Multisource domain factorization network for cross-domain fault diagnosis of rotating machinery: An unsupervised multisource domain adaptation method

Abstract Unsupervised domain adaptation (DA) provides a promising approach for tackling fault diagnosis tasks of target datasets without labeled data and has been actively studied in recent years. Most of them focus only on single-source DA, compared to multisource DA (MDA), which has remarkable advantages in generalized knowledge learning and generalization performance. Nevertheless, there are very few fault diagnosis studies based on MDA, and it remains challenging to reduce multiple domain shifts to improve diagnostic performance and mitigate negative transfer during learning. To this end, a novel unsupervised MDA-based transfer learning approach called multisource domain factorization network (MDFN) is proposed in this paper, where the generalized diagnosis knowledge is learned from multiple sources and then used for diagnosing the target task. The highlights of MDFN are that the shared-space component analysis and transferability-based entropy penalty strategy are employed to significantly mitigate negative transfer from the two levels of feature representation and instance transferability and effectively learn shared feature representation. Therefore, the MDFN can extract shared features that combine domain-invariance and discriminability, thereby performing better. The results of two experimental cases on six datasets, including cross-operating-condition and cross-component diagnosis tasks, validate the effectiveness and superiority of the proposed method.