[ros-users] Actuating a wheeled robot URDF model in gazebo

I am trying to make a urdf model for the pioneer 3dx robot that can be
used in gazebo. The robot is a 2-wheeled diff drive robot with a singe
rear caster.I have the robot visualizing correctly in rviz. However, I
want this robot to be drivable. I am a little unclear from the wiki
tutorials regarding gazebo and urdf on how to accomplish this? Is the
GazeboRosDiffdrive node something that I could use for the pioneer as
well as the erratic? What information do I need to have about the
pioneer in order to make a urdf model work in gazebo?