摘要
传统白光干涉测量方法对振动干扰非常敏感,振动干扰会引起扫描步长误差,进而降低白光干涉的测量精度.为抑制振动干扰的影响,提出一种三点反正弦的白光干涉测量算法.三点反正弦法将干涉图序列中每相邻三幅分为一组,利用扫描过程中干涉条纹连续移动的特点,从每组干涉图的有效条纹区域计算出相移偏差,进而得到每幅干涉图的实际扫描步长.基于计算的实际扫描步长,构建了非等步长的调制度与相位最小二乘计算方法,并重构表面高度.由于计算步长仅利用三幅干涉图,三点反正弦法频段响应宽,能够探测快变、大幅的扫描步长误差.仿真和实验证实,在振动干扰下三点反正弦法能获得高达 0.5%的测量准确性(台阶高度为 10 μm),并适合多种类构型表面形貌的测量.理论分析和实验表明,三点反正弦法能够抑制多种形式扫描步长误差的影响,适用于宽频段振动干扰下的白光干涉测量.
Abstract
The traditional white-light interferometer is highly sensitive to vibrations,causing scanning step errors and reducing measurement accuracy.To address this,a three-point arcsine(3P-Asin)algorithm is proposed.This method divides WLI interferograms into groups of three adjacent frames,with overlap be-tween groups.By analyzing fringe movement,the phase shift deviation and exact scanning step are deter-mined.Using this step,a least-squares method calculates phase and modulation for non-equal step scan-ning to reconstruct surface height.The 3P-Asin algorithm detects fast and large scanning step errors using only three interferograms,with no approximation.Simulations and experiments show it achieves an accura-cy of 0.5%for a 10 μm step height and adapts to various surfaces in mechanical machining.Both theoreti-cal and experimental results demonstrate that the 3P-Asin algorithm effectively attenuates scanning step er-rors across a wide frequency range,making it suitable for WLI in vibrating environments.
基金项目
国防科工局技术基础科研项目(JSZL2022212B001)
国家科技期刊平台
NSTL
万方数据