Reactive mode handling of flexible manufacturing systems

This paper deals with a new modeling approach for mode handling of flexible manufacturing systems (FMS). Based on a review of the modeling methods and the specification formalisms in the existing approaches, we show that the mutual benefit of functional modeling and synchronous languages is very convenient for mode handling problem. We start by introducing the context of our work and the basic concepts of the proposed modeling approach. Then we present the steps of functional modeling and we illustrate them through an example of a flexible manufacturing cell. Functional modeling is completed by generic behavioral specifications representing the states of a subsystem or the whole system. The specification method is modular, hierarchical and supports reuse concept. The established model is generic and well adapted to our control system context. Mode handling function role within the control system is then studied. This function enables a reactive update of the availability of the resources and functions and the transmission of high level control and reconfiguration orders.