Snake-like motions of multibody systems over a rough plane

Motions of multibody systems over a rough horizontal plane are investigated. The system under consideration is a linkage consisting of several rigid bodies connected by revolute joints with vertical axes. Control torques are created by actuators installed at the joints. Dry friction forces between the linkage and the plane act upon the system. It is shown that the multibody system can move in an arbitrary direction: lengthwise, sideways, and rotate. Different modes of motion of two-link, three-link, and multilink systems are investigated. The control laws for periodic and wave-like motions are proposed. The displacements and speed of motions are estimated, and optimal parameters are obtained which maximize the average speed. The results of computer simulation are presented. The obtained results are discussed with respect to motions of snakes and other animals, as well as to possible applications to mobile robots