THE STANDARD DECOMPOSED SYSTEM AND NONINTERACTING FEEDBACK-CONTROL OF NONLINEAR-SYSTEMS

Conditions for achieving noninteraction in nonlinear multivariable systems via the decomposition of state space are well established. The main contribution of this paper is to fully characterize the class of decomposing control laws. The characterization corresponds to a family of simple control laws which are applied to a standard decomposed system (SDS). The SDS is similar to the decomposed system of Isidori, Krener, Gori-Giorgi, and Monaco, but has a finer structure. The finer structure parallels the one used by Gilbert for linear systems. A weaker form of noninteraction, based on input-output behavior, is decoupling. Some connections between decomposition and decoupling are also established. An example illustrating the importance of the results is given.