How to setup Pioneer 3-dx for building a map

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In the navigation/tutorial/RobotSetup

http://wiki.ros.org/navigation/Tutorials/RobotSetup

I tried to set up my Pioneer 3-dx following the transform configuration, sensor information, and odometry information. But I failed all the time, I don't know how to change those codes to fit my robot.

For example, I feel that the transform configuration is not really essential. How to set the velocity in the odometry information?

Thank you so much, if anybody could give me some advice.