Multivariable frequency–response curve fitting with application to modal parameter estimation

• Published in: Automatica (Oxford) Vol. 41; no. 10; pp. 1773 - 1782
• Main Authors: Verboven, P., Guillaume, P., Cauberghe, B.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.2005; Elsevier
• Subjects: Applied sciences; Computer science; control theory; systems; Control theory. Systems; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Miscellaneous; Modal analysis; Modelling and identification; Physics; Solid mechanics; Structural and continuum mechanics; System identification; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Modal analysis; System identification; Cost minimization; Parameter estimation; Vibration; Complex system; Frequency domain method; Modeling; Frequency weighting; Discrete function; Projection method; Function minimization; Discrete time; Matrix method; Frequency response; Transfer function; Dynamic model; Multivariable system; Structural analysis
• ISSN: 0005-1098; 1873-2836
• DOI: 10.1016/j.automatica.2005.03.023

This paper presents a computational approach for the frequency-domain identification of multivariable, discrete-time transfer function models based on a cost function minimization. The algorithm is optimized for the parametric characterization of complex high-order multivariable systems requiring a large number of model parameters, including sparse matrix methods and QR-projections for the reduction of computation time and memory requirements. The algorithm supports a multivariable frequency-dependent weighting, which generally improves the quality of the transfer function model estimate. The overall approach is successfully demonstrated for a typical case encountered in experimental structural dynamics modelling (using modal analysis) and compared with related algorithms in order to assess the gain in computational efficiency.