Novel mechanisms and simple locomotion strategies for an in-pipe robot that can inspect various pipe types

In this paper, we present a new design and simple locomotion strategies for a pipe inspection robot that can travel through various pipe configurations including vertical, elbow, and branch pipes. Two specific mechanisms in the robot are important for successful locomotion: the Adaptable Quad Arm Mechanism (AQAM) and the Swivel Hand Mechanism (SHM). The AQAM allows the robot to travel in reduced branch pipes and branch pipes with zero-radius of curvature, which are both common in real life but which pose a challenge to the previously developed in-pipe robots. The SHM enables the robot to change its orientation, and in particular, allows it to bypass bumps. Modeling and simulations were conducted to test the validity and practicality of the proposed design and strategies. The prototype was able to travel successfully through elbow and vertical pipes with a diameter of 305 mm and zero-radius of curvature reduced branch pipes of at least 305 mm × 259 mm to 305 mm × 290 mm or smaller.