An Identification Method of Multiinput, Multioutput Linear Dynamical Systems for the Experimental Modal Analysis of Mechanical Structures

Abstract

A parameter identification method is proposed that can be used to evaluate dynamic characteristics of mechanical structures modeled as multiinput multioutput linear dynamical systems. The discrete transfer function matrix is identified in two steps, one for the denominator and the other for the numerators, where the model order is determined with the aid of a “prediction” error function. The continuous counterpart is then obtained by herein developed formula that links discrete and continuous models, from which vibration modal parameters are derived. Finally, the method is applied to the data obtained from vibration experiments of a test structure, and verified its practical usefulness.