基于改进奇异值分解法降噪的频分复用Φ-OTDR  

Denoising of Frequency-Division Multiplexed Φ-OTDR Based on Improved Singular Value Decomposition Method

作　　者：陈娟 张红娟[1] 王鹏飞 高妍[1] 靳宝全[2] Chen Juan;Zhang Hongjuan;Wang Pengfei;Gao Yan;Jin Baoquan(College of Electrical and Power Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China;Key Laboratory of Advanced Transducers and Intelligent Control System,Ministry of Education,Taiyuan 030024,Shanxi,China)

机构地区：[1]太原理工大学电气与动力工程学院,山西太原030024 [2]太原理工大学新型传感器与智能控制教育部山西省重点实验室,山西太原030024

出　　处：《中国激光》2024年第22期209-218,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金(62375197);山西省重点研发计划项目(202102130501021);山西省基础研究计划(202103021222010);中央引导地方科技发展资金项目(YDZJSX20231B004);山西省科技创新团队项目(201805D131003)。

摘　　要：针对采用频分复用(FDM)相位敏感光时域反射仪(Φ-OTDR)技术监测高频声波信号时出现强噪声干扰问题,提出改进奇异值分解(SVD)抑制噪声的处理方法。构造Hankel奇异值矩阵,提取背景声纹特征,利用阈值法确定有效奇异值数量,准确划分高频信号的目标信号和噪声信号,实现噪声抑制。实验证明:频分复用方法提升相位敏感光时域反射仪(Φ-OTDR)系统的频带范围为62.5 kHz,并利用改进奇异值分解法精确重构范围为0~3.5 kHz的非平稳声音信号,最终实现10 kV电力电缆的局部放电信号采集和噪声抑制,放电有效信号的波形相似度为0.963,均方根误差低至0.0099,信噪比增益达16.182 dB。本方法为频分复用Φ-OTDR系统实现高频声波信号监测提供一种新的解决思路。Objective Phase-sensitive optical time-domain reflectometry(Φ-OTDR), owing to its unique advantages in the sensor domain, has received significant attention. Among the pivotal advancements in this field, the introduction of frequency-division multiplexing(FDM) is notable as it significantly enhances the system's frequency-response bandwidth and overcomes the limitations imposed by the fiber length on the maximum response frequency. This breakthrough has considerably expanded the utility of FDM Φ-OTDR,particularly in applications requiring high-frequency vibration monitoring and ultrasonic sensing for partial-discharge detection.However, the practical deployment of FDM Φ-OTDR systems is typically accompanied by substantial challenges, including interference from external environmental factors and phase noise from the light source, which severely compromises the accuracy of high-frequency detection. Addressing these issues is critical for the advancement and broader application of Φ-OTDR. Previous attempts to mitigate noise interference, such as wavelet denoising and variational-mode decomposition, indicate limitations, including dependence on base functions and the inability to achieve a satisfactory signal-to-noise ratio(SNR) in nonstationary environments.This study proposes an innovative approach, i. e., an improved singular value decomposition(SVD) method for noise reduction,which addresses the specific challenges encountered by FDM Φ-OTDR systems in high-frequency signal detection. By constructing a Hankel singular-value matrix to distinguish between signal and noise components and employing a thresholding method to identify significant singular values, this method not only effectively suppresses noise but also preserves essential high-frequency information.This study aims to provide a novel perspective and a robust solution for noise suppression in FDM Φ-OTDR systems, thus enhancing their performance in critical applications such as infrastructure monitoring and the diagnosis of electrical-cable faults.

关 键 词：频分复用相位敏感光时域反射仪 奇异值分解法 噪声抑制 局部放电监测 

分 类 号：O436[机械工程—光学工程]