Abstract: Snake-like robots show higher capability of movement than conventional mobile robots. In order to achieve three-dimensional locomotion of snake-like robots, a 3D snake-like robot called Perambulator-II is developed with the acquirement of powerful propulsion and high mobility. Perambulator-II robot is composed of 3-DOF module, which implements pitching, yawing and rolling motion. The coupling drive is achieved through the differential mechanism composed of three bevels. A series of passive rollers are fixed on the unit cylinder body to add agility to the robot. The degrees of freedom of module are analyzed in detailing and the structure is designed on the basis of the mobility of robots. The control architecture of snake-like robot is presented. The decoupling of variables is completed. Serpentine and twist locomotion are applied on Perambulator-II to test its performance. The experimental results show that Perambulator-II has powerful mobility and agility.

Key words: Mechanism design, Serpentine locomotion, Shell shape, Snake-like robot