Minimal state-space model realisation of a nonlinear helicopter

T Clarke, X D Sun

Research output: Contribution to journalArticlepeer-review


The observer-Kalman filter/eigensystem realisation algorithm is applied to the problem of generating a minimal state-space model realisation from a nonlinear helicopter model. The paper presents an interim result using a 10th order linear model, discusses the implications of this and generates some general guidelines before applying the technique to a nonlinear model. The outcome is a linear realisation which gives a better representation of the nonlinear model than obtained using small perturbation linearisation methods. The technique is capable of extracting unstable plant models from closed-loop stabilised systems, even when the feedback dynamics are not known.

Original languageEnglish
Pages (from-to)415-422
Number of pages8
Issue number4
Publication statusPublished - Jul 1998


  • helicopter identification
  • eigensystem realisation algorithm
  • nonlinear systems

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