Enhanced wheel system for step climbing

Although wheels are very efficient in flat and tight terrain locomotion, they cannot climb up stairs or even a step. Stairs or a step are the most popular obstacles in outside applications of mobile robots. This paper provides a new wheel-feet hybrid mechanism, named the Enhanced Wheel System (EWS), for rough terrain locomotion, especially for climbing up stairs or a step. To climb up stairs or a step by the EWS, several 'feet' combined on each wheel are kept horizontal by parallel link mechanisms controlled by the servo-mechanism. A prototype machine with the EWS has been made and the author shows that the prototype is able to run smoothly on flat terrain by wheels and climb up stairs using those 'feet' .