Tracking control for snake robot joints

This paper considers the problem of model based control of the joints of a snake robot without wheels. The potential range of applications for snake robots are numerous, and delicate operations such as inspection and maintenance in industrial environments or performing search and rescue operations require precise control of a snake robot joints. To this end we present a controller that asymptotically stabilizes the joints of the snake robot to a desired reference trajectory. The controller is based on input-output linearization of a control plant model of the snake robot dynamics also developed in this paper. In addition, we provide a formal Lyapunov-based proof of the closed-loop stability, together with simulation results for a smooth dynamical model. Finally, the performance of the controller is tested on a non-smooth snake robot model with set-valued Coulomb friction that offers an accurate description of the stick-slip transitions during locomotion.