Embedded supervisory control of discrete-event systems

In this paper we propose to implement supervisory control by extending the plant Finite State Machine (FSM). Plant and supervisor are modeled by regular FSM. Supervisory control is introduced by extending the plant with boolean variables, guard formulas and updating functions. Boolean variables are used to encode the supervisor's states. Event observation is captured by a set of boolean functions that update the value of boolean variables and are triggered by the occurrence of events. Finally, control is introduced by guarding events with boolean formulas. The resulting Extended Finite State Machine (EFSM) implements the supervisory control map in the sense that the languages closed and marked by the EFSM are equal to those of the supervised system. An application of our approach in the synthesis of communication protocols is presented.