Decentralized nondeterministic supervisory control of discrete event systems

Abstract

This paper studies the decentralized supervisory problem using nondeterministic supervisors. Nondeterministic supervisory control under partial observation was proposed by Kumar et al. [11] by allowing nondeterminism in control policies, which lead to the existence condition of achievability that is weaker than controllability and observability combined and is algebraically better behaved. In this paper, we extend nondeterministic control to the decentralized setting. Using the simple conjunctive rule of decision fusion, we present a de£nition of co-achievability to characterize the languages which can be achieved through decentralized nondeterministic supervisors. Co-achievability is weaker than controllability and co-observability combined. Other properties of co-achievable languages are presented, and the relationship between achievability and co-achievability is established. We derive necessary and suf£cient conditions for target and range control problems. The existence conditions are polynomially veri£able, and also local supervisors can be polynomially synthesized.Index Terms-Discrete event system, Nondeterministic supervisory control, Decentralized supervisory control, Coachievability 43rd IEEE Conference on Decision and Control