + publish_delay_ ) 00115 { 00116 state_publisher_.publishTransforms(joint_positions, now, (now - max_publish_delay_)); 00117 00118 if( last_publish_time_ - now > publish_delay_*2 || last_publish_time_ - now < publish_delay_*2) 00119 last_publish_time_ = now; 00120 else 00121 last_publish_time_ += publish_delay_; 00122 } 00123 }