🤖 AI Summary
This work proposes a Causal Graph Spatio-Temporal Autoencoder (CGSTAE) to address the inadequate modeling of dynamic variable relationships and causal structure identification in industrial process monitoring. The method integrates a spatial self-attention mechanism to learn a dynamic correlation graph among process variables and employs a three-step algorithm grounded in the principle of causal invariance to extract a stable causal structure. This causal graph is then incorporated into a graph convolutional LSTM-based spatio-temporal autoencoder to achieve high-fidelity time-series reconstruction. Experimental results on the Tennessee Eastman process benchmark and real-world air separation unit data demonstrate that CGSTAE significantly improves fault detection accuracy, model generalization, and interpretability compared to existing approaches.
📝 Abstract
To improve the reliability and interpretability of industrial process monitoring, this article proposes a causal graph spatial-temporal autoencoder (CGSTAE). The network architecture of CGSTAE combines two components: a correlation graph structure learning module based on spatial self-attention mechanism (SSAM) and a spatial-temporal encoder-decoder module utilizing graph convolutional long short-term memory (GCLSTM). The SSAM learns correlation graphs by capturing dynamic relationships between variables, while a novel three-step causal graph structure learning algorithm is introduced to derive a causal graph from these correlation graphs. The algorithm leverages a reverse perspective of causal invariance principle to uncover the invariant causal graph from varying correlations. The spatial-temporal encoder-decoder, built with GCLSTM units, reconstructs time series process data within a sequence-to-sequence framework. The proposed CGSTAE enables effective process monitoring and fault detection through two statistics in the feature space and residual space. Finally, we validate the effectiveness of CGSTAE in process monitoring through the Tennessee Eastman process (TEP) and a real-world air separation process (ASP).