Design of Monitor-based Supervisors in Labelled Petri Nets

In this paper we propose a method to compute a monitor-based supervisor that enforces a GMEC in labelled Petri nets. Due to the presence of indistinguishable transitions, an observable GMEC may not be enforceable by a monitor place in general. To solve this problem we introduce the notion dependency of transitions that can be used to judge whether an event is generated by an input/output transition or its spurious ones, and we present an algorithm to design a monitor-based supervisor based on the notion of Hilbert basis. This approach is purely structural with low online computational cost. Moreover, our supervisor is robust to some change of initial markings or irrelevant part of the plant net.