Preliminary design of a novel helical locomotion-based soft crawling robot for in-pipe inspection

This paper presents a novel helical locomotion-based soft crawling robot for in-pipe inspection. In robotics, helical locomotion is a mechanism that enables a crawling robot to move forward. This is particularly evident for wave-like robots that exploit the actuation of one or more helical shafts to generate a propulsive wave. This mechanism may potentially be suitable for pipeline inspection because it features a compact design along the pipe’s transverse section, and it can adapt to the structural variations of the pipes thanks to the flexibility achievable by modifying the shaft geometry. However, the pipeline environment is inherently affected by some factors, such as oil, sediment, and rust, that can compromise the robot's locomotion, and the robot itself may contaminate the external environment. The core idea of the paper is to enable the robot to perform its inspection operations while remaining isolated from the surrounding environment through a compliant tube that encloses it.