Neural networks output feedback controllers using nonlinear parametric wavelet functions

Abstract

Purpose

The purpose of this paper is to propose an adaptive output feedback controller using wavelet neural networks with nonlinear parameterization for unknown nonlinear systems with only system output measurement.

Design/methodology/approach

An error observer is used to estimate the tracking errors through output measurement information, and the wavelet neural networks are utilized to online approximate an unknown control input by adjusting their internal parameters.

Findings

The controller integrates an error observer and wavelet neural networks with nonlinear parameterization into adaptive control design and is derived in accordance with implicit function and mean value theorem. The adjustment mechanism for the parameters of the wavelet neural networks can be derived by means of mean value theorem and Lyapunov theorem, and the stability of the closed‐loop system can be guaranteed.

Originality/value

This paper utilizes the nonlinear parametric wavelet neural networks with estimate state inputs to obtain the adaptive control input for nonaffine systems with only system output measurement, and the nonlinear wavelet parameters can be adjusted efficiently.

Citation

Leu, Y. and Hong, Y. (2010), "Neural networks output feedback controllers using nonlinear parametric wavelet functions", International Journal of Intelligent Computing and Cybernetics, Vol. 3 No. 4, pp. 672-685. https://doi.org/10.1108/17563781011094214