http://engineeringtv.com/blogs/etv/archive/2008/10/14/impass-wheel-leg-hybrid-robot.aspxIMPASS is a wheel-leg hybrid robot that can walk in unstructured environments by independently extending, or retracting, three actuated spokes on each wheel. IMPASS stands for Intelligent Mobility Platform with Actuated Spoke System. The robot has beenenCommunityServer 2007.1 (Debug Build: 20917.1142)