Decentralized supervisory control: a new architecture with a dynamic decision fusion rule

Abstract

We consider a decentralized control architecture for discrete-event systems where local supervisors are allowed to change dynamically the manner in which their local decisions are combined globally. This is done by changing the default decisions regarding the enablement of common controllable events. In previous work, this default was fixed a priori and remained constant throughout the operation of the system. We show that under dynamic decision fusion rules, a larger class of languages can be achieved as compared with architectures with static fusion rules. A dynamic version of the notion of co-observability appears in the necessary and sufficient conditions for the existence of supervisors in the new architecture. The dynamic co-observability relaxes (static) co-observability. The existence of a set of local dynamic default decision rules that ensures dynamic co-observability can be decided in polynomial time.