小波包络新方法在液压泵故障诊断中的应用

提出了一种基于小波簇的带通滤波和包络解调新方法。通过合理的选择小波参数,用多个单Morlet小波组成的小波簇可构成具有零相移、平顶通带及快速衰减过度带特性的带通滤波器,用于提取振动信号的高频成分。由于该小波簇的虚部是实部的Hilbert变换,可实现包络解调,从而提取振动信号在高频谐振带的包络成分。将该方法用于轴向柱塞泵故障的诊断中,结果表明可有效地提取了故障特征频率,诊断结果验证了该方法的有效性。

Application of a Wavelet Cluster-Based Envelope Demodulation Approach For Fault Diagnosis in Hydraulic Pump

A Morlet-like wavelet clusterbased method for band-pass filtering and envelope demodulation is described.Via appropriate choice of wavelet parameters,a wavelet cluster combined with multi-Morlet-like wavelet can be used as a band-pass filter with zero phase shift,flat topped pass-band and rapid attenuation in the transition band.It can be used to extract high frequency natural vibration components.The imaginary part of the Morlet-like wavelet cluster is the Hilbert transform of its real part.This can be used to implement envelope demodulation and extract the envelope component of the high frequency resonance band.The method is applied for fault diagnosis relating to hydraulic pump.It is shown that the fault characteristic frequencies can be extracted effectively.The efficacy of the method is demonstrated in experimental studies.