Articulated Robot Application in End Milling of Sculptured Surface

Abstract

End milling of a sculptured surface is attempted employing an articulated robot with six degrees of freedom. In this application, the machining error due to the positioning accuracy and elastic deformation of robots should be considered. In order to improve positioning accuracy, a new robot calibration method has been developed and applied. After the calibration, the robot is operated by off-line teaching programs effectively, and experimental end milling is finished with improved machining accuracy. Furthermore, a postprocess error compensation has been realized to minimize the machining error caused by all of factors such as the positioning error, elastic deformation and joint backlash of the robot. Experimental end milling shows that the machining accuracy is improved to near the positioning repeatability of the robot after repeating compensation twice. Additionally, a sensor feedback teaching method which is another way to achieve end milling of a sculptured surface has been developed.