A new modeling formalism and automata model generator for a class of discrete event systems

Abstract

The control of discrete event systems (DES) requires a correct model of the system and of its control specifications. In this paper we present a new modeling formalism for generating valid models of complex systems. The class of systems this applies to, is one which consists of signals that take binary values. The technique presented here makes task of modeling considerably less cumbersome, less error prone, and is user-friendly. Another advantage of using this modeling formalism is that the size of the system model is polynomial in the number of signals; whereas the number of states in the automata models is exponential in the number of signals. We present automated techniques for deriving a state machine based model from the model in the proposed formalism. Such a state machine model can then be used for the purpose of automated supervisor synthesis for which a vast body of tools already exists, based upon the Ramadge & Wonham (1987) supervisory control theory (SCT). We illustrate the modeling formalism using examples drawn from manufacturing systems and process control.