Time-Frequency Squeezing and Generalized Demodulation Combined for Variable Speed Bearing Fault Diagnosis
Time-Frequency Squeezing and Generalized Demodulation Combined for Variable Speed Bearing Fault Diagnosis
复制标题
时频压缩与广义解调相结合的变速轴承故障诊断
DOI：
10.1109/tim.2018.2868519
复制
发表时间：
2019-08-01
影响因子：
5.6
通讯作者：
Zhu, Zhongkui
中科院分区：
文献类型：
--
作者：
Huang, Weiguo;Gao, Guanqi;Zhu, Zhongkui
高分辨率时频表示（TFR）方法是信号分析和特征检测的有效方法。然而，对于变速轴承振动信号，传统的TFR方法容易产生模糊，影响瞬时频率估计的准确性。此外，传统的阶次跟踪依赖于等角复位，通常存在插值误差。针对这一问题，本文提出了联合时频压缩和广义解调的方法来实现变速轴承故障诊断。该方法能准确地表征时变故障特征频率，且不受扰动。首先，利用快速谱峭度选择对滚动轴承故障敏感的最佳频带，并在所选最佳频带内进行希尔伯特变换提取包络。然后，采用基于短时傅里叶变换的高质量TF聚类方法对包络进行TF分析，得到清晰的TF，从而得到GD的频率信息。最后，通过TF分析，通过峰值搜索处理基本解调器，得到GD的TFR，以获得无重采样的阶谱。基于更清晰的TFR获得的更精确的TF信息，可以通过GD诊断轴承故障，而无需转速计或任何复位，避免了复位的幅度误差和低计算效率。仿真研究和实验信号分析表明，该方法比传统的基于TF分析和恢复的方法具有更好的性能。
High-resolution time-frequency representation (TFR) method is effective for signal analysis and feature detection. However, for variable speed bearing vibration signal, conventional TFR method is prone to blur and affect the accuracy of the instantaneous frequency estimation. Moreover, the traditional order tracking, relying on equi-angular resampling, usually suffers from interpolation error. To solve such problems, we propose a joint time-frequency (TF) squeezing method and generalized demodulation (GD) to realize variable speed bearing fault diagnosis. The method can represent the time-varying fault characteristic frequency precisely and be free from resampling. First, using fast spectral kurtosis to select the optimal-frequency band which is sensitive to rolling bearing fault, and extracting envelope by Hilbert transform within the selected optimal frequency band. Next, a high-quality TF clustering method based on short-time Fourier transform is applied to the TF analysis of the envelope to get a clear TFR, from which the frequency information for GD is obtained. Finally, processing the basic demodulator via the peak search through the TF analysis results in the TFR for GD to gain a resampling-free-order spectrum. Based on the more precise TF information from the clearer TFR, the bearing fault can be diagnosed via GD without tachometer or any resampling involved, avoiding the amplitude error and low computational efficiency of resampling. Simulation study and experimental signal analysis validate that the proposed method has better performance than those methods based on conventional TF analysis and resampling.