Digital twin driven group fault diagnosis method for faults with similar symptoms

The electro-hydraulic composite control system is widely used in industrial equipment. It has the advantages of fast response speed and high load level. Sudden faults would lead to shutdown of the production. These would cause production losses, even the safety accidents. Fault diagnosis can obtain the states of equipment faults, promptly alert when faults occur, reduce accidents, and minimize production losses. Due to the large number of components and few sensors in the electro-hydraulic composite system, the faults of many components often exhibit the same characteristics. This increases the difficulty of troubleshooting. To identify faults that require similar features, a digital twin-driven group fault diagnosis method is proposed for faults with similar symptoms. A functional fault grouping strategy was introduced for grouping faults for diagnosis. A fault diagnosis model was established for inferring faulty components during the diagnosis and re diagnosis process. A digital twin model was established to simulate diagnostic results and verify their correctness. The proposed method is evaluated through application to an electro-hydraulic system. The results indicate that the grouping diagnosis strategy improves diagnostic accuracy by approximately 3%–5%.