On the selection of states to be retained in a reduced-order model

A criterion is proposed for selecting the most important states of a high-order system to be retained in a reduced model. The effective participation of each state is estimated by evaluating its contribution to the total impulse response energy at the output of the system. A procedure for obtaining the reduced model, based on this criterion, is described. The method may be regarded as the combination of singular perturbation and aggregation. An error analysis is included, along with examples comparing the proposed approach with existing methods.