Effectively representing relationships among process variables is essential for industrial process fault diagnosis. Although graph-based methods have been introduced to address the limited ability of conventional deep learning approaches to explicitly...
Effectively representing relationships among process variables is essential for industrial process fault diagnosis. Although graph-based methods have been introduced to address the limited ability of conventional deep learning approaches to explicitly model such relationships, existing studies remain limited in their integrated use of data-driven and process-knowledge-based relations. Moreover, even when multiple relations are considered, interaction-based fusion that accounts for their redundancy and complementarity has not been sufficiently investigated. Most existing methods also focus on fusing all constructed relations, with limited attention to selecting and interpreting relation combinations that are effective for fault diagnosis.
To address these limitations, this study proposes a multi-relational graph-based fault diagnosis model that integrates data-driven and process-knowledge-based relations while explicitly considering interactions among them. Process variables are represented as nodes, and each type of relation is constructed as an individual adjacency matrix. A relation interaction map is then generated by measuring the structural similarity between the adjacency matrices and is used to select effective relation combinations. The selected relations are transformed into a unified process representation through a hierarchical multirelational embedding module. Specifically, relation-specific graph-level embeddings are first extracted, after which message passing is performed among the relation embeddings according to the relation interaction map. This enables the model to jointly capture information from individual relation graphs and structural interactions among different relations.
Experiments on the Tennessee Eastman Process dataset showed that the proposed model achieved performance comparable to or better than that of baseline models for most fault classes. Ablation studies further demonstrated the contributions of multirelational representation, the integration of data-driven and process-knowledge-based relations, relation interaction-based fusion, and effective relation selection. Analysis of the selected relation combinations also indicated that data-driven and process-knowledgebased relations were jointly selected and used in a complementary manner. These results demonstrate that the proposed method can identify effective relation combinations and learn process representations that incorporate interactions among multiple relations for industrial process fault diagnosis.