I clean up my last post, I'm sorry for it seems a little chaos.
I realized the tutorial of Checking collisions for a given robot state,
http://www.ros.org/wiki/motion_planning_environment/Tutorials/Tutorial%20A Everything is done following the above toturial except that I don't know how to add the ghost robot for checking collision.
In specific words, how "the 9th rviz topic marked State Validity" is added, which kind State Validity is and which kind of topic State Validity has.
My simulation result is like this :
But the tutorial simulation result like this:
I want to know how to add the ghost robot. Thank you