EAAI Journal 2026 Journal Article
A fine-grained information fusion and inference method for out-of-distribution detection in fault diagnosis
- Guoliang Wu
- Xinde Li
- Fir Dunkin
- Chuanfei Hu
- Heqing Li
- Zhentong Zhang
- Kaixuan Wu
- Erfeng Liu
While intelligent fault diagnosis has achieved remarkable success on known faults, its reliance on in-distribution (ID) assumptions often leads to overconfident misclassification of out-of-distribution (OOD) samples. Existing OOD detection methods typically exploit only single-granularity class information and thus fail to capture fine-grained subclass distinctions, limiting detection accuracy. To address this limitation, we propose FIFI (Fine-grained Information Fusion and Inference), which integrates fine-grained subclass evidence to improve the separability between ID and OOD samples. FIFI consists of three phases: (1) Bayesian Gaussian Mixture Model (BGMM)-based adaptive subclass modeling, (2) fuzzy fusion from subclass- to class-level memberships, and (3) membership aggregation for ID membership score estimation in OOD detection. Experiments show that FIFI consistently outperforms strong baselines in terms of FPR95, demonstrating a practical and reliable solution for fault diagnosis under complex industrial conditions.