Constraint Databases Technology for Polynomial Models Diagnosis

Model-based Diagnosis allows the identification of the parts which fail in a system. The models are based on the knowledge of the system to diagnose, and they can be represented by constraints associated to the components. The variables including in these constraints can be observable or non-observable, depending on the situation of sensors. In order to obtain the minimal diagnosis in a system, an important issue is related to find out the minimal possible conflicts in an efficient way. We consider that Constraint Databases represent an excellent approach in order to solve this problem in complex systems, where a tuple in a relational database could be replaced by a conjunction of constraints. In this work we have used a novel logical architecture of Constraint Databases which has allowed us to obtain these possible minimal conflicts by means of a standard query language though the information is stored in a conventional relational database. Moreover, we have considered Gröbner bases as a projection operator to obtain the minimal possible conflicts of a system.