Supervisory Control of Networked Fuzzy Discrete Event Systems

In a distributed system, the plant and its controlling entity, the supervisor, are situated in separate locations, communicating remotely. This setup introduces delays and the potential for information loss during communication. This study delves into the supervisory control of networked fuzzy discrete event systems, an area relatively unexplored in existing literature. The plant is conceptualized as a fuzzy discrete event system with inherent constraints. Events within this system are both observed and managed from a distance by the supervisor, encountering two types of delays and losses. One type occurs during observation, where the plant transmits information to the supervisor, whereas the other arises during control, stemming from communication between the supervisor and the plant. The article first addresses the challenge of estimating states in the presence of observation delays and losses. An online methodology is devised to compute these state estimates. Leveraging these estimates, a supervisor is then designed to selectively enable or disable events, ensuring that the plant never transitions into undesirable or unsafe fuzzy states. A necessary and sufficient condition is established to guarantee the existence of such a supervisor. In addition, online techniques are developed to implement the computation of the supervisor's control actions.