In: Proc. 2000 American Control Conference, 28-30 June 2000, Chicago, IL, Vol. 5, pages 3172-3176. 2000.
Abstract: Petri nets (PNs) show good properties in modeling control algorithms. However, they provide no means for modeling the connection between an algorithm and its environment. To overcome this problem, different extensions of the basic PN model have been proposed. This paper uses a model which associates transitions with firing conditions depending on external signal instead. Furthermore, the model called signal interpreted Petri net (SIPN) sets the output signals depending on its marking. The problems arising by applying results of standard PN analysis methods to SIPN are illustrated and the source of these problems, dynamic synchronization (DS), is identified. Based on DS, necessary and sufficient conditions for the validity of PN analysis are derived. For the cases when PN analysis is not sufficient to determine the properties of SIPN, an algorithm for the calculation of SIPN reachability graph is presented, and it is shown how the properties of the SIPN are determined using this reachability graph.
Keywords: control algorithms, dynamic synchronization, signal interpreted Petri nets.