The integration of different model types for model-based diagnosis

This paper describes an architecture for model-based diagnosis that was developed during the BEHAVIOR joint project. The focus of BEHAVIOR was the application of model-based knowledge representation and reasoning techniques to the domain of dynamic, technical systems. Within this context, Fraunhofer IITB and the University of Hamburg developed a tool box to integrate different modeling approaches to be used in model-based diagnosis. Toward this end, a diagnostic engine derived from the general framework Generic Diagnostic Engine (GenDE) was used. This engine was able to treat all model types uniformly.The basic approach for modeling the behavior of the system was to focus on the components, supplemented by an approach that focused on the processes. This allowed modeling of the domain using either components, processes, or combinations of both. In addition, models of spatial interactions were used to describe structural changes for diagnostic purposes. This repertory was supplemented by a language that described combinations of quantitative and qualitative descriptions. This approach, along with the use of event models, was used to describe the kinds of behavior that are difficult to explain using purely quantitative methods. The functionality and usefulness of the integrated approach was demonstrated using the domain of water ballasting systems.Water ballasting systems can be found on offshore-platforms or ships. The purpose of such systems is to keep the platform or ship balanced even when the sea is rough or when moving heavy loads. The water ballasting system of the ship under investigation consisted of more than 40 tanks. Example faults from this domain were used that required several modeling and analysis methods.