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An Eigensystem Realization Algorithm for Modal Parameter Identification and Model Reduction

Authors: Jer-Nan Juang, Richard S. Pappa

Published: 1985 (Journal Paper)

Source: Journal of Guidance, Control, and Dynamics

Algorithm: ERA

DOI: 10.2514/3.20031

Summary

Introduces ERA, which extracts modal parameters (natural frequencies, damping ratios, mode shapes) from free-decay or impulse response data via eigendecomposition of a Hankel matrix, enabling reduced-order model construction for structural dynamics.

Abstract

A method called the eigensystem realization algorithm is developed for modal parameter identification and model reduction of dynamic systems from test data. A new approach is introduced in conjunction with the singular-value decomposition technique to derive the basic formulation of minimum order realization which is an extended version of the Ho-Kalman algorithm. The basic formulation is then transformed into modal space for modal parameter identification. Two accuracy indicators are developed to quantitatively identify the system and noise modes. For illustration of the algorithm, an example is shown using experimental data from the Galileo spacecraft.

Primary

Paper researchgate.net

Standard

DOI 10.2514/3.20031

Alternate

people.duke.edu PDF people.duke.edu arc.aiaa.org arc.aiaa.org

Tags

  • System identification

  • Modal analysis

  • Model reduction

  • Eigensystem realization algorithm

  • ERA

  • Algorithm

  • Structural dynamics