Generating gaits for snake robots by annealed chain fitting and Keyframe wave extraction

Abstract

Snake robots have many degrees of freedom, which makes them both extremely versatile and complex to control. In this paper, we address this complexity by introducing two algorithms. Annealed chain fitting efficiently maps a continuous backbone curve to a set of joint angles for a snake robot. Keyframe wave extraction takes joint angles fit to a sequence of backbone curves, and identifies parameterized periodic functions which produce those sequences. Together, they allow a designer to conceive a gait in terms three-dimensional shapes and translate them into easily manipulated wave functions. We validate the algorithms by using them to produce rolling gaits for crawling and climbing.