Fault diagnosis of rolling bearing based on generalized S-transform and dropout CNN

Author(s):  
Lei Yang ◽  
Qing-Rong Wang
Author(s):  
Jianhua Cai ◽  
Yongliang Xiao

In view of the fact that the random noise interferes with the characteristic extraction of a rolling bearing fault signal, a new method of fault feature extraction is proposed based on the combination of the generalized S transform and singular value decomposition (SVD). Firstly, the 2D time–frequency spectrum bearing fault signal is obtained by applying the generalized S transform, and the time–frequency spectrum matrix is used as the objective matrix of SVD to solve the singular values. Then the K-means clustering algorithm is used to classify the singular value sequence, and the singular values for reconstruction are determined. Finally, the de-noised matrix is carried out the generalized S inversion transform to get the de-noised fault signal, and the power spectrum is calculated to finish the fault diagnosis. By analyzing the simulated signal and the actual bearing fault data, results show that the proposed method can effectively identify typical faults of rolling bearings and improve the diagnosis effect of rolling bearing faults. And it provides a new way to realize the fault diagnosis of rolling bearings under noise.


2017 ◽  
Vol 24 (15) ◽  
pp. 3338-3347 ◽  
Author(s):  
Jianhua Cai ◽  
Xiaoqin Li

Gears are the most important transmission modes used in mining machinery, and gear faults can cause serious damage and even accidents. In the work process, vibration signals are influenced not only by friction, nonlinear stiffness, and nonstationary loads, but also by strong noise. It is difficult to separate the useful information from the noise, which brings some trouble to the fault diagnosis of mining machinery gears. The generalized S transform has the advantages of the short time Fourier transform and wavelet transform and is reversible. The time–frequency energy distribution of the gear vibration signal can be accurately presented by the generalized S transform, and a time–frequency filter factor can be constructed to filter the vibration signal in the time–frequency domain. These characteristics play an important role when the generalized S transform is used to remove the noise in the time–frequency domain. In this paper, a new gear fault diagnosis based on the time–frequency domain de-noising is proposed that uses the generalized S transform. The application principle, method steps, and evaluation index of the method are presented, and a wavelet soft-threshold filtering method is implemented for comparison with the proposed approach. The effectiveness of the proposed method is demonstrated by numerical simulation and experimental investigation of a gear with a tooth crack. Our analyses also indicate that the proposed method can be used for fault diagnosis of mining machinery gears.


Author(s):  
B Li ◽  
P-L Zhang ◽  
S-B Liang ◽  
Y-T Zhang ◽  
H-B Fan

In this study, a novel feature extraction scheme was proposed for engine fault diagnosis utilizing the generalized S-transform combined with the non-negative tensor factorization (NTF). To represent the information of the non-stationary vibration signals acquired from engine, the generalized S-transform was used to get a time–frequency distribution with enhanced energy concentration. Meanwhile, a newly developed technique called NTF, which can preserve more structure information hiding in original two-dimensional matrices compared to the non-negative matrix factorization (NMF), was adopted to extract more informative features from the time–frequency matrices. Five operating states of engine were tested in an experiment for evaluating the proposed feature extraction scheme. Four different types of learning algorithms were employed to conduct the fault classification task. The NMF technique was also used for feature extraction and compared with the NTF approach. The experimental results have demonstrated that the proposed feature extraction scheme can achieve a satisfactory performance when applied to diagnose the engine faults.


Author(s):  
Shangbin Zhang ◽  
Qingbo He ◽  
Haibin Zhang ◽  
Kesai Ouyang ◽  
Fanrang Kong

The extraction of single train signal is necessary in wayside fault diagnosis because the acoustic signal acquired by a microphone is composed of multiple train bearing signals and noises. However, the Doppler distortion in the signal acquired by a microphone effectively hinders the signal separation and fault diagnosis. To address this issue, we propose a novel method based on the generalized S-transform, morphological filtering, and time–frequency amplitude matching-based resampling time series for multiple-Doppler-acoustic-source signal separation and correction. First, the original time–frequency distribution is constructed by applying generalized S-transform to the raw signal acquired by a microphone. Based on a morphological filter, several time–frequency distributions corresponding to different single source Doppler fault signals are extracted from the original time–frequency distribution. Subsequently, the time–frequency distributions are reverted to time signals by inverse generalized S-transform. Then, a resampling time series is built by time–frequency amplitude matching to obtain the correct signals without Doppler distortion. Finally, the bearing fault is diagnosed by the envelope spectrum of the correction signal. The effectiveness of this method is verified by simulated and practical signals.


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