Robust and Adaptive Control With Aerospace Applications

462 Pages·2013·3.471 MB·English

by  Lavretsky, Eugene, Wise, Kevin A

Advanced Textbooks in Control and Signal Processing
SeriesEditors
ProfessorMichaelJ.Grimble,ProfessorofIndustrialSystemsandDirector
ProfessorMichaelA.Johnson,ProfessorofControlSystemsandDeputyDirector
IndustrialControlCentre,DepartmentofElectronicandElectricalEngineering,
UniversityofStrathclyde,GrahamHillsBuilding,50GeorgeStreet,GlasgowG11QE,UK
Forfurthervolumes:
http://www.springer.com/series/4045
Eugene Lavretsky (cid:129) Kevin A. Wise
Robust and Adaptive Control
with Aerospace Applications
EugeneLavretsky
TheBoeingCompany
HuntingtonBeach,California,USA
KevinA.Wise
TheBoeingCompany
BoeingPhantomWorks
St.Louis,Missouri,USA
ISBN978-1-4471-4395-6 ISBN978-1-4471-4396-3(eBook)
DOI10.1007/978-1-4471-4396-3
SpringerLondonHeidelbergNewYorkDordrecht
LibraryofCongressControlNumber:2012951336
#Springer-VerlagLondon2013
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Series Editors’ Foreword
The topics of control engineering and signal processing continue to flourish and
develop.Incommonwithgeneralscientificinvestigation,newideas,concepts,and
interpretations emerge quite spontaneously, and these are then discussed, used,
discarded, or subsumed into the prevailing subject paradigm. Sometimes, these
innovative concepts coalesce into a new subdiscipline within the broad subject
tapestryofcontrolandsignalprocessing.Thispreliminarybattlebetween oldand
newusuallytakesplaceatconferences,throughtheInternetandinthejournalsof
thediscipline.Afteralittlemorematurityhasbeenacquiredbythenewconcepts,
thenarchivalpublicationasascientificorengineeringmonographmayoccur.
Anewconceptincontrolandsignalprocessingisknowntohavearrivedwhen
sufficient material has evolved for the topic to be taught as a specialized tutorial
workshop or as a course to undergraduate, graduate, or industrial engineers.
Advanced Textbooks in Control and Signal Processing is designed as a vehicle
forthesystematic presentationofcourse materialforboth popular andinnovative
topics in the discipline. It is hoped that prospective authors will welcome
theopportunitytopublish astructuredandsystematicpresentation ofsomeofthe
neweremergingcontrolandsignalprocessingtechnologiesinthetextbookseries.
AnaimoftheAdvancedTextbooksinControlandSignalProcessingseriesisto
createalibrarythatcoversallthemainsubjectstobefoundinthecontrolandsignal
processing fields. It is a growing but select series of high-quality books that now
covers some fundamental topics and many more advanced topics in these areas.
Wearethereforeveryfortunatetohavethistextbook fromEugeneLavretskyand
Kevin Wise on Robust and Adaptive Control with Aerospace Applications enter
the series. In many ways, this textbook is a departure for the series since it deals
with the fundamental topics of robust and adaptive control and has very strong
materialfromtheaerospaceapplicationsfield.Thus,itispossibletoseeclearlyhow
the stringent performance requirements of the applications motivate and are met
by the control theory developments. From the aerospace control applications, the
reader will appreciate the industrial context where aircraft operates across a wide
rangeofflightconditions,givingrisetomanydesignpoints.Theaerospaceindustry
solves this problem by using many strategically selected control design points
v
vi SeriesEditors’Foreword
and gain schedules the resulting controllers. Another part of the design context is
theneedforcontroldesignsthatareabletotrackarangeofreferencesignalswhile
remainingrobusttobothparametricandnonparametricmodeluncertainties.These
issuesareallconsideredinPartIofthetextunderthetitleofRobustControl.
Oneofthequestionsarisingfromtheapplicationofgainschedulesiswhetherit
ispossibletoreducethenumberofcontrollersbeingusedandstillmeetthesystem
performancerequirements.Thisisaseriouspracticalquestion,andtheauthorsfind
a solution in the methods of model reference adaptive control (MRAC) that form
PartIIofthetextbook:RobustAdaptiveControl.Thesechaptersfollowasequence
of developments, each one dealing with some practical aspect of MRAC, and
illustrated by very appropriate case study examples. The techniques of Lyapunov
stabilitytheoryareimportanttoolsinthesedevelopmentsandthewholeofChap.8is
devotedtothistopic.Thesetoolsarethenusedtoprovideavarietyofperformance
guarantees for the adaptive control algorithms. Beginning from state feedback
MRAC, the chapter sequence moves on, adding integral control, followed by
inculcating robustness, and then improving the adaptation dynamics and
culminating in the use of output feedback, which is the contribution of the last
chapter (Chap. 14). All the chapters are supported by reference lists and sets of
exercisesforthereader.
Sinceitisnotoftenthatthetextbookseriescontainsavolumefromwriterswho
are based in industry, it is also fitting to say something about the authors in this
Foreword.
Dr.EugeneLavretskyisaBoeingSeniorTechnicalFellowatBoeingResearch
andTechnology,HuntingtonBeach,California,USA.Hehasbeenresponsiblefor
theflightcontrolsystemsofseveraladvancedaircraftandhaspublishednumerous
technical articles on control and aerospace topics. He is a senior member of the
IEEE and was a recipient of the AIAA Mechanics and Control of Flight Award
(2009),theIEEEControlSystemMagazineOutstandingPaperAward(2011),and
the AACC Control Engineering Practice Award (2012), for his work in the aero-
spacefield.
Dr. Kevin A. Wise is a Boeing Senior Technical Fellow at Boeing Phantom
Works, St. Louis, Missouri, USA. He has been responsible for a wide range of
aerospacedevelopmentsincludingflightcontrolsystems,ejectorseatsystems,and
autonomy in unmanned aerial vehicles. Dr. Wise is a fellow of the IEEE and has
receivedbothIFAC(2007)andAIAA(2004)awardsforhisworkandpublications.
Bothauthorshavetaughtthematerialofthistextbookingraduate-levelcoursesat
USuniversities.
ThisnewtextbookisanexcellentadditiontotheAdvancedTextbooksinControl
andSignalProcessingseries.
IndustrialControlCentre M.J.Grimble
Glasgow,Scotland,U.K. M.A.Johnson
May2012
Preface
Afterworkingintheaerospaceindustryforclosetoaquarterofacentury,bothof
us felt strongly about writing this book, with the main goal to share our lessons
learned and design insights into the development and analysis of robust and
adaptivecontrolsystems.Ourfocusisonthesystemsthatarepracticalyethavea
formal basis for performing their design, analysis, and performance evaluations.
DuringourprofessionalcareersattheBoeingCompany,wehavehadamultitudeof
opportunities to design and flight test guidance, navigation, and control (GN&C)
algorithms for a variety of platforms, ranging from commercial aircraft to fully
autonomous experimental aerial vehicles. Over time and after numerous trade
studies,we have collectedanumberofGN&C methods thathave performed well
onavarietyofaircraftsystems.So,wedecidedtowritethisbookandsharewiththe
readerourexperiencesandlessonslearnedinthedesign,analysis,andevaluationof
control technologies, with an emphasis on flight systems. The latter is not a
prerequisite for understanding the book material, as these methods and design
insights apply to all control systems. Aerospace applications and examples
presentedinthisbookareratheramotivationtochallengesinconstructingreliable
andnumericallyefficientcontrolalgorithms.
Manypartsofthisbookarebasedonundergraduateandgraduatecontrolcourses
thatwehavetaughtovertheyearsattheWashingtonUniversityinSaintLouis,the
University of Missouri – Rolla, the Southern Illinois University in Edwardsville
MO, and at the California Institute of Technology (Caltech). As such, the book
materialisquitesuitableforseniorundergraduateandgraduatestudents,aswellas
forpracticingengineersandresearchscientists,whohavehadanexposuretobasic
principlesincontrolsanddynamics,suchasanundergraduatelevelcontrolcourse,
covering classical methods (root locus, Bode diagrams, and Nyquist plots).
Inaddition,weassumethatthereaderhasabasicunderstandingoflinearalgebra,
ordinary differential equations, and is familiar with using state space methods for
analysisandnumericalmodelingofdynamicalsystems.Thesearetheprerequisites.
Motivated and driven by aerospace applications, this book focuses on systems
whosedynamicsarecontinuous.Extensionsofthesemethodologiestodiscreteand
vii
viii Preface
hybrid systems are possible and can be found elsewhere in the vast literature
devotedtocontrolofdynamicalsystems.
Overall,thisbookisself-containedwhilecoveringtheoreticaldevelopmentand
practicalapplicationsofformalmethodsinrobustandoptimallinearcontrol,robust
stabilityanalysis,Lyapunovstabilitytheory,andmodelreferenceadaptivecontrol
(MRAC).Throughoutthisbook,wepresentdetailedsimulationexamplesandcase
studies to illustrate key design steps and the benefits of applying robust and
adaptive control methodologies to transport aircraft and experimental aerial
platforms.
Therearetwomajorpartsinthisbook.PartIpresentsrobustcontroldesignand
analysis methods for linear time-invariant systems. Part II focuses on MRAC
methodsforsystemswithnonlinearanduncertaindynamics.
Readers will benefit from the two-part distinct structure of this book. Such an
arrangementenablesaseamlesstransitionfromtheclassicallinearcontrolconcepts
tothestateoftheartinadaptivesystemswhileillustratingeachdesignwithrealistic
aerospace applications. Also, the two-part book organization allows us to present
self-containedmaterial,coveringlinearandrobustadaptivecontroltechniquesfor
dynamical systems that operate in the presence of uncertainties. Toward that end,
weconsistentlygivestructureddescriptionsofbothclassicalandadvancedcontrol
techniques, key design procedures and guidelines, worked examples, and Matlab
simulations.Eachpartendswithasetofeducationalandchallengingexercisesthat
aredirectlyrelatedtothematerialpresented.Allthesefeaturesconstitutethebook’s
educationalvalue.
PartIbeginswithanintroductiontochallengesincontroldesign,analysis,and
simulationofaerial vehicles. Generalaviationbackgroundand current trends that
leadtotheneedformoreadvancedcontrolarediscussed.Alsopresentedisabrief
survey of control-theoretic methods for existing and future aerial vehicles. The
theoreticalportionofPartIstartswiththeintroductionofrobustandoptimallinear
control methods for linear systems. Command tracking using linear quadratic
regulators(LQR)withintegralactionispresented.Thispartalsocoverstwooutput
feedbackdesignmethods,suchasprojectivecontrolandlinearquadraticGaussian
controlwithLoopTransferRecovery(LQG/LTR).Thesealgorithmsareemployed
todevelopbaselinecontrolarchitecturesforlinearsystemswithknowndynamics.
PartIIbeginswithself-containedmaterialonthedesignandanalysisofadaptive
statefeedbackcontrollersforlinearandnonlinearuncertaindynamicalsystemsin
continuous-time domain. An overview of Lyapunov stability theory is given,
followed by theoretical fundamentals for MRAC systems. Next, approximation
propertiesofartificialneuralnetworksandtheirapplicationstothedesignofdirect
adaptivesystemsareintroduced,andseveralapproximation-basedMRACmethods
are discussed. The part proceeds withthe development of state feedback adaptive
augmentation architectures for robust baseline linear controllers, followed by
extensionsandmodificationstoachievetransientperformanceinadaptivesystems,
aswellastoaccommodateoutputfeedbackconstraints.Inthispart,wealsopresent
adaptiveaugmentationdesignmethodstocombinerobustbaselinecontrollerswith
adaptivefeedback.
Preface ix
Throughout this book, we discuss motivations to the design, analysis, and
implementation of robust and adaptive controllers, with the aim to addressing
realistic challenges that often arise in the flight control of aerial vehicles and
othersystems.