A Case Study in the Design of Control Systems for Flexible Production Cells

Most control systems of exible production cells have a hierarchical structure. Hierarchical control systems become very complicated and diicult to maintain and modify when the underlying production cells grow in size and complexity. Moreover , they are characterized by a relatively high sensitivity to failures. As opposed to hierarchical systems, heterarchical control systems are exible, modular, easy to modify, and | to some extent | fault-tolerant. In this paper, a heterarchical control system of a exible production cell is formally speciied. For speciication, the CSP-based language is used which is well suited for the description of autonomous components cooperating with each other by exchanging information. Speciications deened in can be validated by simulation.