Online system identification development based on recursive weighted least square neural networks of nonlinear hammerstein and wiener models.

The realistic dynamics mathematical model of a system is very important for analyzing a system. The mathematical system model can be derived by applying physical, thermodynamic, and chemistry laws. But this method has some drawbacks, among which is difficult for complex systems, sometimes is untr...

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Main Author: Kwad, Ayad Mahmood
Format: Thesis
Language:English
English
English
Published: 2022
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spelling my-uthm-ep.84042023-02-26T02:58:26Z Online system identification development based on recursive weighted least square neural networks of nonlinear hammerstein and wiener models. 2022-03 Kwad, Ayad Mahmood QA76.75-76.765 Computer software The realistic dynamics mathematical model of a system is very important for analyzing a system. The mathematical system model can be derived by applying physical, thermodynamic, and chemistry laws. But this method has some drawbacks, among which is difficult for complex systems, sometimes is untraceable for nonlinear behavior that almost all systems have in the real world, and requires much knowledge. Another method is system identification which is also called experimental modeling. System identification can be made offline, but this method has a disadvantage because the features of a dynamic system may change over time. The parameters may vary as environmental conditions change. It requires big data and consumes a long time. This research introduces a developed method for online system identification based on the Hammerstein and Wiener nonlinear block-oriented structure with the artificial neural networks (NN) advantages and recursive weighted least squares algorithm for optimizing neural network learning in real-time. The proposed method aimed to obtain a maximally informative mathematical model that can describe the actual dynamic behaviors of a system, using the DC motor as a case study. The goodness of fit validation based on the normalized root-mean-square error (NRMSE) and normalized mean square error, and Theil’s inequality coefficient are used to evaluate the performance of models. Based on experimental results, for best Wiener parallel NN model and series-parallel NN model are 93.7% and 89.48%, respectively. Best Hammerstein parallel NN polynomial based model and series-parallel NN polynomial model are 88.75% and 93.9% respectively, for best Hammerstein parallel NN sigmoid based model and series-parallel NN sigmoid based model 78.26% and 95.95% respectively, and for best Hammerstein parallel NN hyperbolic tangent based model and series-parallel NN hyperbolic tangent based model 70.7% and 96.4% respectively. The best model of the developed method outperformed the conventional NARX and NARMAX methods best model by 3.26% in terms of NRMSE goodness of fit. 2022-03 Thesis http://eprints.uthm.edu.my/8404/ http://eprints.uthm.edu.my/8404/1/24p%20AYAD%20MAHMOOD%20KWAD.pdf text en public http://eprints.uthm.edu.my/8404/2/AYAD%20MAHMOOD%20KWAD%20COPYRIGHT%20DECLARATION.pdf text en staffonly http://eprints.uthm.edu.my/8404/3/AYAD%20MAHMOOD%20KWAD%20WATERMARK.pdf text en validuser phd doctoral Universiti Tun Hussein Onn Malaysia Fakulti Kejuruteraan Elektrik dan Elektronik
institution Universiti Tun Hussein Onn Malaysia
collection UTHM Institutional Repository
language English
English
English
topic QA76.75-76.765 Computer software
spellingShingle QA76.75-76.765 Computer software
Kwad, Ayad Mahmood
Online system identification development based on recursive weighted least square neural networks of nonlinear hammerstein and wiener models.
description The realistic dynamics mathematical model of a system is very important for analyzing a system. The mathematical system model can be derived by applying physical, thermodynamic, and chemistry laws. But this method has some drawbacks, among which is difficult for complex systems, sometimes is untraceable for nonlinear behavior that almost all systems have in the real world, and requires much knowledge. Another method is system identification which is also called experimental modeling. System identification can be made offline, but this method has a disadvantage because the features of a dynamic system may change over time. The parameters may vary as environmental conditions change. It requires big data and consumes a long time. This research introduces a developed method for online system identification based on the Hammerstein and Wiener nonlinear block-oriented structure with the artificial neural networks (NN) advantages and recursive weighted least squares algorithm for optimizing neural network learning in real-time. The proposed method aimed to obtain a maximally informative mathematical model that can describe the actual dynamic behaviors of a system, using the DC motor as a case study. The goodness of fit validation based on the normalized root-mean-square error (NRMSE) and normalized mean square error, and Theil’s inequality coefficient are used to evaluate the performance of models. Based on experimental results, for best Wiener parallel NN model and series-parallel NN model are 93.7% and 89.48%, respectively. Best Hammerstein parallel NN polynomial based model and series-parallel NN polynomial model are 88.75% and 93.9% respectively, for best Hammerstein parallel NN sigmoid based model and series-parallel NN sigmoid based model 78.26% and 95.95% respectively, and for best Hammerstein parallel NN hyperbolic tangent based model and series-parallel NN hyperbolic tangent based model 70.7% and 96.4% respectively. The best model of the developed method outperformed the conventional NARX and NARMAX methods best model by 3.26% in terms of NRMSE goodness of fit.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Kwad, Ayad Mahmood
author_facet Kwad, Ayad Mahmood
author_sort Kwad, Ayad Mahmood
title Online system identification development based on recursive weighted least square neural networks of nonlinear hammerstein and wiener models.
title_short Online system identification development based on recursive weighted least square neural networks of nonlinear hammerstein and wiener models.
title_full Online system identification development based on recursive weighted least square neural networks of nonlinear hammerstein and wiener models.
title_fullStr Online system identification development based on recursive weighted least square neural networks of nonlinear hammerstein and wiener models.
title_full_unstemmed Online system identification development based on recursive weighted least square neural networks of nonlinear hammerstein and wiener models.
title_sort online system identification development based on recursive weighted least square neural networks of nonlinear hammerstein and wiener models.
granting_institution Universiti Tun Hussein Onn Malaysia
granting_department Fakulti Kejuruteraan Elektrik dan Elektronik
publishDate 2022
url http://eprints.uthm.edu.my/8404/1/24p%20AYAD%20MAHMOOD%20KWAD.pdf
http://eprints.uthm.edu.my/8404/2/AYAD%20MAHMOOD%20KWAD%20COPYRIGHT%20DECLARATION.pdf
http://eprints.uthm.edu.my/8404/3/AYAD%20MAHMOOD%20KWAD%20WATERMARK.pdf
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