Separability Index-Based Feature Selection and a Two-Tier Classifier for Improving Diagnostic Performance in Bearings
Faults in bearings have traditionally been diagnosed by identifying the characteristic defect frequencies in the envelope power spectrum (EPS). Although EPS-based methods are effective for constant operating conditions, it makes difficult to detect a fault when the machine operates at variable shaft speeds. To address this issue, we propose a method that performs as follows: (a) a feature extraction technique is used to extract as many information as possible from different sub-bands using a non-stationary signal analysis method (e.g., discrete wavelet pack transform (DWPT)), (b) a novel feature selection method is then applied to select the most informative features from the extracted high-dimensional feature pool, and (c) the selected features are further fed to a two tiers classifiers to identify the condition of a bearing. This two tiers classifier includes the combination of support vector machine groups in the first tier and the combination multilayer perceptron in the second tier. The proposed method is tested for a bearing fault diagnosis application using acoustic emission (AE) signal under various conditions.
KeywordsBearing fault diagnosis Support vector machine Multilayer perceptron Feature selection
This work was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (Nos. 20162220100050, 20161120100350, 20172510102130). It was also funded in part by The Leading Human Resource Training Program of Regional Neo industry through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and future Planning (NRF-2016H1D5A1910564), and in part by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2016R1D1A3B03931927).
The authors declare that there is no conflict of interest regarding the publication of this manuscript.
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