Development of pipe inspection robot

Despite the COVID lockdown inhibiting lab access, RAIN PDRA Nick Castledine has been making great progress developing prototypes for a pipe inspection platform. Read on to hear more about his latest research progress. He also presented his work at one of the recentRAIN webinars.

The focus of our work at the University of Leeds is to develop a pipe inspection robot capable of navigating 2″ pipe networks. This will be a tethered, single use robot with the mobility to traverse tight bends and T-sections, with a minimum operational range of 10 meters. The robot will be equipped with a video camera to locate deposits of materials and aid with navigation within the pipes; and a radiation sensor.

The concept for this robot was inspired by a robot previously developed at the University of Leeds, intended for mobile endoscopy of the colon. It had a wall press robot design, featuring three radially distributed wheels that demonstrated good stability and mobility. This concept was re-engineered and tailored to the space constraints of a 2” stainless steel pipe environment.

The current design iteration of the robotic module consists of two wall press sections, each with three arms which are spring loaded outwards to maintain wheel contact with the pipe walls. Embedded in each arm is a motor which controls a diamond cutting disk wheel, shown to give excellent traction within the pipe bore. These two sections are connected using a compression spring, allowing each section to bend over 90 degrees relative to each other. This large bending range, and each section having independent pitch and yaw orientation control within the pipe gives the robot significant mobility. The payload of a radiation sensor will be attached to the tether, located between two of these robotic modules as it moves through the pipe.

This robot module can fold down to a minimum diameter of 20 mm for small pipe entry points, and has a maximum linear speed of 45 mm/s. It was shown to be capable of traversing branches and T-sections, although further work is ongoing to increase the reliability of this; and to improve orientation control within the pipe.