超声导波检测公路护栏立柱信号处理研究

发布时间：2018-04-10 08:32

本文选题：超声导波　切入点：匹配追踪算法　出处：《交通运输研究》2016年05期

【摘要】：由于超声导波多模态、易频散的特性,导致其在检测高速公路护栏立柱时会产生复杂的回波信号,现有方法很难从中提取出有效的特征信号。为了解决该问题,首先提出了一种改进的子空间匹配追踪算法(ISMP)。它是将回波信号的先验信息在过完备Chirp原子库上逐次迭代,得到强相关原子集,然后对其再次进行迭代得到待匹配信号的最佳时频原子,从而实现对护栏立柱回波信号的特征提取。利用中心频率为128k Hz和64k Hz的检测信号进行实验验证,结果表明,ISMP可以有效提取出超声导波回波信号的特征原子,立柱检测长度与实际长度误差小于1%,满足工程检测要求。此外,还提出了一种基于离散傅里叶变换的相位检波算法,通过设置相位检测误差减少噪声带来的干扰。实验表明,在128k Hz和64k Hz检测信号下,可以得到设定相位的有用回波信息,满足工程检测要求。
[Abstract]:Because of the multi-mode and frequency-dispersive characteristics of ultrasonic guided wave, complex echo signals will be produced in the detection of highway guardrail columns, from which the existing methods are difficult to extract effective characteristic signals.In order to solve this problem, an improved subspace matching tracking algorithm is proposed.The priori information of the echo signal is iterated over an overcomplete Chirp atom library to obtain the strongly correlated atom set, and then iterated again to obtain the best time-frequency atom of the signal to be matched.In order to achieve the fence column echo signal feature extraction.The experimental results show that ISMP can extract the characteristic atoms of ultrasonic guided echo signal effectively, and the error between the detection length and the actual length of the column is less than 1, which meets the requirements of engineering detection.In addition, a phase detection algorithm based on discrete Fourier transform (DFT) is proposed to reduce the interference caused by noise by setting the phase detection error.The experimental results show that the useful echo information can be obtained at 128kHz and 64kHz signals, which can meet the requirements of engineering detection.
【作者单位】：交通运输部科学研究院;江西省高速公路投资集团有限责任公司宜春管理中心;
【分类号】：U417.12

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