A complete characterization of decoupling control laws for a general class of nonlinear systems

In the past decade, conditions for feedback decoupling of nonlinear systems have been studied extensively; the class of control laws which decouple has received relatively little attention. In this paper, a characterization of the whole class of nonlinear decoupling control laws for real analytic nonlinear systems is obtained. This result is important from both mathematical and engineering viewpoints. For instance, we present an example where former results do not allow stable decoupling, while our result does. The main result is proved and several examples which illustrate its generality are presented.