Revision history [back]

The best way is to create a model of your robot in URDF (or, in a .xacro file that is converted to URDF by xacro). That's an XML model of each of the links and joints in your robot. Each link will have a reference frame, and each joint will have a joint angle. You use the robot_state_publisher and joint_state_publisher nodes to automatically publish appropriate frame transformations for your link frames. You can then publish new joint angles and the frame transformations will be updated automatically by those nodes.

I've only used rolling robots with ROS so far, with fixed joint angles, so I'm working from the tutorial information here. You need to do the following:

1. Create the URDF (or .xacro, as mentioned).
2. Create a launch file that launches robot_state_publisher and joint_state_publisher, configuring joint_state_publisher with the topics on which you want to publish joint states.
3. In your custom node, publish joint states on your chosen topics, configured in step #2.

You'll want to read the URDF tutorials: http://wiki.ros.org/urdf/Tutorials

Start with the tf tutorial, then read 2.1, 2.2, and 2.4. Also read 4.5, which talks about how to publish joint states.

You'll probably also need to read the documentation for robot_state_publisher and joint_state_publisher:

• http://wiki.ros.org/robot_state_publisher
• http://wiki.ros.org/joint_state_publisher

And maybe the xacro documentation: http://wiki.ros.org/xacro