Development of a Wheeled Wall-Climbing Robot with a Shape-Adaptive Magnetic Adhesion Mechanism

This paper presents a wheeled wall-climbing robot with a shape-adaptive magnetic adhesion mechanism for large steel structures. To travel up and down various curved ferromagnetic surfaces, we developed a 2 DOF rotational magnetic adhesion mechanism installed on each wheel that can change the orientation of the magnets to keep the magnetic force direction always normal to the contact surface. These magnetic wheels have a spherical shape and can move relative to the main body by a non-elastic suspension mechanism so that the robot can climb up small obstacles on the ground and find contact points for each wheel on a wall with an arbitrary curved shape. Being geometrically stable is important for the robot because this robot is intended to be a mobile base for a welding manipulator. The detailed design of the mechanism and the results of climbing tests are presented.