A generalization of state avoidance policies for controlled Petri nets

This paper presents a generalization of forbidden state control synthesis methods for a broad class of controlled Petri nets (CtlPN). An algebra is defined for characterizing the interaction of paths in the Petri net. Given a specification of a forbidden marking set, the net structure is analyzed to determine an algebraic expression to represent the specification. For any net marking (state), evaluation of the expression will indicate whether forbidden markings are reachable and whether control is necessary. The expression is then used for efficiently determining the maximally permissive controls for the marking