Mechanical system scaling based on output only identification and mass perturbations by state projections

In this article the authors develop a new method for input-output system parametrization based on mechanical output only identification, mass perturbations, and state projections. Based on a brief summary of mechanical model parametrization, the authors develop a central relation of reference and altered structural states based on a general system theoretic approach. By applying a state space description, the novel state projections for system scaling (SP2S) method is defined. The proposed numerical solution based on a least-squares approach follows a reordering by Kronecker product. Very importantly, applied state space parameters can be in general coordinates and the model order is not restricted (for instance to the number of measurement positions). Finally, SP2S is applied and verified based on simulated and real experimental measurements of a laboratory set-up. (C) 2020 Elsevier Ltd. All rights reserved.