同心圆光栅二自由度误差测量系统

提出了一种基于同心圆光栅莫尔条纹图象处理的超精密二自由度误差测量(TDFM)方法,介绍了该测量方法的基本原理,包括同心圆光栅莫尔条纹产生机理、三光栅光学系统原理、影像光学原理以及CCD莫尔条纹图象处理的方法.通过实验对实际测量系统进行了分析与标定,并将测量结果与双频激光干涉仪进行了比较.结果表明该测量方法可实现超精密二自由度的误差在线测量及补偿,测量精度优于0.1μm.

A two-degree-of-freedom measuring system based on concentric-circle gratings

A method is presented for ultra-precision two-degree-of-freedom measurem ent (TDFM) based on image processing of interferential fringes in real time, which a re generated by three concentric-circle gratings and captured by CCD (Charge co u pled Device) camera. The basic measuring principles are described in this paper including the generation of Moiré fringes of concentric-circle gratings, three - grating-system, imaging optics, and the method of image processing. The ac t ual measuring system is analyzed and calibrated through experiments and the meas urement results are compared with laser interferometer system. Test shows that t his system can be adopted to on-line measurement and compensation of ultra-pre ci sion process. It has a long measuring range of 200mm and can measure two dimensi onal error components at the same time with an accuracy of better than 0.1μm.