Teachingless grinding robot depending on three force information

Abstract

When an industrial robot grinds a curved surface of a workpiece, an operator must teach the robot the contour of the surface accurately. This instruction, however, is a very troublesome job because of the large number of teaching points. This paper proposes a grinding robot that requires no teaching. The robot system consists of a manipulator mounted on a cylindrical grinding wheel on the end effector, instruments to measure the three different forces and a computer equipped with an A/D converter. The force information consists of the grinding torque and the two components of the grinding force which is applied to the grinding wheel from the workpiece. The coordinates of the points where the wheel contacts the workpiece are calculated from the force information by the computer. Therefore, the robot is able to recognize the contour of the workpiece and to grind it without teaching. Experiments using an articulated robot arm with five degrees of freedom show that the proposed robot system is applicable to the grinding of the continuous curved surface of a workpiece.