Implementing supervisory control maps with PLC
Mohammad Moniruzzaman, Peyman Gohari · Proceedings of the ... American Control Conference/Proceedings of the American Control Conference · 2007
The supervisory control theory of discrete-event systems (DES) can be used to construct a supervisor for any event-driven system in which the state space is discrete. To implement supervisors we propose to use programmable logic controllers (PLCs), which are widely used in industrial applications. In our work, we develop a new conversion algorithm which directly transforms a supervisor represented by a finite automaton to a ladder logic diagram (LLD). To demonstrate the correctness of our proposed approach, we design supervisors for a boiler control system using supervisory control theory of Ramadge and Wonham, convert DES supervisors to PLC controllers using our conversion technique, and verify using a PLC simulation software that the converted LLD can be executed by the PLC and that the original behavior of the DES supervisors under PLC implementation can be achieved.