The notion of the state in systems theory and artificial intelligence

This paper discusses the methodological analogies and differences of the systems theoretic and the knowledge-based approaches to modelling and simulation of dynamical systems. This comparison is based on the notion of the dynamical system as defined in systems theory, in particular on the concept of state. Two examples show that these notions are relevant for quantitative models as used in systems theory and for qualitative models that are given in the knowledge base of a rule-based system. Moreover, a formalisation of rule-based systems within the concept of dynamical systems is given. It shows that the main motivation for using the knowledge-based approach in control engineering is given by the lack of online information about the state of the physical system