Algebraic synthesis of logical controllers despite inconsistencies in specifications

This paper deals with the problem of consistency of the requirements which are the starting point of controller synthesis methods for Discrete Event Systems (DES). In previous papers, an algebraic synthesis method for logical systems has been proposed. This method includes a theorem allowing the proof of consistency of the set of specifications. In this paper, we show that if inconsistencies are detected, the conditions of these inconsistencies can be given to the designer. It is therefore possible for the designer to propose priority rules between the involved requirements allowing the correction of incoherent specifications. Both the mathematical and the methodological aspects of this work are presented. In an illustrative purpose, the study case of a hydraulic press is developed.