Hierarchical modelling and distributed control systems design of a flexible manufacturing system

Abstract

This paper presents the modelling and supervisory control design of a flexible manufacturing system (FMS). We propose a design technique to model the system using finitely recursive processes. The model is constructed using the system's modular structure and the connections between inputs and outputs of its subsystems which is appropriate for complex manufacturing processes operating in parallel, and where a modular top-down design is required. Next we develop control strategies in order to ensure desirable behaviour of the model. We propose a distributed control system where each component of the system is controlled by a local controller following global specifications. Such a local controller can perform "dynamic" control in the sense that it disables and enables events depending on the (dynamic) process behaviour. This technique is appropriate for complex discrete event systems or for "dynamic" plants, where no automaton representation is available.<>