In this paper we introduce tumbling, a relatively unexplored method of locomotion in which the robot utilizes net body rotations while ambulating. Tumbling for mobile robots is attractive in that it can enable increased mobility on smaller scales, often while reducing hardware requirements. As motivation for this interesting form of locomotion we provide a geometric analysis of a vertical step climbing task, one that tumbling robots perform well with respect to their size and complexity. In addition to our analysis we present results of a hardware experiment with a tumbling robot performing the task for varying combinations of frictional coefficients at the step and ground.
