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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Control of surfaces in confined spaces : Tab-aileron control system development

Rupert, Francois Johannes 03 1900 (has links)
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: This thesis forms part of the Control Surfaces in Confined Spaces (CoSICS) project conducted at Stellenbosch University. The aim of this project is reduction of control surface actuator footprints on the existing wing structures of commercial airliners such as the Airbus A320 and A330. This is achieved by reducing control surface hinge moments through the application of trailing edge tabs. This results in smaller actuator requirements. The first tier of the project focussed on the geometric optimisation of the tab applied to an aileron. This thesis focusses on the development of dynamic control of the aileron through either tab-only or concurrent tab and aileron actuation. In the effort to develop dynamic control, a fully coupled generalised dynamic model of the tab and aileron is derived and presented. Through linearisation of this model, linear controllers are developed. Two distinctly different controllers are presented; the first controller makes use of classical methods for control of the tab-only actuated aileron and the second controller makes use of modern control techniques such as full state feedback to facilitate controlled concurrent tab and aileron actuation. Each proposed controller is evaluated in terms of dynamic performance, robustness, disturbance rejection and noise immunity. Based on the controller development, a summary of dynamic actuator requirements is given. Practical verification of the model and the controller performance is then undertaken. The development of the necessary hardware and software is also presented. The concept of aileron control through tab-only actuation and concurrent tab and aileron actuation is then validated. Conclusion are then drawn about the accuracy of the theoretical model and the practical performance of the controllers. The thesis is concluded with recommendations for future work to increase the fidelity of the model. Important aspects about the practical implementation of the concept on commercial jetliners are also summarised. / AFRIKAANSE OPSOMMING: Hierdie tesis is deel van die Control Surfaces in Confined Spaces1 projek by Stellenbosch Universiteit. Die doel van hierdie projek behels die verkleining van die aktueerder spasie en ondersteunings struktuur vereistes, op die bestaande vlerk struktuur van kommersiële vliegtuie soos die Airbus A320 en Airbus A330. Dit is bereik deur die vermindering van die beheeroppervlak skarnier se draaimoment met behulp van aerodinamiese hulpvlakke. Kleiner aktueerders word dus benodig. Die eerste stadium van die projek fokus op die geometriese optimisering van die hulpvlak op ’n aileron. Hierdie tesis fokus op die ontwikkeling van dinamiese beheer van die aileron deur middel van hulpvlak aktueering alleenlik of met die gelyktydige aktueering van die hulpvlak en aileron. In die proses van onwikkeling is ’n volgekoppelde veralgemeende dinamiese model van die hulpvlak en aileron afgelei en voorgelê. Deur middel van linearisasie van die model is linieêre beheerders ontwikkel. Tans is twee verskillende beheerders ontwikkel. Die eerste beheerder is gebaseer op die klassieke metodes en maak staat op die aktueering van die hulpvlak alleenlik. Die tweede beheerder maak gebruik van moderne beheer tegnieke soos vol toestand terugvoer om gelyktydige hulpvlak en aileron aktueering te realiseer. Die beheerders is elk geëvalueer in terme van dinamiese gedrag, robuustheid, versteurings verwerping en ruis verwerping. Die beheerstelsel ontwikkeling lei tot ’n opsomming van die dinamiese aktueerder vereistes. Dit word gevolg deur praktiese verifikasie van die model en die beheerstelsel gedrag. ’n Opsomming van die ontwikkeling van nodige hardeware en sagteware word voorgelê. In hierdie proses is die konsep van beide hulpvlak alleenlike aktueering en gelyktydige hulpvlak en aileron aktueering bewys. Gevolgtrekkings word gemaak oor die akkuraatheid van die model en die praktiese gedrag van die beheerders. Die tesis word afgerond met voorstelle vir toekomstige werk wat die model se betroubaarheid kan verbeter. Verder word belangrike punte oor die praktiese aspekte van konsep implementering op kommersiële vliegtuie ook uitgelig.
2

Control surfaces in confined spaces : the optimisation of trailing edge tabs to reduce control surface hinge moments

Jaquet, Christopher Denis 03 1900 (has links)
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This thesis describes the first project relating to the Control Surfaces in Confined Spaces (CoSICS) project at Stellenbosch University. The aim of CoSICS project is to reduce the size of control surface actuators, and this thesis considers the aileron system of commercial aircraft such as the Airbus A320 and A330. Specifically the project aims to reduce the aileron hinge moment, as this will result in smaller actuators. Possible methods are discussed where aerodynamic forces are used to reduce the aileron hinge moment through the use of a wing-aileron-tab configuration. In order to examine the use of the configuration, first order aerodynamic modelling is performed using two-dimensional thin-aerofoil theory, which is also extended to a basic three-dimensional approximation. To determine the maximum reduction in hinge moment several optimisations are performed where only the tab chord length is varied, both tab and aileron chord lengths are varied, and finally the tab chord length and aileron span are varied. The optimisation methods used, namely the gradient-based sequential quadratic programming (SQP) and a real-encoded genetic algorithm (REGA) are discussed in detail and include general implementations which are then applied to the problem. The optimisations performed are dual-layered where optimal deflection angles are determined as well as the optimal geometry. The results of the optimisation are tested using a roll manoeuvre in a specially developed Simulink simulation environment for this purpose. The study produces results where new hinge moment values are an order of magnitude smaller than those of the old configuration, while maintaining suitable lift and rolling moment coefficients. The optimisation and simulation infrastructure developed in this thesis provides a platform for higher-fidelity models and components being developed in future work to provide higher fidelity results. / AFRIKAANSE OPSOMMING: Hierdie tesis beskryf die eerste projek in die Control Surfaces in Confined Spaces-projek1 (CoSICS-projek) uitgevoer by die Universiteit Stellenbosch. Die doel van die COSICs-projek is om die grootte van beheervlak aktueerders te minimeer en hierdie tesis handel oor die aileron stelsel van kommersiële vliegtuie soos die Airbus A320 en A330. Die doel van hierdie tesisis om die skarnier draaimoment van die aileron te minimeer deur aërodinamiese kragte in te span in ’n vlerk-aileron-hulpvlak konfigurasie. Eerste-orde aërodinamiese modelle is afgelei met behulp van twee-dimensionele dunvlerkteorie en is gebruik om die konfigurasie te analiseer. ’n Eerste orde drie-dimensionele benadering is ook ontwikkel. Om die maksimum vermindering in die skarnier draaimoment te bepaal, is verskeie optimerings uitgevoer waar eers die hulpvlak se koordlengte gevarieer word, daarna beide die aileron en hulp-vlak se koordlengtes en laastens die hulp-vlak se koordlengte en wydte. Die twee optimerings metodes wat gebruik is, nl. ’n sekwensiële kwadratiese programmerings (SKP) tegniek, en ’n reële getal-geënkodeerde genetiese algoritme (RGGA), word bespreek en ontwikkel voor hulle toegepas word op die probleem. Twee-vlak optimerings word uitgevoer waar beide die optimale defleksiehoeke en die optimale geometrie bepaal word. Die resultate van die optimering word daarna getoets deur middel van ’n rol maneuver wat uitgevoer word in ’n Simulink simulasie omgewing wat daarvoor geskep is. Hierdie studie lei tot goeie resultate met skarnier draaimoment waardes ’n ordegrootte kleiner as dié van die vorige stelsel, terwyl goeie waardes van rol-moment en verheffingskrag koëffisiënte behou word. Die optimering en simulasie infrastruktuur wat hier ontwikkel word verskaf ’n platform vir meer akkurate modelle en komponente wat ontwikkel word in toekomstige projekte om meer akkurate resultate te lewer.

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