A simple derivation of right interactor for tall plant and its application to inner-outer factorization

An interactor matrix plays several important roles in the control system theory. In this paper, we present a simple method to derive the right interactor for tall transfer function matrix using Moore-Penrose pseudoinverse. By the presented method, all zeros of the interactor lie at the origin. Moreover, the interactor by the proposed method has all-pass property in discrete-time. The method will be applied to the inner-outer factorization. It will be shown that the choice of interactor does not influence the result of the factorization.