Tale Project

8/12/2019 Tale Project

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Acknowledgement

During the course of our senior project work, there were many people who wereinstrumental forwards my accomplishing the task before me. Without their guidance,

help and patience, we would have never been able to accomplish the work of thissenior project. We would like to take this opportunity to acknowledge them all.

We would like to express our gratitude and appreciation to our senior project advisor Mr.Destaw, for his expertise, understanding, and patience, throughout ourundergraduate programs. He provided encouragement, and guidance at all levels of thesenior project work. He has been so amaing!

We would also like to thank Dr."inyl for supporting us with his bound of expertise. He hasbeen nice with everything.

We would also like to thank the department of electrical engineering and the entire staff fortheir support.

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TABLE OF CONTENTS

Acknowledgment 1

Abstract 8

1. Introducton

1.1 !ro"ect O#er#ew $

1.% Ob"ect#e o& t'e (ro"ect 1)

1.* +e&nton o& ,agnetc Le#taton 1)

1.- Statement o& t'e (roblem 11

1. ,et'odolog/ 11

1.0 Sco(e o& t'e (ro"ect 1%

1. (ro"ect Outlne 1%

%. Lterature 2e#ew o& ,agnetc Le#taton S/stem

%.1 Introducton 1-

%.% ,agnetsm Bascs 1-

%.* T'e In#sble Feld 1

%.- ,agnetc Le#taton Tec'n3ues 10

%.-.1 Sur#e/ o& Le#taton !ro"ect O#er#ew 10

%.-.% !rnc(les and Lmtaton o& Electromagnetc tec'n3ues o& sus(enson and Le#taton 1

%.-.* Le#taton usng !ermanent ,agnet 1

%.-.- Le#taton usng damagnetc materals 1$

%.-. Le#taton usng su(erconductors 1$

%.-.0 Le#taton usng nduced edd/ currents %1

%.-. Le#taton usng &orces actng on current carr/ng conductors stuated n magnetc &elds %*

%.-.8 Sus(enson usng a Tuned LC2 Crcut and Electrostatc Force o& Attracton %*%.-.$ Sus(enson usng a Tuned LC2 Crcut and Electromagnetc Force o& Attracton %-

%.-.1) Sus(enson usng Controlled +C Electromagnet %

%. ,agnetc Tec'nologes and A((lcatons %0

%..1 ,agnetc Bearngs %0

%..% Su(erconductng ,agnetc Bearngs %0

%..* Smaller and Better ,agnets %

%..- En#ronmental ,agnets %

%.. Su(erconductng ,agnets %

%..0 ,agle# Trans %8

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%.0 Introducton to Com(ensator %$

%. T'e Com(ensat#e Network *1

%.8 ,crocontroller *1

%.8.1 !IC ,IC2OCONT2OLLE2S *%

%.8.1.1 T'e !IC10F8A *%

%.$ T'e L%$*+ 3uadru(le 'al&45 dr#er *

%.1) !'oto Sensors

%.11 So&tware and !rograms used n t'e (ro"ect

%.11.1 ,atlab

%.11.% !rotues ISIS !ro&essonal

%.11.* ,kro C

%.1% !rogrammng n C

*. S/stem 6eneral +escr(ton

*.1 Introducton

*.% Com(ensaton +esgn Block dagram

*.* ,crocontroller based control block dagram

*.- S/stem Anal/ss and +esgn

*. !arameter +etermnaton

*.0 Non4Lnear Control and 7rtual !ole Cancellaton

*. Electromagnet +esgn

-. Controller +esgn

-.1 Inward and Outward A((roac'

-.1.1 Outward A((roac'

-.1.% Inward A((roac'

-.% S/stem Trans&er Functon

-.%.1 Lnear Algebrac ,et'od

-.%.% A((lcaton o& t'e Lnear Algebrac ,et'od

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Lst o& Tables

TABLE *.19 I NITIAL !A2A,ETE2S OF E;!E2I,ENTAL S<STE,...................................................................................................*0

TABLE .19 O!TICAL SENSO2 C5A2ACTE2ISTICS............................................................................................................................)TABLE .%9 !5OTO+IO+E O!TIONS.......................................................................................................................................................%

TABLE .*9 T<!ICAL O:T!:T !O=E2 OF 7A2IO:S LE+S............................................................................................................*

TABLE .-9 +ETECTO2 !5OTO+IO+E 2 ES!ONSE TO 7A2IO:S LI65TIN6 CON+ITIONS.......................................................

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Lst o& FguresFI6:2E

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1.19 =ATT>S FL< BALL 6O7E2NO2..........................................................................................................................................-

%.19 T5E ,A6NETIC FIEL+ OF LINES IN T5E BA2 ,A6NET AN+ 5O= A STEEL BALL LE7ITATE...........................1

%.%9 T5E ?:,!IN6 2IN6 E;!E2I,ENT....................................................................................................................................%%*.19 T5E !5<SICAL S<STE, OF T5E ,A6NETIC LE7ITATION...................................................................................... ..*)

*.%A9 : NCO,!ENSATE+ 2OOT LOC:S OF T5E ,A6NETIC LE7ITATION S<STE,.....................................................*$

*.*9 CONT2OL S<STE, BLOC@ +IA62A, OF T5E ,A6NETIC LE7ITATION S<STE,...............................................-)-.19 BLOC@ +IA62A, OF :NIT< FEE+BAC@ CONT2OL S<STE,.....................................................................................--

-.*. SE2IES CO,!ENSATION O2 CASCA+E+ CO,!ENSATION................................................................................... .....1

-.-9 !A2ALLEL CO,!ENSATION..............................................................................................................................................%-.9 SE2IES4!A2ALLEL CO,!ENSATION...............................................................................................................................%

-.09 !5ASE4LEA+ CO,!ENSATO2 NET=O2@.....................................................................................................................*

-.9 ,A6NETIC LE7ITATION S<STE, =IT5 !5ASE4LEA+ CO,!ENSATO2...............................................................0)

-.$9 !OLE4E2O +IA62A, OF T5E !5ASE4LEA+ NET=O2@.........................................................................................0%

-.1)9 BLOC@ +IA62A, OF :NIT< NE6ATI7E FEE+BAC@ CONT2OL S<STE,............................................................0*

-.1%9 CO,!ENSATE+ 2OOT LOC:S OF T5E ,A6NETIC LE7ITATION S<STE, !OLES IN T5E 25!..................00-.1*9 BO+E AN+ !5ASE !LOT OF T5E ,A6NETIC LE7ITATION S<STE,.....................................................................0

.19 I NITIAL ,A6LE7 CONCE!T.............................................................................................................................................0$

.%9 O!TICAL S!ECT2:,..........................................................................................................................................................1

.*9 S!ECT2AL 2 ES!ONSE OF +ETECTO2 !5OTO+IO+E.................................................................................................1.-9 NA22O=4BAN+ 7S. =I+E4BAN+ LE+S......................................................................................................................-.9 I NF2A2E+ LI65T E,ITTIN6 +IO+ES...............................................................................................................................

.09 !5OTO T2ANSISTO2 CI2C:IT...........................................................................................................................................0

.9 O!E2ATIN6 C5A2ACTE2ISTICS OF O!TO4+ETECTO2.................................................................................................

.89 +IFFE2ENCE A,!LIFIE2 :SIN6 O!A,!.............................................................................................8

.$9 !5ASE LEA+ NET=O2@.....................................................................................................................................................81

.119 !2ACTICAL CI2C:IT OF !5ASE LEA+ NET=O2@......................................................................................................8%.1%9 O:T!:T A,!LIFIE2........................................................................................................................................................8*

.1*9 N:T AN+ =AS5E2 :SE+ =IN+IN6 T5E COIL............................................................................................................80

.1-9 LE7ITATO2 COIL AN+ !O=E2 A,!LIFIE2 T2ANSISTO2....................................................................................... .88

.1- 9 T5E O7E2ALL SC5E,ATICS OF ,A6NETIC LE7ITATION S<STE,.....................................................................$)

.19 T5E !S!ICE SI,:LATION OF ,A6NETIC LE7ITATION S<STE,.......................................................................$%

.109 T5E !S!ICE SI,:LATION 2 ES:LT FO2 T5E 6AIN OF T5E FI2ST O!A,!..........................................$*.19 T5E !S!ICE SI,:LATION 2 ES:LT OF T5E +IFFE2ENCE A,!LIFIE2...............................................................$-

.189 T5E !S!ICE SI,:LATION 2 ES:LT =IT5 !5ASE LEA+ CO,!ENSATO2 O:T!:T..........................................$

.1$9 T5E ,A6NETIC LE7ITATION SA,!LE 1 !5OTO......................................................................................................$

FI6:2E .%)9 T5E ,A6NETIC LE7ITATION SA,!LE % !5OTO.....................................................................................................$$

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Abstract,agnetc le#taton 'as e#ol#ed nto an m(ortant consderaton n desgnng s/stems re3urng

low losses due to &rcton and low energ/ consum(ton. A((lcatons rangng &rom 'g'4s(eed ral

trans(ortaton s/stems to #arous ndustral a((lcatons e.g. magnetc bearngsD. ,agnetsm and

closed4loo( control s/stem are t'e secrets to makng an ob"ect &loat n md4 ar. T's (ro"ect wll

n#ol#e t'e desgn o& controllers t'at make a magnetc le#taton s/stem

stable.

In our (ro"ect a magnetc le#taton on a steel ball and ts control are desgned n two wa/s one n

a classcal wa/ o& controllng and mcrocontroller based wa/ o& controllng. An n&rared emtter

and detector are mounted as lg't transmtter and lg't rece#er &or creatng an n#sble beam &or

t'e control crcut. As t'e magnetc attracton causes t'e ball to rse towards t'e col t'e ball begns

to block t'e beam. T'e control crcut uses &eedback &rom n&rared detector &rom rece#erD to

ad"ust t'e col current to kee( t'e ob"ect (recsel/ centered n t'e n&rared beam. T'e ('ase lead

com(ensator control crcut and t'e mcrocontroller based controller are desgned so t'at

e3ulbrum s reac'ed w'ere t'e magnetc attracton &orce eactl/ balances t'e &orce o& gra#t/

(ullng on t'e ball. T'e ball t'en remans (er&ectl/ sus(ended below t'e col wt' no #sble

means o& su((ort.

T's ,agnetc le#taton s/stem wll am to (ro#de a means &or students to gan nsg'ts nto and

de#elo( anal/ss and desgn tec'n3ues a((ro(rate &or suc' a s/stem. It wll also ncor(orate

t'e dea o& magnetc le#taton demonstratng ts wde range o& a((lcatons as t s termed as t'e

&utureG

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C'a(ter One

Introducton

1.1 !ro"ect O#er#ew

T'e de#elo(ment o& electroncs and electrc e3u(ment 'as re#olutonHed e#er/t'ng n t'e

#cnt/ o& ('/scal world. It 'as re#olutonHed e#er/t'ng &rom small c'(s used n cellular

('ones to tremendousl/ bg and ntellgent surger/ robots used n medcal m(lants. T'e

(roducton o& 'g' 3ualt/ (arts o& suc' amaHngl/ small sHe re3ures tec'nologcal

m(ro#ements n mac'nng and moton. In order to stablHe (arts and mo#e t'em wt' a 'g'

le#el o& (recson a new class o& actuators s re3ured. Among t'ese mac'nes magnetc

le#tators (ro#de man/ bene&ts not &ound n com(ettors. It s t'e ntent o& t's (ro"ect

work to m(lement a sngle degree o& &reedom magnetc actuator t'at wll (roduce (recse

moton control o& t'e le#tated ob"ect. T'e ob"ect be'nd t'e o(eraton o& ,agnetc Le#taton

'as been e(ressed to nclude a ,agle# de#ce nto Industral Control S/stems. To

accommodate t's a magnetc le#taton de#ce wll be constructed w'c' can demonstrate t'e

magnetc le#taton w'c' s o& a great rele#ance t'ese da/s. A ,agle# de#ce s a s/stem t'at

uses magnetc &elds as a means to le#tate an ob"ect n a (artcular (oston. ,ost (eo(le 'a#e

e(ermented wt' (ermanent magnets and understand t'at le#tatng an ob"ect s 3ute d&&cult.

I& an ob"ect s (laced too &ar awa/ &rom t'e magnetc source t'e magnetc &eld s too weak to

su((ort t'e weg't o& t'e ob"ect. I& (laced too close to t'e magnetc source t'e magnetc &eld

becomes too strong and causes t'e ob"ect to mo#e towards t'e source untl t makes ('/scal

contact wt' t'e magnet. From t'e abo#e t s s'own t'at a ,agle# de#ce s an eam(le o& an

n'erentl/ unstable s/stem. To o#ercome t's nstablt/ an electromagnet wll 'a#e to be

constructed. T's electromagnet s a sm(le de#ce made u( o& a magnetc materal wound wt' a

current conductng col. T's col allows a #ar/ng current to generate a #ar/ng magnetc &eld

and 'ence a #ar/ng &orce to be eerted on an/ ob"ect n ts #cnt/. @nowng t'at we can

control t'e amount o& &orce eerted on t'e test ob"ect we can t'en de#elo( a stablHng

controller to stablHe t'e (oston o& t'e ob"ect.

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1.% Ob"ect#e o& t'e senor (ro"ect

T'e g#en (roblem s to desgn magnetc Le#taton o& a s/stem w'c' wll le#tate a steel ball

below t'e electromagnet and mo#e t n a sngle as wt' 'g' (recson.

T'e general ob"ect#e o& t's (ro"ect was to desgn and buld t'e magnetc le#taton s/stem. T'e

magnetc Le#taton s/stems 'as been anal/Hed mat'ematcall/ and desgn a control s/stem w'c'

le#tates a steel ball below t'e electromagnet &or an nde&nte (erod o& tme at a((romatel/ *4

1) mllmeters &rom t'e base o& t'e electromagnet.

T'e s(ec&c ob"ect#e o& t's (ro"ect work s to anal/He t'e magnetc le#taton s/stem

anal/ss and desgn two t/(es o& controllers one w'c' uses analog com(onents and classcal

wa/ o& controllng and anot'er t'at uses dgtal com(onents and a dgtal wa/ o& controllng to

make t'e le#taton s/stem stable. T'ese ,agnetc Le#taton s/stems can be used to

demonstrate t'e recent tec'nologcal ad#ancements regardng t's tec'nolog/ and ns(re &ellow

students to stud/ t'ese s/stems more n order to allow our countr/ 'a#e t'e ca(act/ to own ts

own magnetcall/ le#tated trans bearng and &rctonless motors and t'e lke someda/.

1.* +e&nton o& ,agnetc Le#taton

+ctonares de&ne Le#taton as9 rasng o& a 'uman bod/ abo#e ground wt'out su((ort and

wt'out materal 'el(. It s nearl/ antgra#t/ t'e mass n le#taton not trans&erred to groundD.

In etendng t'e de&nton to 'ea#/ materal ob"ects and rede&nng t'e condton wt'out

materal 'el( to no su((ort de#ce w'c' 'as a massD a magnetc &eld t'at kee(s n

(ostonD an ob"ect n sus(enson abo#e t'e ground wt'out an/ materal between t'e ground and

an/ (ont o& t'e ob"ect (ut t's ob"ect n le#taton de&nes magnetc le#taton. T'us a ball o&

tenns table &loatng on a water "et donJt le#tate t'e &lud t'at sustans t 'a#ng mass.

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1.- Statement o& t'e (roblem

As magnetc le#taton s a s/stem o& 'g' nstablt/ +esgnng a controller t'at makes t's

s/stem stable remaned to be t'e man (roblem o& t'e senor (ro"ect. In order to desgn t's

controller t'e magnetc s/stem need to be modeled mat'ematcall/ consderng t to be a stableone and t'en contnued t'e desgn o& t'e nstablt/ stablHer controller. T's (ro"ect

conssts two t/(es o& controller desgns one w'c' &ollows classcal wa/ o& controllng .e.

usng com(ensators and anot'er w'c' &ollows modern or dgtal wa/ o& controllng .e. usng

mcrocontrollers. Bot' wa/s o& controllng t'e magnetc le#taton s/stem are to be dscussed

bre&l/ n t's document.

1. ,et'odolog/As t 'as been descrbed n (re#ous sectons o& t's document a magnetc le#taton s/stem s a

'g'l/ unstable s/stem due to t'e n'erentl/ unstable magnetc be'a#or o& t'e electromagnet

used n t'e s/stem. T'ere are man/ wa/s o& obtanng t'e stablt/ n 3ueston. T's ma/ nclude

a !I+ s/stem a !+ s/stem a com(ensator a mcrocontroller based s/stem and an F!6A based

s/stem. Among t'ese wa/s t'e !I+ !+ and com(ensator s/stems classcal controllng

met'odsD are smlar n desgnng w'le t'e mcrocontroller and F!6A s/stems are somew'at

d&&erent. To le#tate a metal ball we used to met'ods o& controllng t'e le#taton among t'e

abo#e. T'e met'ods used n t'ese two are descrbed (recsel/ n t'e &ollowng cou(le o&

(aragra('s.

T'e &rst met'od t'at we used was t'e classcal wa/ o& controllng b/ usng a com(ensator. On

t'e course o& t's met'od t'e &rst t'ng t'at we dd was to desgn a &eedback s/stem a lg't

sensor as t'e &eedback elementD and &nd ts trans&er &uncton. And t's trans&er &uncton was

easl/ be tested &or stablt/ w'ere t (ro#ed t'at t'e entre s/stem was unstable. T'en we went

to desgn t'e com(ensator t'at made t'e s/stem stable. And t'ese were c'ecked b/ d&&erent

tools to (ro#e ot'erwse.

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T'e second met'od t'at we used was t'e dgtal wa/ o& controllng b/ usng a mcrocontroller

s(ec&call/ t'e !IC 10F8A. =e used t'e s(ecal &eature o& t's mcrocontroller t'e CC!

module w'c' contans t'e !=, to control t'e stablt/ o& t'e s/stem. T'e control was

conducted b/ controllng t'e current su((led to t'e electromagnet 'ence t'e magnetc &orce.

F#e lg't sensors rece#er and emtter (arsD were em(lo/ed as sensors to su((l/ t'e

mcrocontroller wt' a &eedback o& t'e (oston o& t'e ball to be le#tated. An 54brdge was also

em(lo/ed n controllng t'e current wt' n(uts &rom t'e mcrocontroller.

T'e abo#e (aragra('s descrbe t'e mere met'odologes o& t'e (ro"ect and t'ose met'odologes

wll be e(laned n t'e comng sectons o& t's document.

1. Sco(e o& t'e (ro"ect

T'e sco(e o& t's (ro"ect wll range &rom descrbng t'e w'ole s/stem mat'ematcall/ .e.

desgnng t'e mat'ematcal model o& t'e s/stem to controllng t n two wa/s as t 'as been

descrbed n t'e (re#ous sectons o& t's document. And we wll &nall/ m(lement one o& t'e

desgns n 'ardware &orm to llustrate t'e w'ole (ont o& magnetc &eld realstcall/. T's (ro"ect

s a small scale model o& t'e magnetc le#taton s/stem. As a result t s not to be e(ected to be

used drectl/ n to real l&e a((lcatons but t'e met'ods used n t'e desgn (rocesses can. It s to

be noted t'at t's magnetc le#taton s/stem onl/ su((orts one degree o& &reedom mo#ement .e.

#ertcal sus(enson onl/.

1.8 (ro"ect>s Outlne

T's (ro"ect re(ort s se(arated nto s dstnct c'a(ters. A bre& descr(ton o& eac' c'a(ter s

as &ollows9

C'a(ter 1 4 T's c'a(ter (ro#des a general ntroducton outlne o& t'e (ro"ect

to(c met'odolog/ t'at was em(lo/ed to ensure t'at t'e stated goals and ob"ect#es were

ac'e#ed.

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C'a(ter % 4 T's c'a(ter descrbes t'e !'/scs o& ,agnetc Le#taton and anot'er

conce(ts and de#ces used durng t'e course o& t's senor (ro"ect.

C'a(ter * 4 T's c'a(ter descrbes t'e ,at'ematcal ,odelng and t'e ('/scal

c'aracterstcs o& t'e ,agnetc le#taton s/stems. It also contans t'e two t/(es o&

controller desgns

C'a(ter - 4 T's c'a(ter dscusses controller desgn o& t'e magnetc le#taton s/stem.

C'a(ter 4 T's c'a(ter descrbes smulatons and results

C'a(ter 04 T's c'a(ter contans a &nal concluson o& t'e (ro"ect and &uture

recommendaton o& t'e magnetc le#taton s/stems.

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C'a(ter Two

Lterature 2e#ew o& ,agnetc Le#taton

%.1 Introducton

T'e researc' n#ol#ed n t's (ro"ect centered on t'e constructon o& an electromagnet modelng and

stablt/ tec'n3ues sensng tec'n3ues and controller desgn. T'e background knowledge needed

was ganed &rom (re#ous undergraduate courses. In (er&ormng t'e lterature re#ew &or t's

(ro"ect t was e(ected t'at a &ew de&nt#e gudes on buldng a magnetc le#taton de#ce would

be &ound. Electromagnetc researc'er 'as s'own t'at an electromagnet can be ade3uatel/ controlled

to le#tate a steel ball. T's can be done because t'e magnetc &orce s (ro(ortonal to t'e current

tra#elng t'e cols o& t'e electromagnet.

%.% ,agnetsm Bascs

,agnetsm s a basc &orce o& nature. A magnet s a (ece o& metal4rc' materal t'at attracts

some metal ob"ects and attracts or re(els ot'er magnets. Steel and ot'er man4made

combnaton metals and allo/s are magnetHable w'ereas alumnum lead gold and brass are not

magnetc. 2ocks and mnerals t'at contan ron o&ten e'bt magnetc (ro(ertes. ,agnets come

n d&&erent s'a(es and sHes ncludng bar magnets rng magnets and 'orses'oe magnets.

2egardless o& t'er s'a(e or sHe all magnets 'a#e two t'ngs n common9 a nort' (ole and a

sout' (ole. T'e two (oles o& a magnet are named nort' and sout' because o& t'er tendenc/ to

(ont toward t'e eart'>s nort' and sout' (oles. A bar magnet 'as one (ole at eac' end and a

'orses'oe magnet 'as a (ole on eac' t( o& t'e 'orses'oe cur#e. I& a magnet s broken nto small

(eces eac' (ece wll become a magnet wt' a Nort' and Sout' !ole. T'ere s no suc' t'ng as

a magnet wt' onl/ a nort' (ole or onl/ a sout' (ole.e. I& two magnets are (laced wt' lke (oles toget'er Nort' and Nort' or Sout' and Sout'D t'e magnets wll re(el or (ull toget'er or

(us' awa/. On t'e ot'er 'and & unlke (oles Nort' and Sout'D are (laced toget'erK t'e/ wll

attract or (ull toget'er. Attractng and re(ellng are basc (ro(ertes o& magnetsm. ,agnets

e'bt t'ese attractng and re(ellng (ro(ertes because o& t'e arrangement o& t'er atoms. Lke

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all materals ron cobalt and nckel are com(osed o& atoms. In t'ese (otentall/ magnetc

materals clusters o& atoms be'a#e lke tn/ magnets. T'ese atoms are called domans. ='en t'e

domans are 'a('aHardl/ arranged t'e materal does not e'bt magnet (ro(ertes. On t'e ot'er

'and & t'e materal comes n contact wt' a magnet t'e atom domans wll algn n a sngle

drecton and t'e materal wll become magnetHed.

%.* T'e In#sble Feld

T'e n#sble magnetc (ower surroundng a magnet s called ts magnetc &eld. T'e magnetc

&eld etends awa/ &rom t'e magnet n all drectons but t s strongest at t'e two (oles. It 'as

boundares and an ob"ect (ostoned outsde ts &elds wll not be a&&ected b/ t. Stronger

magnets 'a#e larger magnet &elds and weaker magnets 'a#e smaller magnetc &elds. A

magnetc &eld ma/ be strong enoug' to (enetrate non4magnetc materals suc' as (a(er glass

(lastc water and cardboardD and stll eert a magnetc &orce on a magnetc materal.

E#en t'oug' magnetc &elds are n#sble t'e/ can be re#ealed b/ a sm(le demonstraton

w'ere a (ece o& st&& (a(er s (laced o#er a magnet and ron &lngs s(rnkled on t'e (a(er. T'e

ron &lngs s(read out n an arc4lke (attern algnng nto t'e lnes o& &orce w'c' #suall/

re(resent t'e magnetc &eld. Because t'e magnetc &eld s strongest near t'e (oles t'e densest

concentraton o& ron &llngs s around t'e (oles. T'e concentraton o& ron &lngs s around t'e

(oles. T'e concentraton t'ns toward t'e magnets center as t'e magnetc &eld weakens.

Fgure %.19 T'e magnetc &eld o& lnes n t'e bar magnet and 'ow a steel ball le#tate

~ 14 ~




%.- ,agnetc Le#taton Tec'n3ues

%.-.1 Sur#e/ o& Le#taton !ro"ect O#er#ew

T'e ('enomena o& le#taton 'a#e &ascnated ('loso('ers t'roug' t'e ages and n recent tmes t

'as attracted muc' attenton &rom scentsts as a means o& elmnatng &rcton or ('/scal

contact. Alt'oug' t'e area o& &rctonless bearngs s m(ortant t s t'e a((lcaton o&

contactless sus(enson and le#taton to 'g' s(eed ground trans(ortaton w'c' 'as rece#ed t'e

most attenton es(ecall/ n t'e (o(ular meda. Besdes t'e arcus'on (rnc(le o& su((ortng

rotatng s'a&ts or #e'cles as used n t'e Aerotran n France or t'e Tracked 5o#ercra&t n t'e

:@ t'ere are nne Electromagnetc met'ods o& su((ortng mo#ng or rotatng masses 1M. T'ese

met'ods are as &ollows9

1. Le#taton usng &orces o& re(ulson between (ermanent magnets.

%. Le#taton usng &orces o& re(ulson between damagnetc materals.

*. Le#taton usng su(erconductng magnets.

-. Le#taton b/ &orces o& re(ulson due to edd/ currents nduced n a conductng sur&ace or

bod/.

. Le#taton usng t'e &orce w'c' acts on a current carr/ng lnear conductor n a magnetc

&eld.

0. Sus(enson usng a tuned LC2 crcut and t'e electrostatc &orce o& attracton between two

(lates.

. Sus(enson usng a tuned LC2 crcut and t'e magnetc &orce o& attracton between an

electromagnet and a &erromagnetc bod/.

8. Sus(enson usng controlled +C electromagnet and t'e &orce o& attracton between

magnetHed bodes.

$. ,ed s/stem o& le#taton w'ere s t'e (ermeablt/ o& t'e materal.

Some o& t'e (ossble met'ods o& sus(enson or le#taton are o& manl/ academc nterest but

ot'ersK t'ere n (artcular were t'e sub"ect o& ntens#e e(ermental act#t/ n t'e earl/ 1$)s.

It s &rst o& all necessar/ to draw a dstncton between t'ose met'ods w'c' uses &orce o&

~ 15 ~




attracton and t'ose w'c' use &orce o& re(ulson. T'e &ormer s called Le#taton and t'e latter

Sus(ensonK eac' o& t'e nne (ro(osed met'ods s #rtuall/ a tec'nolog/ n ts own rg't.

%.-.% !rnc(les and Lmtaton o& Electromagnetc

tec'n3ues o& sus(enson and Le#taton

E#er/ one o& t'e met'ods 'as at one tme or anot'er been t'e sub"ect o& ent'usastc

n#estgaton. T'e d&&cultes o& ac'e#ng stable sus(enson or le#taton are 'owe#er

'g'lg'ted b/ an eamnaton o& t'e nature o& &orces n t'e case w'en an n#erse s3uare law

relates &orce and dstance. Earns'aw %M n 's (a(er w'c' s now consdered a classc b/ all

workers n t'e &eld o& electromagnetc sus(enson s'ows mat'ematcall/ t'at t s m(ossble&or a (ole (laced n a statc &eld o& &orce to 'a#e a (oston o& stable e3ulbrum w'en an

n#erse s3uare law o(eratesK t's &undamental calculaton s known as Earns'aw>s t'eorem.

Braunbeck 10M carred out a smlar anal/ss s(ec&call/ &or un#ar/ng magnetc and electrc

&elds and deduced t'at sus(enson or le#taton s not (ossble n suc' &elds w'en all materals

(resent 'a#e r 1 or Pr Q 1 but t'at t s (ossble w'en materals o& r Q 1 or Pr Q 1 are

ntroducedK r s t'e relat#e (ermeablt/ and Pr s t'e relat#e (ermtt#t/ o& t'e materal.

Sus(enson 'as been ac'e#ed usng damagnetc materals and as a result o& t'e e&&ect o&

currents n t'e sus(ended ob"ects. Se#eral #arants o& t'e latter met'od n (artcular are at

(resent t'e sub"ect o& etens#e n#estgatons.

%.-.* Le#taton usng !ermanent ,agnet

It &ollows &rom Earns'aw>s t'eorem and BraunbeckRs anal/ss t'at stable sus(enson or

le#taton s m(ossble wt' a s/stem o& (ermanent magnets or &ed current electromagnetsD

unless (art o& t'e s/stem contans et'er damagnetc materal r Q 1D or a su(erconductor r

)D and t'at t s altoget'er m(ossble to ac'e#e le#taton n electrostatc &elds snce t'ere are no

known materals wt' Pr Q 1.

~ 16 ~




=ork on t'e use o& (ermanent magnets began around 18$) and was at t'at tme concerned wt'

rele& o& (art or t'e w'ole o& t'e load or a rotor or s'a&t magnetcall/. In s(te o& t'e large

number o& (atents none o& t's work a((ears to 'a#e been commercall/ success&ul. Interest n

t'e to(c seems to 'a#e langus'ed untl t'e 1$*)s and t'e ad#ent o& m(ro#ed (ermanent

magnet materals. T'e most common a((lcaton o& magnets o& &ed strengt' s n t'e

sus(enson o& s'a&ts or s(ndlesK sus(enson o& t'e s(ndles o& watt4'our motors n order to

rele#e t'e load on t'e (#ot bearng 'as been 'as been a constant target 1M18M1$M.

2ecent de#elo(ments n &abrcatng (ermanent magnets &rom 'g' coerc#t/ &errte materals

'a#e once agan rased nterest n t'e dea o& usng suc' magnets &or le#taton o& #e'cles.

!olgreen n 1$$ was t'e &rst to (ro(ose an a((lcaton n t'e &orm o& a #e'cle usng newl/

de#elo(ed barum &errte magnets n t'e re(ulson mode. Smlar (ro(osals ncludng one &or

'g' s(eed tra#el n e#acuated tubes across t'e :SA were made b/ ot'ers at about t'e same

tme. In all t'ese (ro(osals t was assumed t'at barum &errte would be c'ea( to manu&acture n

t'e large 3uanttes w'c' would be re3ured w'en la/ng down t'e track. One o& t'e ad#antages

o& usng &errtes &or t'e track s t'at t'ere are no nduced edd/ currents w'ose reacton would

lead to et'er a drag &orce or a loss o& l&t. ,cCag and Ba'man/ar and Ellson 'a#e made a

stud/ o& t'e l&tng &orces con&guratons and track desgns. 5owe#er an/ (ractcal s/stems

bult around t'ese deas would re3ure dam(ng n t'e #ertcal drectons and gudance as well as

dam(ng n t'e lateral drecton. T's 'as been consdered onl/ b/ 7ogt w'o (ro(osed dr#ng

a current (ro(ortonal to #ertcal #eloct/ n a col around t'e (ermanent magnets. 2ecentl/ a

new magnetc materal 'as a((eared namel/ samarum4cobalt w'c' 'as e#en greater

coerect#t/ t'an barum &errte. T'e ntrnsc coerc#e &orce o& t'ese cobalt rare eart' materals

ma/ be %) to ) tmes t'at o& t'e con#entonal (ermanent magnets (roducng l&tng ca(abltes

n t'e re(ulson mode w'c' are to 1) tmes greater. In s(te o& t'ese sgn&cant m(ro#ements

n t'e materals a#alable t'ere reman man/ (ractcal d&&cultes n t'e m(lementaton o&

trans(ortaton sc'emes usng (ermanent magnet tracks. 5owe#er &or nstrument a((lcatons

t'ere s a real (ossblt/ o& usng controlled (ermanent magnet sc'emes w'ereb/ t'e (ower

consum(ton n t'e stead/ state can be made #rtuall/ Hero.

~ 17 ~




%.-.- Le#taton usng damagnetc materals

Le#taton can be ac'e#ed n statc magnetc &elds b/ em(lo/ng damagnetc materals.

5owe#er e#en t'e two materals w'c' e'bt t'e most (ronounced damagnetc (ro(ertes .e. bsmut' and gra('te are so weakl/ damagnetc t'at onl/ small (eces can be le#tated. T'e

to(c o& le#taton n t'e (resence o& damagnetc materals 'as been studed b/ Braunbeck and

Boerd"k . Braunbeck le#tated small (eces o& bsmut' measurng ). % mm and weg'ng 8

mg and o& gra('te measurng % 1% mm weg'ng $ mg between s(ecall/ &ormed (oles o&

an electromagnet ca(able o& (roducng a &eld o& &lu denst/ %.* tesla. Boerd"k re(eated t's

e(erment on a smaller scale usng (ermanent magnets and also (er&ormed an alternat#e

e(erment w'c' n#ol#ed le#tatng a magnetHed dsc o& dameter 1mm between a magnet

attractng t u(wards and a (ece o& damagnetc materal below t. 5s anal/ss concludes t'at t

s'ould be (ossble to le#tate magnetHed (artcles o& mcrometrc sHe o& a &racton o& a

mllmeter abo#e a (ece o& bsmut' or gra('te wt'out t'e ad o& a surmounted magnet. A

&urt'er eamnaton o& damagnetc le#taton s contaned n a re(ort b/ 6eneral Electrc :SD

%)M but t'e general concluson to be drawn &rom t'e results o& t'at work s ne#tabl/ t'at t'e

('enomenon o& damagnetc le#taton s o& academc nterest onl/.

%.-. Le#taton usng su(erconductors

Certan metals and allo/s w'en cooled to a tem(erature a((roac'ng ) @ 4%*)CD become

su(erconductors. T'e su(erconductng state s ndcated b/ t'e com(lete absence o& electrcal

resstance and once ntated a current wll contnue to &low wt'out t'e (resence o& a #oltage

source n t'e crcut. T's s accom(aned b/ re"ecton o& magnetc &lu n t'e su(erconductng

bod/ w'c' s known as t'e ,essner e&&ect and w'c' causes t'e su(erconductor to be'a#e as

a (er&ectl/ damagnetc materal r )D. Stable sus(ensons usng (ermanent magnets are

t'ere&ore (ossble *M. T'e &rst recorded demonstratons o& t's (rnc(le were b/ Arkade# n

1$- and n#ol#ed t'e le#taton o& 1 mm bar magnet o#er a su(erconductng lead (late. In t'e

subse3uent attem(t to de#elo( a cr/ogenc magnetc sus(enson g/rosco(e su(erconductng

~ 18 ~




s('eres were le#tated o#er #arous arrangements o& electromagnets. A sc'eme &or le#tatng a

#e'cle o#er two (arallel su(erconductng rals was (ro(osed b/ (owell n 1$0*. Later a second

s/stem was desgned n w'c' su(erconductng magnets were attac'ed to t'e #e'cleK t'ese

magnets would rde o#er rals wt'out touc'ng t'em t'us elmnatng t'e need &or

su(erconductng rals. T'ere were also (ro(osals to su((ort a rocket launc'ng sledge ca(able o&

s(eeds o& kms and &urt'er studes o& baselne s(ec&catons &or (assenger carr/ng #e'cles.

An electro4d/namcall/ le#tated #e'cle s l&ted and guded b/ re(ulson &orces between

su(erconductng magnets on t'e #e'cle and secondar/ crcuts on t'e track edd/ currents & t'e

track crcuts are (ass#eD. T'e le#taton s sel&4stablHng and clearance between magnets and

secondar/ crcuts can be larger t'an 1) cm. 5owe#er t'e st&&ness and dam(ng o& t'e

sus(enson are low and t'e #e'cle must be n moton n order to generate l&t. T'ere s t'ere&ore

a mnmum #eloct/ w'c' must be eceeded be&ore t'e #e'cle becomes le#tated and t'e

s/stem s generall/ consdered a((lcable onl/ to 'g' s(eed trans(ort s/stems n ecess o& -))

km' D. Some o& t'e (roblems and drawbacks w'c' stll reman unsol#ed are t'at n addton to

t'e aerod/namc drag on suc' #e'cles t'ere s an edd/ current drag w'c' s large at low

s(eeds. T's (laces 3ute a substantal burden on t'e (ro(ulson s/stem durng acceleraton. T'e

drag reduces at 'g' s(eeds but n order to get a 'g' l&t4to4drag rato w'c' s a &gure o& mert

&or t'ese s/stems a large 3uantt/ o& conductng materal alumnumD s re3ured n t'e

secondar/ crcut trackD. At 'g' s(eeds t'e low n'erent dam(ng coe&&cent o& t'e s/stem

reduces &urt'er and can n &act become negat#e w'c' (resents 3ute serous (roblems o&

#e'cle stablt/ n general. It 'as been re(orted t'at (ass#e dam(ng ma/ be nade3uate.

!ro(osals consdered 'a#e been to #ar/ t'e col currents or to #ar/ t'e dr#e to t'e lnear

s/nc'ronous motor n accordance wt' #ertcal acceleraton sgnals &ed back or n order to

(roduce more dam(ng at t'e e(ense o& t'e &gure o& mert. 2esearc' n t'e su(erconductng

le#taton s/stems s 3ute act#e n Canada ?a(an and England. T'e ?a(anese Natonal

2alwa/s (roduced n 1$% at * and U tone #e'cle w'c' 'ad a l&t o& 0 cm but n w'c'

gudance was (ro#ded b/ w'eels on t'e sdes o& t'e gudewa/. A second and more ad#anced

#e'cle o(eratng on a %) km track was re(orted n 1$$ to 'a#e ac'e#ed s(eeds n ecess o&

%) km. T'ere were two (ro"ects o& t's t/(e n t'e :S. One was a collaborat#e e&&ort between

#arous un#erstes and ndustral laboratores under t'e drecton o& t'e +e(artment o&

~ 19 ~




Trans(ortaton. T'e ot'er called t'e ,agne(lane (ro"ect was (artl/ under t'e drecton o&

Natonal Scence Foundaton. Bot' studes were largel/ t'eoretcal t'e e(ermental sde

n#ol#ng (ermanent magnets. 2esearc' n t'e :S a((ears to 'a#e been sus(ended nde&ntel/

snce about 1$. T'e researc' n Canada n su(erconductng le#taton s/stems &or 'g' s(eed

ground trans(ortaton usng s/nc'ronous lnear motor (ro(ulson s beng carred out b/ an

nterdsc(lnar/ team o& scentsts and engneers &rom t'e :n#erstes o& Toronto Vueens and

,c6ll. A w'eel o& dameter .0 mm rotatng about a #ertcal as wt' a mamum (er('eral

s(eed o& 1)) km' s beng used to carr/ out &ull4scale tests o& t'e (ro(ulson le#taton and

gudance s/stems. In t'e :@ work 'as been n (rogress &or a number o& /ears at t'e :n#erst/

o& =arwckK and a 0)) m track 'as been constructed to test a small #e'cle w'c' ntall/ s to

be towed b/ a ro(e at s(eeds u( to * ms. T's small #e'cle s * m long and weg's 1) kg.

Studes are also beng carred out b/ a consortum o& Semens AE6 and Brown Bo#er atErlangen n =est 6erman/ and a #e'cle 'as undergone (relmnar/ tests on a %8) m dameter

crcular track. It s bele#ed t'at because o& t'e (roblems o& gudance and edd/ current drag t's

work 'as been dela/ed 3ute consderabl/.

%.-.0 Le#taton usng nduced edd/ currents

A &orce o& re(ulson s generated between a col carr/ng alternatng current and an electrcall/

conductng sur&ace n t'e (romt/ o& t'e col so t'at t'e alternatng magnetc &eld o& t'e col

nduces edd/ currents n t'e conductor. T's e&&ect can be utlHed &or le#taton o& conductng

ob"ects and one o& t'e earl/ (atents (ur(ortng to do so s t'at o& Ansc'utH4@aem(&e n

g/rosco(c a((lcatons. T's tec'n3ue 'as also been used &or smultaneous le#taton and

meltng o& s(ecmens at 1) k5H &or Hone re&nng o& metals. T's 'as become a standard

tec'n3ue &or (re(araton o& small 3uanttes o& allo/s wt'out contamnaton &rom crucbles.

Bed&ord !eer and Tonks descrbe a (late le#tator n w'c' two concentrc cols carr/ ) 5H

currents n o((oste drectons and can le#tate a crcular conductng (late n stable condtonsK

se#eral ot'er e(ermental s/stems &or le#taton o& (lates s('eres etc. are descrbed b/

Lntw'te *M.

~ 20 ~




Fgure %.%9 T'e "um(ng rng e(erment.

,ore recentl/ 'owe#er due to de#elo(ments n lnear nducton motors (artcularl/ o& t'e

trans#erse &lu t/(e t 'as been clamed t'at suc' mac'nes mg't be used &or combned

le#taton and (ro(ulson o& 'g' s(eed #e'cles. T'e combned le#taton and (ro(ulson

sc'emes em(lo/ng lnear motors &or #e'cles weg'ng n ecess o& ) tones ma/ 'a#e

(er&ormance com(arable to t'at o& t'e su(erconductng magnet sc'emes. One o& t'e ad#antages

clamed &or suc' sc'emes termed Rmagnetc r#ers> s t'at t'e/ o&&er t'e (ossblt/ o& l&t and

gudance w'ere t'e motor necessar/ &or (ro(ulson s t'e source o& suc' &acltes. It s also

clamed t'at &or a (artcular t'rust t'e secondar/ (ower n(ut n a le#tatng lnear motor wll be

t'e same as n a mac'ne desgned &or t'rust onl/. Ob#ousl/ a great deal o& work (artcularl/

t'eoretcal needs to be done but t s d&&cult to en#sage t'at t'ere ma/ be dramatc

m(ro#ements to (rmar/ react#eD (ower n(ut &or t'e large ar ga(o(eraton clamed as one o&

ts o(eratng &eatures and also t'at t'e st&&ness and magntude o& t'e gudance and l&t &orces

are ade3uate n t'e geometres eamned so &ar &or t'e (ro(osed ad#anced ground trans(ortaton

a((lcatons. 2ecentl/ East'am 8M 'as s'own t'at t'e t'eoretcal mnmum react#e n(ut to a

) tons #e'cle energHed &rom a ) 5H su((l/ s *).8 ,7A2 &or le#taton at a ga( o& ).1 m

com(ared to *.% ,= re3ured to (ro(el t'e #e'cle at 1%) ms to o#ercome aerod/namc drag.

East'am also s'ows t'at suc' a mac'ne wll 'a#e an n'erentl/ (oor (ower &actor and & on4

board (ower &actor correcton e3u(ment s used to brng t u( to unt/ (ower &actor t'ere s

substantal weg't (enalt/. T'e o#erall e&&cenc/ tmes t'e (ower &actor (roduct s t'en ).*8 &or

~ 21 ~




suc' a #e'cle. 5owe#er t'e use o& trans#erse &lu lnear nducton motors as (ro(ulson unts

onl/ remans #er/ (romsng.

%.-. Le#taton usng &orces actng on current carr/ng

conductors stuated n magnetc &elds

T'e &orce actng on a conductor o& lengt' l carr/ng a current I and stuated n a trans#erse

magnetc &eld o& &lu denst/ B s g#en b/ F BlI and t'e &orce acts n a drecton normal to

bot' t'e conductor and t'e &eld. !&ann and 5agelbarger re(ort *M 'a#ng su((orted t'e molten

(ortons o& a metal rod undergong Hone meltng b/ locatng t'e molten n t'e trans#erse

magnetc &eld and (assng a current t'roug' t'e rod. Alt'oug' t'e current s ad"usted to g#e an

u(ward &orce a((romatel/ e3ual to t'e weg't o& t'e molten metal sur&ace tenson also

contrbutes to kee(ng t'e molten Hone n (lace. T'e 'eatng o& t'e molten Hone s carred out

et'er b/ nducton 'eatng or b/ torc' &lame. T'us unlke t'e edd/ current le#taton tec'n3ue

t'e &unctons o& meltng and le#taton are ke(t se(arate. 2ods o& ron nckel and tn 'a#e been

le#tated b/ t's met'od. A #arant o& t'e same tec'n3ue was (ro(osed b/ !owell &or le#taton

o& a #e'cle o#er two (arallel su(erconductng rals carr/ng a (ersstent current. Attac'ed to t'e

#e'cle are two su(erconductng n#erted troug's w'c' rde o#er t'e rals wt'out touc'ng

t'em. Le#taton s e&&ected b/ (ersstent currents &lowng n t'e longtudnal wres o& w'c' t'e

troug's are constructed. T'e troug's are desgned to g#e t'e #e'cle stable e3ulbrum bot'

#ertcall/ and laterall/.

%.-.8 Sus(enson usng a Tuned LC2 Crcut and

Electrostatc Force o& Attracton

An electrcall/ conductng s'a&t or rotor ma/ be 'eld n sus(enson b/ electrostatc &orce

between a (ar o& electrodes w'ere one o& t'e electrodes s t'e bod/ to be sus(ended. T'e

sus(ended bod/ and t'e &ed electrode &orm t'e ca(act#e element o& a tuned LC2 crcut n

~ 22 ~




suc' a manner t'at t'e (otental d&&erence between t'e two electrodes ncreases as t'e dstance

between t'em ncreases and #ce #ersa .e. t'e crcut s tuned to resonance at #alues o&

ca(actance less t'an t'at at t'e sus(enson ga(. T'e electrodes must be mantaned at a (otental

d&&erence o& se#eral klo#olts. A((lcatons o& t's (rnc(le 'a#e been n#estgated &or #acuum

g/ros. T's tec'n3ue does not seem to 'a#e been as etens#el/ n#estgated as t'e one usng t'e

magnetc &orce o& attracton n tuned LC2 crcuts. It s 'owe#er almost certan t'at besdes t'e

(roblem o& t'e #er/ 'g' #oltages w'c' are re3ured to ac'e#e sus(enson t's met'od also

su&&ers &rom n'erent nstablt/ due to t'e use o& tuned LC2 crcuts and t'e (roblems o&

(ro#dng dam(ng and 'g' react#e (ower are "ust as ad#erse as n t'e LC2 s/stems em(lo/ng a

#aratons o& nductance wt' ga( wdt'.

%.-.$ Sus(enson usng a Tuned LC2 Crcut and

Electromagnetc Force o& Attracton

T'e #araton o& nductance o& an electromagnet n t'e (romt/ o& &erromagnetc ob"ect

de(endng on t'e se(araton between t'e two s utlHed n t's met'od to regulate t'e current

and 'ence t'e &orce o& attracton. T's s ac'e#ed b/ ncor(oratng t'e electromagnet wt'n an

LC2 crcut tuned n suc' a wa/ t'at w'en t'e ob"ect to be sus(ended mo#es awa/ &rom t'e

electromagnet t'e crcut tends to become resonant t'us ncreasng t'e current and 'ence t'e

&orce actng on t. Con#ersel/ w'en t'e ob"ect mo#es towards t'e electromagnet t'e current and

t'e &orce o& attracton dmns'es. I& t'ere&ore t'e &orce s balanced aganst t'at gra#t/ at some

dstance o& se(araton t s (ossble to get a statcall/ stable st (ont o& sus(enson o& t'e bod/.

5owe#er t'e tuned LC2 crcuts (ossess a large tme constant w'c' means t'at once

dstrbuted &rom t's statc stable (ont t'e ob"ect usuall/ goes nto a d#ergent oscllaton unless

some means are em(lo/ed to control and s(eed u( t'e current c'anges or to (ro#de dam(ng n

some ot'er wa/. @a(lan &ound t'at at &re3uences o& t'e order o& 0 to %0 k5H leak/ ca(actors

rangng &rom ).-F to ).)%F !ro#ded ade3uate dam(ng to obtan sus(enson o& a &errte dsc

and rod weg'ng *. g and 1*. g res(ect#el/. In ot'er met'ods ol dam(ng s used t'e bod/

to be sus(ended n submerged n ol. T'e st&&ness o& sus(enson usng AC tuned crcut met'od

~ 23 ~




tends to be rat'er low &or man/ a((lcatons. T'e man dsad#antage 'owe#er stem &rom t'e

&act t'at at t'e statc st (ont t'e crcut s (redomnantl/ nduct#e and 'ence react#e (ower

n(ut s rat'er largeK and t'at t'e ron structure ncludng t'e ob"ect to be sus(ended must be

lamnated. T'us alt'oug' t's met'od seems to o&&er at &rst sg't an n'erentl/ stable &orce4

dstance c'aracterstc and t'ere&ore consderable ad#antages &or sus(enson o& &erromagnetc

bodes rat'er dsa((ontngl/ t su&&ers &rom too man/ drawbacks to 'a#e resulted n man/

(ractcal a((lcatons.

%.-.1) Sus(enson usng Controlled +C Electromagnet

T'e met'od s at (resent b/ &ar t'e most ad#anced tec'nologcall/ and s t'e sub"ect o& world4

wde n#estgaton &or ad#anced ground trans(ortaton sc'emes and also &or a((lcaton n

contactless bearngs &or 'g' and #er/ low s(eeds s t'at usng controlled +C electromagnets.

T's tec'nolog/ was de#elo(ed durng t'e 1$)s n 6erman/ ?a(an t'e :S and t'e :@ and

#e'cles o& #arous sHes weg'ng between 1 ton and * tons 'a#e been o(erated success&ull/

n t'ese countres at s(eeds rangng &rom a &ew klometers (er 'our to o#er -)) km (er 'our.

T'e ?a(anese #e'cle 5SST4)% s (ro(elled b/ a lnear nducton motor mounted on t'e #e'cle

but t'e 6erman #e'cle Transra(d4) w'c' was demonstrated on a $))m track s a long stator

mac'ne .e. t'e stator mac'ne .e. t'e stator wndng s on t'e track. Furt'er t'e mac'ne s a

s/nc'ronous lnear motor w'c' uses t'e l&t magnets as ectaton magnets. It s (ro(osed t'at

t'e 1%1 tons #e'cle wll 'a#e an ar cored lnear s/nc'ronous motor wt wndngs on t'e track

and (er'a(s su(erconductng ectaton magnets. T's sc'eme t'ere&ore elmnates t'e need to

collect (ower t'roug' sldng brus' contacts at 'g' s(eeds. A no#el &eature o& t'e 6erman

#e'cles s t'at t'e magnets are mounted on nd#duall/ s(rung members and t's conce(t 'as

been labeled t'e Rmagnets are mounted on nd#duall/ s(rung members and t's conce(t 'as

been labeled t'e Rmagnet w'eel>. A #arant o& t's a s(rung c'asss smlar to t'at n motor cars

'as been used b/ ?a(an Ar Lnes &or t'er 5SST4)% #e'cle b/ 6eneral ,otors and b/ t'e

aut'or at t'e :n#erst/ o& Susse. A(art &rom t'e ac'e#ements descrbed abo#e n t'e #e'cle

area consderable work s n (rogress n a((l/ng controlled +C electromagnets to contactless

or &rctonless su((orts n (lace o& con#entonal bearngs.

~ 24 ~




%. ,agnetc Tec'nologes and A((lcatons

%..1 ,agnetc Bearngs

A magnetc bearng s a metal s'a&t surrounded b/ a casng t'at contans magnets. T'e s'a&t s

sus(ended and rotated wt'n t'e casng b/ magnetc &orces. Because o& t'e magnetc &orces t'e

s'a&t 'as no contact wt' ot'er (arts o& t'e e3u(ment and #er/ lttle &rcton or #braton w'c'

wears out (artsD occurs. In addton no lubrcaton s re3ured and t'e bearngs can wt'stand

#er/ 'g' tem(eratures. ,agnetc bearngs 'a#e an unlmted l&e. T'ese bene&ts sa#e mone/ n

e3u(ment re(lacement.

%..% Su(erconductng ,agnetc Bearngs

T'e use o& reduced &rcton magnetc bearngs n mec'ancal com(onents s not new. ='at s

new s t'e de#elo(ment o& su(erconductng magnetc bearngs t'at (roduce %W less &rcton

t'an regular magnetc bearngs. T'e su(erconductng materals used n t'ese magnetc bearngs

were dsco#ered n 1$80. T'e nearl/ &rctonless bearng s (roduced w'en a magnetc bearng s

(ostoned o#er t'e su(erconductng materal t'at s t'en cooled b/ l3ud ntrogen to mnus *))

degrees Fa'ren'et. At t's tem(erature t'e su(erconductng materal (roduces an e3ual but

o((oste magnetc &eld n relaton to t'e magnet and t'e magnetc bearng le#tates n res(onse

to t'e o((osng magnetc &eld. Su(erconducton magnetc bearngs 'a#e man/ a((lcatons.

One eam(le s a su(ere&&cent &l/w'eel de#elo(ed b/ t'e Argonne Natonal Laborator/. A

&l/w'eel s a mec'ancal mec'ansm used &or storng etra energ/ (roduced b/ (ower (lants.

T's energ/ can be ta((ed later to (ro#de etra energ/ &or (eak consum(ton 'ours. Anot'er

eam(le s usng t'e su(er4e&&cent &l/w'eel to store energ/ n electrc cars nstead o& usng

batteres &or energ/ storage. Currentl/ batter/ (acks de#elo(ed &or electrc cars take about 1)

'ours to rec'arge. 2ec'argng t'e su(er4e&&cent &l/w'eel would take "ust a lttle longer t'an

re&llng a car>s gas tank and (ro#de greater (ower out(ut as well.

~ 25 ~




%..* Smaller and Better ,agnets

New 'ouse'old a((lances wll soon be workng more e&&centl/. T'e magnets normall/ used n

a((lance motors wll be re(laced b/ stronger /et smaller neod/mum4ron4boron magnetsde#elo(ed b/ 6eneral ,otors Cor(oraton. T'e magnets wll m(ro#e energ/ e&&cenc/ and

allow addtonal s(ace &or ot'er uses. T'e demand &or (ol/mer4bonded magnets used n cars

consumer electroncs and com(uters s &ar eceedng t'e su((l/. T'ese (ermanent magnets

normall/ a#alable &or ndustral uses onl/ are (roduced b/ n"ecton4moldng mac'nes t'at

control t'e (olart/ o& t'e magnetc materal.

%..- En#ronmental ,agnets

2es(ondng to t'e nterest n usng rec/cled materals ,aster ,agnets a Brts' com(an/ 'as

de#elo(ed a magnetc se(arator to be used n rec/clng (lants. It 'as man/ ad#antages o#er

electromagnetc se(arators. Because t'e ,astermag T/(e @ !ermanent ,agnetc Se(arator s a

strong (ermanent magnet no electrcal (ower s needed to generate a magnetc &eld and t'e

resultng attracton.

%.. Su(erconductng ,agnets

Ar Force scentsts and (r#ate ndustr/ researc'ers 'a#e de#elo(ed small (ower&ul magnets

t'at weg' muc' less t'an tradtonal magnets. T'ese magnets are o#al4s'a(ed magnetc cols

made b/ wndng lengt's o& su(erconductng wre. Because su(erconductng wre conducts

electrct/ wt' #er/ lttle resstance t'e cols (roduce stronger magnetc &elds. T'e

su(erconductng col s relat#el/ lg't n weg't and can be used n man/ a((lcatons

ncludng magle# tran s/stems com(act generators motors and satelltes. Su(erconductng

magnets are also beng de#elo(ed &or (ower (lant energ/ storage. Ot'er t/(es o& energ/ storage

s/stems re3ure batteres or mec'ancal &l/w'eels to store energ/ and addtonal energ/ s

re3ured to recon#ert t'e stored energ/ &or (ower (lant use. T'e su(erconductng magnet energ/

~ 26 ~




storage s/stem s t'e most e&&cent s/stem. It re3ures no etra ste(s or energ/ &or con#erson. To

ac'e#e t'e su(erconductng (ro(ertes t'e wre must be cooled w'c' s an ne(ens#e and

sm(le (rocess. It s also lkel/ t'at 'g'er tem(erature materals wll be de#elo(ed soon to

obtan su(erconductng (ro(ertes closer to room tem(erature.

%..0 ,agle# Trans

,agle# magnetcall/ le#tated ground trans(ortatonD s lkel/ to become an m(ortant mode o&

&uture trans(ortaton. ,agnets located n a monoral4lke tran and n t'e walls o& t'e tran track

sus(end (ro(el and control t'e cars abo#e t'e track. T'e tran4lke cars lterall/ &loat abo#e t'e

track and t'ere s no &rcton. ,agle# trans can tra#el *)) mles (er 'our and o&&er t'e s(eed o&

arlne tra#el wt' t'e con#enence o& numerous sto(s (ro#ded b/ ral s/stems. For eam(le a

ten4'our car tr( between Los Angeles and San Francsco could be reduced to one and one4'al&

'ours on a magle# tran. ?a(an and 6erman/ alread/ 'a#e magle# s/stems. Florda s

n#estgatng t'e (ossblt/ o& a magle# s/stem. ,agle# trans(ort was &rst researc'ed b/

Amercan scentsts n 1$1% but was not consdered serousl/ untl t'e 1$0)s. ,agle# s a good

en#ronmental c'oce. =des(read use o& t'e tran s/stem as a trans(ortaton alternat#e would

'el( (reser#e &ossl &uels used b/ cars and ar(lanes and reduce ar (olluton. T'e s/stem s #er/

3uet and would reduce nose (olluton as well. 5g'wa/ and ar(ort e(ansons would be

reduced easng demand &or scarce and e(ens#e land. Fnall/ usng magle# would reduce

automoble and arlne congeston and s'orten long commutes n large ctes. Se#eral :.S.

agences are n#ol#ed wt' magle# nterests and ongong researc' ncludng t'e :.S. Arm/

Cor(s o& Engneers Argonne Natonal Laborator/ :.S. +e(artment o& Trans(ortaton :.S. Ar

Force and t'e Federal 2alroad Admnstraton. T'e :.S. Ar Force s act#el/ testng a magle#

s/stem &or de&ens#e wea(ons and NASA s consderng t'e use o& a #ertcal magle# s/stem

called magl&t t'at would 'el( to (ro(el rockets nto s(ace.

~ 27 ~




%.0 Introducton to Com(ensator

A well4desgned control s/stem must 'a#e less error good accurac/ good s(eed o& res(onse

good relat#e stablt/K good dam(ng so t'at undue o#ers'oots etc can be a#oded. :suall/

&rst (ro(ert/ s g#en to gan ad"ustment. !ractcall/ t 'as been &ound t'at ad"ustng t'egan alone t s #er/ d&&cult to obtan a sats&actor/ result. A 'g'er #alue o& gan m(ro#es

t'e stead/4state be'a#or but transent res(onse o& t'e s/stem becomes (oor. T'ere&ore desgn

o& a control s/stem s a c'allengng task &or a control s/stem engneer. To &ul&ll t'e re3ured

s(ec&caton t s re3ured to desgn control s/stem. An eternal de#ce s added to t'e s/stem.

T's (rocess o& redesgn b/ addng an eternal de#ce s called com(ensaton o& control

s/stem w'ereas t'e eternal de#ce s known as a com(ensator. An eternal de#ce termed

com(ensator can be added n a s/stem an/w'ere de(endng u(on t'e re3urement t'ere are

t'ree t/(es o& com(ensator

aD Seres com(ensaton

='en t'e com(ensator s (laced n seres wt' t'e &orward (at' trans&er &uncton o& t'e (lant t'e

sc'eme s known as seres com(ensaton. It s also termed as cascade com(ensaton

Fgure %.*9 T'e block dagram o& seres com(ensaton

In seres com(ensaton t'e sgnal &lows &rom lower energ/ le#el towards a 'g'er energ/ le#el

.e. addtonal am(l&ers are re3ured to ncrease t'e gan as well as to (ro#de necessar/

solaton.

~ 28 ~



-------------------------------------M A G N E T I C L E V I T A T I O N S Y S T E M----------------------------------

bD !arallel com(ensaton

I& t'e &eedback s taken &rom some nternal element and a com(ensator s ntroduced n suc' a

&eedback (at' to (ro#de an addtonal nternal &eedback loo( t's sc'eme s known as

&eedback com(ensaton or (arallel com(ensaton.

Fgure %.-9 T'e block dagram o& (arallel com(ensaton

In (arallel com(ensaton t'e sgnal &lows &rom 'g'er energ/ le#el towards a lower energ/

le#el .e. addtonal am(l&ers are not re3ured.

cD Seres4!arallel com(ensaton

Sometmes a stuaton demands to (ro#de bot' t/(es o& com(ensaton seres as well as

&eedback. T's sc'eme s known as seres4(arallel com(ensaton.

~ 29 ~




%. T'e Com(ensat#e Network

A com(ensator s a ('/scal de#ce w'c' ma/ be an electrcal network mec'ancal unt

(neumatc '/draulc or a combnaton o& #arous t/(es o& de#ces. Onl/ Electrcal networks

w'c' are used t'e &ollowng com(ensatng networks are generall/ used

1. !'ase4Lead com(ensator

%. !'ase4Lag Com(ensator

*. !'ase4Lag4Lead Com(ensator

Closel/ related to !I+ control s t'e dea o& lead lag com(ensaton. T'ese deas are

&re3uentl/ used n (ractce es(ecall/ w'en com(ensators are bult wt' electronc 'ardware

com(onents also called analogue com(onentD. T'e trans&er &uncton o& t'e com(ensators s

o& t'e &orm

C sD s X 1

Y 1

sX% Y1

='ereX1

X% s &or !'ase4lead network w'le

X1 Q X% &or a !'ase4lag network.

%.8 ,crocontroller

T'e stuaton we &nd oursel#es toda/ n t'e &eld o& mcrocontrollers 'as ts begnnngs n t'e

de#elo(ment o& tec'nolog/ o& ntegrated crcuts. It enabled us to store 'undreds o& t'ousands o&

transstors nto one c'( w'c' was a (recondton &or t'e manu&acture o& mcro(rocessors. T'e

&rst com(uters were made b/ addng eternal (er('erals suc' as memor/ n(utout(ut lnes

tmers and ot'er crcuts to t. Furt'er ncreasng o& (ackage denst/ resulted n desgnng an

ntegrated crcut w'c' contaned bot' (rocessor and (er('erals. T's s 'ow t'e &rst c'(

contanng a mcrocom(uter later known as t'e mcrocontroller was de#elo(ed 2e& NumberM.

~ 30 ~




T'ere are d&&erent t/(es o& mcrocontrollers manu&actured b/ d&&erent manu&acturers. But t's

senor (ro"ect re(ort wll dscuss about !IC mcrocontrollers s(ec&call/.

%.8.1 !IC ,IC2OCONT2OLLE2S!IC mcrocontrollers desgned b/ ,croc'(. T'e orgnal name o& t's mcrocontroller s

!ICmcro !er('eral Inter&ace ControllerD but t s better known as !IC. Its ancestor called t'e

!IC10) was desgned n 1$ b/ 6eneral Instruments. It was meant &or totall/ d&&erent

(ur(oses. Around ten /ears later t's crcut was trans&ormed nto a real !IC mcrocontroller b/

addng EE!2O, memor/. Toda/ ,croc'( Tec'nolog/ announces t'e manu&acture o& t'e

bllont' sam(le. Among d&&erent t/(es o& mcrocontrollers we used t'e !IC 10F8A &or t's

(ro"ect. And t's was due to t'e &act t'at t owns a #er/ a((lausable CC! module allowng us use

t>s !=,.

%.8.1.1 T'e !IC10F88A

T'e !IC10F88A s a well4known (roduct b/ ,croc'(. It &eatures all t'e com(onents w'c'

modern mcrocontrollers normall/ 'a#e. For ts low (rce wde range o& a((lcaton 'g' 3ualt/

and eas/ a#alablt/ t s an deal soluton n a((lcatons suc' as t'e control o& d&&erent

(rocesses n ndustr/ mac'ne control de#ces measurement o& d&&erent #alues etc.

='/ !IC 10F8AZ

=e c'ose t's mcrocontroller due to t'e s(arklng &act t'at t contans a CC! module a module

w'c' s used to generate !=, sgnals. In terms o& a#alablt/ and cost t>s also t'e most

recommended t/(e o& mcrocontroller among t'e ot'ers. S(eed and sHe weren>t taken n to

consderatons w'le selectng our mcrocontroller t'oug'.

~ 31 ~




Fgure %.9 T'e !IC 10F8A

Some o& t'e man &eatures o& t'e !IC 10F8A are lsted below.

[ 2ISC arc'tecture

o Onl/ * nstructons to learn

o All sngle4c/cle nstructons ece(t branc'es

[ O(eratng &re3uenc/ )4%) ,5H

[ !recson nternal oscllator

o Factor/ calbrated

o So&tware selectable &re3uenc/ range o& 8,5H to *1@5H

[ !ower su((l/ #oltage %.)4.7

o Consum(ton9 %%)uA %.)7 -,5HD 11uA %.) 7 *% @5HD )nA stand4b/

modeD

[ !ower4Sa#ng Slee( ,ode

[ Brown4out 2eset BO2D wt' so&tware control

[ o(ton

[ * n(utout(ut (ns

o 5g' current sourcesnk &or drect LE+ dr#e

~ 32 ~




o so&tware and nd#duall/ (rogrammable (ull4u( resstor

o Interru(t4on4C'ange (n

[ 8@ 2O, memor/ n FLAS5 tec'nolog/

o C'( can be re(rogrammed u( to 1)).))) tmes

[ In4Crcut Seral !rogrammng O(ton

o C'( can be (rogrammed e#en embedded n t'e target de#ce

[ %0 b/tes EE!2O, memor/

o +ata can be wrtten more t'an 1.))).))) tmes

[ *08 b/tes 2A, memor/

[ A+ con#erter9

o 1-4c'annels

o 1)4bt resoluton

[ * nde(endent tmerscounters

[ =atc'4dog tmer

[ Analogue com(arator module wt'

o Two analogue com(arators

o Fed #oltage re&erence ).07D

o !rogrammable on4c'( #oltage re&erence

[ !=, out(ut steerng control

[ En'anced :SA2T module

o Su((orts 2S4-8 2S4%*% and LIN%.)

o Auto4Baud +etect

[ ,aster S/nc'ronous Seral !ort ,SS!D

[ su((orts S!I and I%C mode

[ CC! ,odules

o Two CC! modulesK CC!1 and CC!%o Ca(ture ,ode allows tmng &or t'e duraton o& an e#ent.

o Com(are ,ode com(ares #alues contaned n two regsters at some (ont.

o !=, 4 !ulse =dt' ,odulaton can generate sgnals o& #ar/ng &re3uenc/ and

dut/ c/cle.

~ 33 ~




%.$ T'e L%$*+ 3uadru(le 'g'4current 'al&45 dr#er

T'e L%$*+ s a 3uadru(le 'g'4current 'al&45 dr#er. T'e L%$*+ s desgned to (ro#de

bdrectonal dr#e currents o& u( to %. A at #oltages &rom -. 7 to *0 7. Bot' de#ces are

desgned to dr#e nduct#e loads suc' as rela/s solenods dc and b(olar ste((ng motors as

well as ot'er 'g'4current'g'4#oltage loads n (ost#e4su((l/ a((lcatons. All n(uts are TTL

com(atble. Eac' out(ut s a com(lete totem4(ole dr#e crcut wt' a +arlngton transstor snk

and a (seudo4+arlngton source. +r#ers are enabled n (ars wt' dr#ers 1 and % enabled b/

1%EN and dr#ers * and - enabled b/ *-EN. ='en an enable n(ut s 'g' t'e assocated

dr#ers are enabled and t'er out(uts are act#e and n ('ase wt' t'er n(uts. ='en t'e enable

n(ut s low t'ose dr#ers are dsabled and t'er out(uts are o&& and n t'e 'g'4m(edance state.

=t' t'e (ro(er data n(uts eac' (ar o& dr#ers &orms a &ull45 or brdgeD re#ersble dr#e

sutable &or solenod or motor a((lcatons. On t'e L%$* eternal 'g'4s(eed out(ut clam(

dodes s'ould be used &or nduct#e transent su((resson. A 7CC1 termnal se(arate &rom

7CC% s (ro#ded &or t'e logc n(uts to mnmHe de#ce (ower dss(aton. It s c'aracterHed

&or o(eraton &rom )\C to )\C.

~ 34 ~




Fgure %.09 T'e L%$*+ 54brdge

='/ L%$*+ 54brdgeZ

T'e L%$*+ 54brdge wasn>t our (rmar/ selecton. =e wanted to use t'e SN--1)

Vuadru(le 54dr#er due to ts ablt/ to dr#e t'e col at a 'g'er current. But due to ts

una#alablt/ n t'e market and t'e !roteus com(onents lbrar/ we com(romsed to use L%$*+ as t

s t'e onl/ 54brdge dr#er a#alable n t'e !roteus lbrar/.

%.1) !'oto Sensors

In a magnetc le#taton s/stem transducers are re3ured &or t'e measurement o& (oston. T'e

sm(lest t/(e o& (oston transducers t'at can be used t'e O(tcal transducer. T'e o(tcal

transducer reles on t'e lg't &allng on t's o(tcal transducer. T'e o(tcal transducer used n t's

magnetc le#taton s/stems are t'e In&rared +ode as a Transmtter and a !'oto Transstor as a

detector. T'e lg't &allng on t'e ('ototransstor beng nterce(ted b/ t'e sus(ended steel ball.

='lst a collmated beam s desrable &or m(ro#ed (er&ormance or accurac/ o& (ostonng t s not

m(ossble to obtan sus(enson wt'out t'ese re&nements. +&&erent o(tcal sensor

con&guratons were a#alable &or t's a((lcaton. T'ree cost e&&ect#e and realstc c'oces were

a#alable9 ('otocells ('ototransstors or ('otododes.




Table %.19 Com(arson o& !'oto sensors a#alable

Table %.1 clearl/ s'ows t'at t'e ('otododes and ('oto transstor would be t'e best o(ton &or

t's a((lcaton. From Table %.1 t s s'own t'at t'e ('otododes are e3ual to or better t'an t'er

counter(arts n t'e m(ortant c'aracterstcs o& senst#t/ lneart/ stablt/ and cost. Also all o&

t'e ('otododes ratngs are consdered et'er #er/ good or ecellent. T'e ('otodode selected

ncludes a (ackagng materal t'at blocks #sble lg't and 'as (eak senst#t/ at $) nm. =t'

#sble lg't beng n t'e range o& -)) 4 )) nm t's selecton o& ('otodode mnmHed t'e

a&&ects o& ambent lg't on t'e magnetc le#taton de#ce.

%.11 So&tware and !rograms used n t'e (ro"ect

=e used d&&erent knds o& so&tware durng t'e course o& t's (ro"ect. Some o& t'em are9 ,atlab

!roteus and ,kro C.A s'ort and (recse descr(tons o& t'ese so&tware &ollows9

%.11.1 ,atlab

,ATLAB s an ntegrated tec'ncal com(utng en#ronment t'at combnes numerc

com(utaton ad#anced gra('cs and #sualHaton and a 'g'4le#el (rogrammng language. It

contans 'undreds o& commands to do mat'ematcs. It can be used to gra(' &unctons sol#e

e3uatons (er&orm statstcal tests and do muc' more. It s a 'g'4le#el (rogrammng language

t'at can communcate wt' ts cousns e.g. FO2T2AN and C. It can (roduce sound and anmate

gra('cs. It also can do smulatons and modelng SI,:LIN@]D. It can (re(are materals &or

e(ort to t'e =orld =de =eb. In addton It can be used n con"uncton wt' e word (rocessng

and deskto( (ubls'ng &eatures o& ,croso&t =ord] to combne mat'ematcal com(utatons

wt' tet and gra('cs to (roduce a (ols'ed ntegrated and nteract#e document. A (rogram

t's so('stcated contans man/ &eatures and o(tons. T'ere are lterall/ 'undreds o& use&ul

commands to do all t'e abo#e. T'e ,ATLAB 'el( documentaton contans t'ousands o& entres.

T'e standard re&erences w'et'er t'e ,at' =orks :ser>s 6ude &or t'e (roduct or an/ o& our

com(ettors contan m/rad tables descrbng an endless stream o& commands o(tons and

&eatures t'at t'e user mg't be e(ected to learn or access. ,ATLAB s more t'an a &anc/

~ 36 ~




calculatorK t s an etremel/ use&ul and #ersatle tool. E#en & /ou onl/ know a lttle about

,ATLAB /ou can use t to accom(ls' wonder&ul t'ngs. And n our contet t can wdel/ be

used to make calculatons eas/ n t'e &eld o& control stream. It can (er&orm t'ngs lke

calculatng matrces and trans&er &unctons (lottng d&&erent gra('s and stablt/ anal/ss

met'ods 2oot locus N/3ust (lot etc.D and more m(ortantl/ t can be used to model 'ardwares n

ts Smulnk and gude 6:I modeler (ackages. It can also be used to generate c cYY and 5+L codes

to be dum(ed on mcrocontrollers and F!6As. T'e gra('cal nter&ace o& ,atlab and Smulnk

can be seen on A((end4A.

%.11.% !rotues ISIS !ro&essonal

!roteus s so&tware &or mcro(rocessor smulaton sc'ematc ca(ture and (rnted crcut board

!CBD desgn. It s de#elo(ed b/ Labcenter Electroncs %1M. It s used &or smulatng d&&erent IC

com(onents &rom ts wde range lbrar/. It also contans !CB lbrares t'at make makng !CB

boards #er/ eas/. It conssts t'e &ollowng com(onents wt' n ts #cnt/%1M.

[ ISIS Sc'ematc Ca(ture 4 a tool &or enterng desgns.

[ !2OS!ICE ,ed mode S!ICE smulaton 4 ndustr/ standard S!ICE*F smulator

combned wt' a dgtal smulator.

[ A2ES !CB La/out 4 !CB desgn s/stem wt' automatc com(onent (lacer r(4u( and

retr/ auto4router and nteract#e desgn rule c'eckng.

[ 7S, 4 7rtual S/stem ,odellng lets cosmulate embedded so&tware &or (o(ular mcro4

controllers alongsde 'ardware desgn.

[ S/stem Bene&ts Integrated (ackage wt' common user nter&ace and &ull/ contet

senst#e 'el(.

T'e 6:I nter&ace o& ISIS (ro&essonal s &ound on a((end4B

~ 37 ~

http://en.wikipedia.org/wiki/Microprocessor

http://en.wikipedia.org/wiki/Printed_circuit_board

http://en.wikipedia.org/w/index.php?title=Labcenter_Electronics&action=edit&redlink=1

http://en.wikipedia.org/wiki/Printed_circuit_board

http://en.wikipedia.org/w/index.php?title=Labcenter_Electronics&action=edit&redlink=1

http://en.wikipedia.org/wiki/Microprocessor




%.11.* ,kro C

,kroC s a &ull4&eatured ANSI C com(ler &or d&&erent mcrocontroller arc'tectures. It s t'e

best soluton &or de#elo(ng code &or /our &a#orte mcrocontroller. It &eatures ntut#e I+E

(ower&ul com(ler wt' ad#anced SSA o(tmHatons lots o& 'ardware and so&tware lbrares

and addtonal tools t'at wll 'el( /ou n /our work. Eac' com(ler comes wt' com(re'ens#e

5el( &le and lots o& read/4to4use eam(les desgned to get /ou started n no tme. It s used to

generate .'e &les to be loaded to mcrocontrollers &or use n (roteus smulatons or n real l&e

'ardware. T'e 6:I nter&ace o& mcro c s a#alable on A((end4C o& t's document.

%.1% !rogrammng n C

T'ere are d&&erent knds o& languages used &or (rogramng mcrocontrollers. Assembl/ and C can

be named as eam(les. T'e (rogramng language used n our (ro"ect s C. It was c'osen because

o& ts sm(lct/. O& course t'ere are ot'er sm(ler (rogramng languages but due to t'e &act t'at t so

muc' resembles CYY t got easer &or us to use t as we are well &amlar wt' t'e CYY language

&rom our (recous courses.

Some o& t'e codes we used are lsted below9

Codes used &or ntalHatons9

!O2TB)K

T2ISB)K

!O2T+)

T2IS+%K

T'e &rst two lnes are used to reset and ntalHe (ort B as an out(ut (ort w'le t'e ot'er two lnes

are used to reset and ntalHe !O2T+ as an n(ut.

~ 38 ~




Codes used &or !=,9

#od !=,1]Intconst long &re3DK

#od !=,1]Set]+ut/unsgned s'ort dut/]ratoDK

#od !=,1]Start#odDK

T'e code at t'e &rst lne ntalHes t'e !=, module wt' dut/ rato ). !arameter &re3 s a

desred !=, &re3uenc/ n 5H re&er to de#ce data s'eet &or correct #alues n res(ect wt' FoscD.

T's routne needs to be called be&ore usng ot'er &unctons &rom !=, lbrar/.

T'e code at t'e second lne sets !=, dut/ rato. !arameter dut/ takes #alues &rom ) to % w'ere

) s )W 1% s )W and % s 1))W dut/ rato. Ot'er s(ec&c #alues &or dut/ rato can be

calculated as !ercent^%D1)).

T'e code used at t'e t'rd lne starts t'e !=, (ro#ded t'at t'e dut/ c/cle s set.

Codes used wt' t'e LC+9

#od Lcd]IntDK

#od Lcd]Outc'ar row c'ar column c'ar ^tetDK #od

Lcd]Cmdc'ar out]c'arDK

T'e code a((earng at t'e &rst lne abo#e IntalHes LC+ module. T'e code at t'e net lne

(rnts tet on LC+ startng &rom s(ec&ed (oston. Bot' strng #arables and lterals can be

(assed as a tet. ='le t'e last lne code s used to (ass command to t'e LC+ module.

~ 39 ~




C'a(ter T'ree

S/stem 6eneral +escr(ton

*.1 Introducton

T'e ('/scal s/stem as s'own n Fgure *.1 conssts o& a steel ball t'at s to be le#tate under an

electromagnet. For t'e (ur(oses o& t'eoretcal anal/ss and s/stem be'a#oral stud/ realstc but

arbtrar/ s/stem (arameters were selected. For t'e electromagnet t'e re3ured (arameters were

assumed to be a resstance an nductance a magnetc constant and mass o& t'e steel ball and an/

'/steress e&&ects o& t'e electromagnet were assumed to be neglgble. T'e ('/scal s/stem s

s'own below.

Fgure *.19 Sc'ematc o& t'e 6eneral s/stem

~ 40 ~




T's senor (ro"ect re(ort concentrates on t'e desgn o& a controller &or kee(ng a steel ball

sus(ended n t'e ar. In t'e deal stuaton t'e magnetc &orce (roduced b/ current &rom an

electromagnet wll counteract t'e weg't o& t'e steel ball. Ne#ert'eless t'e &ed

electromagnetc &orce s #er/ senst#e and t'ere s nose t'at creates acceleraton &orces on t'e

steel ball causng t'e ball to mo#e nto t'e unbalanced regon. T'e man &uncton o& t's

controller s to mantan t'e balance between t'e magnetc &orce and t'e ball>s weg't. T'e

controller was desgned n two wa/s9 Anal/tcal and dgtal based controllers. Accordng to t'e

anal/tcal met'od t'e mat'ematcal model o& t's magnetc le#taton s/stem was establs'ed

wt' t'e goal o& desgnng t'e control s/stem. S/stem lnearHaton and ('ase4lead com(ensaton

were em(lo/ed to desgn t'e controller o& t's unstable nonlnear s/stem. T'e modelng

(ro(osed n t's senor (ro"ect (ro#des a robust closed4loo( magnetc le#taton s/stem w'c'

can stablHe t'e s/stem o#er a large range o& #aratons o& t'e sus(ended mass. Accordng to t'e

dgtal wa/ o& desgnng t'e controller a mcrocontroller was em(lo/ed and was setu( to get

&eedback n(uts &rom &#e lg't sensors emtter and rece#er (arsD and g#es ts out(ut to an 54

brdge dr#er t'at s used to control t'e current w'c' n turn controls t'e magnetc &eld strengt'

o& t'e electromagnet t'us stablHng t'e s/stem. T'e block dagrams re(resentng bot' wa/s o&

control are drawn below. T'ese desgn met'ods o& t's s/stem are (resented n t's senor (ro"ect

bre&l/ n t'e comng sectons.

*.% Com(ensaton +esgn Block dagram

5ere 6sD s t'e general trans&er &uncton o& t'e uncom(ensated s/stem w'c' also ncludes t'e

&eedback &rom t'e ('oto sensors. 6csD s t'e com(ensaton to be added to t'e s/stem to make t

stable.

~ 41 ~




Fgure *.%9 Block dagram o& com(ensated s/stem

*.* ,crocontroller based control block dagram

5ere t'e ('oto sensors (ro#de t'e mcrocontroller wt' n(uts contanng t'e (oston o& t'e

ob"ect to be le#tated. And t'en t'e mcrocontroller sends t'e a((ro(rate sgnal !=,D to t'e '4

brdge. Fnall/ t'e '4brdge based on t'e n(uts &rom t'e mcrocontroller ncreasesdecreases t'e

current su((led to t'e col strengt'enng weakenng ts &eld w'c' l&ts t'e ball u(down based on

ts (oston to make t stable.

LCD

16F877A

Fgure *.*9 6eneral Block dagram o& t'e entre ,crocontroller based s/stem

~ 42 ~




*.- S/stem Anal/ss and +esgn

T'e magnetc le#taton s/stem n t's senor (ro"ect s llustrated n Fgure 1K t kee(s a steel ball

sus(ended n t'e md4ar b/ counteractng t'e ball>s weg't wt' t'e electromagnetc &orce. tD

s t'e dstance between t'e steel ball and t'e electromagnet. ) s t'e re&erence (oston or t s

t'e (ro(er le#taton dstance. T'e electromagnetc &orce &D acts t'e ball w'c' can be

e(ressed as t'e &ollowng d/namc &ormula n u(ward drecton accordng to Newton>s law

='ere m s t'e weg't o& t'e ball and g s t'e gra#tatonal constant.

E3uaton *.1D also ma/ be descrbed as

='ere d=e s c'ange o& electrcal n(ut and d=&l s c'ange o& stored energ/ assumng d=e

e3uals Hero &or lnear s/stem.

T'e electromagnetc &orce (roduced b/ E3uaton *.*D s as &ollows

='ere LD s t'e total nductance o& t'e electromagnetc col and s t'e (oston o& t'e ball.

T'e sus(ended steel ball contrbutes to t'e nductance o& t'e electromagnetc col. As t'e ball

a((roac'es t'e magnet t'e total nductance ncreases. As t'e ball mo#es &art'er &rom t'e

~ 43 ~




magnet t'e nductance decreases reac'ng t'e mnmal #alue as t'e ball a((roac'es to n&nt/.

T'e mnmum #alue o& course t'e nductance o& t'e magnet. I& L1 s t'e nductance wt'out t'e

ball and L) s t'e ncremental nductance wt' t'e ball t'en t'e nductance o& t'e electromagnet

can be a((romated

I& we take t'e ncremental #araton o& t'e total nductance and substtute nto t'e &orce e3uaton

*.-D

='ere C s t'e &orce constant and e(ressed as

T'e (oston o& t'e ball wll n&luence t'e nductance o& t'e electromagnet col and t'e c'anges

are nonlnear. In addton t'e balance (ont between t'e electromagnetc &orce and gra#t/ s

n'erentl/ unstable. To sol#e t's (roblem t'e nonlnear electromagnetc &orce must be lnearHed

as &ollows

~ 44 ~




='ere I) e3uals t'e current o& t'e col w'en t'e ball s at ) ) s at e3ulbrum (ostonD. ='en

t'e magnetc &orce balances t'e gra#tatonal &orce on t'e ball t'e acceleraton o& t'e ball s Hero

and E3uaton *.1D becomes

In E3uatons *.1D *.8D and *.$D we neglect t'e 'g'er order terms and conclude t'at t'e

control &orce &1 kee(ng t'e ball balanced s g#en b/ E3uaton *.1) below.

To &nd t'e control &orce usng E3uaton *.1D *.8D and *.$D we get

For t'e electrcal e3uaton we assume t'at t'e electromagnet col s ade3uatel/ modeled as a

seres resstor4nductor combnaton. Note t'at t'e nductor ncludes t'e steel ball and 'as t'e

total nductance descrbed (re#ousl/. T'e #oltage4current relatons'( &or t'e col s g#en b/

T's e3uaton s actuall/ 3ute com(lcated because o& t'e nonlnear de(endence o& t'e nductor

on t'e ball (oston. =e can sm(l&/ t'e anal/ss b/ assumng t'at w'en t'e s/stem s (ro(erl/

desgned t'e ball wll reman close to ts e3ulbrum (oston .e ;;). T's means t'at LD s

~ 45 ~




sm(l/ LYL). =e make &urt'er sm(l&/ng assum(ton t'at t'e n'erent nductance o& t'e col L1

s muc' larger t'an t'e nduct#e contrbuton o& t'e ball L) and get t'e &nal e3uaton

T'e ds(lacement o& t'e ball s measured b/ t'e sensor ('oto4detector w'c' s t'e out(ut and

can be &ormulated as

='ere _ s t'e sensor gan

Combnng t'e La(lace trans&ormaton o& E3uaton *.1)D *.11D *.1*D and *.1-D wt' t'e

#oltage o& t'e electromagnet as t'e n(ut and t'e ball (oston ds(lacement as t'e out(ut

='ere

~ 46 ~




And also

Substtutng E3uaton *.1D and *.18D nto E3uaton *.1$D we obtan

T'e o#erall trans&er &uncton between t'e col n(ut #oltage 7sD and t'e ball sensor out(ut

#oltage 7;sD s g#en b/

='ere




Furt'er sm(l&es

*. !arameter +etermnaton

T'e (arameter n t'e s/stem e3uatons s determned as &ollows. T'e col resstance and

Inductance 2 and LD can be measured wt' 2LC Brdge meter. A small metal globe s used &or

t'e ballK ts mass m s measured on a scale. T'e desred ntal ball dstance ) s t'e e&&ect#e

dstance t'roug' w'c' t'e ball can be le#tated. ;) s measured b/ t'e 'eg't gauge as t'e ball

ntersects t'e lg't beam o& t'e ('oto detector. For t'e (ur(ose o& t'eoretcal and s/stem

be'a#oral stud/ realstc but arbtrar/ (arameters were selected s'own n Table *.1.

Table *.19 Intal (arameters used &or t'e desgn

T'e sensor gan _ s &ound b/ ds(lacng t'e ball 1mm and measurng t'e out(ut o& ('oto

detector. To &nd I) a (edestal was used to set t'e ball at ) and t'e col current was ncreases untl

t'e ball "ust l&ted o&& t'e (edestal. Substtutng t'e measured (arameters ) I) m and t'e

gra#tatonal constant nto E3uaton *.8D /elds t'e (arameter C.




T'e calculated (arameter C and t'e ntal (arameters ) and I) are used to determne t'e

(arameters @ I @ ; @ 1 @ % and !*

Substtute t'e abo#e constant nto E3uaton *.%-D.we obtan t'e o(en loo( trans&er &uncton

T'e 3uantt/ t'at can be drectl/ controlled a +C am(l&er dr#ng t'e magnet s ts #oltage

out(ut and Tm1(*L12 re(resents t'e lag n t'e resultng current due largel/ to t'e magnet

nductance. 5owe#er t'e term s%40*.*D arses &rom t'e &orce4dstance c'aracterstcs w'c'

ma/ be consdered analogues to s(rng st&&ness constant but n t's case negat#e. T'e

conse3uence o& t'e negat#e s(rng st&&ness c'aracterHed b/ @% causes t'ese s/stems to be

bascall/ unstable. T'e e(lanaton n control termnolog/ s t'at t'e term s%40*.*D re(resents

(oles at √ on t'e s4(lane and t'e (ole at √ contrbute to t'e nstablt/.

~ 49 ~




T'ese (arameters are used n E3uaton *.%0D and t'e (oles o& t'e loo( trans&er &uncton 6sD are

der#ed to be re4wrte t'e o(en loo( trans&er &uncton

To draw t'e root locus &or t'e o(en loo( ,agnetc Le#taton s/stem usng t'e o(en loo( trans&er

&uncton

T'e o(en loo( (oles are s11*.8 s%%.0 and s*%.0. T'e loc starts at (oles and ends at

Heros T'e breakawa/ (onts on t'e real as calculated as

T'e necessar/ condton &or o(tmum

=e c'oose sa s b1%.-* and t'e breakawa/ gan calculated as usng E3uaton *.%8D at

sa s b1%. @ b1*.1%. T'e uncom(ensated root locus as s'own n Fgure *.%

~ 50 ~




Fgure *.-a9 :ncom(ensated root locus

Fgure *.-b9 :ncom(ensated root locus wt' s/stem (arameters

~ 51 ~




Fgure *.9 Control s/stem Block dagram &or t'e magnetc le#taton s/stem

*.0 Non4Lnear Control and 7rtual !ole Cancellaton

A good controller s'ould be able to control t'e (oston o& t'e le#tated ball e#en w'en t'eweg't o& t'e ball c'anges. From E3uaton *.%D we know t'at t'e o(en loo( (oles ( 1 and (%

c'ange wt' t'e ball>s weg't. 5owe#er (ole (* &ormed b/ t'e col resstance and nductanceremans unc'anged des(te c'anges n t'e weg't o& le#tated ball. T's m(les t'at (ole (* can be

counteracted b/ usng t'e #rtual (ole cancellaton met'od. Feedback can not onl/ desenstHe t'e (arameter #aratons but also mod&/ t'e non4lneart/ n t'e control s/stem. T'e &ront o& t'e s/stemncludes an o(eratonal am(l&er w'ose trans&er &uncton s

='ere `' s t'e 4*db 'g' &re3uenc/ o& t'e am(l&er.

Conse3uentl/ n Fgure *. t'e loo( trans&er &uncton between 7C and IsD can be e(ressed as

~ 52 ~




='ere A s t'e gan o& t'e am(l&er and B stands &or t'e trans&er &uncton o& t'e non4lnear

(ower nter&ace and t'e electromagnet col. E'btng t'e o(eratonal Am(l&er L,-1 as an

eam(le t'e (arameters A and `' are a((romatel/ %1) and % radsec res(ect#el/.

Conse3uentl/ AB`' s larger t'an sY `'D. T's m(les t'at E3uaton *.*1D can be sm(l&ed to

T's tec'n3ue s called t'e #rtual (ole cancellaton met'od. 5ence t'e trans&er &unctons 6sD o&

t'e le#taton s/stem can be etended to 61sD s'own n Fgure *.*. A&ter usng E3uaton *.*%D

t'e trans&er &uncton o& 61sD can be obtaned as

Ob#ousl/ t'e order o& t'e magnetc le#taton s/stem s reduced &rom * to % w'c' makes t

easer to control. Substtutng t'e constants t'e trans&er &uncton o& 61sD becomes

*. Electromagnet +esgn

T'e desgn o& magnets (artcularl/ &or (ro#dng l&t n magnetc sus(enson s/stems n#ol#es

consderaton o& #arous nteractng (arameters. Consderaton s g#en to &actors suc' as

met'ods o& generatng magneto4mot#e &orce sutable col materals t'e closed loo(

(er&ormance and t'e o#erall s/stem re3urements.

T'e Statc desgn consderaton s t'e startng (ont o& t'e desgn (rocedure usng t'e e3uaton

g#ng t'e &orce o& attracton

~ 53 ~




='ere NI am(ere turnsK sus(ensonDarga( ds tan ce K A (ole &ace Area .T'e constant o&

(ro(ortonalt/ s determned b/ t'e detaled geometr/ o& t'e magnet.

T'e d/namc consderaton also m(ortant &or sus(enson are (art o& closed loo( s/stems and t s

essental to consder t'er (er&ormance. Some o& t'e &actors n&luence t'e d/namc c'aracterstcs

are

a# Inductance o& cols and tme constant.

bD O(eratng 7oltage

To (roduce a magnetc &eld w'c' (rmarl/ etends downward &rom t'e l&tng col. So

consder t'ese deas.

[ S'ort and &at cols are better t'an long and sknn/. T'e/ reduce t'e leakage &lu t'at

would ot'erwse esca(e outward &rom t'e sdes.

[ An ron 'at suc' as a &lat was'erD on t'e to( s a good dea. It 'el(s 'old wndngs n

(lace and 'el(s magnetc &lu s(read out &rom t'e to(.

[ A n/lon was'er on t'e bottom or ot'er non4&errous was'erD s a good dea. It 'el(s 'old

t'e wndngs onto a &at col wt'out s'eldng an/ magnetc &lu &rom gong downwards. [

An ron core wll greatl/ ncrease t'e colJs strengt'.[ A col resstance o& 4 ) o'ms dr#en wt' u( to % am(s 'as worked well. A cou(le o&

(ubls'ed desgns o(erate n t's range so t's would be a good target to s'oot &or.

[ =nd some ta(e around t'e bolt be&ore wndng t'e col. T's kee(s t'e t'reads &rom

cuttng t'e nsulaton.

<ou can wnd a col on a carrage bolt. :se one la/er o& ta(e &rst to (rotect t'e wre.D T'e

t'reads can (ro#de ad"ustablt/ b/ screwng t n or outD o& /our wooden &rame.

T'e sHe o& t'e carrage bolt s not crtcal. I used a common carrage bolt - nc'es long and *8

nc'es t'ck c'osen merel/ &or con#enence. Clck on t'e ('oto at le&t to see two eam(les.

~ 54 ~




T'e bottom o& /our steel core col &ormD s'ould ta(er to a (ont. T's g#es a (ont source o&

&lu gong downward. I &ound a &lat4bottomed steel core ga#e too man/ (laces &or t'e ball to

attac' tsel& to and allowed too muc' sde4to4sde moton. Fle o&& an/ roug'ness to ensure t'e

bottom o& /our steel core s (ont/ and smoot'.

T'e w'ole boltcol assembl/ can be turned to rase and lower t. <ou can see a nut w'c' &astens t'e

to( was'er n (lace. T's also 'el(s elmnate #braton and 'um.

I used %-4ga magnet wre n 1*-1 turns on %- la/ers wound on a carrage bolt. T'ere s a

Alumnum &lat4was'er on t'e bottom t'e 'ead endD and a common gal#anHed steel &lat was'er

on t'e to(. T'e col lengt' s twce t'e wdt' o& Scotc' magc trans(arent ta(e w'c' secures t'e

la/ers o& wndngs. T's col 'as .) o'ms o& resstance. +r#en b/ a 17 source t carres about

% am(s o& current. :n&ortunatel/ t tends to get (rett/ warm & le&t &ull on &or ten mnutes. T'e col

s energHed b/ a %N*) N!N (ower transstor on a 'eat snk.

T'e number o& turns wll 'a#e a drect e&&ect on t'e colJs d.c. resstance. A large resstance wll

decrease t'e current & t'e (ower su((l/ s not c'anged. But & /ou buld t'e col &rst and c'oose

t'e #oltage o& t'e (ower su((l/ second t'en /ou can ac'e#e an/ current /ou want. So t'e colJs

magnetc &eld s drectl/ (ro(ortonal to t'e number o& turns actuall/ turnsnc'D and to t'e col

current. It eas/ to mamHe (er&ormance kee( (lng on turns and ncreasng t'e current.

~ 55 ~




C'a(ter Four

CONT2OLLE2 +ESI6NS

-.1 Inward and Outward A((roac'

T'ere are two a((roac'es o& control s/stem desgn. T'ese are Outward A((roac' and

Inward A((roac'.

-.1.1 Outward A((roac'

T'e work o& control desgn starts &rom nsde to outward .e. &rst t'e o(en loo( trans&er &uncton s

s'a(ed b/ controllng t (oles and Heros addng (ro(er control desgn to t'e s/stem so t'at stable

o#erall trans&er &uncton wll be ac'e#ed. T'e outward a((roac' ncludes

a. ,odern State #arable &eedbackD controller desgn met'od w'ere acce(table

(er&ormance o& controller can be ac'e#ed b/ &eedng back state #arables t'at are

accessble to measurement or &ound b/ estmaton o& a#alable n&ormaton &or states t'at

#arables not accessble &or drect measurementD. T's met'od em(lo/s a more

mat'ematcal a((roac' &or t'e desgn control s/stems. ,atr met'ods are usuall/

a((led w'c' allows t'e treatment o& ,ult(le4In(ut4,ult(le4Out(ut ,IO,D s/stems.

b. Classcal Con#entonalD controller desgn met'od w'c' ncludes man/ com(ensators

lead lag lead4lag (ro(ortonal (ro(ortonal der#at#e and (ro(ortonal ntegralD. T's

s sutable &or s/stem wt' n(ut #arable 2tD and out(ut #arable <tD are accessble &or

measurement and error EtD s consdered. T'e anal/ss and desgn o& controller are

carred out usng trans&er &unctons toget'er wt' a #aret/ o& gra('cal tec'n3ues suc'

as root4locus and bode (lots. T's met'od s usuall/ restrcted to Sngle4In(ut 4 Sngle4

Out(ut SISOD s/stems.

-.1.% Inward A((roac'

Anot'er control s/stem desgn a((roac' s called Inward !ol/nomal E3uatonD. In t's

a((roac' t'e re#erse o& t'e outward a((roac' .e. &rst a desred closed loo( trans&er &uncton s

~ 56 ~




desgned and t'en sol#e &or re3ured controller. T's met'od s called a lnear algebrac

met'odolog/ &or controller desgn. It tres to sats&/ a total (rescrbed s/stem trans&er &uncton &or

sngle4n(ut 4 sngle4out(ut SISOD s/stems.

-.% S/stem Trans&er Functon

:sng Lnear Algebrac A((roac' &or a (lant wt' a (ro(er trans&er &uncton o& 6sD

='ere NsD and +sD co(rme w'c' s e3u#alent to t'e controllablt/ and obser#ablt/ o& t'e

s/stemK and t'e trans&er &uncton

='ere 2tD and <tD are n(ut and out(ut o& closed4loo( s/stem res(ect#el/. T'e o#erall

trans&er &uncton 6osD s sad to be m(lement able &9

a. +egree o& +osD mnus degree o& NosD degree o& +sD mnus degree o& NsD.

b. All closed loo( 25! Heros o& NsD are retaned n NosD

c. +osD s 5urwtH .e. all ts roots are n t'e le&t 'and (lane.

T'ese (onts can be #er&ed usng t'e &ollowng closed loo( control dagram wt' controller

trans&er &uncton9




From t's &gure t'e o#erall trans&er &uncton s9

T'e o#erall trans&er &uncton 6osD becomes9

It s clearl/ seen t'at NsD s a &actor o& N)sD. 5ence & NsD 'as a &actor t'at does not also a((ear

n N)sD t'en t must be cancelled b/ +)sD+sDY NCsDNsD .e. t must be made to a((ear n

+)sD. T'e actual cancellaton wll not be (ermtted & Hero o& NsD les n t'e rg't 'and (lane as

t can causes R>nternal nstablt/>>. Assgnng o& 6)sD can determne b/ o(tmal cost &uncton

met'ods suc' as.

1. Integral o& absolute error IAED

%. Integral o& s3uared error ISED

*. Integral o& tme mult(ler absolute error ITAED.

-.%.1 Lnear Algebrac ,et'od

I& we 'a#e a desred model trans&er &uncton 6msD n mnd w'c' s same wt' 6)sD t'en t's s t'e

model4matc'ng (roblem. T'e sm(ler attem(t s wt' a unt/ &eedback trans&er &uncton &rom

Fgure -.1 and ts mat'ematcal re(resentaton b/ e3uaton -.*D s e(ressed as9

Sm(l&/ng t'e abo#e e3uaton g#es9




I& t'ere s an unstable (ole n t'e (lant trans&er &uncton 6sD and t'e same Hero a((ears n t'e

controller 6csD so t'at t'ere s (ossblt/ o& cancellaton between unstable (ole o& 6sD and Hero o&

6csD.T's ma/ cause nternal nstablt/ due to dsturbance n(ut. T's lmts a((lcaton o& model4

matc'ng tec'n3ue.

T'e (oles are (laced w'ere desred wt' Heros le&t uns(ec&ed. For t'e unt/ &eedback

arrangement &or 6sD 6csD and 6osD as de&ned abo#e and wt' degree o& NsD degree o&

+sD n &rom e3uaton -.-D we 'a#e

T's s a (ol/nomal e3uaton w'ere +csD and NcsD are unknown (ol/nomals. E3uaton -.D can

be sol#ed usng t'e S/l#ester matr tec'n3ue e(andng t'e (ol/nomals as &ollows.

Substtutng -.8D n -.D

T'e (ol/nomal coe&&cents F) F1 FnYm are obtaned &rom (ole4(lacement o& 6 o sD .

E3uatng (owers o& s n -.$D leads to

~ 59 ~




T's can be rewrtten n t'e &orm o& S/l#ester matr as &ollows.

E3uaton -.11D and -.1%D 'as soluton & t'e matr o& coe&&cents S/l#ester matr4;D 'as &ull

row rank. In ot'er wards t'e &ollowng condton 'old true.

n Y m Y 1 %m Y 1D or n 4 1 m -.1*D

To ac'e#e arbtrar/ (ole4(lacement t'e degree o& controller 6CsD n t'e unt/ &eedback

con&guraton must be m n 4 1 or 'g'er. I& t s less t'an n41 t ma/ be (ossble to assgn some

~ 60 ~




o& t'e (oles but not all. T'e degree o& t'e c'aracterstc e3uaton +)sD o& o#erall trans&er

&uncton 6)sD s n Y m. T'e unknowns n -.D can be determned b/ -.1%D so t'at &or s(ec&ed

(er&ormance and coe&&cents 6)sD and 6CsD are g#en b/ t'e &ollowng e(ressons.

-.%.% A((lcaton o& t'e Lnear Algebrac ,et'od

For t'e stablHaton o& t'e s/stem t'e closed4loo( (oles o& t'e trans&er &uncton 6 )sD must be n

t'e le&t 'and sde o& s4(lane. Transent (er&ormance and stablt/ o& a lnear tme n#arant s/stem s

a((romatel/ determned b/ t'e domnant (oles o& ts c'aracterstc (ol/nomal n t'e

com(le root (lane. Assumng t'at domnant (oles are com(le roots and g#en as9

='ere ) s dam(ng rato o s undam(ed natural &re3uenc/ and d o √ s dam(ed

&re3uenc/.

=e 'a#e to desgn a controller so t'at t'e ste( res(onse o& t'e closed4loo( s/stem meets t'e

&ollowng s(ec&catons.

1. T'e settlng tme TSD s t'e mamum tme at w'c' res(onse o& t'e s/stem wll

attaned %W or W less or more t'an stead/ state res(onse o& t'e s/stem.

%. T'e dela/ tme TdD s t'e tme out(ut takes to reac' one4 'al& o& t'e stead/ state

res(onse #alue o& s/stem. T'e tme dela/ a((romated as




*. T'e mamum o#ers'oot , (D s (eak #alue o& ste( res(onse o& t'e s/stem n t'e

transent regon.

-. T'e dam(ng rato9 ).- ) 1

T'e settlng tme and dela/ tme are measures o& t'e s(eed o& t'e s/stem res(onse. T'e s(eed o& t'e

res(onse can be ncreased b/ ncreasng t'e undam(ed natural &re3uenc/ o. In general t'e

mamum o#ers'oot decreases as t'e dam(ng rato ncreases. 5owe#er as dam(ng rato

ncreases t'e dela/ tme ncreases w'c' causes t'e res(onse o& t'e s/stem sluggs'.

:sng arbtrar/ (ole4(lacement wt' unt/ &eedback t'e controller to stablHe t'e magnetc

le#taton s/stem s desgned net. T'e unstable (lant trans&er &uncton g#en b/

T'e numerator and denomnator (ol/nomals o& 6sD can be wrtten as9

T'e order o& t'e (lant trans&er &uncton s n* and t needs controller 6csD o& t'e order m

n41 %. T's s'ows t'e degree o& t'e c'aracterstc e3uaton +)sD o& t'e o#erall trans&er &uncton

6)sD s n Y m . Based on t'e (er&ormance s(ec&catons settng taken abo#e let t'e domnant

(oles are9

t'en (ol/nomal o& t'e c'aracterstc e3uaton +)sD s g#en b/ e3uaton -.%-D




E(andng e3uaton -.%-D g#es t'e (ol/nomal coe&&cents

!uttng e3uatons -.%*D -.%-D and -.%D n t'e S/l#ester matr &orm to determne t'e

unknown coe&&cents o& (ol/nomals NcsD and +csD so t'at t'e controller 6csD and t'e o#erall

trans&er &uncton 6)sD can be s(ec&ed.

T'e unknown coe&&cents are determned usng matlab command < n#;D^F.

T'ere&ore t'e Controller trans&er &uncton s

~ 63 ~




. ,amum (eakD #alue ) Q ).1)

. Settlng tme4Ts ).)$ sec ).)1*0sec .

Fnal #alue 1.)1

:sng algebrac tec'n3ue dscussed abo#e t'e stablt/ o& t'e s/stem can be sats&actor/

ac'e#ed b/ selecton o& arbtrar/ stable (oles o& o#erall trans&er &uncton o& t'e s/stem. T'e

(er&ormance s(ec&catons o& t'e o#erall s/stem are also met. But t's controller s unrealHable

&or (ractcal m(lementaton because t'e coe&&cents o& t'e controller trans&er &unctons are #er/

large t'at ma/ cause saturaton o& t'e com(onents durng (ractcal m(lementaton. T's s

because o& t'e (oles selecton s done arbtrar/ ece(t t'e domnant (olesD. T'e second reason s

t'at we 'a#e a drect control onl/ &or (oles and Heros o& t'e o#erall closed loo( trans&er

&uncton and no means &or drect control o#er t'e o(en loo( trans&er &uncton (oles and Heros o&

t'e s/stem.

~ 65 ~




-.* !'ase 4Lead com(ensated Controller ,agnetc

Le#taton S/stem

T'e s/stem s desgned to carr/ out t'e ma"or &uncton o& stablHng t'e workng (ont o& t'e

le#taton s/stem. T'e trans&er &uncton o& 6>sD s'ows t'at t's s/stem 'as one stable (ole w'le t'e

ot'er s stll unstable. T'e uncom(ensated root4locus s s'own n Fgure -.8 T's (lot s'ows t'at t'e

uncom(ensated s/stem s unstable and cannot be stablHed sm(l/ b/ c'angng t'e s/stem gan.

T'e sm(lest wa/ to stablHe t'e s/stem s to use t'e ('ase4lead com(ensated controller to

cancel t'e unstable (ole. T'e necessar/ (ole re3ured &or t'e ('ase4lead com(ensated

controller s (laced dee(er nto t'e le&t 'and (lane. T's wll mnmHe t'e m(act o& t'e (ole o& t'e

com(ensated controller on t'e root4locus.

Consder t'e com(ensator (laced n t'e &eed &orward (at' s called a cascaded or !'ase4Lead

com(ensator

Fgure -.*9 ,agnetc Le#taton S/stem wt' !'ase4Lead Com(ensator

Now Let us consder a magnetc le#taton s/stem wt' 5sD1 and desgn a com(ensator based on

root locus a((roac'.

T'e o(en4loo( magnetc le#taton s/stem trans&er &uncton wt'out #rtual (ole cancellaton s g#en b/

~ 66 ~




T'e o(en4loo( magnetc le#taton s/stem trans&er &uncton wt' #rtual (ole cancellaton s

g#en b/

A com(ensator 6CsD s used wt' a (lant 6sD so t'at t'e o#erall loo( gan can be set to sats&/ t'e

stead/4state error re3urement and 6C s used to ad"ust t'e s/stem d/namcs &a#orabl/

wt'out a&&ectng t'e stead/4state error. Consder t'e &rst4order com(ensator wt' t'e trans&er

&uncton o& t'e ('ase4lead com(ensated controller s s'own as

T'e desgn (roblems &or t'e selecton o& H ( and @ n order to (ro#de a sutable (er&ormance.

='en HQ ( t'e network s called a !'ase4Lead network and 'as a (ole Hero s4(lane

con&guraton as s'own n Fgure. -.- D.

~ 67 ~




Fgure -.-9 6eneral Block dagram o& t'e entre ,crocontroller based s/stem

~ 68 ~




T'e (ole and Hero o& t'e com(ensator network s selected to cancel t'e unstable (ole o&

uncom(ensated s/stem. As a rule o& t'umb ( s e3ual to 1) tmes H. To use t'e s/stem

(arameters n Table *.1 t'e desgn #alues o& H and ( are %.0 and %.0 res(ect#el/. T'e

com(ensator trans&er &uncton becomes

To obtan a and T are de&ned &or t'e 2C network

='en H Q ( T'e s(ec&caton &or t'e s/stem are

1. Settlng tme %W crteronD Ts - seconds.

%. !ercent O#ers'oot &or a ste( n(ut *W

*. ,amum !'ase margn e3uals 8.*o

-. T'e mamum &re3uenc/ e3uals 81.15H

+ue to t'e (resence o& domnant non4lneart/ suc' as &uncton dead Hone saturaton etc. t'e out(ut

o& t'e s/stem s ad#ersel/ a&&ected. In s(te o& t'ese nonlneartes t'e out(ut also

becomes naccurate due to some eternal dsturbances suc' as 'g' &re3uenc/ nose n electronc

a((lcaton t'ermal nose n am(l&er.

Fgure -. Block dagram o& unt/ negat#e &eedback control s/stem.

~ 69 ~




T'e trans&er &uncton &or t'e com(ensated closed loo( control dagram usng unt/ negat#e

&eedback

=e need to use t'e 2out'45rwtH stablt/ test to #er&/ t'e closed loo( trans&er &uncton

To get t'e #alue o& @ C we need to use t'e 2out'4 5urwtH stablt/ test to #er&/ t'e closed loo(

trans&er &uncton

~ 70 ~




Ob#ousl/ t'e outcome o& t'e s/stem s stable & @). T's m(les t'at a ball o& an/ weg't can be

controlled. Because t'e s/stem model s lnear a((romaton o& a nonlnear s/stem t s not a good

dea to attem(t (ole4Hero cancellaton. :sng 2out'4 5urwtH stablt/ test c'oosng t'e #alue o&

@ C ). To (ro#de some robustness n t'e s/stem model uncertant/ t'e ero ('ase lead

controller was desgned at Heros e3uals 4*) and t'e ('ase lead controller (ole was c'osen to be an

order 1) awa/ &rom t'e ('ase lead controller Hero and 'ence was set to t'e (ole e3uals 4

*)). T'e trans&er &uncton o& t'e !'ase Lead com(ensator becomes

Fgure -.0 Block dagram o& unt/ negat#e &eedback control s/stem wt'out #rtual (ole cancelaton.

:sng t'e abo#e ('ase lead com(ensator and t'e uncom(ensated s/stem descrbed b/

E3uaton *.%D and E3uaton -.-*D t'e unt/ negat#e &eedback control t'e O#erall s/stem

trans&er &uncton becomes

Substtutng 6CsD and 6sD T'e o#er all trans&er &uncton becomes

~ 71 ~




Fgure *.% s'ows t'at t'e uncom(ensated s/stem s unstable and cannot be stablHe b/ "ust

c'angng t'e s/stem gan. T'e com(ensated root locus and t'e bode (lot o& t'e s/stem &uncton s

s'own n Fgure -. and -.8

Fgure -.9 Com(ensated root locus o& t'e magnetc le#taton s/stem (oles n t'e 25!

~ 72 ~




Fgure -.8 Bode and !'ase (lot o& t'e ,agnetc Le#taton s/stem

~ 73 ~




-.- ,crocontroller based desgn

T's &ar t's document 'as re(orted on 'ow we could control and stablHe t'e magnetc

le#taton s/stem usng a com(ensator. T's secton o& t's document re(orts t'e mcrocontroller

based control and stablHaton o& t'e magnetc le#taton s/stem.

LCD

16F877A

Fgure -.$ ,crocontroller based s/stem

5ere t'e ('oto sensors (ro#de t'e mcrocontroller wt' n(uts contanng t'e (oston o& t'e

ob"ect to be le#tated. And t'en t'e mcrocontroller sends t'e a((ro(rate sgnal !=,D to t'e '4

brdge. Fnall/ t'e '4brdge based on t'e n(uts &rom t'e mcrocontroller ncreasesdecreases t'e

current su((led to t'e col strengt'enng weakenng ts &eld w'c' l&ts t'e ball u(down based on

ts (oston to make t stable. And T'e LC+ s used &or ds(la/ng t'e status o& t'e metallc ball.

T'e #er/ &rst t'ng necessar/ 'ere s to desgn t'e ('oto sensors as t s to &ollow n t'e

remanng sectons o& t's secton.

~ 74 ~




-.-.1 !'oto sensors desgn

As t 'as been descrbed n (re#ous sectons o& t's document !'oto sensor consst o& a ('oto

emtter (ossbl/ an n&raredD and ('oto rece#er. To com(l/ wt' t'e mcrocontroller we

desgned bot' n t'e &ollowng wa/s

-.-.1.1 !'oto Emtter desgn

T'e selected ('otododes and n&rared lg't emttng dodes I2E+D were tested to ensure t'er

a((lcablt/ to our ,agle# de#ce. T'e n&rared lg't emttng dodes can su((ort a mamum

contnuous current o& 1)) mA. :sng a 1 7 +C source and resstors o& decreasng #alues t was

e(ermentall/ determned t'at t'e I2E+s n seres wt' a resstor would allow a((romatel/ *)

mA o& current to &low. T's con&guraton ensures t'at t'e I2E+s are o(eratng n a relable and

consstent manner well below ts mamum ca(abltes. T'e current lmtng resstor s

calculated as

=e c'ose 20) o'm standard #alue.

Fgure -.$ ,crocontroller based s/stem

Fgure -.1) !'oto Emtter crcut

~ 75 ~




-.-.1.% +esgnng t'e !'oto detector Crcut

T'e !'oto detector s an In&rared ('oto transstor detector. It s wred wt' t'e current lmtng

resstor 2. T'e man &uncton o& t's current lmtng resstor s to con#ert t'e In&rared beam nto

a corres(ondng +C #oltage n t'e range )4# w'en t'e lg't strkes t'e n&rared ('ototransstor t (ro#des t'e mcrocontroller wt' a low state #oltage .e. bnar/ )D. But w'en lg't

doesn>t strke t'e n&rared ('oto transstor meanng an ob"ect estng between t'e emtter and

rece#erD t wll (ro#de t'e mcrocontroller wt' a 'g' state #oltage .e. bnar/ 1D.

Fgure -.11 !'oto detector crcut

To &nd t'e current lmtng resstor and also known as current to #oltage con#erter resstor From t'e

data s'eet o& ('oto transstor t'e collector current su((ort a re#erse based current o& 1*A and t'e

collector emtter #oltage becomes 'al& o& t'e su((l/ #oltage .e. %.7

~ 76 ~




A total o& &#e ('oto sensors were used durng t'e desgn. T's s due to t'e &act t'at t's s/stem s a

s/stem t'at needs 'g' (recson. T'e sc'ematc drawng o& t'e ('otosensors s s'own below n t'e

wa/ t'e/ wll be mounted.

Fgure -.1% ,crocontroller based s/stem Sc'ematc dagram and (lacement o& sensors

='en t'e metallc ball s (ut on t'e ('oto sensng regon one o& t'e &#e ('oto sensor>s n&rared

lg't emtted to ts rece#er wll be blocked su((l/ng t'e mcrocontroller wt' an n(ut o& R1>.

T's (ro#des t'e mcrocontroller wt' t'e eact (oston o& t'e metallc ball. T'e

mcrocontroller t'en decdes w'et'er to ncreasedecrease t'e current accordng to t'e &ollowng

algort'm w'ere ('oto sensors are numbered &rom to( to down as de(cted n t'e abo#e &gure9

~ 77 ~




I& t'e metallc ball s (ostoned n t'e sensng regon o& ('oto sensor t'en ncrease t'e current wt'

t'e mamum s(eed o& t'e mcrocontroller.

I& t'e metallc ball s (ostoned n t'e sensng regon o& ('oto sensor - t'en ncrease t'e current wt''al& s(eed o& t'e mcrocontroller.

I& t'e metallc ball s (ostoned n t'e sensng regon o& ('oto sensor * t'en mantan currentconstant as t'e ball s now le#tated.

I& t'e metallc ball s (ostoned n t'e sensng regon o& ('oto sensor % t'en decrease t'e current wt'

'al& s(eed o& t'e mcrocontroller.

I& t'e metallc ball s (ostoned n t'e sensng regon o& ('oto sensor 1 t'en decrease t'e current wt't'e mamum s(eed o& t'e mcrocontroller.

In t'e abo#e algort'ms w'en t'e mcrocontroller ncreases t'e current at mamum s(eed o& t'e

mcrocontroller t'e strengt' o& t'e &eld o& t'e electromagnet ncreases &ast l&tng t'e ball u(.

='en t ncreases t'e current at 'al& o& t'e mamum s(eed t'e strengt' o& t'e &eld o& t'e

electromagnet ncreases at a relat#el/ slower s(eed l&tng t'e ball u( slowl/ as t s now

a((roac'ng ts e3ulbrum (oston .e. !'oto sensor *>s (oston. And w'en t'e mcrocontroller

mantans t'e current constant t means t'at t'e metallc ball s at ts e3ulbrum (oston and t

s le#tated. T'us t's descrbes t'e o(eraton o& t'e ('oto sensors. T'e &low c'art o& t'e w'ole

s/stem s as &ollows9

~ 78 ~




Fgure -.1% Flow c'art o& t'e w'ole s/stem

-.-.% T'e '4brdge

T'e L%$*+ 54brdge was used to dr#e t'e current o& t'e col. It was (owered u( b/ a 7

t'roug' ts 7s and 7ss termnals. T'e two R6N+ (ns were grounded. It gets two n(uts &rom

t'e mcrocontroller. T'e &rst s t'roug' IN% (n t's s alwa/s a R)> because t's sets t'e

drecton o& current n w'c' t'e '4brdge dr#es. And we want our current to be (ost#e. I& t's

(n s &ed a 'g' n(ut t wll re#erse t'e current>s (oston re#ersng t'e drecton o& t'e &eld

and re(ulsng t'e ob"ect to be le#tated. T'e second n(ut s t'e IN1 (n t's s &ed &rom t'e

~ 79 ~




CC!1 module o& t'e mcrocontroller s(ec&call/ t'e 2C% (n. And t &eeds t'e '4brdge wt'

(wm sgnals wt' #ar/ng dut/ c/cles as (er t'e (rogram loaded.

T'e L%$*+ &eeds out(uts to ser#e as t'e n(uts o& t'e col t'roug' ts O:T1 and O:T% (ns. In

w'c' (ost#e current &lows &rom O:T1 to O:T%.

-.-.* T'e C4code

T'e c4code was wrtten n ,kro c and loaded on a !IC 10F8A mcrocontroller on !roteus. It

was wrtten based on t'e &ollowng &low c'art. T's code can be &ound at A((end4+.

~ 80 ~




Fgure -.1* Flow c'art o& t'e C4code

-.-.- !IC 10F8A and t'e nter&aces

Among t'e (orts o& t'e 10F8A mcrocontroller9 !O2TB was set as an out(ut w'c' was

nter&aced wt' t'e LC+ !O2T+ was set as an n(ut w'c' was nter&aced wt' t'e lg't sensors

and t'e 2C% (n w'c' was set to out(ut !=, sgnal w'c' toget'er wt' 2B (n o& !O2TB

were &ed to t'e '4brdge. T'e mcrocontroller was (owered b/ a 7 dc (ower at ts 7s termnal.

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Oscllatons were (ro#ded b/ usng a 3uartH oscllator and two ca(actors t'roug' t'e OSC1 and

OSC% termnals.

T'e lg't sensors were nter&aced to !O2T+ s(ec&call/ 2+)42+- and t'e/ were declared to be

n(uts n t'e s/stem code. T'e LC+ ds(la/ was nter&aced to !O2TB s(ec&call/ 2B)42B anddeclared as out(uts n t'e s/stem code. T'e '4brdge was nter&aced to t'e 2B (n o& !O2TB to

get t'e low out(ut at t'eIN% (nD and t'e 2C% (n to get t'e !=, sgnal at t'e IN1(nD. And

&nall/ t'e col dr#er was nter&aced to t'e O:T1 and O:T% (ns o& t'e '4brdge. T's all can be

s'own at A((end4E.

6enerall/ t'e mcrocontroller based controller rece#es n(uts &rom t'e ('oto sensors to get

n&ormaton about t'e ball to be sus(ended and makes decsons on w'et'er to ncrease t'e dut/

c/cle o& t'e !=,1 decrease t or mantan t constant w'c' n turn s &ed to t'e '4brdge to

ncrease decrease or mantan constant4t'e current &ed to t'e col. T'us b/ gong t'roug' t's ste(

o#er and o#er agan t'e mcrocontroller stablHes t'e le#taton and kee( t'e metallc ball at ts

e3ulbrum (oston. In case t'e s/stem becomes abru(tl/ nstable t'e mcrocontroller wll

contnue to re(eat t'e (rocesses abo#e and t'us t'e stablHaton o& t'e s/stem. Status o& t'e ball s

ndcated on t'e LC+ w'c' s nter&aced at !O2TB.

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C'a(ter F#e

Smulatons and results

=e used d&&erent so&tware durng t'e course o& t's senor (ro"ect. ,atlab was used to draw

gra('s and 'el( us & s/stems were stable. ,kro C was used to wrte c code &or t'e entre

s/stem. And &nall/ !roteus was used to smulate t'e entre s/stem contanng t'e

mcrocontroller.

T'e c code wrtten n ,kro C were buld succe&ull/ and run wt'out an/ error allowng us to

load t'em to t'e !IC 10F8A. T's code can be &ound on A((end4+.

=e were able to test t'e s/stem we desgned anal/tcall/ &or stablt/ wt' ,atlab. And as t'e/ are

ncluded n t'e (re#ous sectons t'e/ n'erentl/ s'ow t'at t'e res(ect#e s/stems are stable and u(

&or runnng

=e were able to success&ull/ smulate t'e mcrocontroller based s/stem and t run wt'out an/

error con&rmng all we 'a#e worked to be true. T's smulaton s burned on a C+ and attac'ed

toget'er wt' t's re(ort. T'e general nter&ace can also be &ound on A((end4E.

~ 83 ~




C'a(ter S

Concluson and 2ecommendaton

0.1 Concluson

T'e magnetc le#taton s/stem s n'erentl/ unstable s/stem because o& t'e s/stem nonlneart/.

And stablHng t could be done n one o& t'e two controllers desgned t'roug' t'e course o& t's

senor (ro"ect.

T's s a great (ro"ect t'at generates a lot o& nterest. Le#tators are &un and /et rarel/ seen. T's

(ro"ect would make a 'g'l/ unusual scence &ar ds(la/ and llustrates t'e (otental o& magle#de#ces ntroducng t'at conce(t to t'e wder range o& t'e students.

T'oug' t'e ob"ect#es o& t's (ro"ect desgnng two controllers t'at stablHe a magnetc

le#taton s/stem 'a#e been success&ull/ ac'e#ed t'e d&&cultes n#ol#ed n de#elo(ng t'e

sensng and current controllng mec'ansms (ro#ed to be t'e most d&&cult and tme consumng

as(ects o& t's (ro"ect.

+ue to t'e growng m(ortance o& sensng tec'n3ues and tec'nologes n ndustral and

commercal a((lcatons t would be suggested t'at more e(osure be (ro#ded durng lectures o&

graduate students. =t' more e(osure n t'ese areas man/ o& t'e d&&cultes encountered durng

t'e de#elo(ment o& t's (ro"ect could 'a#e easl/ been a#oded.

6enerall/ t was a good senor (ro"ect work allowng us to be &amlarHed wt' tons o& conce(ts and

we 'o(e t wll be a great contrbuton to our de(artment and ts students.

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0.% 2ecommendaton

='at c'anges would make t's work betterZ 5ow can I m(ro#e t's desgnZ B/ ncludng a

ke/(ad and workng on algort'm t'at asks t'e weg't o& t'e ob"ect to be le#tated calculates t'e

necessar/ (arameters and le#tates t'e mcrocontroller based desgn can be made &urt'er eas/ to use

and user &rendl/.

~ 85 ~




2e&erences

1M 6ear/ !. ?. ,agnetc and electrc sus(ensons. SI2A 2esearc' 2e(ort No.2*1-

Brt.Sc.Instr. 2es. Assc.1$0-D

%M Earns 'aw S. On t'e. Nature o& t'e molecular &orces w'c' regulate t'e Consttuton o&

t'e lumn&erous et'er. Trans. Camb. !'l.S(c. ((. $411% 18-%D

*M Electromagnetc Le#taton and Sus(enson Tec'n3ues B/ B.7. ?a/awant 1$81

-M Introducton to Control Engneerng b/ !ro&essor 6rma ,ullsa October 1$$

M Control S/stem +esgn usng ,atlab b/ Ba'ram S'a'an and ,c'ael 5assul 1$$*

0M ,odern Control S/stem b/ 2IC5A2+ C.+O2F 2OBE2T 5.BIS5O!1$$8

M Feedback Loo( Stablt/ Anal/ss b/ =alter S. Frau& ,c6raw45ll 1$$8 ISBN )

)4)%%8--4%

8M Electrcal !rnc(les &or Electroncs T'rd Edton b/ Angelo C. 6ls ,c6raw45ll

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$M T'e Art o& Electroncs b/ 5orowtH and 5ll Cambrdge :n#erst/ !ress 1$8)

ISBN )%1%*11

1)M !ractcal Electrct/ !art I b/ Terrell Cro&t ,c6raw45ll 1$%*

11M !ractcal Trans&ormer +esgn 5andbook b/ Erc Lowdon 5oward Sams f Co.

1$8) ISBN )40%4%104-

1%M Foundatons o& Electrcal Engneerng Second Edton b/ ?. 2. Cog dell !rentce

5all 1$$0 ISBN )1*)$%)1

1*M T'e A22L 5andbook &or 2ado Amateurs t'e Amercan 2ado 2ela/ League.

1-M :nderstandng ,agnetsm ,agnets Electromagnetc and Su(erconductng

,agnets b/ 2obert =ood 1$88 b/ Tab books ISBN )8*)0)%%

1M Lnear Electrc Actuators and 6enerators I. Boldea and S/ed A. Nasar Cambrdge

:n#erst/ !ress 1$$ ISBN )%1-8)1

10M !olgreen 6. 2. 2alwa/ wt' magnetc sus(enson. Engneer %%0 ((. 0*%40 1$08D1 !olgreen 6. 2. T'e Jdeal magnet4&ull/ controllable (ermanent magnet &or !ower and

trans(ort .Electroncs and (ower 1% (.%** 1$1D

18M ,agnetc #e'cle sus(ensons &oreseen. =estng'ouse Engneer % ((. $40 1$0D

~ 86 ~




1$M Forgaces 2.L. E#acuated tube #ersus "et arcra&t &or 'g' s(eed trans(ortaton

.(roc.IEEE 01 ((. 0)-410 1$*D.

%)M Baran =. O(tmHng a (ermanent magnet sus(enson s/stem &or 'g' s(eed ground

trans(ort. etsc'r&t &ur angewandt !'/sk *%K* ((. %104181$1D

%1M 'tt(9www.mkroe.comc'a(ters

%%M 'tt(9www.wk(eda.com

~ 87 ~

http://www.mikroe.com/chapters

http://www.wikipedia.com/

http://www.mikroe.com/chapters

http://www.wikipedia.com/




A((end A9 ,atlab 6:I nter&ace

~ 88 ~




A((end4B !roteus 6:I

~ 89 ~




A((end4C ,kro C

~ 90 ~




A((ed4+ ,kro C code

char text[] = "*LEVITATING*";

char text1[]= "*OBJECT*";

char text2[]= "*LEVITATED*";

char text3[]= "*AGNETIC*";

char text![]= "*LEVITATION*";

#$t LCD%&' at &B!%#$t;

#$t LCD%EN at &B(%#$t;

#$t LCD%D! at &B)%#$t;

#$t LCD%D( at &B1%#$t;

#$t LCD%D at &B2%#$t;

#$t LCD%D+ at &B3%#$t;

#$t LCD%&'%D$rect$o, at T&I'B!%#$t;

#$t LCD%EN%D$rect$o, at T&I'B(%#$t;

#$t LCD%D!%D$rect$o, at T&I'B)%#$t;

#$t LCD%D(%D$rect$o, at T&I'B1%#$t;

#$t LCD%D%D$rect$o, at T&I'B2%#$t;

#$t LCD%D+%D$rect$o, at T&I'B3%#$t;

$,t $;

-o$. /a$,0

O&TB=);

T&I'B=);

O&TD=2((;

~ 91 ~




T&I'D=2((;

$=);

41%I,$t0!)));

Lc.%I,$t0;

Lc.%C/.0%LCD%CLEA&;

Lc.%C/.0%LCD%C5&'O&%O66;

7h$8e01

7h$8e09ortD:&D)

Lc.%Ot02<1<text1;

Lc.%Ot01<1<text;

41%'et%Dt0$;

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$> 0$?)

$@@;

.e8a%/01));

Lc.%C/.0%LCD%CLEA&;

7h$8e09ortD:&D1

Lc.%Ot02<1<text1;

Lc.%Ot01<1<text;

41%'et%Dt0$;

41%'tart0;

$>0$?)

$@@;

~ 92 ~




.e8a%/01();

Lc.%C/.0%LCD%CLEA&;

7h$8e09ortD:&D2

Lc.%Ot02<1<text2;

Lc.%Ot01<1<text1;

41%'et%Dt0$;

41%'tart0;

Lc.%C/.0%LCD%CLEA&;

7h$8e09ortD:&D3

Lc.%Ot02<1<text!;

Lc.%Ot01<1<text;

41%'et%Dt0$;

41%'tart0;

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$;

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Lc.%C/.0%LCD%CLEA&;

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Lc.%Ot02<1<text1;

Lc.%Ot01<1<text;

~ 93 ~




41%'et%Dt0$;

41%'tart0;

$>0$2((

$;

.e8a%/01));

Lc.%C/.0%LCD%CLEA&;

41%'et%Dt0$;

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Lc.%Ot01<1<text3;

~ 94 ~




A((end4E Inter&ace and &nal crcut o& t'e

smulaton

~ 95 ~

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