On Nonlinear Parameter Estimation with Random Noise Signals

Document type: Conference Papers
Peer reviewed: Yes
Full text:
Author(s): Andreas Josefsson, Martin Magnevall, Kjell Ahlin
Title: On Nonlinear Parameter Estimation with Random Noise Signals
Conference name: IMAC XXV
Year: 2007
ISBN: 0-912053-96-8
Publisher: Society for Experimental Mechanics
City: Orlando, Florida
Organization: Blekinge Institute of Technology
Department: School of Engineering - Dept. of Mechanical Engineering (Sektionen för teknik – avd. för maskinteknik)
School of Engineering S- 371 79 Karlskrona
+46 455 38 50 00
Authors e-mail: andreas.josefsson@bth.se, martin.magnevall@bth.se, kjell.ahlin@bth.se
Language: English
Abstract: In the field of nonlinear dynamics it is essential to have well tested and reliable tools for estimating the nonlinear
parameters from measurement data. This paper presents an identification technique based on using random
noise signals, as initially developed by Julius S. Bendat. With this method the nonlinearity is treated as a feedback
forcing term acting on an underlying linear system. The parameter estimation is then performed in the frequency
domain by using conventional MISO/MIMO techniques.

To apply this method successfully it is necessary to have some pre-information about the model structure and
thus methods for nonlinear characterization and localization are studied. The paper also demonstrates the various
ways the method can be formulated for multiple-degree-of-freedoms.

The implementation of the method is illustrated with simulated data as well as a practical application, where the
method is used to create a dynamic model of a test-rig with a significant nonlinearity.
Subject: Mechanical Engineering\Structural Dynamics
Keywords: nonlinear, characterization, localization, parameter estimation, reverse-path, geometric nonlinearity