trajectory tracking of a quadrotor unmanned aerial vehicle (uav) via attitude and position control

131 Pages·2014·3.18 MB·English

TRAJECTORYTRACKINGOFAQUADROTORUNMANNEDAERIAL
VEHICLE(UAV)VIAATTITUDEANDPOSITIONCONTROL
ATHESISSUBMITTEDTO
THEGRADUATESCHOOLOFNATURALANDAPPLIEDSCIENCES
OF
MIDDLEEASTTECHNICALUNIVERSITY
BY
EMRECANSU˙IÇMEZ
INPARTIALFULFILLMENTOFTHEREQUIREMENTS
FOR
THEDEGREEOFMASTEROFSCIENCE
IN
AEROSPACEENGINEERING
JULY2014

Approvalofthethesis:
TRAJECTORYTRACKINGOFAQUADROTORUNMANNEDAERIAL
VEHICLE(UAV)VIAATTITUDEANDPOSITIONCONTROL
submitted by EMRE CAN SUI˙ÇMEZ in partial fulfillment of the requirements for
the degree of Master of Science in Aerospace Engineering Department, Middle
EastTechnicalUniversityby,
Prof. Dr. CananÖzgen
Dean,GraduateSchoolofNaturalandAppliedSciences
Prof. Dr. OzanTekinalp
HeadofDepartment,AerospaceEngineering
Assist. Prof. Dr. AliTürkerKutay
Supervisor,AerospaceEnginneringDepartment,METU
ExaminingCommitteeMembers:
Assoc. Prof. Dr. MelinS¸ahin
AerospaceEngineeringDepartment,METU
Assist. Prof. Dr. AliTürkerKutay
AerospaceEngineeringDepartment,METU
Prof. Dr. KemalLeblebiciog˘lu
ElectricalandElectronicsEngineeringDepartment,METU
Assoc. Prof. Dr. MustafaKaya
FlightTrainingDepartment,UTAA
Dr. SebahattinTopal
SpaceTechnologiesResearchInstitude,TÜB˙ITAK
Date:
I hereby declare that all information in this document has been obtained and
presented in accordance with academic rules and ethical conduct. I also declare
that,asrequiredbytheserulesandconduct,Ihavefullycitedandreferencedall
materialandresultsthatarenotoriginaltothiswork.
Name,LastName: EMRECANSU˙IÇMEZ
Signature :
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ABSTRACT
TRAJECTORYTRACKINGOFAQUADROTORUNMANNEDAERIAL
VEHICLE(UAV)VIAATTITUDEANDPOSITIONCONTROL
SU˙IÇMEZ,EMRECAN
M.S.,DepartmentofAerospaceEngineering
Supervisor : Assist. Prof. Dr. AliTürkerKutay
July2014,109pages
In this thesis, trajectory tracking of a quadrotor UAV is obtained by controlling atti-
tudeandpositionofthequadrotorsimultaneously. Twoindependentcontrolmethods
are used to track desired trajectories accurately. One of these methods is a nonlin-
ear control approach called as "backstepping control". The other method is a more
uniqueoptimalcontrolapproachcalledas"LinearQuadraticTracking(LQT)". Inad-
dition, fixed-gain LQR controller which is widely used in literature is also used for
comparison analysis. First, nonlinear dynamic model of quadrotor is obtained by
using Newton’s equations of motion. Then, backstepping controller is obtained in
three steps and simulation model of the backstepping controller is formed. On the
other hand, time-varying optimal control gains of LQT controller are found offline
by solving matrix difference Riccati equation(DRE) backwards in time. Then, LQT
controllerismodeledbyusingtime-varyingoptimalcontrolgainsasastatefeedback
controller. SeveraltrajectoriestobefollowedaregeneratedinMATLABandsentinto
thesimulationmodelsasinputs. Finally,backstepping,LQTandLQRcontrollersare
simulated in MATLAB/Simulink environment, for inital validation. Several trajecto-
ries are tried to be followed by each controller and simulation results of controllers
are compared to each other. It is observed that, LQT controller could track relatively
complex trajectories more accurately and efficiently compared to backstepping and
LQR controllers. Other advantageous and disadvantageous characteristics of each
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control method are also analyzed in details. In this thesis, "AscTech Hummingbird"
quadrotor manufactured by Ascending Technologies is used. "AscTech Humming-
bird" quadrotor gives opportunity to test high level control algorithms generated in
MATLAB/Simulink environment. Therefore, complete validation of controllers ob-
tainedinthisthesiscouldbeperformedbyrealtimeexperimentsinfuture.
Keywords: UAV, Quadrotor, trajectory/path tracking, nonlinear control, optimal con-
trol,disturbancerejection,backstepping,LQT,LQR
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ÖZ
DÖRTROTORLUB˙IR˙INSANSIZHAVAARACININ(˙IHA)YÖNEL˙IMVE
POZ˙ISYONKONTROLÜARACILIG˘IYLAYÖRÜNGETAK˙IB˙I
SU˙IÇMEZ,EMRECAN
YüksekLisans,HavacılıkveUzayMühendislig˘iBölümü
TezYöneticisi :Yrd.Doç.Dr.AliTürkerKutay
Temmuz2014,109sayfa
Butezçalıs¸masında,dörtrotorlubir˙IHA’nınyörünge/yoltakibi,dörtrotorlu’nunyö-
nelimivepozisyonuaynıandakontroledilerekeldeedilmis¸tir.˙Istenilenyörüngelerin
yüksekdog˘ruluklatakipedilmesiiçin,birbirindenbag˘ımsızikifarklıkontrolyöntemi
kullanılmıs¸tır. Bu yöntemlerden biri "geri adımlamalı kontrol" olarak adlandırılan
dog˘rusalolmayanbirkontrolyaklas¸ımıdır.Dig˘eryöntemise"LinearQuadraticTrac-
king(LQT)"olarakadlandırılandahaözgünbiroptimumkontrolyaklas¸ımıdır.Ayrıca,
literatürde yaygın olarak kullanılan sabit-kazançlı LQR(Linear Quadratic Regulator)
kontrolcü kars¸ılas¸tırma analizlerinde kullanılmıs¸tır. ˙Ilk olarak, dört-rotorlu’nun dog˘-
rusal olmayan dinamik modeli Newton hareket denklemleri kullanılarak elde edil-
mis¸tir. Sonrasında, geri adımlamalı kontrolcü üç as¸amada elde edilmis¸tir ve geri-
adımlamalı kontrolcünün simülasyon modeli olus¸turulmus¸tur. Dig˘er taraftan, LQT
kontrolcününzamanagöredeg˘is¸enoptimumkontrolkazançlarımatrisDREzamanda
tersine çözülerek çevrimdıs¸ı olarak elde edilmis¸tir. Sonrasında, LQT kontrolcü, za-
managöredeg˘is¸enoptimumkazançlarıdurumgeribeslemelikontrolcüolarakmodel-
lenmis¸tir. Takip edilecek olan çes¸itli yörüngeler MATLAB kullanılarak olus¸turulmus¸
ve simülasyon modellerine girdi olarak gönderilmis¸tir. Son olarak, geri adımlamalı,
LQT ve LQR kontrolcülerin ilk dog˘rulanması amacıyla, kontrolcüler MATLAB/Si-
mulink ortamında benzetilmis¸tir. Çes¸itli yörüngeler her bir kontrolcü tarafından ta-
kip edilmeye çalıs¸ılmıs¸tır ve kontrolcülerin simülasyon sonuçları birbiriyle kars¸ılas¸-
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tırılmıs¸tır. LQT kontrolcünün, görece kompleks yörüngeleri geri adımlamalı ve LQR
kontrolcüleregöredahadog˘ruveverimliolaraktakipedebildig˘igözlenmis¸tir.Ayrıca,
herbirkontrolcününavantajlıvedezavantajlıözellikleridetaylıolarakanalizedilmis¸-
tir. Bu tez çalıs¸masında, "Ascending Technologies" firması tarafından üretilen "Asc-
Tech Hummingbird" dört rotorlu insansız hava aracı kullanılmıs¸tır. "AscTech Hum-
mingbird" dört rotorlu hava aracı, MATLAB/Simulink ortamında olus¸turulan yüksek
seviye kontrol algoritmalarının test edilebilmesine olanak sag˘lamaktadır. Bu nedenle
gelecek çalıs¸malarda, bu tez çalıs¸masında elde edilen kontrolcülerin tam anlamıyla
dog˘rulanmasıgerçekzamanlıdeneyleraracılıg˘ıylasag˘lanabilir.
AnahtarKelimeler:˙IHA,Dörtrotorlu,yörünge/yoltakibi,dog˘rusalolmayankontrol,
optimumkontrol,bozucubastırma,geri-adımlama,LQT,LQR
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Tomyfamilyandpeoplewhoarereadingthispage
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ACKNOWLEDGMENTS
First of all, I would like to express my sincere gratitude to my advisor Assist. Prof.
Dr. Ali Türker Kutay for its valuable guidance, support and advice throughout my
researchandeducation.
I would also like to express my gratitude to my thesis committee members, Assoc.
Prof. Dr. Melin S¸ahin, Prof. Dr. Kemal Leblebiciog˘lu, Assoc. Prof. Dr. Mustafa
KayaandDr. SebahatinTopalfortheirsignificantreviewsandcomments.
I would like to express my special appreciation to Prof. Dr. Kemal Leblebiciog˘lu,
Prof. Dr. Erol Kocaog˘lan, Prof. Dr. Mustafa Kuzuog˘lu and all other academic staff
ofMETUfortheirinstructiveandrewardinglectures.
I would like to thank entire academic staff of Department of Aerospace Engineer-
ing. I’m also grateful to administrative staff of Aerospace Engineering Department
and special thanks to Derya Kaya and Nilgün Kaplan for their understanding and
supportiveattitudes.
Special thanks to my dear friend and colleague Emre Yılmaz for his support and
sincere friendship. I would also specially thank to Muharrem Özgün, Özcan Yırtıcı,
Özgür Harputlu, Özgür Yalçın, Pınar Eneren, Levent Cevher and all of my other
colleagues and friends at METU for their help and fellowship. I also thank to my
dear friend Erdinç Mermer for his supports. I would also thank to my special friends
Gökhan, Burak, Mert, Anıl, Yasin, Fırat, Berk, Canbert, Çınar, Mehmet that I really
spentgreattimeatsomestagesofmylife.
I am also grateful to my lovely family, Halit, Nurcan, S¸encan, Tekin and our little
sweetguestEzgithatwehopetojoinourfamilysoon. Iwouldliketospeciallythank
myfatherandmotherfortheirinvaluablesupportandloveespeciallyathardtimesof
mylife.
IalsothankGodtogivemetheopportunitytomeetmysweetheartTug˘bawhohelped
me at each stage of my life with her endless love and support. I am also grateful to
Büs¸ra, Murat, Gülay, Fatih, Ceyda and all other friends that I meet via my beloved
Tug˘ba.
Finally, I would like to thank The Scientific and Technological Research Council of
Turkey(TÜB˙ITAK)foritsscholarshipsupport.
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