一种用于外差激光干涉仪的新型模拟插值方法。

A Novel Analog Interpolation Method for Heterodyne Laser Interferometer.

作者信息

Chang Chung-Ping, Chang Syuan-Cheng, Wang Yung-Cheng, He Pin-Yi

机构信息

Department of Mechanical and Energy Engineering, National Chiayi University, Chiayi 600, Taiwan.

Department of Mechanical Engineering, National Yunlin University of Science and Technology, Yunlin 640, Taiwan.

出版信息

Micromachines (Basel). 2023 Mar 21;14(3):696. doi: 10.3390/mi14030696.

DOI:10.3390/mi14030696

PMID:36985103

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10057481/

Abstract

Laser interferometer technology is used in the precision positioning stage as an encoder. For better resolution, laser interferometers usually work with interpolation devices. According to the interpolation factor, these devices can convert an orthogonal sinusoidal signal into several square-wave signals via digital processing. The bandwidth of the processing will be the limitation of the moving speed of the positioning stage. Therefore, the user needs to make a trade-off between the interpolation factor and the moving speed. In this investigation, a novel analog interpolation method for a heterodyne laser interferometer has been proposed. This method is based on the principle of the lock-in amplifier (LIA). By using the proposed interpolation method, the bandwidth of the laser encoder system can be independent of the interpolation factor. This will be a significant benefit for the ultra-high resolution encoder system and the laser interferometers. The concept, design, and experiment are revealed in this manuscript. The experimental results show that the proposed interpolation method can reach nanometer resolution with a heterodyne laser interferometer, and the bandwidth of the signal is independent of the resolution.

摘要

激光干涉仪技术在精密定位平台中用作编码器。为了获得更高的分辨率，激光干涉仪通常与插值装置配合使用。根据插值因子，这些装置可以通过数字处理将正交正弦信号转换为多个方波信号。处理带宽将限制定位平台的移动速度。因此，用户需要在插值因子和移动速度之间进行权衡。在本研究中，提出了一种用于外差激光干涉仪的新型模拟插值方法。该方法基于锁相放大器（LIA）的原理。通过使用所提出的插值方法，激光编码器系统的带宽可以与插值因子无关。这对于超高分辨率编码器系统和激光干涉仪将是一个显著的优势。本文阐述了该概念、设计及实验。实验结果表明，所提出的插值方法在外差激光干涉仪中可实现纳米级分辨率，且信号带宽与分辨率无关。