Research on an aeroengine bearing fault diagnosis method based on WMSST-CNN-BKA-LSSVM

Abstract To effectively extract the fault feature from small sample datasets and improve the accuracy of the model, an aeroengine bearing fault diagnosis method is proposed in this research based on wavelet multi-synchrosqueezed transform-convolutional neural network-black-winged kite algorithm-least squares support vector machine (WMSST-CNN-BKA-LSSVM). WMSST was used to perform modal decomposition on the collected fault data to obtain the time-frequency images. The time-frequency images were input into CNN for fault data feature extraction. The results of the CNN fully connected layer were used as input to the LSSVM, and the BKA was used to optimize the key parameters of the LSSVM to classify aeroengine bearing faults. The method was verified by aeroengine bearing test data from the Harbin Institute of Technology. The research showed that the accuracy is 99.86% when the faulty test samples are 70%, and the accuracy is 93.90% when the faulty samples are 30%. The accuracy showed the applicability of this method in small sample fault diagnosis. By comparing the method with a one-dimensional convolutional neural network (1D-CNN) and the convolutional neural network - long short-term memory (CNN-LSTM), it is found that the accuracy has been dramatically improved.