A Study of an Earthworm type Inspection Robot Movable in Long Pipes

This paper describes development of a three somites earthworm type mobile inspection robot which is able to move in long pipes. We have many small diameter pipes which are gas or water pipes for individual or corporate houses and boilers or hot water pipes for industries. They are settled in the ground horizontally or in the narrow spaces vertically and some of them are covered by casings or hard heat insulating matters. It is very difficult to inspect from out of the pipes. If we can insert a mobile inspection robot into the pipes from the suitable position, we are easy to inspect the pipes. Authors fabricated a three somites earthworm type mobile inspection robot in which we use three rubber bellows as pneumatic actuators. Sixteen rubber friction rings are used to get friction force between pneumatic actuators and the pipes. The electromagnetic valves and air-feeding tubes for the pneumatic actuators are carried on trolleys in order to decrease friction force between the pipes and them. The fabricated three somites earthworm type mobile inspection robot can move in a pipe which is 78 mm in inner diameter and vertical pipe carrying a load that is equivalent to the air-feeding tube of 32 m length. Consequently, the inspection robot was confirmed to move in the long pipes.