超声导波轨底裂纹检测的信号增强技术  

Signal Enhancement Technology Based on Ultrasonic Guided Wave Rail Bottom Crack Detection

作　　者：何继平[1] 周永久 钦佩 张岩 周守镇 王平[2] 周文涛 刘勇 HE Jiping;ZHOU Yongjiu;QIN Pei;ZHANG Yan;ZHOU Shouzhen;WANG Ping;ZHOU Wentao;LIU Yong(Suzhou Rail Transit Group Co.,Ltd.,215100,Suzhou,China;College of Automation Engineering,Nanjing University of Aeronautics and Astronautics,210016,Nanjing,China;Nanjing Paiguang High Speed Transport Intelligent Perception Research Institute Co.,Ltd.,210016,Nanjing,China)

机构地区：[1]苏州市轨道交通集团有限公司,苏州215100 [2]南京航空航天大学自动化学院,南京210016 [3]南京派光高速载运智慧感知研究院有限公司,南京210016

出　　处：《城市轨道交通研究》2025年第4期260-263,268,共5页Urban Mass Transit

摘　　要：[目的]导波在钢轨中的传播过程中存在抗干扰能力差和信号衰减严重问题,不利于识别轨底裂纹。为提高信噪比,有必要提出一种信号增强技术用于增强导波信号。[方法]在传统超声导波检测基础上,利用Barker码作为伪随机序列码,采用BPSK(二进制相位编码)技术将原始激励信号经过编码调制后得到新的激励信号,实现对激励信号的扩频处理,并对采集的接收信号进行解扩。搭建超声导波轨底裂纹检测试验平台,分别对不同尺寸的钢轨轨底人工裂纹进行对比试验,分别在激励信号扩频与非扩频情况下,计算所接收导波信号的衰减系数。[结果及结论]试验结果表明,导波信号使用信号增强技术之后,相较于未经处理的原始导波信号,在传播相同距离时,衰减系数得到了明显降低,超声导波信号将能传播更远距离;相同尺寸人工裂纹所产生的影响更加明显,超声导波对钢轨轨底裂纹的检测灵敏度得到了明显提升。[Objective] During the propagation of guided waves in rails,there are problems of poor anti-interference ability and severe signal attenuation,which hinder the identification of rail bottom cracks.To improve the signal-to-noise ratio,it is necessary to propose a signal enhancement technology to strengthen the guided wave signal.[Method] Based on the traditional ultrasonic guided wave detection,Barker code is used as the pseudo-random sequence code,and BPSK(binary phase shift keying) technology is adopted to obtain a new excitation signal after coding and modulating the original excitation signal,achieving the spread spectrum processing of the excitation signal,to despread the collected received signal.An ultrasonic guided wave rail bottom crack detection test platform is built,and comparative tests are conducted on artificial cracks of different sizes at the rail bottom.The attenuation coefficients of the received guided wave signals are calculated respectively under spread spectrum and non-spread spectrum conditions of the excitation signal.[Result & Conclusion] The experiments prove that after the guided wave signal is processed by the signal enhancement technology,the attenuation coefficient is significantly reduced when propagating the same distance compared with the original unprocessed guided wave signal,and the ultrasonic guided wave signal is able to travel a longer distance.The effect is more obvious for artificial cracks of the same size,and the detection sensitivity of ultrasonic guided waves for rail bottom cracks is significantly improved.

关 键 词：轨道交通 钢轨裂纹检测 Barker码 超声导波 信号增强技术 

分 类 号：U213.43[交通运输工程—道路与铁道工程]