Unsupervised Cross-Domain Fault Diagnosis Using Feature Representation Alignment Networks for Rotating Machinery

In this article, the problem of the cross-domain fault diagnosis of rotating machinery is considered. In a practical setting of this approach, the operating platform of the machine may have a different setup and conditions compared to the experimental platform that is used to collect the training data. This can lead to significant data variations, specifically domain shifts. Conventional data-driven approaches are known to adapt poorly to these domain shifts, resulting in a significant drop in the diagnosis accuracy when the pretrained model is applied in the actual operating situation. In this article, an unsupervised domain adaptation approach is developed to mitigate the domain shifts between the data gathered from the experimental platform (the source domain) and the operating platform (the target domain) by aligning the features extracted from the two data domains. The mutual information between the target feature space and the entire feature space is maximized to improve the knowledge transferability of the labeled data in the source domain. Furthermore, the feature-level discrepancy between the two domains is minimized to further improve diagnosis accuracy. The experiments using public datasets and real-world adaptation scenarios demonstrate the feasibility and the superior performance of the proposed method.