Optimal monitor-based supervisor sythesis for a class of Petri nets with unobservable transitions

This paper deals with constraint transformation problems in a system with unobservable events, which is modeled by Petri nets with unobservable transitions. First, the concept of an unobservable influence subnet is presented and its properties are studied. Next, based on the properties, an algorithm is proposed to transform a given generalized mutual exclusion constraint (GMEC) into an optimal admissible one that can be enforced directly on the net in the form of monitor-based supervisor. The proposed algorithm has high computational efficiency at the expense of application scope. Finally, an example is used to illustrate the application of the proposed method.