基于第二代小波包自适应包络解调故障诊断方法

A fault diagnosis method based on second generation wavelet packet and self adapting envelope demodulation

针对第二代小波包存在频带错位的固有缺陷,研究了克服这一缺陷的移频算法。为了更有效地提取滚动轴承微弱冲击故障特征,提出了一种基于第二代小波包自适应包络解调相结合的滚动轴承故障诊断方法。该方法首先利用第二代小波包对原始信号进行分解与重构,然后为了避免对分解与重构后的所有子带都进行包络谱分析,根据能量最大化准则自适应选择一组故障信息最为丰富的子带进行包络谱分析,最后根据包络谱即可提取微弱冲击故障特征。仿真实验和应用实例表明:该方法可以准确地提取隐藏在强噪声背景中的微弱冲击故障特征。

This paper makes an investigation into frequency shift algorithm to overcome the inherent defects of band dislocation in the second-generation wavelet packet. In order to more effectively ex- tract the fault characteristics of rolling bearing weak impact, a fault diagnosis method is proposed based on the second-generation wavelet packet and self-adapting envelope demodulation. Firstly, the method uses the second-generation wavelet to decompose and reconstruct the original signals. Then, a group sub-band with the most abundant fault information is selected for an envelope spectrum analysis according to the criterion of energy maximization. Simulation experiments and applied examples show that the method can accurately extract the weak impact fault characteristics hidden in the background of strong noises.