Digital twin-enhanced domain generalization for diagnosing few-shot faults in face gears
摘要
As core transmission components in high-end intelligent manufacturing systems, face gears pose challenges in fault diagnosis, such as weak feature discriminability, few-shot fault samples, and cross-domain generalization failure under various working conditions. To address these issues, a digital twin-enhanced domain generalization (DTEDG) framework is proposed for diagnosing few-shot faults in face gears. Analytical dynamics and finite element analysis are combined to construct a digital twin model, enabling the acquisition of virtual vibration measurements under different conditions. With latent features extracted from both virtual and real vibration data, a mutual information alignment is proposed to fuse digital twins for feature enhancement. A one-dimensional U-net diffusion model is then employed to augment those few-shot real vibration features. On this basis, a multiscale information unification strategy is put forward to improve the cross-domain diagnosis capability under different working conditions. The proposed DTEDG was evaluated on a face gear experimental setup, achieving an average accuracy of 92.95% and an F1-score of 92.30% for the few-shot fault diagnosis under multiple working conditions. Digital twin construction fidelity was quantified by the meshing frequency deviation between simulated and measured signals, yielding a mean absolute percentage deviation of 2.63%. The results demonstrate that the proposed method exhibits superior generalization ability and diagnostic performance for face gears in intelligent manufacturing systems compared with existing methods.