Supervisory control of partially observable marked graphs

This note presents a control synthesis approach for discrete event systems modeled by marked graphs with unobservable transitions. It solves forbidden state problems characterized by a set of general mutual exclusion constraints. We prove that for any sequence of observable transitions, there exist a unique marking from which all other possible current markings can be reached unobservably. This salient feature allows us to design efficient control policies based on proper separation of observation and control.