Flight control system design for VSTOL aircraft using switched H∞ controllers

Abstract

This is a design study on a Generic VSTOL Aircraft Model (GVAM) supplied by the Royal Aerospace Establishment, Bedford. Widely varying dynamics requires some form of gain scheduling or switching. The approach taken is to switch between linear controllers designed on linearisations of the non-linear model. The linear designs make use of an open-loop singular-value shaping technique developed by McFarlane and Glover (1988) and McFarlane, (1988) which optimises the system robustness to perturbations of the normalised c oprime factors of the plant. Switching between controllers is achieved using a technique proposed by Hanus, (1987) which permits smooth transition between controllers. A more detailed account of the design here can be found in Hyde, et al. (1990)..

Keywords

H-infinity robust control VSTOL scheduling switching

References

Hanus, R. , Kinnaert, M. and Henrotte, J.L. 1987. 'Conditioning technique - a general anti-windup and bumpless transfer method'. Automatica, 23, (6), 729-739.

Hyde, R.A. and Glover, K. 1990. 'VSTOL aircraft flight control system design using Hx controllers and a switching strategy', CDC (to be published).

Hyde, R.A. , Glover, K. and Williams, S.J. 1990. 'Scheduling by switching of H∞ controllers for a VSTOL aircraft', in Applications of multivariable system techniques , Bradford, UK.

McFarlane, D.C. 1988 Robust controller design using normalized coprime factor plant descriptions, PhD Thesis, University of Cambridge .

McFarlane, D.C. and Glover, K. 1988. 'A loop-shaping design procedure using H∞ synthesis ', submitted to IEEE Trans on Automat Cont, October 1988.

Mustafa, D. 1989. Minimum entropy Hx control, PhD Thesis, University of Cambridge, May.

Postlewaite, I. , Tsai, M.-C. and Gu, D.-W. 1990. 'Weighting function selection in Hx design, in International Federation of Automatic Control 1990.

Sefton, J.A. and Glover, K. 1990. 'Pole/zero cancellations in the general H∞ problem with reference to a two block design', Syst and Cont Lett , 14.

Williams, S.J. and Hyde, R.A. 1990. 'A comparison of different H∞ design methods for VSTOL flight control system design' in American Control Conference, May 1990, San Diego, USA.

10.

Williams, S.J. and Smith, P.R. 1989. 'A comparison of characteristic locus and H∞ methods in VSTOL flight control system design', in AIAA Conference on Guidance Navigation and Control, 565-575.