Measuring a linear approximation to weakly nonlinear MIMO systems

T. Dobrowiecki, Johan Schoukens

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

The paper addresses the problem of preserving the same LTI approximation of a nonlinear MIMO (multiple-input multiple-output) system. It is shown that when a nonlinear MIMO system is modeled by a multidimensional Volterra series, periodic noise and random multisines are equivalent excitations to the classical Gaussian noise, in a sense that they yield in the limit, as the number of the harmonics M → ∞, the same linear approximation to the nonlinear MIMO system. This result extends previous results derived for nonlinear SISO (single-input single-output) systems. Based upon the analysis of the variability of the measured FRF (frequency response function) due to the presence of the nonlinearities and the randomness of the excitations, a new class of equivalent input signals is proposed, allowing for a lower variance of the nonlinear FRF measurements, while the same linear approximation is retrieved.

Original languageEnglish
Pages (from-to)1737-1751
Number of pages15
JournalAutomatica
Volume43
Issue number10
DOIs
Publication statusPublished - Oct 2007

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Frequency response

Keywords

  • Nonparametric frequency response
  • Orthogonal multisines
  • Random multisines
  • Volterra MIMO systems

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering

Cite this

Measuring a linear approximation to weakly nonlinear MIMO systems. / Dobrowiecki, T.; Schoukens, Johan.

In: Automatica, Vol. 43, No. 10, 10.2007, p. 1737-1751.

Research output: Contribution to journalArticle

Dobrowiecki, T. ; Schoukens, Johan. / Measuring a linear approximation to weakly nonlinear MIMO systems. In: Automatica. 2007 ; Vol. 43, No. 10. pp. 1737-1751.
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