Title: Tracking and decoupling of multivariable non-linear systems

Authors: Amir Nassirharand, S.A. Hosseini

Addresses: Department of Mechanical, Materials and Manufacturing Engineering, Faculty of Engineering, The University of Nottingham – Malaysia Campus, 43500 Semenyih, Selangor, Malaysia. ' Space Engineering Department, Faculty of New Technologies and Energy Engineering, Shahid Beheshti University, Evin, Tehran, Iran

Abstract: This paper presents a new systematic procedure for decoupling and command tracking of multivariable, non-linear, and unstable systems. The design methodology is based on stabilisation of the multivariable system followed by generating its describing function models; two algebraic procedures for decoupling and tracking are used. Finally, the design must be verified by a non-linear simulation to make sure that approximations made during design are valid. The major outcome of this research is that controllers of a general class of non-linear systems may be designed taking into account the amplitude dependency features of that system. This amplitude dependency is the most important characteristic of a non-linear system. This is the first paper in the area of simultaneous decoupling and signal tracking of multivariable non-linear systems that is based on the application of the describing function technique and two other algebraic techniques. In fact, this is the first work in the area of decoupling of general unstable multivariable non-linear systems that is based on a describing function technique.

Keywords: control; describing functions; decoupling; Fourier analysis; synthesis; modelling; identification; optimisation; multivariable systems; nonlinear systems; command tracking; signal tracking.

DOI: 10.1504/IJMIC.2009.024741

International Journal of Modelling, Identification and Control, 2009 Vol.6 No.4, pp.341 - 348

Published online: 29 Apr 2009 *

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