Two types of snake-like robots for complex environment exploration: Design, development, and experiment

A snake-like robot has flexible mobility and high stability with low center of mass. It is very useful for complex environment exploration. This article develops two types of snake-like robots with different structure, shape, and modular joints. One (named as HITSZ-Snakebot I) is composed of 10 single degree-of-freedom modular joints, and the other (called HITSZ-Snakebot II) comprised eight 2-degree-of-freedom modular spherical-shape joints. The joints of the two types of robots are arranged as the same layout, that is, “Yaw-Pitch- Yaw-Pitch-….” The difference lies that, for the former, each rotation axes (“Yaw” or “Pitch”) is designed as one modularized unit, while for the latter, two adjacent rotation axes (“Yaw” and “Pitch”) are designed as one modularized unit. The exterior frame of each 2-degrees-of-freedom joint is designed as a spherical structure, which is connected with the motor through two-stage reduction mechanism. Therefore, the drive torques are largely increased. Many small passive wheels are mounted along a circle of the exterior surface. Such design largely decreases the friction between the robot and the road, and it also has the effect of compensating gravity when the space simulation is applied. At last, two types of prototypes are developed and experimented. The results show that the developed robots have high mobility and flexibility.