EAAI Journal 2025 Journal Article
Unsupervised fault diagnosis method for rolling bearings based on federated universal domain adaptation
- Shouqiang Kang
- Yulin Sun
- Xinrui Li
- Yujing Wang
- Qingyan Wang
- Xintao Liang
To address the issues of low diagnostic model accuracy caused by non-sharing of rolling bearing private data, distribution differences, and label space discrepancies across multiple clients, as well as the challenges that certain clients face in obtaining labeled data, an unsupervised fault diagnosis method is proposed for rolling bearings based on federated universal domain adaptation (FUDA). First, privacy protection during the transmission process in federated learning is ensured by implementing random mapping at local clients. Second, the central server employs the proposed mixed radial basis kernel-maximum mean discrepancy (MR-MMD) method to further mitigate distributional disparities between the feature spaces of source and target clients. This achieves unsupervised features alignment between these features. Third, margin vectors are introduced to tackle label space disparities between source and target clients, enabling effective separation of unknown class samples in the dataset of the target client. Finally, a dynamic weighted loss fusion strategy is designed to adaptively optimize the weight ratios of different losses. This enhancement facilitates the learning efficiency of the model. Experimental validation on two datasets demonstrates that the proposed approach can achieve average accuracies of 95. 6 % and 87. 7 % for the respective datasets. Compared with other methods, it represents improvements of 6. 5 % and 8. 1 %, while training time is reduced by at least 27 %. These results validate the effectiveness of the proposed method.