Development of a steering mechanism for a cylindrical elastic crawler

Abstract

There are many pipes in factories, chemical plants and houses, whose insides are inaccessible by human. These pipes must be continuously inspected and repaired to prevent severe accidents. To realize robots which can inspect inside of such pipes, we have developed a simple and compact cylindrical crawler robot based on amoeba locomotion. In this study, we propose a steering mechanism that enables the robot to pass through T-shaped curves in pipes. Many of conventional steering mechanisms for crawler robots use single geared motor per single crawler belt to drive the crawler belts. On the contrary, the proposed mechanism can use a much larger geared motor than conventional steering mechanisms to drive all the crawler belts. Therefore, the crawler robot using the proposed steering mechanism can generate higher torque than one using conventional steering mechanism. This paper presents descriptions of the proposed steering mechanism design, comparison between proposed and conventional steering mechanisms with respect to the torque of the geared motor, and experiments using a 75A pipe with a T-shaped curve. In the experiments, the proposed steering mechanism was evaluated steering performance in a T-shaped pipe of 75A with three routes. The results demonstrated that the robot could pass through all the routes.

Keywords

• narrow path
• pipe inspection
• worm-rack mechanism
• cylindrical crawler
• steering mechanism