Development of Concrete Inspection Robot with Dual Stage Suckers

Abstract

To automate nondestructive inspections for concrete walls by measuring their air permeability, we developed a wall climbing robot with suckers. It is configured to move by alternately moving the central body and the four leg tip suckers forward. The central sucker is a triple ring type, making it useful for climbing and measuring as well as acquiring the air permeability data in the depth direction. The leg tip suckers use a sponge material to ensure good sealing with the concrete wall and are double suckers when incorporated with bellows to generate power that sticks them fast, by pressing the bellows at the beginning of the fast-sticking process. The dual stage fast-sticking process first sucks by using the bellows only and then the whole sucker follows after the sponge parts are almost fast stuck. To automate the dual stage fast-sticking process, we developed two automatic switching systems: one switches relative to the distance between the sucker and the wall surface and the other, relative to the pressure in the bellows. We experimentally demonstrated that with both switching systems, when the sucker approaches a concrete wall with a weak force, the first stage fast-sticking process takes 1 s or lesser and the complete fast-sticking process, approximately 5 s. We also proved that the developed wall climbing robot incorporating the above-mentioned fast-sticking mechanism can climb a concrete wall at approximately 440 mm/min to acquire the concrete’s nondestructive air permeability test data.