An Imbalanced Fault Diagnosis Method Based on TFFO and CNN for Rotating Machinery

Deep learning-based fault diagnosis usually requires a rich supply of data, but fault samples are scarce in practice, posing a considerable challenge for existing diagnosis approaches to achieve highly accurate fault detection in real applications. This paper proposes an imbalanced fault diagnosis o...

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Main Authors: Long Zhang, Yangyuan Liu, Jianmin Zhou, Muxu Luo, Shengxin Pu, Xiaotong Yang
Format: Article
Language:English
Published: MDPI AG 2022-11-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/22/22/8749
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author Long Zhang
Yangyuan Liu
Jianmin Zhou
Muxu Luo
Shengxin Pu
Xiaotong Yang
author_facet Long Zhang
Yangyuan Liu
Jianmin Zhou
Muxu Luo
Shengxin Pu
Xiaotong Yang
author_sort Long Zhang
collection DOAJ
description Deep learning-based fault diagnosis usually requires a rich supply of data, but fault samples are scarce in practice, posing a considerable challenge for existing diagnosis approaches to achieve highly accurate fault detection in real applications. This paper proposes an imbalanced fault diagnosis of rotatory machinery that combines time-frequency feature oversampling (TFFO) with a convolutional neural network (CNN). First, the sliding segmentation sampling method is employed to primarily increase the number of fault samples in the form of one-dimensional signals. Immediately after, the signals are converted into two-dimensional time-frequency feature maps by continuous wavelet transform (CWT). Subsequently, the minority samples are expanded again using the synthetic minority oversampling technique (SMOTE) to realize TFFO. After such two-fold data expansion, a balanced data set is obtained and imported to an improved 2dCNN based on the LeNet-5 to implement fault diagnosis. In order to verify the proposed method, two experiments involving single and compound faults are conducted on locomotive wheel-set bearings and a gearbox, resulting in several datasets with different imbalanced degrees and various signal-to-noise ratios. The results demonstrate the advantages of the proposed method in terms of classification accuracy and stability as well as noise robustness in imbalanced fault diagnosis, and the fault classification accuracy is over 97%.
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spelling doaj.art-bf80468aaa444075a08b5bd17ad657bf2023-11-24T09:55:16ZengMDPI AGSensors1424-82202022-11-012222874910.3390/s22228749An Imbalanced Fault Diagnosis Method Based on TFFO and CNN for Rotating MachineryLong Zhang0Yangyuan Liu1Jianmin Zhou2Muxu Luo3Shengxin Pu4Xiaotong Yang5School of Mechatronics & Vehicle Engineering, East China Jiaotong University, Nanchang 330013, ChinaSchool of Mechatronics & Vehicle Engineering, East China Jiaotong University, Nanchang 330013, ChinaSchool of Mechatronics & Vehicle Engineering, East China Jiaotong University, Nanchang 330013, ChinaSchool of Mechatronics & Vehicle Engineering, East China Jiaotong University, Nanchang 330013, ChinaSchool of Mechatronics & Vehicle Engineering, East China Jiaotong University, Nanchang 330013, ChinaSchool of Mechatronics & Vehicle Engineering, East China Jiaotong University, Nanchang 330013, ChinaDeep learning-based fault diagnosis usually requires a rich supply of data, but fault samples are scarce in practice, posing a considerable challenge for existing diagnosis approaches to achieve highly accurate fault detection in real applications. This paper proposes an imbalanced fault diagnosis of rotatory machinery that combines time-frequency feature oversampling (TFFO) with a convolutional neural network (CNN). First, the sliding segmentation sampling method is employed to primarily increase the number of fault samples in the form of one-dimensional signals. Immediately after, the signals are converted into two-dimensional time-frequency feature maps by continuous wavelet transform (CWT). Subsequently, the minority samples are expanded again using the synthetic minority oversampling technique (SMOTE) to realize TFFO. After such two-fold data expansion, a balanced data set is obtained and imported to an improved 2dCNN based on the LeNet-5 to implement fault diagnosis. In order to verify the proposed method, two experiments involving single and compound faults are conducted on locomotive wheel-set bearings and a gearbox, resulting in several datasets with different imbalanced degrees and various signal-to-noise ratios. The results demonstrate the advantages of the proposed method in terms of classification accuracy and stability as well as noise robustness in imbalanced fault diagnosis, and the fault classification accuracy is over 97%.https://www.mdpi.com/1424-8220/22/22/8749imbalanced datadata expansioncontinuous wavelet transformsynthetic minority oversampling techniqueconvolution neural network
spellingShingle Long Zhang
Yangyuan Liu
Jianmin Zhou
Muxu Luo
Shengxin Pu
Xiaotong Yang
An Imbalanced Fault Diagnosis Method Based on TFFO and CNN for Rotating Machinery
Sensors
imbalanced data
data expansion
continuous wavelet transform
synthetic minority oversampling technique
convolution neural network
title An Imbalanced Fault Diagnosis Method Based on TFFO and CNN for Rotating Machinery
title_full An Imbalanced Fault Diagnosis Method Based on TFFO and CNN for Rotating Machinery
title_fullStr An Imbalanced Fault Diagnosis Method Based on TFFO and CNN for Rotating Machinery
title_full_unstemmed An Imbalanced Fault Diagnosis Method Based on TFFO and CNN for Rotating Machinery
title_short An Imbalanced Fault Diagnosis Method Based on TFFO and CNN for Rotating Machinery
title_sort imbalanced fault diagnosis method based on tffo and cnn for rotating machinery
topic imbalanced data
data expansion
continuous wavelet transform
synthetic minority oversampling technique
convolution neural network
url https://www.mdpi.com/1424-8220/22/22/8749
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