基于激光扫频干涉测距系统的玻璃厚度测量方法  

Measurement Method of Glass Thickness Based on Laser Sweep Interferometric Ranging System

作　　者：王雅婷 孔明 华杭波 刘维 刘璐 曹丽霞 许新科 Wang Yating;Kong Ming;Hua Hangbo;Liu Wei;Liu Lu;Cao Lixia;Xu Xinke(College of Metrology&Measurement Engineering,China Jiliang University,Hangzhou 310018,Zhejiang,China)

机构地区：[1]中国计量大学计量测试工程学院,浙江杭州310018

出　　处：《应用激光》2024年第7期120-126,共7页Applied Laser

基　　金：浙江省自然科学基金(LY19F050008)。

摘　　要：玻璃作为工业原材料的基础,其产量和质量的提升在实际应用中有重要的作用,如何高速且精确地测量玻璃厚度成为了玻璃生产线亟待解决的问题。在众多测量方法中,激光测距具有精度高、速度快、非接触及操作便捷等优点。利用激光扫频干涉测距系统测量激光发射器到玻璃待测件前后表面的距离,计算距离差求得玻璃待测件的厚度。实验先获得距离的拍频信号,对拍频信号利用插值拟合法进行非线性补偿,实现非线性校正。通过对非线性校正后的拍频信号进行插值处理,插值后的测量信号点数为插值前的20倍,相位信号变得光滑,再拼接,减少频谱泄露对实验结果造成的影响,最后对拼接后的信号进行快速傅里叶变换,求得待测玻璃前后表面距离差即玻璃厚度。实验结果表明,未经相位拼接处理的玻璃厚度误差在50μm以内,经过相位拼接处理的玻璃厚度误差在15μm以内,相位拼接方法有效提升了工业上玻璃厚度测量的精度。Glass is the basis of industrial raw materials,and the improvement of its output and quality plays an important role in practical application.How to measure the thickness of glass at high speed and accurately has become an urgent problem to be solved in glass production line.Among many measuring methods,laser ranging has the advantages of high precision,fast speed,non-contact and convenient operation.In this paper,the distance between the laser emitter and the front and rear surfaces of the glass parts to be measured is measured by laser frequency sweep interferometry ranging system,and the thickness of the glass parts to be measured is obtained by calculating the distance difference.Firstly,the beat signal of the distance is obtained,and the beat signal is compensated by interpolation fitting method to realize nonlinear correction.By interpolating the beat signal after nonlinear correction,the number of measured signal points after interpolation is 20 times that before interpolation,and the phase signal becomes smooth.Then,the phase extreme point is selected for phase splicing to increase the number of signal measurements and reduce the influence of spectrum leakage on the experimental results.Finally,the splicing signal is performed by fast Fourier transform to obtain the distance difference between the front and rear surfaces of the glass to be measured,namely the thickness of the glass.The experimental results show that the thickness error of glass without phase splicing treatment is less than 50μm,and the thickness error of glass with phase splicing treatment is less than 15μm.The phase splicing method effectively improves the precision of glass thickness measurement in industry.

关 键 词：激光扫频干涉测距 厚度测量 相位拼接 测距 

分 类 号：TN249[电子电信—物理电子学]