ABSTRACT
A remarkable feature of the concept of flatness, as a dynamic controlled system property, is the fact that the nature of the system does not much prevent one from finding the property rooted at the core of the system's description. In this context, it is not surprising that the flatness property can also be found in a variety of systems described by delay differential systems and by linear partial differential equations. Control systems described by delay differential equations have an enormous practical importance in many fields of applied mathematics and in many areas of process control. The theoretical foundations of flatness in this important class of systems rest in the differential algebraic approach initiated by Fliess and Mounier in [5].
