单光栅与双光栅衍射角度检测对比分析

光栅副是增量式光电编码器最主要组成部分，它的结构和衍射效应直接与检测精度相关。文中深入地分析了单光栅与双光栅衍射特点，并且从空间调制模型的角度推导光栅副对莫尔条纹的影响。从宏观和微观两个角度分析光栅副的屏函数，研究莫尔条纹光电信号输出波形的不确定原因和反差对比度，进而证明单光栅测量可以减少输出信号的频率成分，获得较高的细分精度和反差对比度。为了证明单光栅角度检测的可行性，给出了一套完整的单光栅角度检测方法。

Comparison analysis of single-grating diffraction and doublegrating diffraction angle detection

Grating pair is the most important component of increment encoder, its structure and diffraction effcet are directly related to detection precision. The paper deeply analysed that the characteristics of diffraction single-grating and double-grating, and from the angle of spatial modulation deduce relation, grating pair influence Moire fringe. It analyzed the window function of the grating pair from both macro and micro perspectives, the uncertain reasons of the Moire fringe optoelectric signal waveform and contrast, and then proved that single-grating angle detecting can not only decrease frequency ingredient of output signal but achieve higher division precision and contrast. In order to prove the feasibility of single-grating angle detecting, this paper finally given a complete single-grating angle detecting way.