Modular Implementation of Robust Supervisory Controllers for Discrete Event Systems

In this paper, the problem of designing robust supervisory controllers for uncertain discrete event systems is studied. It is assumed that both the plant behavior and the design specifications can be represented by regular languages. It is also assumed that the unknown model of the uncertain plant belongs to a finite set of possibilities. To solve the problem, a modular approach based on a general recursive robust control scheme is developed. The contribution of the present paper consists in deriving a maximally permissive modular robust supervisory controller for the case of prefix-closed languages, having the advantage of linear complexity in the number of models as opposed to the exponential complexity of the worst-case scenario in the direct implementation of standard supervisors for augmented systems.