基于相参积累激光扫频干涉液位测量方法研究  

Research on laser swept frequency interferometry for liquid level measurement based on phase accumulation

作　　者：金陈凯 刘易 何泽聪 许新科 JIN Chen-kai;LIU Yi;HE Ze-cong;XU Xin-ke(College of Metrology and Measurement Engineering,China Jiliang University,Hangzhou 310018,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：《激光与红外》2024年第7期1037-1044,共8页Laser & Infrared

基　　金：浙江省自然科学基金项目(No.LY19F050008)资助。

摘　　要：工业生产中,容器内液位高度的控制是生产运输过程中对确保设备正常运行和维护人员生命安全具有重要意义。本文提出采用激光扫频干涉测量系统对液位进行测量,该方法具有诸多优势,如测量范围大、非接触式测量、响应速度快和操作便捷等。由于液体对红外光的吸收率相对较高,导致测量系统采集到的回光信号非常微弱,同时信噪比也不够理想。为解决此问题,本文引入相参积累方法,并将其与测量系统相结合,以提高液位检测的精准度。在信号的各个周期中,信号携带的有效信息保持一致,噪声信息是则随机的,因此通过相参积累方法处理后,不仅可以增强信号强度,还可以提升信噪比。再通过扩相频率采样法进行信号的非线性校正,最后对数据进行处理就,即可以获得液位信息。实验结果表明,相参积累方法对增加信号强度与信噪比有显著效果,为解决低信噪比下提升测量精度问题提供了思路。In industrial production,precise control of liquid levels within containers holds paramount importance in ensuring smooth equipment operation and safeguarding the lives of maintenance personnel during production and transportation.This paper proposes the utilization of a laser swept frequency interferometry measurement system for liquid level assessment,which has many advantages,such as large measurement range,non-contact measurement,swift response time and convenient operation.Given that liquids exhibit a relatively high absorption rate for infrared light;the backscattered signal acquired by the measurement system is exceedingly weak,leading to a less-than-ideal signal-to-noise ratio.To address this issue,the phase accumulation method is introduced and combined with the measurement system to improve the accuracy of liquid level detection.In each cycle of the signal,the effective information carried by the signal remains consistent,and the noise information is then random.Therefore,employing the phase accumulation method not only amplifies signal strength but also elevates the signal-to-noise ratio.Further,by utilizing a phase-frequency sampling technique for nonlinear correction of the signal,followed by data processing,the liquid level information can be obtained.The experimental results show that the phase parameter accumulation method has a significant effect on increasing the signal strength and signal-to-noise ratio,thus providing a promising approach to enhance measurement precision under conditions of low signal-to-noise ratio.

关 键 词：激光扫频干涉测距 相参积累 扩相频率采样法 液位测量 

分 类 号：TN249[电子电信—物理电子学] TH74[机械工程—光学工程]