一种自适应Morlet小波包络解调的弱故障检测方法

为自适应实现Morlet小波与故障冲击特征成分的最优匹配,采用基于Shannon小波熵的方法优化带宽参数设计了最优Morlet小波。针对最佳尺度的求取难题,利用谱峭度与小波熵均能敏感反映冲击性的特性,提出了基于峭熵比的最佳尺度的求取方法。基于此,提出基于自适应Morlet小波包络解调的弱故障特征提取方法。仿真实验与实例分析表明:该方法克服了传统包络解调需要人为设定带通滤波器参数的不足,减少人工干预,能自动有效地从强噪背景中提取微弱故障特征,具有一定的工程应用价值。

The Method to Extract Weak Fault Feature Based on Adaptive Morlet Wavelet Envelope Demodulation

In order to achieve adaptive optimal match with the impact component, Shannon wavelet entropy is used to optimize bandwidth parameter of the Morlet wavelet to design the optimal Morlet wavelet. Aimed at the problem of obtaining the optimal scale, the new approach which is based on kurtosis entropy ratio to acquire the optimal scale is presented. In addition, the new method to extract weak fault feature based on adaptive morlet wavelet envelope demodulation is proposed in the paper. The simulation results and analysis on the incipient fault data of ball bearing show that the method overcomes the defect that the parameters of band-pass filter are selected by experience of the user in conventional envelope demodulation, decreases the dependence on user, and can automatic and effectively extract the weak fault feature. So, the method has some application value.