Design and control method for a high‐mobility in‐pipe robot with flexible links

Purpose – The purpose of this paper is to propose a high‐mobility in‐pipe robot platform and its navigation strategy for navigating in T‐branch pipes efficiently. Design/methodology/approach – For high mobility, this robot is developed based on inchworm locomotion. An extensor mechanism with flexible links and clamper mechanisms enable the robot to conduct both steering and inchworm locomotion. The locomotion of the robot is modeled based on a pseudo‐rigid‐body model. From the developed model, this paper introduces a navigation strategy based on defining relay points and generating a path from a main pipe to a T‐branch pipe. Findings – With this navigation strategy, the robot can avoid collisions and enter T‐branch pipes effectively. The path generation algorithm is verified by experiment. In addition, both the navigation strategy and mobility of the robot are demonstrated by experiments conducted in a commercial pipe configuration. Originality/value – This paper describes the mechanism of an inchworm‐type in‐pipe robot that is able to steer and adapt to pipe diameter changes. This paper also describes navigation strategy that enables a robot to avoid collisions and enter T‐branch pipes effectively. This research will help the construction of a fully autonomous in‐pipe robot that can navigate through various types of pipes.