Title: Autopilot design for flexible aerospace vehicles with experimental results

Authors: Amir Nassirharand, Mohammad Hosain Alizadeh

Addresses: Department of Mechanical, Materials and Manufacturing Engineering, The University of Nottingham – Malaysia Campus, Semenyih 43500, Selangor, Malaysia. ' Fara-Faza Company, P.O. Box 1065, 19395 Tehran, Iran

Abstract: This paper aims at providing a solution to the problem of an autopilot design for non-agile aerospace vehicles with large length to diameter ratios. It is shown that quantitative feedback theory (QFT) may effectively be used to design an autopilot accounting for structural bending vibrations; this result is experimentally verified. Furthermore, it is demonstrated that a previously proposed factorisation-based autopilot design procedure for use with rigid aerospace vehicles may easily be adopted to arrive at lucid autopilots for flexible launch vehicles; this result is verified by a previously verified six degree-of-freedom simulation code. Although, both factorisation and QFT design approaches result in satisfactory autopilot systems, the factorisation design is simpler than that of QFT. The factorisation-based design man hour is considerably less than that of the QFT approach.

Keywords: aerospace controls; design methodologies; exact model matching; factorisation theory; QFT; quantitative feedback theory; autopilot design; flexible vehicles; aerospace vehicles; flexible launch vehicles; simulation; structural bending; structural vibrations.

DOI: 10.1504/IJAAC.2009.026779

International Journal of Automation and Control, 2009 Vol.3 No.4, pp.307 - 331

Received: 16 Aug 2008
Accepted: 02 Jan 2009
Published online: 26 Jun 2009 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article