Mastering ROS for Robotics Programming - Second Edition

Interacting with pan-and-tilt joints

We can see that an extra GUI came along with RViz; it contains sliders to control the pan joints and the tilt joints. This GUI is called the Joint State Publisher node, from the joint_state_publisher package:

  <node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher" /> 

We can include this node in the launch file, using this statement. The limits of pan-and-tilt should be mentioned inside the joint tag:

  <joint name="pan_joint" type="revolute"> 
    <parent link="base_link"/> 
    <child link="pan_link"/> 
    <origin xyz="0 0 0.1"/> 
    <axis xyz="0 0 1" /> 
    <limit effort="300" velocity="0.1" lower="-3.14" upper="3.14"/> 
    <dynamics damping="50" friction="1"/> 
  </joint> 

<limit effort="300" ...