基于共振解调和小波包能量谱的声发射信号特征提取

The Extraction of the Feature of Acoustic Emission Signal Based on Resonance Demodulation and the Wavelet Spectrum Packet

将小波包能量谱分析和共振解调法相结合,应用于声发射信号的特征提取中。首先,将声发射信号进行小波包分解,得到若干个子频带;然后计算各个子频带所包含的能量,描述出各子频带能量占信号总能量百分比;再将其与正常声发射信号能量谱对比,分析出变化较为明显的子频带;最后运用共振解调技术,对该频带做Hilbert包络谱分析,得出信号特征。结果表明:该方法可以有效提取出声发射信号的特征,是声发射信号特征提取的一种新方法。

A new approach of combining the method of resonance demodulation and multi-resolution analysis of wavelet packet is presented to characterize the acoustic emission（AE）signals.Firstly,wavelet packet is used to decompose the acoustic emission signal into several frequency bands.Then the energy of each frequency band is calculated to draft the percentages of each band on total energy.Secondly,the above-mentioned results shall be compared with the energy spectrum of normal acoustic emission signal and the sub-bands which change more obviously shall be obtained.Based on the technology of resonance demodulation,the band which changes a lot is decomposed by Hilbert transform to get the feature of signal.According to the experimental data analysis,it shows that this method can effectively extract the characteristic of acoustic emission and it is a new way of acoustic emission feature extraction.