Design and optimization of permanent magnet based adhesion module for robots climbing on reinforced concrete surfaces

Abstract

In this chapter, the detailed design of a novel adhesion mechanism is described for robots climbing on concrete structures. The aim is to deliver a lowpower and sustainable adhesion technique for wall climbing robots to gain access to test sites on large concrete structures which may be located in hazardous industrial environments. A small, mobile prototype robot with on-board force sensor was built which exhibited 360° of manoeuvrability on a 50 × 50mm meshed reinforcement bars test rig with maximum adhesion force of 108N at 35mm air gap. The proposed adhesion module consists of three N42 grade neodymium magnets arranged in a unique arrangement on a flux concentrator. Finite Element Analysis (FEA) is used to study the effect of design parameters such as the distance between the magnets, thickness and material of the flux concentrator, use of two concentrators, etc. Using two modules with minimum distance between them showed an increase of 82N in adhesion force compared to a single module system with higher force-to-weight ratio of 4.36. An adhesion force of 127.53N was measured on a real vertical concrete column with 30mm concrete cover. The simulation and experimental results prove that the proposed magnetic adhesion mechanism can generate sufficient adhesion force for the climbing robot to operate on vertical reinforced concrete structures.