In: Proc. IFAC Conf. on Control Systems Design (CSD'2000), 18-20 June 2000, Bratislava, Slovak Republic, pages 293-298. 2000.
Abstract: The purpose of this paper is to emphasize the adequacy of the CO-NETS approach in specifying and validating a substantial part of the European train control system, namely the generalized railroad crossing system (GRC). This adequacy is particularly expressed by handling in a satisfactory way the following GRC aspects. First, due to CO-NETS capabilities for modeling components for modeling components as a hierarchy of object oriented classes using different forms of inheritance, it is possible to cope with the size complexity in each component, namely train, gate and control system. Second, as the CO-NETS approach provides explicit interfaces for communicating different components, interaction of components in this application becomes very manageable by hiding the complex internal behavior of each component. Third, by providing a full exhibition of intra- as well as inter-object concurrency through CO-NETS semantics expressed in rewrite logic, real (concurrent) scenarios of this application are captured. Fourth, real-time constraints which characterize this application are dealt with straightforwardly by adopting timed rewrite logic for time-dependent transitions. Last but not least, an intrinsic methodology is built for deriving CO-NETS components from a given informal object-oriented description.
Keywords: CO-NETS, GRC, component-based Petri nets, hierarchical modeling, object orientation, railroad crossing systems, system specifications, train control systems.