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Dual adaptive extremum control of Hammerstein models

Fabri, Simon G ; Wittenmark, Björn LU and Bugeja, Marvin K (2015) In International Journal of Control 88(6). p.1271-1286
Abstract
A novel dual adaptive controller for extremum control of stochastic and uncertain nonlinear Hammerstein systems is proposed. The design is based on the innovations dual control cost function originally developed for conventional adaptive control of linear systems. However, the design process is extensively modified and developed so as to cater for the extremum control scenario. This is a more challenging problem because the reference input is itself a nonlinear function of the unknown system parameters, rather than an independent and predefined external reference signal. As in all dual adaptive schemes, it leads to a control law that balances out the need for caution, due to parameter uncertainty, with the conflicting requirement of... (More)
A novel dual adaptive controller for extremum control of stochastic and uncertain nonlinear Hammerstein systems is proposed. The design is based on the innovations dual control cost function originally developed for conventional adaptive control of linear systems. However, the design process is extensively modified and developed so as to cater for the extremum control scenario. This is a more challenging problem because the reference input is itself a nonlinear function of the unknown system parameters, rather than an independent and predefined external reference signal. As in all dual adaptive schemes, it leads to a control law that balances out the need for caution, due to parameter uncertainty, with the conflicting requirement of probing that acts to quickly reduce parameter uncertainty. The proposed controller’s performance is analysed through extensive Monte Carlo simulation trials and compared with several other non-dual adaptive extremum controllers. It is shown that the novel extremum innovations dual controller is superior to other types of adaptive control systems that are based on a certainty

equivalence assumption. In addition, a novel statistical measure is introduced that yields a more objective evaluation of the Monte Carlo simulation results. (Less)
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author
; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
dual control, adaptive control, extremum control, Hammerstein systems
in
International Journal of Control
volume
88
issue
6
pages
1271 - 1286
publisher
Taylor & Francis
external identifiers
  • wos:000353385500016
  • scopus:84928215348
ISSN
0020-7179
DOI
10.1080/00207179.2015.1006452
language
English
LU publication?
yes
id
ec8485f9-fe83-43ea-9ff2-d8e6246c8398 (old id 5276377)
date added to LUP
2016-04-01 10:17:52
date last changed
2022-03-12 04:27:38
@article{ec8485f9-fe83-43ea-9ff2-d8e6246c8398,
  abstract     = {{A novel dual adaptive controller for extremum control of stochastic and uncertain nonlinear Hammerstein systems is proposed. The design is based on the innovations dual control cost function originally developed for conventional adaptive control of linear systems. However, the design process is extensively modified and developed so as to cater for the extremum control scenario. This is a more challenging problem because the reference input is itself a nonlinear function of the unknown system parameters, rather than an independent and predefined external reference signal. As in all dual adaptive schemes, it leads to a control law that balances out the need for caution, due to parameter uncertainty, with the conflicting requirement of probing that acts to quickly reduce parameter uncertainty. The proposed controller’s performance is analysed through extensive Monte Carlo simulation trials and compared with several other non-dual adaptive extremum controllers. It is shown that the novel extremum innovations dual controller is superior to other types of adaptive control systems that are based on a certainty<br/><br>
equivalence assumption. In addition, a novel statistical measure is introduced that yields a more objective evaluation of the Monte Carlo simulation results.}},
  author       = {{Fabri, Simon G and Wittenmark, Björn and Bugeja, Marvin K}},
  issn         = {{0020-7179}},
  keywords     = {{dual control; adaptive control; extremum control; Hammerstein systems}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{1271--1286}},
  publisher    = {{Taylor & Francis}},
  series       = {{International Journal of Control}},
  title        = {{Dual adaptive extremum control of Hammerstein models}},
  url          = {{http://dx.doi.org/10.1080/00207179.2015.1006452}},
  doi          = {{10.1080/00207179.2015.1006452}},
  volume       = {{88}},
  year         = {{2015}},
}