Doppler Effect removal based on instantaneous frequency estimation and time domain re-sampling for wayside acoustic defective bearing detector system
Doppler Effect removal based on instantaneous frequency estimation and time domain re-sampling for wayside acoustic defective bearing detector system
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DOI：
10.1016/j.measurement.2014.01.004
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发表时间：
2014-04
期刊：
影响因子：
5.6
通讯作者：
Chao Wang;Fanrang Kong;Qingbo He;Fei Hu;Fang Liu
中科院分区：
文献类型：
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作者：
Chao Wang;Fanrang Kong;Qingbo He;Fei Hu;Fang Liu
轨道声轴承缺陷检测仪(ADBD)记录的声学信号中存在的多普勒效应现象，给高速列车轴承故障诊断带来了困难，严重影响了在线缺陷检测的有效性。为了提高铁路旁装有麦克风的过往列车轴承状态监测的性能，首先要解决多普勒效应的消除问题。本文提出了一种消除源信号中的多普勒效应的有效方法。采用短时傅里叶变换-维特比算法(STFT-VA)对失真信号进行瞬时频率估计。根据Morse的声学理论，对非线性数据进行拟合，得到拟合后的瞬时频率。从拟合曲线中获取完全基于运动学分析的时间域插值重采样所需的参数，并在时间域中建立重采样序列。作为上述步骤的结果，可以利用恢复的信号对列车轴承进行故障诊断。通过三个相邻频率的仿真和列车轴承外圈和内圈裂纹实际声学信号的实验，验证了该方法的有效性。仿真和实验结果表明，该方法具有良好的消除多普勒效应的性能，可以很好地应用于高速列车轴承的状态监测和故障诊断。
The phenomenon of Doppler Effect in the acoustic signal recorded by the wayside acoustic defective bearing detector (ADBD) leads to the difficulty for fault diagnosis of train bearings with a high moving speed, which is a barrier that would badly reduce the effectiveness of online defect detection. In order to improve the performance of condition monitoring of the bearings on a passing train with microphones amounted besides the railway, the elimination of the Doppler Effect should be solved firstly. An effective method for removing the Doppler Effect embedded in the source signal is presented in this paper. The Short Time Fourier Transform-Viterbi Algorithm (STFT-VA) is applied to obtain instantaneous frequency estimation of the distorted signal. According to the acoustic theory of Morse, the non-linear data fitting is then carried out to get the fitting instantaneous frequencies. The necessary parameters for time domain interpolation re-sampling, which is totally based on the kinematic analysis, are acquired from the fitting curve and the re-sampling sequence could be established in the time domain. As a result of the preceding steps, the fault diagnosis for the train bearings could be implemented with the restored signal. The effectiveness of this proposed method is verified by means of a simulation with three adjacent frequencies and an experiment with practical acoustic signals of train bearings with a crack on the outer race and the inner race. The results of the simulation and the experiment indicate that the proposed method has an excellent performance in removing Doppler Effect, and could be well employed to the condition monitoring and fault diagnosis of train bearings with a high moving speed.