Research of an Open CNC System of Machine Tool for Finding and Repairing Surface Damage on KDP Crystal

Abstract

In order to find and repair surface damage on KDP crystal, an open computer numerical control(CNC) system has been developed. This paper introduces the hardware structure of the control system, explains the development of an open CNC system software, which has friendly human-machine interface (HMI) and can make the finding and repairing process efficiently and conveniently and also expounds the algorithm and related parameters for servo tuning. With the open CNC system, the process of finding surface damage is accomplished in 3 hours and clear images of crystal surface damage is taken by CCD. And also, with the help of the open CNC system, a 600µm-diameter, 25µm-depth Gaussian repair contour with low roughness is obtained. Experimental results prove that the open CNC system for finding and repairing surface damage on KDP crystal meets the requirement of efficient detection and ultra-precision machining.