Design of a teleoperated wall climbing robot for oil tank inspection

Abstract

This paper presents a climbing robot with wheeled locomotion which uses permanent magnets as adhesion mechanism. The robot designed is intended for the inspection of various types of ferromagnetic structures, such as ship hulls, wind turbine towers, bridges, and fuel tanks, in order to detect surface faults or cracks caused by, for example aging or atmospheric corrosion. The proposed robotic system consists of a cordless teleoperated mobile platform which can move on vertical ferromagnetic walls. The robot can be equipped with the various testing probes and cameras that are necessary for different inspection tasks. First, different prototypes of magnetic wall climbing robots are analyzed in order to establish the current state-of-the-art, and to provide the background required to analyse the main advantages and drawbacks of the prototypes presented. The design of the proposed robotic system is then explained, and details are provided of the new approach for the design of the permanent magnetic adhesion mechanism. Finally the mechanical and electrical construction, the control architecture implemented, and the human-machine interface for its control and teleoperation are presented too.

Analysis of Magnetic Wheel Adhesion Force for Climbing Robot

“…This technology lends advantages such as: adaptable clamping to a variety of surfaces, low power consumption, resistant to external contamination, and quick, controllable attachment/detachment. San-Millan (2015;Wu et al, 2012) presents three ways with which permanent magnet adhesion can be implemented. The first two involve standard wheels integrated with several cylindrical magnets.…”

Automated robotic monitoring and inspection of steel structures and bridges

“…Based on the attraction force created by permanent magnets, Leibbrandt et al 27 and Leon-Rodriguez et al 28 developed two different wallclimbing robots carrying NDE devices for detection of welding defects, cracks, corrosion testing that can be used to inspect oil tanks or steel bridges. San-Millan 29 presented the development of a tele-operated wall climbing robot equipped with various testing probes and cameras for different inspection tasks. Zhu et al 30 used a magnetic wall-climbing robot capable of navigating on steel structures, measuring structural vibrations, processing measurement data and wirelessly exchanging information to investigate field performance of flexure-based mobile sensing nodes to be able to identify minor structural damage, illustrating a high sensitivity in damage detection.…”

A reduced actuation mecanum wheel platform for pipe inspection

“…On the basis of these simulations, an array of 12 40x20x10 N42 grade Neodymium magnets was selected, with alternating polarities and a steel backing, which were found to provide the required level of adhesion over a range of standoffs. It can be seen in [21] that a Halbach array configuration could improve the adhesion, however at the expense of increased complexity of the mounting. Consequently, it was not considered for this version.…”