Bearing fault diagnosis in modern industrial applications frequently encounters severe challenges due to data privacy fragmentation, domain shifts induced by varying working conditions, and the insufficiency of single-sensor information. To address these critical bottlenecks, this paper proposes a multi-modal domain generalization federated learning framework. Specifically, a dual-branch 1D-CNN feature extraction network is constructed to independently process horizontal and vertical vibration signals, which are then integrated using multi-scale convolutional blocks and a Squeeze-and-Excitation (SE) channel attention mechanism for robust feature fusion. Furthermore, to mitigate the client drift issue caused by non-IID data distributions across different rotational speeds and loads, a FedProx-based federated optimization strategy with a dynamic proximal term regularization is implemented. Extensive experiments conducted on the XJTU-SY bearing dataset demonstrate that the proposed framework achieves an overall classification accuracy of 67.20% and an F1-score of 67.32% under strict differential privacy constraints (DP-SGD noise multiplier = 0.05). Compared with the baseline federated model, the optimized version provides a significant performance gain of +12.37% in diagnostic accuracy. The proposed approach successfully strikes an optimal balance between data privacy protection and cross-condition domain generalization, offering a reliable paradigm for distributed industrial intelligent maintenance.
Research Article
Open Access