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dc.contributor.authorYoung, Amandaen_US
dc.date.accessioned2014-03-14T20:36:28Z
dc.date.available2014-03-14T20:36:28Z
dc.date.issued2006-05-05en_US
dc.identifier.otheretd-05122006-123657en_US
dc.identifier.urihttp://hdl.handle.net/10919/32642
dc.description.abstractTraditional flight control design is based on linearization of the equations of motion around a set of trim points and scheduling gains of linear (optimal) controllers around each of these points to meet performance specifications. For high angle of attack maneuvers and other aggressive flight regimes (required for fighter aircraft for example), the dynamic nonlinearities are dependent not only on the states of the system, but also on the control inputs. Hence, the conventional linearization-based logic cannot be straightforwardly extended to these flight regimes, and non-conventional approaches are required to extend the flight envelope beyond the one achievable by gain-scheduled controllers. Due to the nonlinear-in-control nature of the dynamical system in aggressive flight maneuvers, well-known dynamic inversion methods cannot be applied to determine the explicit form of the control law. Additionally, the aerodynamic uncertainties, typical for such regimes, are poorly modelled, and therefore there is a great need for adaptive control methods to compensate for dynamic instabilities. In this thesis, we present an adaptive control design method for both short-period and lateral/directional control of a fighter aircraft. The approach uses a specialized set of radial basis function approximators and Lyapunov-based adaptive laws to estimate the unknown nonlinearities. The adaptive controller is defined as a solution of fast dynamics, which verifies the assumptions of Tikhonov's theorem from singular perturbations theory. Simulations illustrate the theoretical findings.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartThesisFinal.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectNonaffine Systemsen_US
dc.subjectAdaptive Controlen_US
dc.subjectFlight Controlen_US
dc.titleAdaptive Control of Nonaffine Systems with Applications to Flight Controlen_US
dc.typeThesisen_US
dc.contributor.departmentAerospace and Ocean Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineAerospace and Ocean Engineeringen_US
dc.contributor.committeechairHovakimyan, Nairaen_US
dc.contributor.committeememberWoolsey, Craig A.en_US
dc.contributor.committeememberStilwell, Daniel J.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05122006-123657/en_US
dc.date.sdate2006-05-12en_US
dc.date.rdate2006-06-02
dc.date.adate2006-06-02en_US


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