MONITOR DESIGN FOR COLORED PETRI NETS WITH UNCONTROLLABLE AND UNOBSERVABLE TRANSITIONS

摘要

In this paper we deal with the problem of designing a supervisory controller that enforces certain specifications on the marking of a Colored Petri net (CPN). In particular, we consider colored Generalized Mutual Exclusion Constraints (GMEC) that represent in a compact way several linear constraints that limit the weighted sum of colored tokens in subsets of places. In a previous work we have shown that, when all transitions are controllable and observable with respect to all colors, these constraints can be enforced by a colored monitor place that can be added to the net to obtain the closed-loop system. The novel contribution of this paper is that of showing how these results can be extended to the case of transitions that are uncontrollable and/or unobservable with respect to certain colors. In particular, we show that the parametrization and the tabular procedure proposed by Moody and Antsaklis for uncolored Petri nets can still be used to compute - when it does exist - a less permissive GMEC that can be forced by an admissible colored monitor place.