PeriodicMFD: A Periodic-Based Framework for Multisource Fault Diagnosis

Cross-speed bearing fault diagnosis based on multiple source domains and their data enables high-performance condition monitoring for variable-speed equipment, such as engines and turbines. Current multisource methods typically employ a fixed-length sampling strategy to construct samples and then align the distributions of these samples from different domains. However, these methods neglect the inherent periodic characteristics of bearing data, resulting in incomplete or redundant periodic features in the samples. To address this challenge, we propose a periodic-based framework, PeriodicMFD, for multisource cross-speed fault diagnosis, which ensures complete periodic information. Our PeriodicMFD framework begins with a periodic sampling strategy designed to construct periodic samples that effectively capture periodic features while maintaining their periodic integrity. Nevertheless, periodic samples from different domains exhibit inconsistencies at both the sample and domain levels. To reconcile these inconsistencies, we introduce sample-level matching to address inconsistencies in feature dimensions and fault patterns among samples from various domains. Additionally, we propose domain-level alignment to handle inconsistencies in space and distribution across different domains. Extensive experiments across three datasets highlight the effectiveness of the PeriodicMFD framework, with a stable average accuracy of 99.55%.