Model-based diagnosis of dynamic processes: A mixed qualitative/quantitative approach † †This work has taken place at the C.N.R.S. U.R.A 817 'Heudiasyc', Université de Technologie de Compiègne. It was supported in part by a grant from Atochem. We would especially like to thank Pierre Fouché for many hours of help in clarifying the ideas presented in this paper

One main problem in dynamic system monitoring is to know over time in which physical situation the system is operating, in order to early anticipate possible failures. This paper addresses the problem of tracking a physical system and presents a model-based diagnostic system architecture, QDIAG, whose goal is to help operators early detect anomalies in dynamic systems in operation. QDIAG integrates both quantitative and qualitative techniques, using QSIM, Kuipers' qualitative simulation algorithm.