高精度激光多普勒在线测长系统设计及算法研究  

The design and algorithm research of a high-precision laser Doppler online length measurement system

作　　者：梁月鹏 胡润峰 刘福 廖同庆[1] LIANG Yuepeng;HU Runfeng;LIU Fu;LIAO Tongqing(School of Electronics and Information Engineering,Anhui University,Hefei 230601,China)

机构地区：[1]安徽大学电子信息工程学院,安徽合肥230601

出　　处：《红外与激光工程》2025年第2期177-183,共7页Infrared and Laser Engineering

摘　　要：针对激光多普勒测长系统中多普勒频率难以提取、测量精度较低的情况,设计了一款基于双光束双散射光路的高精度在线激光多普勒电缆测长仪。首先基于声光调制器引入了光学移频技术,结合高通滤波器有效滤除基底信号,提升了信噪比。接着引入自适应采样算法,进一步减少系统误差、提高低速测量时的精确度;随后引入Zoom-FFT频谱细化算法以及能量重心校正算法进行频谱校正,并仿真分析了自适应采样算法和Zoom-FFT结合能量重心校正算法的精确度。搭建了实验系统,分析了系统的精确度和稳定性。实验结果表明,该系统的测量精度优于0.05%。Objective Laser Doppler measurement technology is a non-contact measurement method characterized by high measurement accuracy,high resolution,and rapid response.Currently,Self-developed laser Doppler length measuring instruments are still relatively few in China.The measurement errors ranging is from 0.5%to 1%in general which can not meet the requirement of cable manufacturing industry(0.3%).In contrast,the measurement errors of mature foreign products,such as the SL-type laser Doppler velocity and length meters developed by Proton Corporation in the UK and the uSpeed series laser Doppler velocity and length meters produced by Elovis in Germany,can reach 0.05%.Therefore,a high-precision laser Doppler length measurement with measurement error better than 0.05%is developed in this paper.Methods First,optical frequency shifting technology is introduced based on an acoustic optical modulator(Fig.1).So,the base signal can be effectively filtered out combined with a high-pass filter.Then,an adaptive sampling algorithm is introduced(Fig.3)to further reduce system errors and enhance measurement accuracy at low speed measurement time.Therewith,Zoom-FFT spectrum thining algorithm is introduced(Fig.5)for dense spectral thining processing and energy centrobaric correction algorithm is introduced for spectral correction.The simulation analysis is carried out(Fig.6-Fig.8).Finally,an experimental system is set up,then accuracy and stability are analyzed(Fig.11).Results and Discussions The accuracy of the adaptive sampling algorithm is analysed by simulations,and the relative errors at each speeds are plotted(Fig.6).The relative errors using the adaptive sampling frequency algorithm are generally lower than those with a fixed sampling frequency,particularly in the low-frequency region(corresponding to the low-speed phase).The impact of the energy centrobaric correction algorithm on Doppler frequency extraction accuracy are verified with 25 Doppler frequencies(Fig.7).The frequency values directly output by the FFT is significantl

关 键 词：激光多普勒效应 在线测长系统 光学移频 自适应采样算法 Zoom-FFT频谱细化 能量重心校正算法 

分 类 号：TH741[机械工程—光学工程]