Open-loop Stability of Time-based vs. Event-based Switching in Locomotion

1 Motivation and State of the Art The compass-gait biped and simplest walking model [1,2] have been useful as tools that abstract away the details of a specific walker, allowing the study of properties of the passive nonlinear dynamics. Similarly, the two-link brachiator of Gomes and Ruina [3] has demonstrated that energy-efficient brachiation is possible, i.e., “walking under the surface” (Figure 1). Recently, Rosa et al. [4] introduced the two-link dynamic wallclimbing Gibbot robot that can achieve a “foothold” at any location in the vertical plane, generalizing the compass-gait biped and the two-link brachiator which only have footholds on a line.