Designing dependable logic controllers using the supervisory control theory

in this paper we deal with the problem of designing a controller for a discrete event system. We argue that the classical approach of supervisory control theory (SCT) can be used as an essential step of such a procedure. However, some of the features that make supervisory control an attractive paradigm to solve theoretical problems are often a major source of difficulty in implementing a controller: such is the case, for instance, of the abstraction level usually considered in SCT. We define a method to obtain the correct abstraction level and present a procedure to design a controller using SCT. This approach is applied to a simple but realistic example: an automatic gate