Vol.9, No 1, 2010 pp. 79 - 86
UDC
621.642.3 519.87 53.088.7
FAULT DETECTION IN A THREE-TANK SYSTEM BASED ON SEQUENTIAL HYPOTHESIS TESTING
Aleksandra Marjanović, Željko Đurović, Branko Kovačević
Department of Signals and systems, Faculty of Electrical Engineering, University of Belgrade, Bul. Kralja Aleksandra 73, 11000 Belgrade, Serbia
E-mail: amarjanovic@etf.rs
Abstract.
The task of fault detection implies discovering and locating the failure in the system. This type of autonomous fault diagnostics reduces further damage and also saves time and cost in repairing the system. This paper presents an online way of retrieving a leak in a Three-tank system. The method being used is the Wald’s sequential hypothesis testing. This is a model based technique that includes residual generation and evaluation. Some conventional fault detection methods have problems with the number of “false alarm“ decisions, which is reduced using the proposed technique.
Key Words:
fault detection and isolation, sequential hypothesis testing, residual, model-based method, three-tank system.
PRIMENA SEKVENCIJALNOG TESTIRANJA HIPOTEZA ZA DETEKCIJU OTKAZA U SISTEMU SA TRI REZERVOARA
Rad predstavlja metodu za detekciju i lokalizaciju otkaza u sistemu sa tri rezervoara, korišćenjem Wald-ovog sekvencijalnog testa koji se primenjuje na sekvencu reziduala dobijenu na osnovu modela. Primenjeni metod minimizira srednji broj potrebnih odbiraka do donošenja odluke, a na osnovu zahtevanih verovatnoća greške. Snimljene su zavisnosti broja potrebnih odbiraka i dobijene verovatnoće greške od zahtevanih verovatnoća greški i ovi su rezultati uporedjeni sa teorijskim.
Ključne reči:
detekcija i izolacija greške, sekvencijalno testiranje hipoteza, residual, metode na bazi modela, sistem sa tri rezervoara
