Review Article

The Importance of Feature Processing in Deep-Learning-Based Condition Monitoring of Motors

Table 4

Application of CNN in condition monitoring of motors.

YearInput data and featuresDL modelApplicationRemarks

2016Raw vibrationCNN + DFT [84]Motor fault classificationOwing to the automatic feature extraction, the method produced promising results compared to classical feature engineering methods
Raw vibrationDTS-CNN [85]Motor fault classificationDislocation layer yielded better performance than standard CNN owing to rich feature extraction
Raw current1D-CNN [86]Bearing fault classificationThe simple architecture of the model allowed real-time detection of the faults
Raw vibrationADCNN [87]Bearing fault classification and their severity level classificationAdaptive architecture of the CNN allowed to learn rich features from the data, which in turn increased its performance

2017Vibration + WPIMultiscale deep CNN [88]Spindle bearing fault classificationNovel feature learning techniques with multiscale deep CNN allowed the model to outperform other traditional models through learning local and global features simultaneously
Raw vibration data from two sensorsIDSCNN [89]Bearing fault classificationImproved data fusion technique produced better classification results by addressing the problems in the conventional feature extraction techniques

2018Raw vibrationTICCN [90]Bearing fault classificationDropout layers with the wide and small convolutional layers supressed the noise of data. Meanwhile, ensemble model allowed to attain high classification accuracy
Raw vibrationCNN [91]Motor health indicationThe method was able to overcome outlier regions and effectively learned features from the data
Raw vibrationDNCCN [92]Bearing fault classificationThe model produced effective classification results by overcoming data imbalance problem

2019Raw vibrationVI-CNN [93]Rolling bearing fault classification2D vibration image allowed the method to effectively classify the faults without any feature learning and denoising technique
Raw vibrationST-CNN [94]Bearing fault classificationThe method produced higher performance than existing methods owing to automatic feature extraction by S-layer
Vibration + STFTICN [95]Bearing fault classificationInception block resulted in better generalization than CNN
Raw current signaturesCNN + IF [96]Bearing fault classificationPromising results were obtained owing to information fusion

2020Raw vibration + WPTCNN [97]Rolling bearing fault classificationClassification performance improved owing to the gray-scale vibration images
Vibration + STFTCNN + SELU function [98]Rolling bearing fault classificationThe method effectively classified the fault owing to the 2D-images of the data and regularization
Raw current signaturesCNN [99]Stator winding fault detectionThe method can effectively detect stator winding faults from raw current data without any preprocessing