An adversarial transfer learning method based on domain distribution prediction for aero-engine fault diagnosis

The utilization of transfer learning enables effective realization of the transferability of aero-engine fault diagnosis models across disparate states. However, the gradual degradation of engine performance and the complex and variable flight states lead to continuous changes in data distribution. The common transfer learning methods employ discrete divisions of data domain distributions, which are insufficient to cope with the continuous changes of the domain. To accomplish transfer learning towards a continuous and multi-dimensional target domain, we propose a continuous domain distribution adversarial network (CDDAN) based on deep domain adversarial network. The method defines the number of effective cycles directly associated with engine degradation as a continuous domain index. When the domain index is extended to multiple dimensions, a hybrid gaussian model is introduced to represent distribution prediction within multi-dimensional continuous domains. Subsequently, we validate the feasibility and superiority of our method using datasets generated based on twin-spool turbofan engines. In comparison to other transfer learning methods, the proposed method achieves superior effect in continuous domain adaptation. The experimental results demonstrate that this method exhibits adaptability to failures in the diagnosis method caused by performance degradation and changes in flight state of the aero engine, while remaining independent of target domain data annotation. This advantage becomes particularly apparent in scenarios with limited target domain data and multi-state fault diagnosis.