System identification method inheriting steady-state characteristics of existing model

ABSTRACTIn this paper, we propose an identification method to construct a state-space model that inherits steady-state characteristics from an existing model. It is assumed that in prior to an identification experiment, a designer has a model which accurately expresses steady-state characteristics of an actual system responding to certain inputs. The characteristics are extracted and inherited to a reconstructed state-space model via the combination with a subspace identification method. By applying a change-of-variable technique, the combined identification problem, which is formulated as nonlinear optimisation, is reduced to a least squares problem. Finally, we show the effectiveness of the proposed method in three different numerical simulations.