State Observation and Diagnosis of Discrete-Event SystemsDescribed by Stochastic Automata

The problems ofstate observation and diagnosis are solved for discrete–event systems, which are described by stochastic automata. As many systems are not observable in the sense that it is possible to reconstruct the state unambiguously, the observation problem is set up as the problem of determining the smallest possible set of states that are compatible with the measured input and output sequences. The diagnostic problem is shown to be, in principle, an observation problem. Conditions for the observability and diagnosability of stochastic automata are presented. The results are illustrated by examples.