A note on pole assignment under changes in the dynamics of multivariable systems

This note presents a formulation based upon algebraic systems theory to deal with the problem of robustness under combined parametrical and/ or structural changes in the plant. The Key design objective is the maintenance the dominant closed -lo op poles closer to their nominal values while prescribing the placement of those due to the unmodelled dynamics to subsets of the complex plane of small in fluence in the system response.