红外发光管是光电编码器的重要组成部分, 而光源参数对莫尔条纹信号的正弦性和正交性有直接影响, 从而影响光电编码器的细分精度和分辨力。文中研究了其发散角、光源宽度对编码器的信号影响。首先, 分析了光源对光栅信号光通量的影响, 运用频域方法导出了透光特性函数; 然后, 分析了两种不同光源对同一码盘形成信号的影响; 最后, 应用Matlab仿真计算了莫尔条纹信号的对比度、正交性、正弦性。实验结果表明, 使用两种不同光源的编码器精度相差达到30%, 改进后的编码器高次谐波占比明显减少, 信号稳定性好。因此研究光源参数对提取高质量莫尔条纹有重要意义, 并为高精度编码器设计提供重要参考依据。

Infrared diodes are important components of photoelectric encoder, the orthogonality and sine of Moire fringe directly affect the segmentation accuracy and resolution of photoelectric encoder, and they affect the light source parameters. According to the investigation, the divergence angle and the width of light source exert a tremendous influence in signal of encoder. Firstly, the effect of light source on the grating signal flux was analyzed. The application of the frequency domain method helped deduce the function of light transmission feature; Then the impact of the two different light source on the signal creation with a yard plate and the contrast ratio was computed; Finally, orthogonality and sinusoidal property of the Moiré stripe signal were simulated at MATLAB environment. The result shows that the encoder accuracy difference between them reached 30% by applying different source. Higher harmonic proportion of the improved decoder decreases significaitly and the signal stability is better. Studying the light source parameters has great significance in extracting the Moire fringe of high quality, and offers valuable reference for designing high-precision encoder.