Design of robust supervisors for discrete event systems with infinite behaviors

Supervisory control in the context of ω-languages is considered. The nominal supervisor design problem is to find a nonblocking supervisor f for a plant G₀ such that the closed-loop infinite behavior equals a specified closed-loop behavior K satisfying lower and upper bounds, (A∩S(G₀))⊂K⊂(E∩S(G₀)), S(G₀ ) being the open-loop infinite behavior of G₀. The robustness of solutions to the nominal problem is defined with respect to variations in the plant. It is shown there exists a supervisor f* which solves the nominal problem and maximizes the set of plants for which the nominal specifications are satisfied under the supervisor f*. Computational issues are discussed and the theoretical results are illustrated with an example