光栅信号振幅合成的软件细分及误差分析

A Software Method of Fine Dividing Moive' Signals Using Amplitude Superposition and its Error Analysis

用正交莫尔条纹信号幅度合成可得近似三角波，经查表软件细分可得到近似不变的细分灵敏度．在同样精度的条件下，可以较大幅度提高莫尔条纹的细分数．本文还对误差进行了细致分析，得出结论，直流电平漂移和信号正交性误差是产生测量误差的主要来源．

By means of superposition of orthogonal moire' signals to obtain triangular wave, the softwave method of fine-dividing moire' signals has a constant snsitivity approximately during all the period of the signal. Since the freguence is double for the composed signal,the higher magnification of fine-dividing can be achieved for the some gratings. The measurement error is also analysed in this paper and it is found that the error is mainly come from the DC voltage shift and orthogonal error of moire' signals.