叠栅条纹信号细分误差的一种动态补偿方法  

Dynamic Compensation for Interpolation Error of Moiré Fringe Signals

作　　者：朴伟英[1] 袁怡宝[1] 

机构地区：[1]哈尔滨工业大学自动化测试与控制系,黑龙江哈尔滨150001

出　　处：《光学学报》2008年第7期1301-1306,共6页Acta Optica Sinica

摘　　要：缺乏有效的误差补偿方法是制约长光栅测量精度提高的关键原因之一。提出一种动态的误差补偿方法,可以消除由直流漂移、两路信号不等幅和非正交导致的细分误差。其原理是跟踪光栅信号在一个周期上的8个特征值点(正余弦信号的过零点及绝对值交点),从特征值点的幅度值中首先分解出正弦信号的直流漂移误差,对其进行补偿;然后继续跟踪补偿后的信号,从中又能分解出余弦信号的直流漂移误差。再补偿,再跟踪,又能依次分解出不等幅误差和非正交误差。最多只需要3个光栅信号周期,就能对三种误差依次实现补偿。分析了谐波对该方法的影响并提出了改进措施。实验证实了该方法的有效性。Lacking effective error compensation method is one of the important reasons that limit the advance of measurement precision of the grating ruler. A dynamic compensation method for eliminating the interpolation error of moire fringe signals is put forward. The interpolation error is caused by zero offset, quadrature phase shift and unequal amplitude of two signals. Eight characteristic points （zero points and absolute amplitude joints of two channels signals） on a grating signal period is traced, and the zero offset of sinusoidal signal is separated from amplitude of characteristic points, and compensated. Then the compensated signal is traced, and the zero offset of cosinusoidal signal can also be separated and compensated. The compensative signal is traced continuely, the unequal amplitude error and the error of quadrature phase shift can be separated and compensated respectively. The above three errors can be totally compensated in no more than three grating signal periods. The influence of harmonics was analyzed and the improvement method was presented. Experiments verify this method＇s validity.

关 键 词：光学测量 动态误差补偿 参量连续性 细分误差 光栅纳米测量 

分 类 号：TH741.6[机械工程—光学工程]