Computer-aided Nonlinear Control System Design: Using Describing Function Models

195 Pages·2012·3.45 MB·English

by  Amir Nassirharand (auth.)

Computer-aided Nonlinear Control System Design

Amir Nassirharand
Computer-aided Nonlinear
Control System Design
Using Describing Function Models
123
AmirNassirharand
FacultyofEngineering
TheUniversityofNottingham
MalaysiaCampus
JalanBroga
43500Semenyih
Malaysia
ISBN978-1-4471-2148-0 e-ISBN978-1-4471-2149-7
DOI10.1007/978-1-4471-2149-7
SpringerLondonDordrechtHeidelbergNewYork
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To Shabnam,Sam, andDanielwho sufferas
Idomyresearch
OfcoursetoNicole, Jessie,Kaydence, and
Kiera
To mymother,ShokatVahdat,and mylate
father,Hassan,who areproudofthiswork

Preface
The aim of this book is to give an in-depth treatment of computer-aided design
of nonlinear control systems using describing function models. The approach
is systematic, and it is based on a describing function platform. A large class
of nonlinear systems is covered with no restrictions on the number, type, and
arrangement of nonlinear terms, system order, and the number of inputs and/or
the outputs. Unlike other books in the area of nonlinear control that are highly
mathematicallyoriented,thisbookissoftwareoriented.
Itisbelievedthattoday’stightcontrolsystemperformancerequirementsdonot
allowalinearframeofmindforthedesigner.Thedesigner’sfirstchoicetolinearize
a nonlinear model places so many unrealistic restrictions on the real model that
drivesupthecostsoffinalproduct.
Afullnonlinearframeofmindfordesignofnonlinearfeedbackcontrolsystems
requires a computer-aided design approach. Many experts argue that such an
approachwouldnotguaranteestability.Here,withoutlossofgenerality,stabilityis
demonstratedusingthefactthatifthesinusoidalinputdescribingfunctionmodels
ofanonlinearsystemisobtainable,thenthatnonlinearsystemisstablearoundthe
operatingregimesofinterest.
Iliketoemphasizethathavingafullnonlinearframeofminddoesnotmeanthat
designers should throw away other available linear and more restricted nonlinear
control literature. On the contrary, one should capitalize on others’ intellectual
developmentstobringgoodlow-costproductsformankind.Thisbookisavehicleto
accountfornonlineareffects,anditsimultaneouslyenablesthedesignertointerface
withothercontrolsystemdesignworks.
A personwithathoroughknowledgeofcalculusandanelementaryknowledge
ofnumericalanalysisandsoftwareengineeringwouldmostbenefitfromthisbook.
Thisbookshouldbeofinteresttoaerospace,chemical,electrical,mechanical,and
mechatronics students and practicing control engineers as well as other practical
engineers and managers who are simply interested in design of low-cost real-life
nonlinearfeedbacksystems.
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viii Preface
ManykeyMATLAB®functionsaredevelopedandpresentedtoalloweasydesign
of nonlinearfeedbacksystems. The algorithmsand the correspondingMATLAB®
functionsaredemonstratedbysolvingexampleproblemsofthesortencounteredin
mechatronics and aerospace. A versatile controller design software based on the
presented describing function design platform (using MATLAB® Graphics User
Interface (GUI)) is under development which will be commercially available by
early2013.
Semenyih,Malaysia AmirNassirharand
Acknowledgments
First, I like to sincerely thank my mentor, teacher, friend, counselor, adviser,
and academic father, Professor James H. Taylor, for his continued support and
encouragementthroughoutmyacademicandprofessionallife.Hehasalwaysbeen
theretoanswermyquestions.
Ialsoliketothankmystudents.SpecialthankstoProfessorAbhijitPatwardhan
whosecontributionsonsearchoftheparameterinsimultaneousstabilizationtheory
shedlightonthisimportantproblemwhilehewaspursuinghisMaster’sdegreeat
theUniversityofKentucky;myapologiesifIwastoohardonyou!Mr.LiSeeChew,
myPh.D.student,whoisworkingonextensionofsomeoftheworkspresentedhere
totheunstablecaseinadirectwayandwhoisapioneerinexperimentalworkamong
my group members, deserves special thanks for putting up with my supervision.
IsincerelythankMr.SzeHongTeh(UniversityofNottingham–MalaysiaCampus,
(UNMC))forextendingmyPh.D.workondual-rangelinearcontrollerdesignfrom
the single-variable nonlinear case to the multi-variable nonlinear case. His other
worksonidlespeedcontrolofautomobileengines,bank-anglecontrolofaerospace
vehicleswithhardnonlinearities,andinitiationofprojectsinchemicalengineering
andcontinuingtoplaywiththespacecraftattitudecontrolproblemhavecontributed
to preparation of this monograph. His collaboration in developing a versatile
softwarepackagetosupportthismonographisacknowledged.Icertainlyhavebeen
luckytohavetheopportunitytoworkwithyou.SupportofBrandon(myMaster’s
degreestudentatUNMC) is appreciated;I appreciatehis aggressivenessto do his
thesis on application of describing function techniques to nonlinear multivariable
problemofsatelliteattitudecontrol.Finallymanythankstoallthoseundergraduate
Mechanical Engineering and Mechatronics students at UNMC (Ahmed, Ajitpal,
Aimen, Arun, Athira, Awaii, Bartholomew, Bushra, Chan, Chin, Gift, Hammad,
Khawja, Lee, Lim, Mohd, Muhammad, Prem, Saeid, Sameer, Sanz, Sean, Shola,
Tan, Tee, Yuvanraj)who selected myprojectsin the dynamicsystems andcontrol
field as their final year theses, final year design projects, and final year group
developmentprojects.
Many thanks to Dr. Karimi and his research group (Norouz, Seyed Mehdi,
SeyedReza,Ali,Davood, :::)atK.N.T.UniversityofTechnologywhotaughtme
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