An in-pipe operation microrobot based on the principle of screw-development of a prototype for running in long and bent pipes

Nowadays many types of pipe such as water pipes, drain pipes, and gas pipes, are underground. Also many types of pipeline are used in places where people cannot enter, such as atomic power plants and chemical plants. Maintenance of these pipes and pipelines is an important issue to keep our social life safe and comfortable. Some maintenance robots have already been developed; but all of these maintenance robots are used for pipes of medium or large sizes. No maintenance robots, which are used for pipes of small size with inner diameter of one inch or less, have been developed. The authors have thus been trying to develop a screw-principle microrobot, which can run in a small pipe one inch in diameter and can inspect the inner wall with a CCD camera. In this paper the screw-principle microrobot has been improved for running in a small pipe which is 20 m in length or longer and have some bends. Also the running performance has been experimentally investigated.