EAAI Journal 2026 Journal Article
An interpretable Transformer–LSTM denoising autoencoder for semi-supervised fault diagnosis in chemical processes
- Lijie Guo
- Jiaqi Shi
- Jianxin Kang
- Ao Li
To tackle key challenges in chemical process fault diagnosis, such as limited labeled data, complex feature extraction, and low interpretability, we propose an interpretable Transformer and Long Short-Term Memory (LSTM) denoising autoencoder (TrLAe) model for semi-supervised fault diagnosis. The encoder combines Transformer and dual-branch LSTMs to capture both global multivariate dependencies and local temporal dynamics, enabling complementary feature fusion. The decoder reconstructs high-dimensional latent features through a series of Transformer–LSTM modules. By leveraging the autoencoder's reconstruction learning, the model effectively uses abundant unlabeled data to learn latent feature distributions in an unsupervised manner, producing robust representations even with limited labeled samples. A denoising mechanism is employed to enhance generalization, and spatiotemporal attention is incorporated to improve interpretability and identify fault-related variables. To support engineering decision-making, these identified fault-related variables are then mapped to the deviation–cause–consequence framework in hazard and operability (HAZOP) analysis, creating a knowledge-driven, interpretable approach to fault propagation. Experiments on the Tennessee Eastman process show that the TrLAe model achieves high diagnostic accuracy and strong generalization, highlighting its potential to enhance the reliability and safety of modern chemical processes.