The objective of this research is a comprehensive study of nondeterministic control of discrete event systems for language/simulation/bisimulation equivalence based specifications. Past work on supervisory control considered mainly the deterministic supervisors. To any end-user it does not matter whether the supervisor is deterministic or nondeterministic rather whether it fulfills the control task. In fact for nondeterministic plants (nondeterminism arises due to unmodeled dynamics, which may be intentional or unintentional), simulation/bisimulation equivalence based specification are more natural, and nondeterministic control may be the only option to enforce them. Also, even for language equivalence based specifications nondeterminism of control can offer several advantages (as reported in our recent work). The proposal is aimed toward developing further understanding of the advantages the nondeterministic control has to offer for supervisory control for language/simulation/bisimulation equivalence. The project includes experimentation with two educational discrete-event "plants" located in our controls laboratory. One is a manufacturing system whereas other is a chemical-process plant. We also propose to extend our existing supervisory control software to include the new algorithms of nodeterministic control synthesis.
The broader impacts of the project lie in it's application areas of discrete-event systems including, manufacturing, telecommunications and networking, traffic and transportation, chemical process control, embedded system control, asynchronous hardware verification, and software verification. With such a wide spread applicability of event-driven systems, it is important to educate graduate students with discrete-event background, and this proposal will involve 2 PhD students. The PI teaches a course on Discrete-Event Systems each year through which the new results will be disseminated.
