Ontology-driven middleware for next-generation train backbones

The current evolution in the railway management software domain heads in the direction of highly modular systems with many different smaller components working together, tuned towards the operator's needs. In order to create an integrated management system for the train and railway domain in general, many different applications from both operators and manufacturers have to cooperate. To create a robust integrated system, a good supporting middleware infrastructure is needed. To the authors' knowledge, very few integrated or standardized techniques for creating higher-level intelligent middleware in the railway domain are publicly defined to date. The solution today towards establishing connectivity through the train makes use of a messaging bus. A service layer, providing mechanisms for e.g. life-cycle management, discovery and information aggregation, is however not provided in this current approach. Therefore, a distributed and modular architecture using ontologies, and widely used standards, such as Ethernet and IP, is detailed in this paper. The architecture provides the required intelligence needed for monitoring distributed applications in the train environment. The middleware allows information to be aggregated and analysed on different levels. Information querying, based on the ontology in the middleware is also discussed. By means of directory functionality, the ontology-driven middleware provides intelligent discovery as well. Finally, the ontologies used in the middleware to structure the domain and corresponding methods for creating such ontologies are presented.