Decentralized control and coordination of discrete-event systems with partial observation

Decentralized supervision and coordination are studied for partially observed discrete-event systems. The authors´ (1988) previous results on decentralized supervision and supervision under partial observation are extended by incorporating both these features in the control structure. In addition, a concept of coordination is introduced, and conditions for the existence of a coordinating supervisor are established. It is concluded that decentralized supervision will be easier to design and implement that centralized supervision; under suitable conditions it will be equivalent with respect to overall closed-loop system behavior. In achieving this equivalence a key role is played by the linguistic property of normality. As shown by an illustrative example, the results have application to such complex systems as manufacturing systems, which the qualitative modeling framework adopted