Decentralized modular control of concurrent Fuzzy Discrete Event Systems

In order to analyze the event driven complex systems with uncertainties in their events and state transitions, Fuzzy Discrete Event Systems (FDES) has been proposed as an extension to the formal Discrete Event Systems theory (DES). In this paper we investigate the decentralized modular supervisory control problem of FDES with partial observation for systems which are composed of concurrently operating, multiple interacting modules with uncertainties in their events and states. The modular decentralized fuzzy supervisor consists of set of local fuzzy supervisors, one for each module and each with its own sensing and acting capabilities. Moreover, the communication is not allowed between the local fuzzy supervisors. The notion of separability for fuzzy languages is introduced and the property of a fuzzy language specification which is called separably - controllable - observable that is required for verifying the existence of modular fuzzy supervisors is defined. Some examples are presented to realize the theoretical developments.