Parametrization of stabilizing controllers without coprime factorizability based on a parallel system

This paper presents a parametrization method of stabilizing controllers in the framework of the factorization approach. The result of this paper does not assume the existence of the coprime factorizability of plants. Under this condition, the number of parameters of the method is less than or equal to that of the previous ones. Further the result is a unification of the previous parametrization methods. This paper employs neither the localization nor the local-global principle which need the knowledge of abstract algebras.