Model reductions using a projection formulation

A new methodology for model reduction of multi-input multi-output systems exploits the notion of an oblique projection. A reduced model is uniquely defined by a projector whose range and orthogonal to the null space are chosen among the ranges of generalized controllability and observability matrices. The reduced order models match various combinations (chosen by the designer) of four types of parameters of the full order system associated with (i) low frequency response, (ii) high frequency response, (iii) low frequency power spectral density and (iv) high frequency power spectral density. Thus, the proposed method is a computationally simple substitute for many existing methods, has an extreme flexibility to embrace combinations of existing methods and offers some new features.