基于信号分离的扩展频谱时域反射法盲区消除研究  

Research on blind spot elimination of spread spectrum time domain reflectometry based on signal separation

作　　者：陈洪圳 王莉[1] 徐昊 杨善水[1] Chen Hongzhen;Wang Li;Xu Hao;Yang Shanshui(College of Automation Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China)

机构地区：[1]南京航空航天大学自动化学院,南京211106

出　　处：《仪器仪表学报》2024年第9期280-289,共10页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(51877102)项目资助。

摘　　要：扩展频谱时域反射法进行线缆故障检测时,因检测盲区的存在而难以对近距离故障有效识别,这不仅减小了检测范围,也限制了其在实际应用中的广泛性。本文针对该方法中的盲区问题,深入分析盲区产生的机理,提出了一种基于信号分离的盲区消除方法。该方法基于入射信号与反射信号线性叠加的特性,通过数字信号处理中的减法运算,有效地实现了两者的分离,使得在盲区内准确地识别反射信号,提取故障信息。本方法通过数字信号处理技术来消除盲区,避免了硬件平台的改动,算法简单,易实现,适应场景广泛。实验结果显示,在中心频率为62.5 MHz的检测系统中,使用本方法进行开路和短路故障在线检测,其最大绝对误差仅为0.16 m,充分验证了所提方法的有效性和实用性。When using the spread spectrum time domain reflectometry for cable fault detection,it is difficult to effectively identify near-distance faults due to the presence of detection blind spot.This not only reduces the detection range but also limits its wide applicability in practical applications.In response to this issue,this paper thoroughly analyzes the mechanism behind the formation of blind spot,and proposes a signal separation-based method to eliminate them.Leveraging the linear superposition of incident and reflected signals,this method applies subtraction in digital signal processing to successfully separate the two signals,enabling accurate identification of reflected signals within the blind zone and extraction of fault information.This method eliminates blind spot through digital signal processing technology,avoiding changes to the hardware platform.The algorithm is simple,easy to implement,and adaptable to a wide range of scenarios.Experimental results show that using this method for online detection of open and short circuit faults in a detection system with a central frequency of 62.5 MHz,the maximum absolute error is only 0.16 m,fully demonstrating its effectiveness and practicality.When using the spread spectrum time domain reflectometry for cable fault detection,it is difficult to effectively identify near-distance faults due to the presence of detection blind spot.This not only reduces the detection range,but also limits its wide applicability in practical use.In this paper,in response to the blind spot issue in this method,the mechanism of blind spot generation is deeply analyzed,and a blind spot elimination method based on signal separation is proposed.This method utilizes the characteristic of the superposition of incident and reflected signals,and through subtraction operation in digital signal processing,effectively separates the two signals,accurately identifying reflected signals in blind spot and extracting fault information.This method eliminates blind spot through digital signal processin

关 键 词：线缆检测 扩展频谱时域反射法 盲区 信号分离 

分 类 号：TH7[机械工程—仪器科学与技术] TM93[机械工程—精密仪器及机械]