Moving Path Following Control System for Fixed-Wing Unmanned Aerial Vehicles

124 Pages·2017·5.28 MB·English

FACULDADE DE ENGENHARIA DA UNIVERSIDADE DO PORTO
Moving Path Following Control System
for Fixed-Wing Unmanned Aerial
Vehicles
Tiago Miguel Monteiro de Oliveira
ProgramaDoutoralemEngenhariaElectrotécnicaedeComputadores
Supervisor: ProfessorAntónioPedroAguiar
Co-Supervisor: ProfessorPedroEncarnação
April21,2017
(cid:13)c TiagoMiguelMonteirodeOliveira,2016
Moving Path Following Control System for Fixed-Wing
Unmanned Aerial Vehicles
Tiago Miguel Monteiro de Oliveira
Programa Doutoral em Engenharia Electrotécnica e de Computadores
April21,2017

Resumo
EstateseabordaoproblemadeMovingPathFollowing(MPF)emqueumveículodeveráconvergir
eseguirumdeterminadocaminhogeométricodesejadoquepoderáestaramover-sedeacordouma
especificação em velocidade linear e angular, generalizando desta forma o problema clássico de
seguimentodecaminhosestacionários. Adinâmicadoerroassociadoédeduzidaparaocasogeral
do seguimento de caminhos que se movem num espaço tridimensional, por veículos aéreos não-
tripulados (UAV) de asa fixa. De seguida, diferentes cenários de aplicação para o método MPF
sãoconsiderados.
Estuda-seprimeirooproblemadeseguimentodeumedemúltiplosalvosnosolo,assumindo
que o UAV voa a altitude constante. Para essa missão, propõe-se um algoritmo de geração de
caminhos juntamente com uma lei de controlo para MPF no espaço bidimensional baseada nos
métodos de Lyapunov. São apresentadas garantias formais de convergência, uma métrica de de-
sempenhoeresultadosdosensaiosemvôo.
Aborda-se depois o problema da proteção aérea de colunas de veículos terrestres, utilizando
um UAV com uma câmara instalada a bordo cujo campo de visão é inferior ao raio de curvatura
mínimodoUAV.Aleidecontrolodeduzidaparaoprimeirocenárioéutilizadaemconjuntocom
uma estratégia de orientação de um caminho geométrico solidário com o centro da coluna de
veículosterrestres,demodoapermitiraumUAVdeasafixaconvergireseguiressecaminho. São
apresentadas as condições sob as quais a estratégia proposta resolve o problema de proteção da
colunaterrestre. Amétricadedesempenhoproposta,juntamentecomosresultadosdasimulação
numérica,demonstramaeficáciadaabordagemadoptada.
Finalmente,édeduzidaanívelcinemáticoumaleidecontroloparaocasogeraldoproblemade
MPFatrêsdimensões, tendoporbaseautilizaçãodequaterniões, incluindo-segarantiasformais
deconvergência. Asoluçãopropostaévalidadaporresultadosnuméricosedeensaiosemvôoda
suaaplicaçãoàaterragemautónomanumnavioemmovimento.
Os ensaios em voo realizados no âmbito desta tese tiveram lugar na base aérea da Ota e no
aeródromodeSantaCruz,emPortugal,utilizandooUAVANTEX-X02.
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Abstract
This thesis introduces the Moving Path Following (MPF) problem where a vehicle is required to
converge to and follow a desired geometric path, that moves according to some specified linear
and angular velocity, thus generalizing the classical problem of following stationary paths. In
the proposed approach to solve the problem, a MPF error dynamical system for the general case
of time varying paths in a three-dimensional space is derived for a fixed-wing Unmanned Aerial
Vehicle(UAV).Subsequently,distinctapplicationscenariosfortheMPFmethodareconsidered.
First, the problem of tracking single and multiple targets on the ground using a UAV flying
at constant altitude is addressed. To this end, a path generation algorithm is proposed together
with a two-dimensional Lyapunov based MPF control law. Formal convergence guarantees, a
performancemetricandflighttestsresultsarepresented.
A second application studied is the problem of convoy protection missions using a fixed-
wingUAVwithacameraonboardwhosefieldofviewissmallerthantheUAVminimumturning
radius. Thepreviouslyderivedtwo-dimensionalMPFcontrollawisusedtogetherwithaguidance
algorithmicstrategyinordertomakeafixed-wingUAVconvergetoandfollowadesiredgeometric
moving path that is attached to the convoy center. Conditions under which the proposed strategy
solvestheconvoyprotectionproblemarederived. Aperformancemetricandnumericalsimulation
resultsdemonstratetheeffectivenessoftheproposedapproach.
Finally,ageneralthree-dimensionalMPFquaternion-basedcontrollawisderivedatkinematic
level. Formalconvergenceproofsareprovided. Theproposedmethodisvalidatedthroughnumer-
ical and flight test results, considering the mission scenario of autonomous landing on a moving
vessel.
The flight tests presented here took place in the Ota air base and the Santa Cruz airfield, in
Portugal,usingtheANTEX-X02UAV.
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Acknowledgements
Wordscannotexpressmyimmensegratitudetothepeoplewhohavehelpedmetoaccomplishthe
achievementofwritingthisthesis. Iamdeeplygrateful...
to my supervisors, Professors Pedro Aguiar and Pedro Encarnação, for their insightful com-
ments and thorough suggestions which were crucial to the successful conclusion of this thesis. I
amalsogratefulfortheircontinualavailability,patienceandfriendship,thatalwaysmademefeel
very well supported. Without their permanent support, encouragement and guidance, this thesis
wouldnothavebeenpossible;
to the chiefs of the Portuguese Air Force Research group (CIDIFA), Colonel José Morgado,
Lieutenant-ColonelMariaNunesandMajorAurélioSantos,fortheirconfidenceinmywork;
to Major Carlos Silva and all the Portuguese Air Force flight operations members, namely
SergeantsCarlosBandeiras,FernandoSantos,PauloTeixeira,JoaquimGomes,PauloMendesand
JorgeFernandes,withoutwhomitwouldnothavebeenpossibletoperformtheflighttests;
to Major Paula Gonçalves, that given the common challenges we had to face, was always an
exampleofabnegationandperseveranceinthearduouspathtoobtainaPh.D.degree;
toMajorElóiPereira,forthepreliminaryrevisionofthisthesisandforsharinghisexperience
asaseniorresearcher,whichallowedmetobroadenhorizonsandputthingsintoperspective;
to Captain Gonçalo Cruz, for being always there when I needed. His friendship, loyalty and
supportineveryaspectofourdailyworkwereessentialtoachievethisgoal;
to Captain Francisco Machado, for sharing the responsibility of teaching Avionic Systems at
thePortugueseAirForceAcademy,andalsoforallthedisconcertinganduselessdebates;
to Pedro Marques da Silva and Lieutenant Diogo Silva, for their crucial contributions on the
softwaretoolsthatwereessentialfortheexecutionofthecontrolalgorithmsduringtheflighttests;
to all the members of PITVANT and SEAGULL research projects, in particular to the for-
merUnderwaterSystemsandTechnologyLaboratory(LSTS)members,RicardoBencatel,Carlos
Eduardo and Eduardo Marques, for the introduction to the Piccolo autopilot and for the encour-
agementtoproceedwiththisresearchworkwhileitwasstillinitsearlystage;
to the Portuguese Air Force Academy, where most of this research work took place, for pro-
viding all the necessary means that allowed me to be present in several conferences and work
meetings;
to the administrative staff of the Faculty of Engineering, University of Porto (FEUP), in par-
ticular to José António and Zélia Prior, for their availability in dealing with the non-standard
proceduresthatwereneededtoincludemeasaPh.D.studentatFEUP;
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tomymotherandsister,forshowingmeanholisticviewoflife,whichhelpedmethroughthe
hardtimes;
tomywife,MariaEsperança,forherunconditionalloveandpatience,forenduringtheneces-
saryabsences,andforgivingmethebesttimesofmylife;
tomychildren, HelenaandFrancisco,thatwerebornduringthecourseofthisresearchwork
andunknowinglygavemeatremendousmotivationtoconcludeit;
toallmyfriendsandfamily,fortheirunconditionalsupport,loveandeducation.