@article{Nikolic_Milovanovic_Dankovic_Mitic_Peric_Djordjevic_Djekic_2023, title={Identification of Nonlinear Systems Using the Hammerstein-Wiener Model with Improved Orthogonal Functions}, volume={29}, url={https://eejournal.ktu.lt/index.php/elt/article/view/33838}, DOI={10.5755/j02.eie.33838}, abstractNote={<p>Hammerstein-Wiener systems present a structure consisting of three serial cascade blocks. Two are static nonlinearities, which can be described with nonlinear functions. The third block represents a linear dynamic component placed between the first two blocks. Some of the common linear model structures include a rational-type transfer function, orthogonal rational functions (ORF), finite impulse response (FIR), autoregressive with extra input (ARX), autoregressive moving average with exogenous inputs model (ARMAX), and output-error (O-E) model structure. This paper presents a new structure, and a new improvement is proposed, which is consisted of the basic structure of Hammerstein-Wiener models with an improved orthogonal function of Müntz-Legendre type. We present an extension of generalised Malmquist polynomials that represent Müntz polynomials. Also, a detailed mathematical background for performing improved almost orthogonal polynomials, in combination with Hammerstein-Wiener models, is proposed. The proposed approach is used to identify the strongly nonlinear hydraulic system via the transfer function. To compare the results obtained, well-known orthogonal functions of the Legendre, Chebyshev, and Laguerre types are exploited.</p>}, number={2}, journal={Elektronika ir Elektrotechnika}, author={Nikolic, Sasa S. and Milovanovic, Miroslav B. and Dankovic, Nikola B. and Mitic, Darko B. and Peric, Stanisa Lj. and Djordjevic, Andjela D. and Djekic, Petar S.}, year={2023}, month={Apr.}, pages={4-11} }