A study on rubber gas actuators driven by the hydrogen storage alloy for in-pipe inspection mobile robots with flexible structure and on an application.

Abstract

This paper deals with rubber actuators using Hydrogen Storage Alloy for an in-pipe inspection robot, which has the capability of moving inside pipelines with two inches diameter. Since in-pipe inspection robots require flexible mechanisms for going through complicated construction of pipeline networks, the actuators which are light in weight and flexible must first be developed rather than using conventional actuators. For this purpose, rubber actuators with both stretching and shrinking characteristics are shown here for the application of such a robot. The proposed robot uses these actuators with six degrees of freedom, so that it has more flexibility and adaptability in motion : it can move in the inch worm mode through pipelines and has adaptability to the change of pipe diameters and also of passing over the L-joints and T-joints of pipelines. The method of activating the robot is proposed as the robot dock method, thus the robot actuators can initially be activated by hydrogen gas. The control method is also shown with an example of the T-joint movement.