Snake-Like Robot with Controllable Side-Thrust Links: Dynamical Modeling and a Variable Undulation Motion

In this paper, we attempt to design variable amplitude undulation motion in which the input speed and force are bounded, on the basis of the kinematics and inverse dynamics. To realize this motion, we used a snake-like robot with controllable side-thrust links, which was proposed in our previous research. The driving principle of this robot can be considered to correspond to avariable speed transmission system, i.e., this robot moves slowly for a large amplitude of undulation, and it moves fast for small amplitude of undulation. By using this characteristic, we propose a control design method in which the amplitude is varied with respect to time; the corresponding motion is termed as variable undulation motion, and is illustrated by a numerical simulation.