Denominator assignment, invariants and canonical forms under dynamic feedback compensation in linear multivariable systems

A result originally reported in [3] for linear time invariant single input-single output systems and concerning an invariant and a canonical form of the transfer function matrix of the closed loop system under dynamic feedback compensation is generalized for LTI multivariable systems. This result leads to a characterization of the class of closed loop transfer function matrices which are obtainable under feedback through a proper dynamic compensator and gives rise to an algorithmic design procedure for the computation of a proper dynamic (feedback), internally stabilizing and denominator assigning compensator for non-minimum phase plants.