全参数自适应特征模态分解及其在滚动轴承早期故障诊断中的应用

All-parameter adaptive feature mode decomposition and its application on incipient fault diagnosis of rolling bearings

  • 摘要: 针对滚动轴承早期微弱故障特征易淹没在多成分噪声干扰信号中从而难以有效提取的问题,提出了一种全参数自适应特征模态分解方法。首先,通过基于分数阶高斯噪声的数值模拟试验研究了特征模态分解(FMD)的等效滤波特性。其次,分析了关键参数(滤波器长度L、滤波器个数K、模态个数n)对FMD滤波性能的影响。然后,为实现故障信号的自适应分解,构建了一种考虑故障信号频域循环平稳性的稀疏指标,即周期谐波能量比(PHER),以PHER作为金豺优化算法的适应度函数自动确定了带约束的最优全参数组合。最后,开展了仿真信号和实验数据的分析,证实了本方法能够抑制多成分噪声干扰,有效提取轴承故障特征信息,且与PAFMD、MPA-VMD和ISGMD方法相比,本方法具有更加优越的滚动轴承早期微弱故障特征提取能力。

     

    Abstract: Aiming at the problem that the incipient fault features of rolling bearings are easily submerged in the multi-component noise signal and difficult to extract effectively. An all-parameter adaptive feature mode decomposition method was proposed. Firstly, the equivalent filter characteristics of the feature mode decomposition (FMD) was studied by numerical simulation experiment based on fractional Gaussian noise. Secondly, the influence of key parameters (the filter length L, the filter number K, and the mode number n) on the filtering property of FMD was analyzed. Then, in order to realize the adaptive decomposition of fault signals, a sparsity index (periodic harmonic energy ratio PHER) which fully considers its cyclostationarity from the perspective of the frequency domain of the fault signal was constructed, and the PHER was used as the fitness function of the golden jackal optimization algorithm to automatically determine the optimal all-parameter combination. Finally, the simulation signal and experimental data were thoroughly analyzed, demonstrating that the proposed method can suppress multi-component noise interference and effectively extract bearing fault feature information. Compared with PAFMD, MPA-VMD and ISGMD, the proposed method has more superior ability to extract incipient fault characteristics of rolling bearings.

     

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