Authors

Paul Schwerdtner, Matthias Voigt

Abstract

We present a new fixed-order H-infinity controller design method for potentially large-scale port-Hamiltonian (pH) plants. Our method computes controllers that are also pH (and thus passive) such that the resulting closed-loop systems is again passive, which ensures closed-loop stability simply from the structure of the plant and controller matrices. In this way, we can avoid computationally expensive eigenvalue computations that would otherwise be necessary. In combination with a sample-based objective function which allows us to avoid multiple evaluations of the H-infinity norm (which is typically the main computational burden in fixed-order H-infinity controller synthesis), this makes our method well-suited for plants with a high state–space dimension. In our numerical experiments, we show that applying a passivity-enforcing post-processing step after using well-established H-infinity synthesis methods often leads to a deteriorated H-infinity performance. By contrast, our method computes pH controllers, that are automatically passive and simultaneously aim to minimize the H-infinity norm of the closed-loop transfer function. Moreover, our experiments show that for large-scale plants, our method is significantly faster than the well-established fixed-order H-infinity controller synthesis methods.

Keywords

Port-Hamiltonian systems; Large-scale systems; Robust control; H-infinity control; Fixed-order controllers

Citation

BibTeX

@article{Schwerdtner_2023,
  title={{Fixed-order H-infinity controller design for port-Hamiltonian systems}},
  volume={152},
  ISSN={0005-1098},
  DOI={10.1016/j.automatica.2023.110918},
  journal={Automatica},
  publisher={Elsevier BV},
  author={Schwerdtner, Paul and Voigt, Matthias},
  year={2023},
  pages={110918}
}

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References