| In this thesis we propose to apply Ramadge-Wonham supervisory control theory to Reactive Discrete-Event Systems (RDES). A reactive system continually interacts with its environment at the speed dictated by the latter. We will first present our decentralized RDES architecture, which is based on Input/Output (I/O) automata model. After introducing safety and progress, we define the corresponding centralized and decentralized supervisory control problems concerning both safety and progress. We explain through examples why the existing results in supervisory control theory cannot be directly applied. Substitute sufficient and necessary conditions for the existence of decentralized solutions are given. In the special case where only safety is considered, we also study centralized and decentralized supervisory control problems, and present more straightforward sufficient and necessary conditions for the existence of their solutions. An example is presented to illustrate how decentralized RDES are modeled, how decentralized components co-operate with each other, and how the revised decentralized supervisory control theory can be applied to the study of RDES. |
