The manual design of monolithic controllers for flexible manufacturing systems is no longer feasible due to the sheer size of the problem. A well-known approach to tackle this scalability problem is to create a set of smaller controllers and orchestrate their interaction in an architecture. Another approach is to use synthesis techniques to generate a controller model from models of the uncontrolled system and the formalized requirements. In this paper we describe a pragmatic approach that combines the complementary advantages of these two approaches, where we decompose the design problem of the controller into a number of sub-controllers by introducing intermediate interfaces and use supervisory controller synthesis to synthesize the sub-controllers. We have evaluated this approach on an industrial case study, where we examined a large controller in a lithography machine. We found that the approach can successfully be used to generate a large portion of the needed sub-controllers.
- Discrete Event Systems
- Extended Finite-State Machines
- Formal Methods
- Supervisory Control