采用频谱分析技术的高分辨率微位移测量方法

High Resolution Method for Measuring Microdisplacement with Spectrum Analysis Techniques

本文提出了具有高分辨率的微位移测量方法。该方法采用频谱分析技术对干涉条纹进行快速傅里叶变换 (FFT)和滤波处理 ,消除了噪声和干扰 ,获得了清晰的干涉条纹。检测处理后的干涉条纹的移动就能准确地测量出位移。采用 CCD摄像机、图像卡和计算机 ,结合本文设计的麦克尔逊干涉仪对压电晶体 (PZT)的位移曲线进行了测量。结果表明 ,该方法能达到极高的分辨率 ,在总采样点为 5 12 ,连续测量时 ,最小分辨率达到 1.3nm。

This paper presents a method for measuring microdisplacement with a high resolution, in which the spectrum analysis techniques are utilized. The noises in fringes are eliminated by fast Fourier transform and filter, and the reconstructed fringes are very clear, which location can be measured accurately. Therefore, it has high resolution to measure displacement by measuring the fringes shift. We measure PZTs displacement by using CCD camera, picture card, computer and Michelson interferometer that is designed specially. The results show that the method is easy to apply and has high sensitivity. The minimum resolution is 1.3nm when the number of sampling point is 512.