The Force Controlled Propulsion And Adhesion System For A Climbing Robot

Abstract

There are different types of robots for climbing on smooth or rough walls. One technique is to use driven wheels for the propulsion and a vacuum system for the adhesion. The seals for the vacuum chambers are slipping over the surface and it is not guarant that the chambers are always close. Especially over concrete walls a special construction must be found to make the adhesion more safe. On the other side the propulsion system must be able to produce enough force for carrying and accelerating the robot. Any slipping of the wheel must be avoided and this can only be realized if the exiting forces are measured and controll structures are implemented. The paper will present a climbing robot with the described technique. The vacuum system consists of controlled seven chambers for safety reasons. The chamber system was presented in earlier papers and will only be summarized concerning the force theory. The propulsion system will be discussed more detailed. It consist of three omni directional driven wheels which were build up. Additionally they are air proofed, the steering can rotate several times around and a load cell is integrated for detecting all forces. Beside the mechanical realization the prediction algorithm based on a force model will be described. This will avoid critical situations before they occur, like slipping of the wheel and tilting of the robot which will be supported by a inertial navigation system.