Geometric mechanics applied to tetrapod locomotion on granular media

This study probes the underlying locomotion principles of earliest organisms that could both swim and walk. We hypothesize that properly coordinated leg and body movements could have provided a substantial benefit toward locomotion on complex media, such as early crawling on sand. In this extended abstract, we summarize some of our recent advances in integrating biology, physics and robotics to gain insight into tetrapod locomotor coordination and control principles. Here, we observe crawling salamanders as a biological model for studying tetrapod locomotion on sloped granular substrates. Further, geometric mechanics tools are used to provide a theoretical framework predicting efficacious body motions on yielding terrain. Finally, we employ these coordination strategies on a robophysical salamander model traversing a sandy slope. This analysis of salamander-like robotic motion in granular media can be seen as a first application of how tools from geometric mechanics can provide insight into the character and principles of legged locomotion.