Review Article

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

Table 3

Application of DBN and DBM in condition monitoring of motors.

YearInput data and featuresDL modelApplicationRemarks

2016Vibration + hybrid featuresDBM [75]Rolling bearing fault classificationAmong three features, hybrid features allowed the model to perform much better than other models
Multisensor vibration + time domain featuresDBN [76]Bearing fault classificationMultivibrations fusion technique with DBN outperformed the model with single sensor
Vibration + time domain featuresDBN [77]Bearing degradation states classificationWeibull distribution dealt with fluctuations in statistical features, which in turn enhanced the ability to classify the bearing degradation states

2017Vibration + FFTDBN [21]Induction motor fault classificationThe developed automatic fault classifier effectively detected faults of motors in manufacturing

2018Raw vibrationDBM [78]Rolling bearing fault classificationBinary units of DBM were replaced with Gaussian units so that DBM can process real-value data. Results confirmed the usefulness of the method

2019Acoustic emission signalsDBN + PCA + ls-SVM [79]Rolling bearing fault classificationCombination of DBM and PCA enabled for learning better features, which in turn increased the accuracy of the model
Vibration + VMD + HTVHDBN [80]Rolling bearing fault classificationEmployed VMD and HT for better feature extraction. The results of proposed method confirmed great advantages in classification accuracy

2020Raw vibration + sliding window + coarse-grained methodMSDBN [81]Various mechanical fault classificationMultiscale feature extractor enabled for learning better features, which in turn increased the accuracy of the method than standard DBN
Vibration + wavelet package decomposition (WPD)DBN + D-S theory + GA + PSO [82]Bearing fault and severity level classificationGA-PSO algorithm improved learning capability and computation efficiency of the DBM classifier. In addition, the D-S theory-based vibration data fusion increased the accuracy of the model