Static reachability and static decoupling of linear time-invariant systems

The geometric concepts of holdability and static reachability for time-invariant linear multivariable systems are introduced. The geometric structure of multivariable linear systems are analyzed with respect to these concepts. The problem of static decoupling by dynamic feedback is defined, and the necessary and sufficient conditions for its solution for square systems is found to be a generalization of Wolowich´s (1973) results on the same problem with state feedback. It is shown that the concept of static reachability is the key one in this problem´s solution