Legless locomotion: models and experimental demonstration

We show through experiment and simulation that a high-centered round-bodied legged robot can locomote by generating out-of-phase motions of reaction masses attached to its legs. These leg motions create body attitude oscillations which, when coupled with the slip-free contact constraints, locomote the robot. By varying the mean position of the leg oscillations, the robot can move in different directions in the plane. We also present some simplified models, where body attitude dynamics and contact kinematics are decoupled, to explain this form of legless locomotion.