In the next few sections, our
rrbot URDF will be created and incrementally built to incorporate the advantages of each of the Xacro features we discussed for our robot.
For the first iteration of our
rrbot robot arm, we will build a URDF file that defines three links with the
<inertial> tags, and two joints with the
<axis> tags. This is a very similar format to the
dd_robot URDF file that you are familiar with from Chapter 2, Creating Your First Two-Wheeled ROS Robot (in Simulation). The differences for the Xacro format are listed here and explained in more detail after the code is presented: