Design and Control of a Cable-Driven Articulated Modular Snake Robot

This paper presents the design and control of a cable-actuated mobile snake robot composed of modular coupled linkages. The goal of this research is to reduce the size of snake robots and improve their locomotive efficiency by simultaneously actuating groups of links to fit optimized curvature profiles. The basic functional unit of the snake is a four-link, single degree of freedom module that bends using an antagonistic cable-routing scheme. The mechanical and electrical designs of the module are first presented, with emphasis on the cable-routing scheme, key optimizations, and the use of elastic elements. A simplified model of serpentine locomotion is then presented and used to derive some properties of this locomotion gait. Control strategies for snake robots with coupled joints are also developed, including a feedback linearization of the pulley dynamics using the coupled cable equations. Experiments using a fully integrated prototype are presented and compared with simulated results.