Bearing fault diagnosis method based on improved EMD decomposition and sensitive characteristic selection

A sensitive feature, fault diagnosis technology, applied in the direction of mechanical bearing testing, mechanical component testing, machine/structural component testing, etc., can solve the problems of key equipment accidents, economic losses and casualties such as rotating machinery

Inactive Publication Date: 2016-11-09
XIAN TECHNOLOGICAL UNIV
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  • Abstract
  • Description
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Problems solved by technology

[0002] As one of the important parts of rotating machinery, rolling bearings are extremely important to ensure the reliable operation of the entire mechanical system. However, due to the errors in the manufacturing process and the influence of the complex and harsh environment when the bearings work, only a small part of the bearings can meet the design requirements. Life, bearing failure will cause serious accidents of key equipment such as rotating machinery, resulting in huge economic losses and casualties. Therefore, monitoring the operating status of bearings and timely fault diagnosis can ensure the normal operation of rotating machinery and avoid accidents. happened

Method used

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  • Bearing fault diagnosis method based on improved EMD decomposition and sensitive characteristic selection
  • Bearing fault diagnosis method based on improved EMD decomposition and sensitive characteristic selection
  • Bearing fault diagnosis method based on improved EMD decomposition and sensitive characteristic selection

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Embodiment 1

[0102] The present invention illustrates improving the decomposition effect of EMD through the following simulation experiments. The mathematical expression of the simulated signal is: x(t)=cos[2π×20t+0.2sin(2π×10t)]+sin(2π×60t), the sampling frequency of the signal is 3600Hz, and the sampling time is 0.8s. The base frequency is 20Hz, the modulated signal with frequency modulation of 10Hz and the sinusoidal signal with frequency of 60Hz are superimposed. Gaussian white noise with a signal-to-noise ratio of 10db is superimposed on the simulated signal, and its time-domain waveform is as follows image 3 as shown, Figure 4 It is the result of its EMD decomposition. It can be seen that the decomposition produces 9 IMF components, of which IMF4 and IMF5 correspond to the 60Hz sinusoidal signal and 20Hz modulation signal in the simulation signal respectively. Due to the interference of noise, these two frequency components are distorted. At the same time, the former The three IM...

Embodiment 2

[0105] (1) Rolling bearing data source

[0106] The experimental data used in the present invention comes from the bearing data center of U.S. Case Western Reserve University. The vibration signal of the bearing is measured by the vibration acceleration sensor installed near the bearing seat of the motor drive end, and the vibration signal is analyzed by a 16-channel data acquisition card. The sampling frequency is 12KHz. A total of 10 states of the bearing are collected. Each state includes 29 samples, and each sample has 4096 data points. The specific data set classification is shown in Table 1 below:

[0107] Table 1 Classification of bearing fault sample data

[0108]

[0109] (2) Bearing vibration signal processing and feature extraction

[0110] The improved EMD decomposition is carried out on the vibration signals of the bearing under 10 states. Firstly, wavelet noise reduction is performed on each sample data in each state. In this example, the db10 wavelet basis ...

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Abstract

The invention discloses a bearing fault diagnosis method based on improved EMD decomposition and sensitive characteristic selection. The method comprises steps of: performing wavelet noise reduction and EMD decomposition on the original vibration signals of a bearing in different fault states to obtain a plurality of IMF components; selecting, by quantitatively computing the correlation of each IMF component and the corresponding original vibration signal, the first h IMF components including the main fault information of the bearing as an object from which fault characteristic information is extracted, and extracting the characteristic parameters from the IMF components to form a original characteristic set; determining the sensitivity factor of each characteristic in the original characteristic set according to a distance evaluation method and constructing a sensitive characteristic set; inputting the sensitive characteristic vector of a training sample in the fault sample of the bearing into a SVM to be trained, optimizing the kernel function parameter g and the penalty factor c of the SVM according to a genetic algorithm, and identifying the fault of a tested sample. The method may reduce the dimensionality of the fault characteristic vector and the computational scale of a classifier, and increasing fault diagnosis accuracy of the antifriction bearing.

Description

technical field [0001] The invention belongs to the technical field of bearing fault diagnosis, and in particular relates to a bearing fault diagnosis method based on improved EMD decomposition and sensitive feature selection. Background technique [0002] As one of the important parts of rotating machinery, rolling bearings are extremely important to ensure the reliable operation of the entire mechanical system. However, due to the errors in the manufacturing process and the influence of the complex and harsh environment when the bearings work, only a small part of the bearings can meet the design requirements. Life, bearing failure will cause serious accidents of key equipment such as rotating machinery, resulting in huge economic losses and casualties. Therefore, monitoring the operating status of bearings and timely fault diagnosis can ensure the normal operation of rotating machinery and avoid accidents. happened. [0003] Because bearings often work in complex, harsh,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01M13/04
CPCG01M13/045
Inventor 丁锋栗祥瞿金秀程文冬韩兴本
Owner XIAN TECHNOLOGICAL UNIV
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