Document Type



Computer Engineering | Robotics


A number of attempts have been made to integrate the efficiency of wheeled locomotion with the terrain versatility of legged locomotion, e.g., Univ.Michigan’s Rhex platform and Case Western’s Whegs. Those platforms cast legs as rotating spokes placed traditionally at the corners of a rectangular platform. In this paper, we present an alternate approach, with three legs radiating down from a central hub. The energy to move the platform is generated by a rotating reaction mass mounted at the hub and, at rest, rotating parallel to the ground plane.

Our approach is to construct a platform whose natural, uncontrolled motion is energy efficient and useful, and which requires only a small amount of control to produce effective locomotion. We describe the platform and analyze the characteristics of its uncontrolled motion. Several strategies to produce directed motion will be presented and evaluated. Simulation models and a prototype platform have been built and will be discussed.

Article Number


Publication Date



10th Int. Conference on Climbing and Walking Robots. 16-18 July 2007, Singapore

This research was conducted at the Fordham University Robotics and Computer Vision Lab. For more information about graduate programs in Computer Science, see, and the Fordham University Graduate School of Arts and Sciences, see

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