Joint amplitude and frequency demodulation analysis based on local mean decomposition for fault diagnosis of planetary gearboxes
Joint amplitude and frequency demodulation analysis based on local mean decomposition for fault diagnosis of planetary gearboxes
复制标题
基于局部均值分解的联合幅频解调分析用于行星齿轮箱故障诊断
DOI：
10.1016/j.ymssp.2013.05.016
复制
发表时间：
2013-10-01
影响因子：
8.4
通讯作者：
Liu, Zhiliang
中科院分区：
文献类型：
--
作者：
Feng, Zhipeng;Zuo, Ming J.;Liu, Zhiliang
由于齿轮损伤引起的振动具有调幅和调频特性（AMFM），以及时变振动传递路径（局部齿轮损伤情况）和行星轮经过（分布齿轮损伤情况）所引起的附加倍增调幅（AM）效应，故障行星齿轮箱的振动信号具有复杂的频谱结构。行星齿轮箱故障谱的复杂性导致了故障诊断的困难。针对行星齿轮箱振动信号的幅值包络和瞬时频率与故障齿轮的特征频率相关的特点，提出了一种幅频联合解调的行星齿轮箱故障诊断方法。为了满足瞬时频率估计的单分量要求，首先利用局部均值分解（LMD）方法将信号分解为乘积函数（PF）。然后，最早提取的PF，具有一个瞬时频率波动周围的齿轮啮合频率或其谐波被选择用于进一步分析，因为它包含了大部分的齿轮故障的信息。通过对所选PF的幅值包络进行傅立叶变换，可以完成幅值解调分析。对于频率解调分析，对所选PF的估计瞬时频率进行傅立叶变换，以揭示其波动频率，从而获得瞬时频率的频谱。联合应用幅频解调方法，通过将包络谱和瞬时频谱中的主峰与故障齿轮的理论特征频率进行匹配，可以诊断行星齿轮箱的故障。所提出的方法的性能示出了模拟信号分析，并验证了实验室行星齿轮箱故意创建点蚀和自然发展的磨损的实验信号分析。(c)2013爱思唯尔有限公司版权所有。
The vibration signals of faulty planetary gearboxes have complicated spectral structures due to the amplitude modulation and frequency modulation (AMFM) nature of gear damage induced vibration and the additional multiplicative amplitude modulation (AM) effect caused by the time-varying vibration transfer paths (for local gear damage case) and the passing planets (for distributed gear damage case). The spectral complexity leads to the difficulty in fault diagnosis of planetary gearboxes. Observing that both the amplitude envelope and the instantaneous frequency of planetary gearbox vibration signals are associated with the characteristic frequency of the faulty gear, a joint amplitude and frequency demodulation method is proposed for fault diagnosis of planetary gearboxes. In order to satisfy the mono-component requirement by instantaneous frequency estimation, a signal is firstly decomposed into product functions (PF) using the local mean decomposition (LMD) method. Then, the earliest extracted PF that has an instantaneous frequency fluctuating around the gear meshing frequency or its harmonics is chosen for further analysis, because it contains most of the information about the gear fault. The amplitude demodulation analysis can be accomplished through Fourier transforming the amplitude envelope of the chosen PF. For the frequency demodulation analysis, Fourier transform is applied to the estimated instantaneous frequency of the chosen PF to reveal its fluctuating frequency, thus obtaining the spectrum of the instantaneous frequency. By joint application of the amplitude and frequency demodulation methods, planetary gearbox faults can be diagnosed by matching the dominant peaks in the envelope spectrum and the spectrum of instantaneous frequency with the theoretical characteristic frequencies of faulty gears. The performance of the proposed method is illustrated by simulated signal analysis, and is validated by experimental signal analysis of a lab planetary gearbox with intentionally created pitting and naturally developed wear. (c) 2013 Elsevier Ltd. All rights reserved.