Fig. 1 ( a ) Three-layer wavelet packet decomposition process and ( b ) examples of subband sequences More about this image found in ( a ) Three-layer wavelet packet decomposition process and ( b ) examples o...

Fig. 2 Overall flowchart of time-domain feature extraction based on FGAE More about this image found in Overall flowchart of time-domain feature extraction based on FGAE

Fig. 3 ( a ) FGAE refactoring effect demonstration, ( b ) AE reconstruction effect demonstration, and ( c ) extract fault feature results and compare More about this image found in ( a ) FGAE refactoring effect demonstration, ( b ) AE reconstruction effect...

Fig. 4 Euclidean distance, correlation coefficient, and cosine similarity obtained feature results More about this image found in Euclidean distance, correlation coefficient, and cosine similarity obtained...

Fig. 5 Frequency domain feature extraction flowchart based on wavelet packet energy spectrum More about this image found in Frequency domain feature extraction flowchart based on wavelet packet energ...

Fig. 6 The frequency domain features proposed in this article, spectral entropy and spectral flatness proposed characterization results More about this image found in The frequency domain features proposed in this article, spectral entropy an...

Fig. 7 Flowchart of fault diagnosis More about this image found in Flowchart of fault diagnosis

Fig. 8 Original data curve More about this image found in Original data curve

Fig. 9 Reconstructed voltage curves using different wavelet functions for a three-level wavelet packet decomposition: ( a ) original data, ( b ) Symlets, ( c ) Biorthogonal, ( d ) Haar, ( e ) Daubechies, and ( f ) Meyer More about this image found in Reconstructed voltage curves using different wavelet functions for a three-...

Fig. 10 Reconstructed voltage curves using wavelet packet decomposition at different levels: ( a ) 2-level decomposition, ( b ) 3-level decomposition, and ( c ) 4-level decomposition More about this image found in Reconstructed voltage curves using wavelet packet decomposition at differen...

Fig. 11 ( a ) Feature maps obtained for signals processed without noise reduction, ( b ) feature extraction results in time domain, ( c ) feature extraction results in frequency domain, and ( d ) isolated forest outlier detection results More about this image found in ( a ) Feature maps obtained for signals processed without noise reduction, ...

Fig. 12 Fault diagnosis results for ( a ) LOF, ( b ) DBSCAN, and ( c ) isolated forest More about this image found in Fault diagnosis results for ( a ) LOF, ( b ) DBSCAN, and ( c ) isolated for...

Fig. 13 Vehicle 2 raw data More about this image found in Vehicle 2 raw data

Fig. 14 ( a ) Vehicle 2 time-domain fault feature extraction results, ( b ) fault feature extraction results in frequency domain, and ( c ) outlier detection results More about this image found in ( a ) Vehicle 2 time-domain fault feature extraction results, ( b ) fault f...

Fig. 15 Detection results of unidimensional outliers in time domain and frequency domain for two vehicles: ( a ) time-domain characteristics of vehicle 1, ( b ) vehicle 1 frequency domain characteristics, ( c ) time-domain characteristics of vehicle 2, and ( d ) vehicle 2 frequency domain characte... More about this image found in Detection results of unidimensional outliers in time domain and frequency d...

Fig. 1 XRD patterns of SDC, PNO, and SDC–PNO composites at different sintering temperatures More about this image found in XRD patterns of SDC, PNO, and SDC–PNO composites at different sintering tem...