Generating on-board diagnostics of dynamic automotive systems based on qualitative models

On-board diagnostic systems play an important role in the current generatio n of cars and will play an increasingly important role in the next future. The design of on-board diagnostic systems is a challenging problem under se veral points of view. In this paper we discuss the experience we made on su ch a problem within the VMBD project. In particular, we discuss an approach which tries to reconcile two goals: satisfying all the requirements and co nstraints imposed by the on-board application, and exploiting the advantage s of the model-based approach as much as possible. The approach is based on qualitative deviation models for the automatic derivation of on-board diag nostics based on decision trees. In the paper we use a specific application , the Common Rail fuel delivery system, as a concrete example, briefly disc ussing the on-board diagnostics we designed for such a system and its proto type implementation and demonstration.