Shigeyuki Tateno

FAULT DIAGNOSIS OF THE CHEMICAL PROCESS UTILIZING SIGNED DIRECTED GRAPH; Improvement and Evaluation of the Diagnosis Accuracy

Abstract The fault diagnosis algorithm using a signed directed graph as a model of the system is useful to real-time diagnosis of failures that occur in processes. The accuracy of the algorithm has been improved so much that it can select the candidates that are the most likely to be the real cause of failure, utilizing the concept of amplifying branch. The accuracy of the improved algorithm has been examined by its application to data obtained in the experiments of fault diagnosis in tank-pipeline systems, and estimated by the size of the greatest set of candidates.

Optimal Allocation of Sensors for Fault Diagnosis System Using the Signed Directed Graph

Abstract An allocation of sensors in a chemical plant is usually decided for the purpose of not fault diagnosis but process control, production control and so on. This is one reason for poor accuracy of fault diagnosis. This paper discusses the problem to search the optimal allocation of sensors with the constraint of the required specification (especially, diagnostic accuracy) for a fault diagnosis system using a signed directed graph. An algorithm to solve the problem is successfully applied to a mini-plant to demonstrate its usefulness.