Modeling and path-following for a snake robot with active wheels

Snake robots with active wheels provide interesting opportunities within many areas such as inspection and maintenance and search and rescue operations. The highly-articulated body of a snake robot combined with the advantages of wheeled locomotion makes it ideal for locomotion in, for example, pipes and other narrow or constricted structures. In this paper we present a mathematical model of the dynamics of a snake robot with active wheels together with a novel path-following approach for such robots. The path-following approach includes both how to find a desired turning angle for the snake robot head given a reference path, together with a module coordination strategy based on a n-trailer kinematic model. The path-following approach is tested and verified by simulations with the dynamic model. In addition, simulations suggest that the proposed approach results in reduced commanded joint and wheels shaft torques and, in most cases, a reduced path-following error compared to an implementation of a follow-the-leader algorithm.