Abstract: By analyzing the locomotion and the skeleton of the snake, a new kind structure of implement-unit, which can be assembled in different style in terms of the different motion, and control-system for snake-robot have been presented, which is modularized and can be interchanged. The kinematical model of the snake-robot has been built up and the gaitfor concertina- motion has also been planned. Forward and backward concertina-motion has been implemented. Via the experiment, the feasibility of the mechanism and the kinematical model has been proved.

Key words: Concertina-motion, Controlsystem, Snake-robot, Structure of implement-unit