脉冲压缩在超声导波钢轨断裂检测的应用研究  

Research on the application of pulse compression in ultrasonicguide wave rail fracture detection

作　　者：许溢航 王平[1] 杨元 王勇[1] Xu Yihang;Wang Ping;Yang Yuan;Wang Yong(School of Automation,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：《电子测量技术》2025年第3期112-117,共6页Electronic Measurement Technology

基　　金：江苏省重点研发计划(BE2021621);江苏省工业和信息产业转型升级专项资金项目(苏工信综合[2022]115号)资助。

摘　　要：为提高超声导波钢轨断裂检测距离与断面定位精度,保证钢轨服役期间安全性。本研究采用Barker码编码方式与凯塞窗函数对激励信号进行调制,扩展激励信号时宽,增强发射信号能量,通过对检测信号进行脉冲压缩处理,提高缺陷信号分辨率。开展有限元仿真研究,搭建钢轨三维仿真模型,并模拟钢轨断裂损伤情况。钢轨断裂程度为20%时,采用多周期正弦波信号激励,直达波信号的主波包信号与相邻波包信号峰峰值之比为1.065,而采用Barker13编码信号激励,直达波信号的主波包信号与相邻波包信号峰峰值比提高到2.542。分析不同断裂程度下的缺陷回波信号特征,采用Barker13编码激励信号回波信号强度幅值变化在40 dB以上,经有限元仿真研究可知,编码激励与脉冲压缩技术有效提高检测信号的分辨率与信号幅值。结合线下长距离钢轨检测实验,采用多周期正弦波信号所得到的检测信号,始波与回波信号成分复杂,时间差计算困难,而脉冲压缩技术有效提高检测信号信噪比,改善始波信号与回波信号的信号分辨率,断面定位准确率为99.3%。编码激励和脉冲压缩技术有效提高检测信号的幅值以及检测定位精度,为长距离钢轨断面定位提供技术手段。In order to improve the detection distance and section location accuracy of rail fracture with ultrasonic guided wave and ensure the safety of rail during service.In this study,Barker code encoding and Kaiser window function were used to modulate the excitation signal,expand the excitation signal time width,enhance the energy of the transmitted signal,and improve the resolution of the defect signal through pulse compression processing of the detected signal.The finite element simulation was carried out,the rail 3D simulation model was built,and the rail fracture damage was simulated.When the rail fracture degree is 20%,the peak-to-peak ratio of the main wave packet signal and the adjacent wave packet signal of the direct wave signal is 1.065 by using multi-period sine wave signal excitation,while the peak-to-peak ratio of the main wave packet signal and the adjacent wave packet signal is increased to 2.542 by using Barker13 coded signal excitation.The characteristics of defect echo signal under different fracture degrees are analyzed,and the amplitude of the echo signal intensity changes above 40 dB by Barker13 coded excitation signal.The finite element simulation shows that the encoded excitation and pulse compression technology can effectively improve the resolution and signal amplitude of the detected signal.Combined with the offline long-distance rail detection experiment,the detection signal obtained by using multi-period sine wave signal has complex components and difficult calculation of time difference.However,pulse compression technology can effectively improve the signal-to-noise ratio of detection signal and improve the signal resolution of the initial wave signal and the echo signal,and the accuracy rate of section positioning is 99.3%.Coding excitation and pulse compression technology can improve the amplitude of detection signal and the accuracy of detection and positioning effectively,and provide technical means for long-distance rail section positioning.

关 键 词：钢轨断裂 超声导波检测 巴克码 凯塞窗 脉冲压缩 

分 类 号：TN911.7[电子电信—通信与信息系统]