Diagnosis model for dynamical systems Part 2. Continuous system

While most existing systems requiring diagnosis are dynamical, most models proposed for diagnosis are static. Consequently, a mathematical model of differential equations is used for a model-based diagnosis of dynamical systems. Although this model-based diagnosis has been well studied, it is not used much in practice owing to the computational difficulty and the difficulty of obtaining the mathematical model. We propose a diagnosis model for continuous dynamical systems. The model can be expressed by a signed directed-graph, which has been studied extensively in qualitative matrix theory. We interpret these qualitative results in terms of the diagnosis model, and also present new results for the model. The dynamic aspects of the qualitative stabilities of the model are mainly discussed. The distinguishability of the sign pattern is also studied with a new concept of invariant fault pattern defined in the model. Strategies for monitoring as well as for the diagnosis of the dynamical systems are derived by these qualitative results.