Supervisor Localization of Discrete-Event Systems Based on State Tree Structures

Recently we developed supervisor localization, a top-down approach to distributed control of discrete-event systems in the Ramadge-Wonham supervisory control framework. Its essence is the decomposition of monolithic (global) control action into local control strategies for individual agents. In this technical note, we establish a counterpart localization theory in the framework of State Tree Structures, known to be efficient for control design of very large systems. We prove that the collective localized control behavior is identical to the monolithic optimal (i.e. maximally permissive) and nonblocking controlled behavior. Further, we propose a new and more efficient localization algorithm which exploits BDD computation.