Table Of ContentAdvanced Textbooks in Control and Signal Processing
Stephen J. Dodds
Feedback
Control
Linear, Nonlinear and Robust
Techniques and Design with Industrial
Applications
Advanced Textbooks in Control
and Signal Processing
Serieseditors
MichaelJ.Grimble,Glasgow,UK
MichaelA.Johnson,Kidlington,UK
Moreinformationaboutthisseriesathttp://www.springer.com/series/4045
Stephen J. Dodds
Feedback Control
Linear, Nonlinear and Robust Techniques
and Design with Industrial Applications
123
StephenJ.Dodds
SchoolofArchitecture,ComputingandEngineering
UniversityofEastLondon
London,UK
Additionalmaterialtothisbookcanbedownloadedfromhttp://extras.springer.com.
ISSN1439-2232
AdvancedTextbooksinControlandSignalProcessing
ISBN978-1-4471-6674-0 ISBN978-1-4471-6675-7 (eBook)
DOI10.1007/978-1-4471-6675-7
LibraryofCongressControlNumber:2015944090
SpringerLondonHeidelbergNewYorkDordrecht
©Springer-VerlagLondon2015
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To Margaret
Preface
SubjectMatter
This book is on feedback control systems covering many applications such as
spacecraft orientation, positioning of mechanisms in industry, liquid level and
temperature control, and engine management. The general approach taken is
to commence with the simplest tentative solution to a control problem and in
some cases to demonstrate and explain why this is insufficient and introduce
appropriate measures to ensure that satisfactory performance is achieved, thereby
giving the reader a full understanding of the features of different controllers.
This approach enables the reader to apply traditional control techniques where
these are sufficientbut also encouragesthe creation of more sophisticated control
systemsthatworkbetterforotherapplicationsthroughtakingadvantageofmodern
digitalimplementation.For ease ofunderstanding,the bookis self-containedwith
very little reliance on references, much attention being paid to explanations of
the underlyingconcepts and detailed mathematical derivations being given where
necessary,showingeverystep.Ampleuseismadeofdiagramstoaidtheconceptual
explanations. The reader’s interest in the subject matter is maintained by giving
reasonsfortheinclusionofeverytopicandbringingthematerialtolifebyfrequent
reference to real applications. The numerouscontrol system examples are backed
up by simulations. The reader’s understanding is reinforced by a set of problems
and solutions on each chapter provided in the book website, designed to develop
thereader’sabilitytotackleoriginalandsometimesunusualcontrolproblems.The
reader’sunderstandingisdevelopedfurtherbythe opportunityto experimentwith
anyofthefullycommentedMATLAB®–SIMULINK® controlsystemsimulations
that may be downloaded from the book website. These are also intended to help
readerstodevelopsimulationsoftheirowncontrolapplications.
vii
viii Preface
PurposeandReadership
The main benefit of reading the book is to develop the understanding and skills
neededtopursuearewardingcareerasacreativecontrolengineer.Thereaderswill
include(a) undergraduatesin the finalyear ofan engineeringdegree,(b)master’s
students studying feedback control, (c) PhD students carrying out research in the
controltechniquescoveredordevelopingfeedbackcontrolsystemstosupporttheir
projectsand (d)researchand developmentengineersin industrywishingto create
controlsystemsfullybenefittingfromthemoderndigitalimplementationmedia.
Thenumerouscontrolsystemexamplestogetherwiththesimulationswouldbe
suitableforseedingand/orsupportingfinal-yearundergraduateormaster’sprojects.
Contentof theChapters
Chapter1. Introduction
After defining the notation and nomenclature used throughoutthe book, a review
of the traditional industrial controllers is given, commencing with the simplest.
This ensures some continuity between the elementary studies that will already
have been undertaken by the reader and the more advanced material. Then a
comprehensive treatment of the correlation between the relative pole and zero
locationsof the Laplace transferfunctionof a linear time-invariantsystem and its
dynamic characteristics is given, quantified by the pole-to-pole and pole-to-zero
dominanceratios.
Chapter2.Plant Modelling
This chapter developsthe backgroundtheory and providesthe knowledgeneeded
togenerateplantmodels.Afteranintroductiontothebasiccharacterofplantsand
theircomponents,asubsectiononphysicalmodellingispresented.Thisisbasedon
theunderlyingscienceofthevariousapplications.Withinthespacelimitations,the
mainemphasisisonmechanicalsystemsandelectricmotorsasactuatorstocaterfor
a large proportionof the applications.Some introductorymaterialon thermaland
fluidsystemsisalsogiven.Thisisfollowedbyasubstantialsectionofidentification
ofplantmodelsfrominputandoutputsignalsinthefrequencyandtimedomains.
The appendixcontainsa comprehensivetreatmentof the kinematicsof vehicle
attitudecontrol,relevanttoapplicationssuchasspacecraft,aircraftandunderwater
vehicles. This is followed by a presentation of plant model determination from
frequencyresponsedataincludingproceduresforidentifyingplantswithrelatively
Preface ix
closepolesand/orzeros.Finally,acasestudyofplantmodellingintheautomotive
industryispresentedthatembodiessomeofthetechniquescoveredinthechapter.
Chapter3.Plant Model ManipulationandAnalysis
Further to the physical modelling and identified transfer functions developed in
Chap. 2, this chapter presents means of converting these to other forms of plant
modelneededforthe applicationof specificcontroltechniques,includingtransfer
functionblockdiagramsandstatespacemodels,bothcontinuousanddiscrete.
The theory of the z-transform is reviewed, and means of directly generatingz-
transfer function models including the sample/hold are derived that are directly
useful for control system design. These are included in Table 3 of the Tables
sectionprecedingtheindexattheendofthebookalongsidethez-transformsusually
presentedelsewhere.
Staterepresentationandtheassociatedtransformationsarecovered.Theobserver
canonicalform,thecontrollercanonicalformandthemodalformforsingle-input,
single-outputandmultivariableplantsarestudied.Controllabilityandobservability
analysesforbothcontinuousanddiscretestatespacemodelsareincluded.
Chapter4.TraditionalControllers:Model Based Design
This chapter commences with the simplest feedback control systems to ensure
continuity and provide some revision for readers who have only undertaken one
year of undergraduatestudy of linear control systems. As the chapter progresses,
various performance demands are introduced together with increases in the plant
order.Controllersareselected throughtheneedsofapplicationexamples.At each
stage,features,eitherinthecontrolstructureordesignmethodology,areintroduced
thatmeetthespecification.Withthisapproach,thereaderwillfullyunderstandthe
featuresandbeabletoselectthesimplestsuitabletraditionalcontrollerforaplant
of first or secondorder and calculate its gains,based on pole assignment,to meet
a given performancespecification in terms of settling time, steady state error and
sensitivity/robustness.
The behaviour of linear systems of the third and higher order is studied in
preparationfordesigningcontrolsystemsforsecond-orderplantsusingtraditional
controllers containing integral terms and the more general control systems of
Chap.5.Theauthor’ssettlingtimeformulaearederivedforuseinconjunctionwith
thepoleassignmentdesignofsystemsofarbitraryorder.
Finally,connectionsbetweenperformancespecificationsinthetimedomainand
thefrequencydomainareestablished.
Description:This book develops the understanding and skills needed to be able to tackle original control problems. The general approach to a given control problem is to try the simplest tentative solution first and, when this is insufficient, to explain why and use a more sophisticated alternative to remedy the
