Diagnoser with Hybrid Structure for Fault Diagnosis of a Class of Hybrid Dynamic Systems

• Main Authors: H. Louajri, M. Sayed-Mouchaweh, C. Labarre
• Format: Article
• Language: English
• Published: AIDIC Servizi S.r.l. 2013-07-01
• Series: Chemical Engineering Transactions
• Online Access: https://www.cetjournal.it/index.php/cet/article/view/6222

In this paper, we propose a new model-based approach for the fault diagnosis of hybrid dynamic systems (HDS), in particular discretely controlled continuous system (DCCS). The goal is to construct a diagnosis module (called diagnoser) able to diagnose parametric and discrete faults. Parametric faults are characterized by abnormal changes in some system parameters whereas discrete faults are attributed to undesired changes in the system configuration. This approach is based on a diagnoser with hybrid structure composed of three parts: discrete diagnoser, continuous diagnoser and coordinator. The discrete diagnoser is modelled as a discrete time hybrid automata model. It is used to detect and to isolate the discrete faults. The continuous diagnoser is based on a set of residuals comparing the measured and estimated values of each continuous variable in order to diagnose the parametric faults. The coordinator combines the discrete and continuous decisions of the two diagnoser sin order to diagnose faults requiring the interaction between both diagnosers.