Knowledge-based Coordination of Qualitative Online Diagnostic Tests

Abstract It is shown, how active diagnostic tests and their coordination can be integrated within an existing prototype of a knowledge-based extension of a process management system. A generic coordination unit loads the specific tests from a library. Once loaded, a test activates, adapts, interprets the data and unloads itself. The structure of all the tests is the same, while the tests can be quantitative or qualitative. On the example of blocked dampers in a heating and ventilating plant, three qualitative diagnostic tests are described in order to illustrate how qualitative knowledge can be used to detect and diagnose faults. The explicit representation of the assumptions and constraints upon which a test is based, allows to make tests during special operation phases that seldom appear, but that are very instructive.