CONTROL SYSTEMS ENGINEERING Fourth Edition

T pics are then divided int clearly numbered and labeled secti ns c ntainingexplanati ns, examples, and, where appr priate, skill-assessment exercises withanswers.. Cyber Exploration Lab

i(t)

Desired azimuth angle input

Differential amplifier and power amplifier

Potentiometer

θ Potentiometer

θo(t)

Azimuth angle output θ

Differential preamplifier

θo (s)

s + a s(s + a m)

N te: reader may fill in C nfigurati n 2 and C nfigurati n 3 c lumns after c

m-pleting the antenna c ntr l Case Study challenge pr glems in Chapters 2 and 10,

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Nise, N rman S.

C ntr l Systems Engineering/N rman S Nise.—4 ed.

Includes bibli graphical references.

1 Aut matic c ntr l 2 Systems engineering I Title.

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Cyber Exploration Laboratory

Control Systems Engineering

This b k intr duces students t the the ry and practice f c ntr l systemsengineering The text emphasizes the practical applicati n f the subject t theanalysis and design f feedback systems

The study f c ntr l systems engineering is essential f r students pursuingdegrees in electrical, mechanical, aer space, r chemical engineering C ntr lsystems are f und in a br ad range f applicati ns within these disciplines, fr maircraft and spacecraft t r b ts and pr cess c ntr l systems

is suitable f r upper-divisi n c llege and versity engineering students and f r th se wh wish t master the subject matterthr ugh self-study The student using this text sh uld have c mpleted typical l wer-divisi n c urses in physics and mathematics thr ugh differential equati ns Otherrequired backgr und material, including Laplace transf rms and linear algebra, isinc rp rated in the text, either within chapter discussi ns r separately in the ap-pendixes r n an acc mpanying CD-ROM This review material can be mittedwith ut l ss f c ntinuity if the student d es n t require it

uni-The key features f this f urth editi n areStandardized chapter rganizati nQualitative and quantitative explanati ns

and thr ugh ut the text

C ntr l S luti ns P wered by JustAsk!

experimentsAbundant illustrati ns

Numer us end- f-chapter pr blemsEmphasis n design

Flexible c verage

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Preface vii

Standardized Chapter Organization

Qualitative and Quantitative Explanations

Examples, Skill-Assessment Exercises, and Case Studies

Emphasis n c mputer-aided analysis and design

Ic ns identifying maj r t pics

CD-ROM c ntaining additi nal material

Let us l k at each feature in m re detail

Each chapter begins with a list f chapter bjectives, f ll wed by a list f casestudy bjectives that relate the chapter bjectives t specific student perf rmance

in s lving a practical case study pr blem, such as an antenna azimuth p siti n

c ntr l system

T pics are then divided int clearly numbered and labeled secti ns c ntainingexplanati ns, examples, and, where appr priate, skill-assessment exercises withanswers These numbered secti ns are f ll wed by ne r m re case studies, as will

be utlined in a few paragraphs Each chapter ends with a brief summary, severalreview questi ns requiring sh rt answers, and a set f h mew rk pr blems

Explanati ns are clear and c mplete and, where appr priate, include a brief review

f required backgr und material T pics build up n and supp rt ne an ther in a

l gical fashi n Gr undw rk f r new c ncepts and termin l gy is carefully laid t

av id verwhelming the student and t facilitate self-study

Alth ugh quantitative s luti ns are bvi usly imp rtant, a qualitative r itive understanding f pr blems and meth ds f s luti n is vital t pr ducing theinsight required t devel p s und designs Theref re, whenever p ssible, new c n-cepts are discussed fr m a qualitative perspective bef re quantitative analysis anddesign are addressed F r example, in Chapter 8 the student can simply l k atthe r t l cus and describe qualitatively the changes in transient resp nse that willccur as a system parameter, such as gain, is varied This ability is devel ped withthe help f a few simple equati ns fr m Chapter 4

intu-Explanati ns are clearly illustrated by means f numer us numbered and labeled

thr ugh ut the text Where appr priate, a secti n c ncludes with

These are c mputati n drills, m st with answers, that test

c mprehensi n and pr vide immediate feedback C mplete s luti ns can be f und

n the acc mpanying CD-ROM

Br ader examples in the f rm f can be f und after the last bered secti n f every chapter, with the excepti n f Chapter 1 These case studiesare practical applicati n pr blems that dem nstrate the c ncepts intr duced in thechapter Each case study c ncludes with a “Challenge” pr blem that students may

num-w rk in rder t test their understanding f the material

One f the case studies, c ncerning an antenna azimuth p siti n c ntr l system,

is carried thr ugh ut the b k The purp se is t illustrate the applicati n f newmaterial in each chapter t the same physical system, thus highlighting the c ntinuity

f the design pr cess An ther, m re challenging case study, inv lving an UnmannedFree-Swimming Submersible Vehicle, is devel ped ver the c urse f five chapters

Preface

viii

Control Solutions Powered by JustAsk!

Cyber Exploration Laboratory Experiments

Cyber Exploration Laboratory

Abundant Illustrations

Numerous End-of-Chapter Problems

Emphasis on Design

Design Problems Progressive Analysis and

The Control Solutions Companion

The Control Solutions Companion

pr blems are w rked in detail and explanati ns f every facet f the s luti ns are

pr vided As such, this Web site is a valuable t l in the use f this b k This site

is passw rd pr tected and can be accessed by purchasing

, ISBN 0471483885 This c mpani n supplies y u with an access c de

t the C ntr l S luti ns Web site as well as instructi ns n h w t use the Web site

can be purchased n the b k c mpani n Website, www.wiley.c m/c llege/nise

C mputer experiments using MATLAB, Simulink, and the C ntr l System T

l-b x are f und at the end f the Pr l-blems secti n f Chapters 4 thr ugh 13 under thesubheading The experiments all w the reader

t verify the c ncepts c vered in the chapter via simulati n The reader als canchange parameters and perf rm ”what if” expl rati n t gain insight int the effect

f parameter and c nfigurati n changes The experiments are written with statedObjectives, Minimum required s ftware packages, as well as Prelab, Lab, and P st-lab tasks and questi ns Thus, the experiments may be used f r a lab rat ry c ursethat acc mpanies the class

The ability t visualize c ncepts and pr cesses is critical t the student’s standing F r this reas n appr ximately 750 ph t s, diagrams, graphs, and tablesappear thr ugh ut the b k t illustrate the t pics under discussi n

under-Each chapter ends with a variety f h mew rk pr blems that all w students ttest their understanding f the material presented in the chapter Pr blems vary

in degree f difficulty and c mplexity, and m st chapters include several practical,real-life pr blems t help maintain students’ m tivati n Als , the h mew rk pr b-lems c ntain a pr gressive analysis and design pr blem that uses the same practicalsystem t dem nstrate the c ncepts f each chapter

This textb k places a heavy emphasis n design Chapters 8, 9, 11, 12, and 13

f cus primarily n design But even in chapters that emphasize analysis, simpledesign examples are included wherever p ssible

Thr ugh ut the b k, design examples inv lving physical systems are fied by a ic n End- f-chapter pr blems that inv lve the design

identi-f physical systems are included under the separate heading andals , in chapters c vering design, under the heading

Because visualizati n is s vital t understanding design, this text carefullyrelates indirect design specificati ns t m re familiar nes F r example, the lessfamiliar and indirect phase margin is carefully related t the m re direct and famil-iar percent versh t bef re being used as a design specificati n.

F r each general type f design pr blem intr duced in the text, a meth d l gy

f r s lving the pr blem is presented—in many cases in the f rm f a step-by-step

pr cedure, beginning with a statement f design bjectives Example pr blemsserve t dem nstrate the meth d l gy by f ll wing the pr cedure, making simpli-fying assumpti ns, and presenting the results f the design in tables r pl ts that

c mpare the perf rmance f the riginal system t that f the impr ved system.This c mparis n als serves as a check n the simplifying assumpti ns

Transient resp nse design t pics are c vered c mprehensively in the text Theyinclude

Design via gain adjustment using the r t l cus

Design f c mpensati n and c ntr llers via the r t l cus

Design via gain adjustment using sinus idal frequency resp nse meth dsDesign f c mpensati n via sinus idal frequency resp nse meth ds

Design f c ntr llers in state space using p le-placement techniques

Design f bservers in state space using p le-placement techniques

Design f digital c ntr l systems via gain adjustment n the r t l cusDesign f digital c ntr l system c mpensati n via -plane design and the Tustintransf rmati n

Steady-state err r design is c vered c mprehensively in this textb k andincludes

Gain adjustment

Design f c mpensati n via the r t l cus

Design f c mpensati n via sinus idal frequency resp nse meth ds

Design f integral c ntr l in state space

Finally, the design f gain t yield stability is c vered fr m the f ll wingperspectives:

R uth-Hurwitz criteri n

R t l cus

Nyquist criteri n

B de pl ts

State Space State Space

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Thr ugh ut the b k state-space meth ds are presented al ng with the cal appr ach Chapters and secti ns (as well as examples, exercises, review ques-

classi-ti ns, and pr blems) that c ver state space are marked by a

ic n and can be mitted with ut any l ss f c ntinuity Th se wishing t add abasic intr ducti n t state-space m deling can include Chapter 3 in the syllabus

In a ne-semester c urse, the discussi ns f state-space analysis in Chapters 4,

5, 6, and 7, as well as state-space design in Chapter 12, can be c vered al ng withthe classical appr ach An ther pti n is t teach state space separately by gather-ing the appr priate chapters and secti ns marked with the ic nint a single unit that f ll ws the classical appr ach In a ne-quarter c urse, Chap-ter 13, “Digital C ntr l Systems,” c uld be eliminated

C ntr l systems pr blems, particularly analysis and design pr blems using the r t

l cus, can be tedi us, since their s luti n inv lves trial and err r T s lve these

pr blems, students sh uld be given access t c mputers r pr grammable lat rs c nfigured with appr priate s ftware In this f urth editi n, MATLAB

calcu-c ntinues t be integrated int the text as an pti nal feature

Many pr blems in this text can be s lved with either a c mputer r a held, pr grammable calculat r F r example, students can use the pr grammablecalculat r t (1) determine whether a p int n the -plane is als n the r t l -cus, (2) find magnitude and phase frequency resp nse data f r Nyquist and B dediagrams, and (3) c nvert between the f ll wing representati ns f a sec nd- rdersystem:

hand-P le l cati n in p lar c rdinates

P le l cati n in Cartesian c rdinatesCharacteristic p lyn mial

Natural frequency and damping ratiSettling time and percent versh tPeak time and percent versh tSettling time and peak timeHandheld calculat rs have the advantage f easy accessibility f r h mew rk andexams Please c nsult Appendix G, l cated n the encl sed CD-ROM, f r a dis-cussi n f c mputati nal aids that can be adapted t handheld calculat rs.Pers nal c mputers are better suited f r m re c mputati n-intensive applica-

ti ns, such as pl tting time resp nses, r t l ci, and frequency resp nse curves,

as well as finding state-transiti n matrices These c mputers als give the student

a real-w rld envir nment in which t analyze and design c ntr l systems Th se

n t using MATLAB can write their wn pr grams r use ther pr grams, such as

Pr gram CC Please c nsult Appendix G, n the acc mpanying CD-ROM, f r adiscussi n f c mputati nal aids that can be adapted f r use n c mputers that d

n t have MATLAB installed

With ut access t c mputers r pr grammable calculat rs, students cann tbtain meaningful analysis and design results and the learning experience will

-The MATLAB ic n identifies MATLAB discussi ns, examples, exercises, and

pr blems MATLAB c verage is pr vided as an enhancement and is n t required

t use the text

The Simulink ic n identifies Simulink discussi ns, examples, exercises, and

pr blems Simulink c verage is pr vided as an enhancement and is n t required tuse the text

The GUI T l ic n identifies MATLAB GUI T ls discussi ns, examples, ercises, and pr blems The discussi n f the t ls, which includes the LTI Viewer,the Simulink LTI Viewer, and the SISO Design T l, is pr vided as an enhance-ment and is n t required t use the text

ex-The Symb lic Math ic n identifies Symb lic Math T lb x discussi ns,examples, exercises, and pr blems Symb lic Math T lb x c verage is pr vided

as an enhancement and is n t required t use the text

The State Space ic n highlights state-space discussi ns, examples, exercises,and pr blems State-space material is pti nal and can be mitted with ut l ss f

c ntinuity

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P werP int is a registered trademark f Micr s ft C rp rati n.

Acr bat is a registered trademark f Ad be Systems Inc rp rated.

Simulink is a registered trademark f The MathW rks, Inc

1 2 3

New to this Edition

The Design ic n clearly identifies design pr blems inv lving physical systems

C ntr l S luti ns p wered by JustAsk! is a Web site that c tains step-by-step s luti ns t ver 150 end- f-chapter pr blems Details are de-scribed under Key Features earlier in this Preface

n-A CD-ROM disk acc mpanies the textb k The disk c ntains the f ll wing:

P werP int and Acr bat files c ntaining m st figures fr m the textb k.The files may be used as a c nvenient meth d t pr ject graphics n a screen

t enhance lectures

S luti ns t skill-assessment exercisesAll M-files used in the MATLAB, Simulink, GUI T ls, and Symb lic Math

T lb x tut rialsAdditi nal c mputer pr grams that can be used by readers with ut access tMATLAB

C pies f Cyber Expl rati n Lab rat ry experiments f r c nvenience in ing, f r the purp se f including the experiment questi ns and tasks as a c versheet f r the lab rep rts

print-Additi nal appendixes; t pics in Table f C ntents

A link t the JustAsk! Website

The f ll wing list describes the key changes in this f urth editi n

There is at least a 10% change in the pr blems at theend f the chapters

C ntr l S luti ns p wered by JustAsk! is a Web site that c tains step-by-step s luti ns t ver 150 end- f-chapter pr blems Details are de-scribed under Key Features earlier in this Preface

The use f MATLAB f r c mputer-aided analysis and design c tinues t be integrated int discussi ns and pr blems as an pti nal feature in the

n-f urth editi n The MATLAB tut rial has been updated t MATLAB Versi n 6.5 the

C ntr l System T lb x Versi n 5.2, and the Symb lic Math T lb x Versi n 3.0

The use f Simulink t sh w the effects f n ties up n the time resp nse f pen-l p and cl sed-l p systems appears again in