MODAL PARAMETER ESTIMATION AND MODEL ORDER SELECTION OF A RANDOMLY VIBRATING SYSTEM

✍ Scribed by J. Lardies

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 229 KB
• Volume: 12
• Category: Article
• ISSN: 0888-3270
• DOI: 10.1006/mssp.1998.0179

✦ Synopsis

A vibrating system was excited by a random force and only the multi-output responses were measured. A state-space modelling of the sensors output was then considered, which consisted of the state equation and the observation equation. The modal parameters were obtained from the transition matrix of the vibrating system. Three methods for transition matrix determination are presented using shift property of a block Hankel matrix of the covariances, calculated from the data, and using a shift property of the observability matrix and of the controllability matrix. The order of the state-space system is obtained from a test which is based on the ratio of the determinants of the innovations covariance matrices of the process, from models of two different sizes. This test exploits the distributional properties of the canonical correlation coefficients. A numerical example illustrates the procedure for identifying the order and parameters of a vibrating system.