Design and Optimization of Permanent Magnet Based Adhesion Module for Robots Climbing on Reinforced Concrete Surfaces

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 low-power 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 3600 of manoeuvrability on a 50×50 mm meshed rein-forcement bars test rig with maximum adhesion force of 108 N at 35 mm 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 be-tween 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 82 N in adhesion force compared to a single module system with higher force-to-weight ratio of 4.36. An adhesion force of 127.53 N was measured on a real vertical concrete column with 30 mm 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.