Wall Climbing Robot Based on Two-end Adsorption for Weld Seam Amending

In order to carry out automatic weld seam amending on large-scale steel-made components, a special wall climbing robot scheme is proposed and developed. Both ends, i.e., repairing end effector and mobile platform of the robot, are adsorbed to the surface of workpiece with permanent magnets in a noncontact manner. These two adsorbed ends are linked by a multi-degree-of-freedom manipulator which consists of several active and passive joints. The requirements of adsorption force for the repairing end effector is described mathematically, and advantages of the new mechanism are analyzed and compared with the wall climbing robot composed of single-end adsorption and serial cantilever manipulator. Finally, a prototype robot is produced, and performance parameters of the robot are testified. It is proven that the manner of two-end adsorption can greatly decrease the demands for the manipulator's stiffness, furthermore, the passive joints of the manipulator bring adaptabilities to climbing robot on curved surfaces.