On the use of orthogonal polynomials in high order frequency domain system identification and its application to modal parameter estimation

Abstract

In this paper a maximum likelihood frequency domain identification technique is presented for the parametric transfer function of very high order linear time invariant systems. Through the use of orthogonal polynomials, the numerical stability of both the estimation and the calculation of derived quantities (zeros, poles) is obtained. Stochastical uncertainty bounds are provided for both estimated and derived quantities. The method will be used to perform the identification of modal analyses problems: a 50-mode simulated system and a 60-mode measured beam-structure. >