On computation of distributed supervisory controllers in discrete-event systems

This paper refines an earlier localization procedure used to design optimal nonblocking distributed supervisory controllers in discrete-event systems (DES). The earlier algorithm needed a control consistency relation involving two conditions, and introduced superfluous selfloops. We propose a refined procedure, including a newly defined weak control consistency relation, and a cleanup algorithm, which results in simpler and cleaner controllers. It is proved to be correct, and illustrated by a Transfer Line plant.