SUPERVISORY CONTROLLER OF PETRI NETS UNDER PARTIAL OBSERVATION

摘要

We propose in this paper a control synthesis policy for the forbidden state problems of bounded Petri nets (PN) with liveness requirement and uncontrollable / unobservable transitions. The proposed approach computes a maximally permissive PN controller, whenever such a controller exists. The first step, based on a Ramadge-Wonham theory, determines the refined controlled observer reachability graph of the controlled PN. In the second step, the theory of regions is used to generate a set of control places to be added to the plant PN model. These control places guarantee the desired behavior. The proposed approach is illustrated on a manufacturing example.