Petri Net Controller Synthesis for Discrete Event Systems Using Weighted Inhibitor Arc

This work is supported by the National Natural Science Foundations of China (69974035, 60025308), Excellent Youth Teacher for Teaching and Research Award Foundation in Institutions of Higher Learning of China and the Natural Science Key Foundation of Zhejiang Province (ZD9905). Abstract In this paper the Petri net (PN) with weighted inhibitor arc is exploited to solve the forbidden state problem of discrete event systems (DES). The forbidden state problem considered here is described as the linear inequality constraint of the place marking. We first review the relevant work on the control of DES using inhibitor arc. Then, the design of the PN controller is introduced with two steps. The first step of the design is to track the state of the system. Then, the weighted inhibitor arcs are exploited to disable the relative transitions in the case the firing of these transitions will violate the constraints. A simple example of discrete manufacturing system in the reported literature is used to show the detailed procedure of the controller synthesis and the advantages of the presented method.