New finishing system for metallic molds using a hybrid motion/force control

In this paper, a finishing system with a mounted abrasive tool is proposed for finishing of metallic molds. The shape of the mounted abrasive tool is a ball-end type. When a metallic mold with curved surface is polished, the orientation of the mounted abrasive tool is not only fixed but also its revolution is locked. The motion of the mounted abrasive tool is feedforwardly controlled based on an initial trajectory calculated in advance. The surface is polished by a polishing force which consists of a contact force, motion and viscous frictions acting between the mold and the mounted abrasive tool. The velocities in the normal and tangent directions are delicately controlled so that the polishing force can track the desired value. The effectiveness of the proposed system is proved by some experiments using an industrial robot with an open architectural controller.