Analysis and control of a snake-like robot with controllable side-thrust links

Abstract

In this paper, we propose a novel kind of snakelike mobile robot as well as a new example of nonholonomic systems. The proposed robot consists of multiple links connected to each other by passive joints, which have active omnidirectional wheels at their center to drive sideways. The head and tail links are prohibited to move in the lateral direction due to the attachment of passive ordinary wheels. We derive the kinematic model of the robot and clarify its singular posture. Based on analysis of controllability Lie algebra and corresponding holonomy, we clarify the locomotion principle of the robot and propose translation, rotation and transformation control strategies. The proposed strategies are tested with numerical simulations.