Tieu Luan Matlab Simulink

8/14/2019 Tieu Luan Matlab Simulink

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Gii thiu chungiu khin t ng ho ng vai tr quan trng trong s pht trin ca khoa hc v k

thut. Lnh vc ny hu hiu khp ni t h thng phi thuyn khng gian, h thng iu khintn la, my bay khng ngi li, ngi my tay, my trong cc qu trnh sn xut hin i vngay c trong i sng hng ngy: iu khin nhit , m

Trong l thuyt iu khin t ng c in cc nh bc hc Jame Watt, Hazen, Minorsky,

Nyquist, Evan. a ra nhng phng php gii qut nhiu vn n gin nh: b iu tcly tm iu chnh nhit my hi nc, chng minh tnh n nh ca h thng c th cxc nh t phng trnh vi phn m t h thng, xc nh tnh n nh ca h thng vng kntrn c s p ng vng h i vi cc tn hiu vo hnh Sin trng thi xc lp

Khi cc my mc hin i ngy nay cng phc tp hn nhiu tn hiu vo v ra th vicm t h thng iu khin hin i ny i hi mt lng rt ln cc phng trnh. L thuytiu khin c in lin quan cc h thng mt ng vo v mt ng ra tr nn bt lc phn tchh thng nhiu u vo, nhiu u ra. K t khong nm 1960 tr i nh my tnh s cho php taphn tch cc h thng phc tp trong min thi gian, l thuyt iu khin hin i pht trin i ph vi s phc tp ca h thng hin i. L thuyt iu khin hin i da trn phn tchmin thi gian v tng hp dng cc bin trng thi, cho php gii cc bi ton iu khin c ccyu cu cht ch v chnh xc, trng lng v gi thnh ca cc h thng trong lnh vc kngh khng gian v qun s.

S pht trin gn y ca l thuyt iu khin hin i l trong nhiu lnh vc iu khinti u ca cc h thng ngu nhin v tin nh. Hin nay my vi tnh ngy cng r, gn nhngkh nng x l li rt mnh nn n c dng nh l mt phn t trong cc h thng iu khin.

Matlabl mt chng trnh phn mm ln ca lnh vc tnh ton s. Matlab chnh lch vit tt t MATrix LABoratory, th hin nh hng chnh ca chng trnh bao gm mt shm ton cc chc nng nhp / xut cng nh cc kh nng lp trnh vi c php thng dng mnh ta c th dng nn cc Scripts. Matlab c rt nhiu phin bn nh: 3.5, 4.0, 4.2, 5.0,5.2,6.0, 6.5 . Hin ti c phin bn mi nht 7.1. Trong bi tiu lun ny chng ta ch yutm hiu v phin bn 6.5.

Simulink l mt phn mm m rng ca Matlab (1 Toolbox ca Matlab) dng m hnhho, m phng v phn tch mt h thng ng. Thng thng dng thit k h thng iukhin, thit k DSP, h thng thng tin v cc ng dng m phng khc.

Simulink l thut ng m phng d nh c ghp hai t Simulation v Link, Simulinkcho php m t h thng tuyn tnh, h phi tuyn, cc m hnh trong min thi gian lin tc, haygin on hoc mt h gm c lin tc v gin on.


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Phn I : C s v MATLABMATLAB l mt chng trnh phn mm ln v lnh vc ton s . Tn b chng trnh

chnh l ch vit tt t MATrix LABoratory, th hin nh hng ca chng trnh l nhng phptnh vector v ma trn . Phn ct li ca chng trnh bao gm mt s hm ton , cc chc nnngnhp /xut cng nh cc kh nng iu khin chu trnh m nh c th dng trn cc Scripts .

Trong phn nay bao gm cc Toolbox lin quan ti iu Khin T ng ha nh: Control

System Toolbox, Signal Processing Toolbox, Optimization Toolbox, Stateflow Blockset, PowerSystem Blockset , Real Time Workshop va SIMULINK. SIMULINK l mt toolbox c vai trbc bit quan trng: Vi tr ca mt cng c mnh phc v m hnh ha v m phng cc hthng K thut Vt l trn c s s cu trc dng khi . Cng vi SIMULINK , StatefowBlockset to cho ta kh nng m hnh ha v m phng cc automat trng thi hu hn.

1.1. Nhng bc i du tin vi MATLAB

1.1.1 Mn hnh MATLAB

Sau khi khi ng MATLAB , mi trng tch hp vi nhng ca s chnh nhhnhdi :

- Ca s Launch Pad : Ca s ny cho php ngi s dng truy cp nhanh cc cng cca MATLAB, Phn Help (tr gip) hoc Online Documents (ti liu trc tuyn), m Demos(chng trnh trnh din).


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- Ca s th mc hin ti Current Directory Browser : Nh ca s ny ngi s dngnhanh chng nhn bit, chuyn i th mc hin ti ca mi trng cng tc, m File, to thmc mi.

- Ca s mi trng cng tc Workspace Browser : Tt c cc bin, cc hm tn titrong mi trng cng tc u c hin th ti ca s nyvi y cc thng tin nh: Tn loibin/hm, kch thc ty theo Bytes v loi d liu. Ngoi ra cn c th ct vo b nh cc dliu , hoc s dng chc nng Array Editor (son tho mng) thay i cc bin

- Ca s lnh Command Windows : y l ca s chnh ca MATLAB . Ti y tathc hin ton b vic nhp d liu v xut kt qu tnh ton. Du nhp nhy >> bo hiu chngtrnh sp hot ng:

- Mi ln nhp d liu c kt thc bng ng tc nhn phm ENTER. Nguyn tc nhn, chia thc hin trc cng , tr v th tu tin ca du ngoc vn nh bnh thng . Sc gi tr ln thng c nhp vi hm e m (c th vit E) . C th kt thc chng trnh bngcch ng mn hnh MATLAB , hoc gi lnh quit, exithoc nhn t hp phm Ctrl+q

- Ca s qu khCommand History : Tt c cc lnh s dng trong CommandWindows c lu gi v hin th ti y, c th lp li lnh c bng cch nhy chut kp volnh . Cng c th ct, sao hoc xa c nhm lnh hoc tng lnh ring r.

1.1.2 Tin ch tr gip (Help) ca MATLABTin ch tr gip ca MATLAB l v cng phong ph . Ty theo nhu cu , hoc gi

Help [command] xem ni dung h tr ca lnh command trc tip trn Command Windowshoc s dng cng c truy cp Help


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C th gi ca s Help bng cch gi trn Menu , gi lnh helpwin hay doc trc tip trn ca sCommand Windows . Bng lnh loockfor searchstringta c th tm chui k tsearchstringtrong dngu ca mi MATLAB File trong th mc MATLAB

>> help log

LOG Natural logarithm.

LOG(X) is the natural logarithm of the elements of X.Complex results are produced if X is not positive.

See also LOG2, LOG10, EXP, LOGM.

Overloaded methods

help gf/log.m

help sym/log.m

help fints/log.m

help designdev/log.m>>

Cc lnh lin quan ti tin ch help c tp hp trong bng sau:

1.1.3 Cc bin

Thng thng , kt qu cu cc bin c gn cho ans . S dng du bng ta c th nhngha mt bin , ng thi gn gi tr cho bin d . Khi nhp tn ca mt bin m khng gn gitr , ta thu gi tr hin ti ca bin . Tt c cc bin u l bin global trong Workspace. Tn

ca bin c th cha ti 32 ch ci , gch ngang thp (_) cng nh ch s . Ch vit hoa to v chvit nh u c phn bit .

Vic nhp gi tr c th c thc hin thnh mt chui trong cng mt dng , ch cchnhau bi du (;) . Nu s dng du phy(,) tch cc lnh khi y cc gi tr s c xut ramn hnh :

>> x=25; y=10;

>> x

Helphelp[command] Tin ch Help trc tuyn ca MATLAB trong ca

s lnh Commmand Workspacehelpwin[command] Tin ch Help trc tuyn ca MATLAB trong ca

S truy cp Helpdoc[command] T liu trc tuyn ca MATLAB trong ca s truy

cp Helplookforsearchstring Tm chui k t searchstringtrong dng u tin

ca mi MATLAB Files trong thmc MATLAB


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x =

25

>> a=x+y,A=x/y

a =

35

A =2.5000

Mt s bin nh : pi , i , jv inf c MATLAB dng r ch cc hng s hay khiu, vy ta phi trnh s dng chng . i vi cc php tnh bt nh (v d 0/0), trn mn hnhs xut hin kt qu NaN(Not a Number) . esp cho ta bit cp chnh xc tng i khi biu dins vi du phy ng (v d : esp = 2.2204e-016):

>> 1/0

Warning: Divide by zero.

(Type "warning off MATLAB:divideByZero" to suppress this warning.)

ans =

Inf Inf: infinite (v cng)

>> 0/0

Warning: Divide by zero.

(Type "warning off MATLAB:divideByZero" to suppress this warning.)

ans =

NaN NaN: not defined (bt nh )

1.1.4 Cc hm ton hc

Chng trnh MATLAB c sn rt nhiu hm ton tp hp trong bng sau y . Tt c cchm trong bng u c kh nng s dng tnh ca vector

Cc k hiu= Gn gi tr cho bin

+ - * / ^ Cc php tnh; Nhp gi tr (cn gi vai tr du cch khi nhp nhiu gi trtrong cng mt dng )

, Du cch khi xut nhiu gi tr trong cng mt dngesp Cp chnh xc tng i khi s dng gi tr du phy ngi j Ton t oinf V cng ( )NaN Not a Numberpi Hng s


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1.2 Vector v ma trn

MATLAB c mt s lnh c bit khai bo hoc s l vector v ma trn . Cch n

gin nht khai bo , to ln vector hoc ma trn l nhp trc tip . Khi nhp trc tip cc phnt ca mt hng c cch bi du phy hoc v tr cch b trng1, cc hng c cch bi du(;) hoc ngt dng.

>> vector=[3 4 5]

vector =

3 4 5

>> matran=[vector; 1 2 3]

matran =

3 4 5

1 2 3Vector c cc phn t tip din vi mt bc nht nh , c th nhp mt cch n gin

nh

Ton t (:) nh sau (start: increment; destination) (xut pht : bc; ch). Nu ch nhpstart v destination , MATLAB s t ng t increment l +1.

Cng c th nhp cc vector tuyn tnh cng nh vector c phn hng logarithm bngcch dng lnh linspace(start, destination, number) (Trong number l s lng phn t cavector). Ta cng c th nhp bng lnh logspace, start v destination c nhp bi s m thpphn , v d : thay v nhp 100 = (102)ta ch cn nhp 2.

>> long=1:5

long =

1 2 3 4 5

>> deep = 10:-2:2

deep =

10 8 6 4 2

>> longer=linspace(1,15,5)

Cc hm tonsqrt(x) Cn bc hai rem(x,y) S d ca php chia x/yexp(x) Hm m c s e round(x) Lm trn slog(x) Logarit t nhin ceil(x) Lm trn lnlog10(x) Logarit c s thp phn floor(x) Lm trn xungabs(x) Gi tr tuyt i sum(v) Tng cc phn t vector

sign(x) Hm du prod(v) Tch cc phn t vectorreal(x) Phn thc min(v) Phn t vector b nhtimag(x) Phn o max(v) Phn t vector ln nhtphase(x) Gc pha ca s phc mean(v) Gi tr trung bnh cng

Cc hm lng gicsin(x) Hm sin atan(x) Hm arctg 900cos(x) Hm cos atan2(x,y) Hm arctg 1800tag(x) Hm tg sinc(x) Hm sin(x)/ (x)


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longer =

1.0000 4.5000 8.0000 11.5000 15.0000

>> licreace=logspace(1,2,5)

licreace =

10.0000 17.7828 31.6228 56.2341 100.0000

Bng cc hm ones(line,column)v zeros(line, column) ta to cc ma trn c phn t l 1hoc 0. Hm eye(line) to ra ma trn n v, ma trn ton phng vi cc phn t 1 thuc ngcho , tt c cc phn t cn li l 0. Kch c ca ma trn hon ton ph thuc ngi nhp:

>> M= ones(2, 3)

M =

1 1 1

1 1 1

Vic truy cp tng phn t ca vector hoc ma trn c thc hin bng cch khai bo chs ca phn t , trong cn lu rng : ch s b nht l 1 ch khng phI l 0. c bit , khicn xut tng hng hay tng ct , c th s dng ton t (:) ng mt mnh , iu y c ngha l :

phi xut mi phn t ca hng hay ct :>> matran(2,2)

ans =

2

>> matran(2,:)

ans =

1 2 3

MATLAB c mt lnh rt hu ch , phc v to ma trn vi chc nng tn hiu th l :rand(m,n). Khi gi ta thu c ma trn m hng v n ct vi phn t mang cc gi tr ngu nhin:

>> mt_ngaunhien=rand(2,3)

mt_ngaunhien =

0.4565 0.8214 0.6154

0.0185 0.4447 0.7919

Khai bo vector v ma trn[x1 x2 ; x3 x4 ] Nhp gi tr cho vector v ma trnstart: increment: destination Ton t (:)linspace (start,destination ,number) Khai bo tuyn tnh cho vectorlogspace (start,destination ,number) Khai bo logarithm cho vectoreye(line) Khai bo ma trn n vones(line,column) Khai bo ma trn vi cc phn t 1zeros(line,column) Khai bo ma trn vi cc phn t 0rand(line,column) Khai bo ma trn vi cc phn t nhp

ngu nhin


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1.2.1 Tnh ton vi vector v ma trn

Nhiu php tnh c th p dng cho vector v ma trn . V d : Php nhn vi k hiu(*)c dng tnh tch ca vector v ma trn . Vic chuyn v ca vector v ma trn c thchin nh lnh transpose hoc () . Nu vector v ma trn l phc , ta dng thm lnh lctranspose hoc () tm gi tr phc lin hp. i vi cc gi tr thc hai lnh trn nhnhau

>> M*matran

ans =4 6 8

4 6 8

Nu nh trong cc php tnh * / ^ cn c thc hin cho tng phn t ca vector v matrn , ta s phi t thm vo trc k hiu ca php tnh k hiu (.). Php tnh i vi ccbin v hng lun c thc hin cho tng phn t mt :

>> M ./ matran

ans =

0.3333 0.2500 0.2000

1.0000 0.5000 0.3333Php tnh trn cng c hiu lc c khi ma trn c cc phn t phc:

>> matranphuc = [1+i 1-i; 1 2 ]

matranphuc =

1.0000 + 1.0000i 1.0000 - 1.0000i

1.0000 2.0000

>> matranphuc*matranphuc

ans =

1.0000 + 1.0000i 4.0000 - 2.0000i

3.0000 + 1.0000i 5.0000 - 1.0000i

>> matranphuc.*matranphuc

ans =

0 + 2.0000i 0 - 2.0000i

1.0000 4.0000

Lnh diff(vector [n]) tnh vector sai phn. Bng lnh conv(vector_1, vvector_2) ta chp haivector vector_1 v vector_2. Nu hai vector cn chp c phn t l cc h s ca hai a thc, ktqu thu c s ng vi cc h s sau khi nhn hai a thc vi nhau :

>> diff(vector)

ans = 1 1

Hai lnh inv v detdng nghch o ma trn ton phng v tnh nh thc ca ma trn. Gi tr ring ca ma trn matrixc tnh bi lnh eig(matrix) v hng ca n c tnh bilnh rank(matrix), Nu cn chuyn v ma trn ta dng lnh transpose(matrix):

>> matrix=[1 2 3;3 4 5;5 6 7]


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matrix =

1 2 3

3 4 5

5 6 7

>> rank(matrix)

ns =2

>> eig(matrix)

ans =

12.9282

-0.9282

0.0000

>> det(matrix)

ans =

0

>> inv(matrix)

Warning: Matrix is close to singular or badly scaled.

Results may be inaccurate. RCOND = 1.850372e-018.

ans =

1.0e+016 *

0.4504 -0.9007 0.4504

-0.9007 1.8014 -0.9007

0.4504 -0.9007 0.4504>> transpose(matrix)

ans =

1 3 5

2 4 6

3 5 7

Tnh ton vi vector v ma trn.* ./ .^ Cc php tnh vi tng phn t

transpose(matrix) hoc matrix Chuyn v ma trn matrixctranspose(matrix) hoc matrix Chuyn v ma trn matrixc phn tphc lin hp

inv(matrix) o ma trndet(matrix) Tnh nh thc ca ma trneig(matrix) Tnh gi tr ring ca ma trnrank(matrix) Xc nh hng ca ma trndiff(vector[n]) Tnh vector sai phnconv(vector_1,vector_2) Chp vector (nhn a thc)


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1.2 Cu trc v trng1.2.1 Cu trc thun tin cho vic qun l v s dng , ta c th tp hp nhiu bin li trong mt cu trc .Trong mi mng c mt tn ring (mt chui k t string) t gia hai du ( ) c km theogi tr . Mt cu trc c to nn bi lnh struct(name_1,value_1,name_2,value_2,..):

>>my_structure = struct(data, matrix, size, [2 3]);

Vic truy cp vo d liu c thc hin bi vi du cch(.);

>>my_structure (2) . data = matrix.^(-1) ;

ans =

1.0000 0.5000 0.3333

Ngoi ra MATLAB cn c cc lnh v cu trc mc vng nh cu trc nhp bi lnh componist.

1.2.2 TrngTng qut mt mc cao hn cu trc l trng(Cell Array). chnh l cc Array

(mng nhiu chiu), cha Cell (t bo) vi d liu thuc cc loi v kch c khc nhau . Ta c thto ra Cell Array bng lnh cell , hoc n gin hn bng cch ghp cc phn t bn trong du

ngoc {}. Tng phn t ca Cell Array c th c truy cp nh cc vector , ma trn thngthng nh cc Array nhiu chiu , ch cn lu rng : Thay v dng du ngoc trn ( ) ta sdng du ngoc mc {}.

Gi s ta to ra mt Cell Array rng c tn my_cell nh sau :

>> my_cell = cell(2,2)

my_cell =

[] []

[] []

By gi ta ln lt gn cho tng mng ca my_cell cc gi tr sau y:

>> my_cell{1,1} ='chao cac ban';>> my_cell{1,2} ='chuc cac ban hoc tap tot';

>> my_cell{2,1} =[1 2; 3 4];

>> my_cell{2,2} =10;

Khi nhp tn ca Cell Array trn mn hnh xut hin ln y cu trc ca n. C th bit nidung (hay gi tr ) ca mt hay nhiu Cell khi ta nhp cc ch s ca Cell:

>> my_cell

my_cell =

'chao cac ban' [1x24 char]

[2x2 double] [ 10]

>> my_cell{1,1}

ans =

chao cac ban

>> my_cell{1,2}


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ans =

chuc cac ban hoc tap tot

>> my_cell{2,1}

ans =

1 2

3 4

Phn trn l nhng khi nim khi qut v nhng v d c th gii thiu mt phn nh

nhng ng dng m phn mm MATLAB c th thc hin .MATLAB l mt phn mm ln tronglnh vc ton s v cn c kh nng ca mt ngn ng lp trnh bc cao vi tnh nng haphong ph. MATLAB vi nhng cng c nh : Control System Toolbox (cng c kho st thit kh thng iu khin ), Optimization Toolbox (cng c tnh ton ti u) v Signal ProcessingToolbox (cng c s l tn hin ). MATLAB ang l phn mm m cc k s cc sinh vin sdng rng ri nh vo tnh nng u vit ca phn mm ny

Cu trc (Structure) v trng (Cell Array)Structure(n1,v1,n2,v2, ) Khai bo cu trcStructure.name Truy cp vo phn t nameMy_cell = {} To Cell Array rngCell(n) To nn Cell Array

Cell(m,n) To mn Cell Array


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Phn II

Gii thiu mt s nhm lnh c bn MATLAB

I. LNH C BN1. Lnh ANS

a) Cng dng: (Purpose)

L bin cha kt qu mc nh.

b) Gii thch: (Description)

Khi thc hin mt lnh no m cha c bin cha kt qu, th MATLAB ly bin Anslm bin cha kt qu .

2. Lnh CLOCK


Thng bo ngy gi hin ti.

b) C php:(Syntax)

c = clock

c) Gii thch: (Description)

thng bo d c ta dng hm fix.

3. Lnh COMPUTER


Cho bit h iu hnh ca my vi tnh ang s dng Matlab.

b) C php: (Syntax)

computer

[c,m] = computer

c) Gii thch: (Description)

c: cha thng bo h iu hnh ca my.

m: s phn t ca ma trn ln nht m my c th lm vic c vi Matlab.

4. Lnh DATE


Thng bo ngy thng nm hin tib) C php: (Syntax)

s = date

5. Lnh CD

a) Cng dng:

Chuyn i th mc lm vic.

b) C php:


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cd

cd diretory

cd ..

c) Gii thch:

cd: cho bit th nc hin hnh.

diretory: ng dn n thmc mun lm vic.cd .. chuyn n thmc cp cao hn mt bc.

6. Lnh CLC

a) Cng dng:

Xa ca s lnh.

b) C php:

clc

7. Lnh CLEAR

a) Cng dng:

Xa cc mc trong b nh.

b) C php:

clear

clear name

clear name1 name2 name3

clear functions

clear variables

clear mex

clear globalclear all

c) Gii thch:

clear: xa tt c cc bin khi vng lm vic.

clear name: xa cc bin hay hm c ch ra trong name.

clear functions: xa tt c cc hm trong b nh ph

clear variables: xa tt c cc bin ra khi b nh.

clear mex: xa tt c cc tp tin .mex ra khi b nh.

clear: xa tt c cc bin chung.clear all: xa tt c cc bin, hm, v cc tp tin .mex khi b nh. Lnh ny lm cho b

nh trng hon ton.

8. Lnh DELETE

a) Cng dng:

Xa tp tin v i tng ha.

b) C php:

delete filename


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delete (n)

c) Gii thch:

file name: tn tp tin cn xa.

n: bin cha i tng ha cn xa. Nu i tng l mt ca s th ca s s ng liv b xa.

9. Lnh DEMO

a) Cng dng:

Chy chng trnh mc nh ca Matlab.

b) C php:

demo

c) Gii thch:

demo: l chng trnh c sn trong trong Matlab, chng trnh ny minh ha mt s chcnng ca Matlab.

10. Lnh DIARY

a) Cng dng:Lu vng thnh file trn a.

b) C php:

diary filename

c) Gii thch:

filename: tn ca tp tin.

11. Lnh DIR

a) Cng dng:

Lit k cc tp tin v th mc.

b) C php:

dir

dir name

c) Gii thch:

dir: lit k cc tp tin v thmc c trong thmc hin hnh.

dir name: ng dn n th mc cn lit k.

12. lnh DISP

a) Cng dng:

Trnh by ni dung ca bin (x) ra mn hnhb) C php:

disp (x)

c) gii thch:

x: l tn ca ma trn hay l tn ca bin cha chui k t, nu trnh by trc tip chui kt th chui k t c t trong du

13. Lnh ECHO


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a) Cng dng:

Hin th hay khng hin th dng lnh ang thi hnh trong file *.m.

b) C php:

echo on

echo off

c) Gii thch:on: hin th dng lnh.

off: khng hin th dng lnh.

14. Lnh FORMAT

a) Cng dng:

nh dng kiu hin th ca cc con s.

C php Gii thch V d

Format short Hin th 4 cons sau du chm

3.1416

Format long Hin th 14con s sau duchm

3.14159265358979

Format rat Hin th dngphn s ca phnnguyn nh nht

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Format + Hin th s

dng hay m

+

15. Lnh HELP

a) Cng dng:

hng dn cch s dng cc lnh trong Matlab.

b) C php:

help

help topic

c) Gii thch:help: hin th vn tt cc mc hng dn.

topic: tn lnh cn c hng dn.

16. Lnh HOME

a) Cng dng:

em con tr v u vng lm vic.

b) C php:


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home

17. Lnh LENGTH

a) Cng dng:

Tnh chiu di ca vect.

b) C php:

l = length (x)c) Gii thch:

l: bin cha chiu di vect.

18. Lnh LOAD

a) Cng dng:

Np file t a vo vng lm vic.

b) C php:

load

load filename

load filename

load finame.extension

c) Gii thch:

load: np file matlap.mat

load filename: np file filename.mat

load filename.extension: np file filename.extension

Tp tin ny phi l tp tin dng ma trn c ngha l s ct ca hng d i phi bng s ctca hng trn. Kt qu ta c mt ma trn c s ct v hng chnh l s ct v hng catp tin vn bn trn.

19. Lnh LOOKFOR

a) Cng dng:

Hin th tt c cc lnh c lin quan n topic.

b) C php:

lookfor topic

c) Gii thch:

topic: tn lnh cn c hng dn.

20. Lnh PACK

a) Cng dng:Sp xp li b nh trong vng lm vic.

b) C php:

pack

pack filename

c) Gii thch:


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Nu nh khi s dng Matlap my tnh xut hin thng bo Out of memory th lnhpack c th tm thy mt s vng nh cn trng m khng cn phi xa bt cc bin.

Lnh pack gii phng khng gian b nh cn thit bng cch nn thng tin trong vngnh xung cc tiu. V Matlab qun l b nh bng phng php xp chng nn cc onchng trnh Matlab c th lm cho vng nh b phn mnh. Do s c nhiu vng nhcn trng nhng khng cha cc bin ln mi.

Lnh pack s thc hin:

+ lu tt c cc bin ln a trong mt tp tin tm thi l pack.tmp.

+ xa tt c cc bin v hm c trong b nh.

+ ly li cc bin t tp tin pack.tmp.

+ xa tp tin tm thi pack.tmp.

kt qu l trong vng nh cc bin c gp li hoc nn li ti a nn khng blng ph b nh.

Pack.finame cho php chn tn tp tin tm thi cha cc bin. Nu khng ch ra tntp tin tm thi th Matlab t ly tn tp tin l pack.tmp.

Nu dng lnh pack m my vn cn bo thiu b nh th bt buc phi xa bt ccbin trong vng nh i.

21. Lnh PATH

a) Cng dng:

To ng dn, lit k tt c cc ng dn ang c.

b) C php:

path

p = path

path (p)

c) Gii thch:path: lit k tt c cc dng dn ang c.

p: bin cha ng dn.

path (p): t ng dn mi.

22. Lnh QUIT

a) Cng dng:

Thot khi Matlab.

b) C php:

quit

23. Lnh SIZE

a) Cng dng:

Cho bit s dng v s ct ca mt ma trn.

b) C php:

d = size (x)

[m,n] = size (x)

m = size (x,1)


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n = size (x,2)

c) Gii thch:

x: tn ma trn.

d: tn vect c 2 phn t, phn t th nht l s dng, phn t cn li l s ct.

m,n: bin m cha s dng, bin n cha s ct

24. Lnh TYPEa) Cng dng:

Hin th ni dung ca tp tin.

b) C php:

type filename

c) Gii thch:

filename: tn file cn hin th ni dung.

Lnh ny trnh by tp tin c ch ra.

25. Lnh WHAT

a) Cng dng:

Lit k cc tp tin *.m, *.mat, *.mex.

b) C php:

what

what dirname

c) Gii thch:

what: lit k tn cc tp tin .m, .mat, .mex c trong th mc hin hnh.

dirname: tn thmc cn lit k.

26. Lnh WHICHa) Cng dng:

Xc nh chc nng ca funname l hm ca Matlab hay tp tin.

b) C php:

which funname

c) Gii thch:

funname: l tn lnh trong Matlab hay tn tp tin

d) V d:

which invinv is a build-in function

which f

c:\matlab\bin\f.m

27. Lnh WHO, WHOS

a) Cng dng:

Thng tin v bin ang c trong b nh.


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b) C php:

who

whos

who global

whos global

c) Gii thch:who: lit k tt c cc tn bin ang tn ti trong b nh.

whos: lit k tn bin, kch thc, s phn t v xt cc phn o c khc 0 khng.

who global v whos: lit k cc bin trong vng lm vic chung.

II. CC TON T V K T C BIT1. Cc ton t s hc (Arithmetic Operators):

Ton t

Cng dng

+ Cng ma trn hoc i lng v hng (cc ma trn phi c cng kch thc).

- Tr ma trn hoc i lng v hng (cc ma trn phi c cng kch thc).

* Nhn ma trn hoc i lng v hng (ma trn 1 phi c s ct bng s hngca ma trn 2).

.* Nhn tng phn t ca 2 ma trn hoc 2 i lng v hng (cc ma trn phic cng kch thc).

\ Thc hin chia ngc ma trn hoc cc i lng v hng (A\B tng ngvi inv (A)*B).

.\ Thc hin chia ngc tng phn t ca 2 ma trn hoc 2 i lng v hng(cc ma trn phi c cng kch thc).

/ Thc hin chia thun 2 ma trn hoc i lng v hng (A/B tng ngvi A*inv(B)).

./ Thc hin chia thun tng phn t ca ma trn ny cho ma trn kia (cc matrn phi c cng kch thc).

^ Ly tha ma trn hoc cc i lng v hng.

.^ Ly tha tng phn t ma trn hoc i lng v hng (cc ma trn phi ccng kch thc).


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4. K t c bit (Special Characters):

Khiu

Cng dng

[] Khai bo vector hoc ma trn.

() Thc hin php ton u tin, khai bo cc bin v cc ch sca vector.

= Thc hin php gn.

Chuyn v ma trn tm lng lin hip ca s phc.

. im chm thp phn.

, Phn bit cc phn t ca ma trn v cc i s trong dnglnh.

; Ngn cch gia cc hng khi khai bo ma trn.

% Thng bo dng ch thch.

! M ca s MS DOS.

III. CC HM LOGIC (LOGICAL FUNCTION)1. Lnh ALL

a) Cng dng:

Kim tra vector hay ma trn c gi tr 0 hay khng.b) C php:

y = all(x)

c) Gii thch:

y: bin cha kt qu

x: tn vedtor hay ma trn

y = 1 khi tt c cc phn t khc 0

y = 0 khi c 1 phn t bng 0

2. Lnh ANYa) Cng dng:

Kim tra vector hay ma trn c gi tr khc 0 hay khng.

b) C php:

y = any(x)

c) Gii thch:

y: bin cha kt qu.


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x: tn vector, hay ma trn.

y = 1 khi c 1 phn t khc 0.

y = 0 khi c 1 phn t bng 0.

3. Lnh EXIST

a) Cng dng:

Kim tra bin hay file c tn ti hay khng.b) C php:

e = exist(item)

c) Gii thch:

item: l tn file hay tn bin.

e: bin cha gi tr tr v.

e

ngha

0 item khng tn ti trong vng lm vic

1 item l bin ang tn ti trong vng lm vic

2 item ang tn ti trn a (ch kim tra trong thmc hinhnh)

3 item l MEX-file

4 item l file c dch t phn mm Simulink

5 item l hm ca Matlab

4. Lnh FIND

a) Cng dng:

Tm phn t trong vector hay ma trn theo yu cu.

b) C php:

k = find(x)

[i,j] = find(x)

[i,j,s] = find(x)

c) Gii thch:k: ch v tr ca phn t cn tm trong vector.

i,j: ch s hng v s ct tng ng ca phn t cn tm.

s: cha gi tr ca phn t cn tm.

x: tn vector, ma trn hay l yu cu ra. Nu khng nu ra yu cu th mc nhin l tmcc phn t khc 0.


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IV. NHM LNH LP TRNH TRONG MATLAB

1. Lnh EVAL

a) Cng dng:

Chuyn i chui k t thnh biu thc.

b) C php:

kq = eval(string)

c) Gii thch:

kq: bin cha kt qu.

Nu string l cc k s th chuyn thnh nhng con s.

Nu string l cu lnh th chuyn thnh cc lnh thi hnh c.

2. Lnh FOR

a) Cng dng:

Dng thc hin 1 cng vic cn lp i lp li theo mt quy lut, vi s b

c lp xcnh trc.

b) C php:

for bin iu khin = gi tr u : gi tr cui,

thc hin cng vic;

end

c) Gii thch:

Cng vic chnh l cc lnh cn thi hnh, c th c nhiu lnh, kt thc lnh phi c du;

3. Lnh FUNCTION

a) Cng dng:To thm hm mi.

b) C php:

function s = n(x)

c) Gii thch:

s: tn bin cha gi tr tr v sau khi thi hnh hm.

n: tn gi nh.

4. Lnh INPUT

a) Cng dng:Dng nhp vo 1 gi tr.

b) C php:

tn bin = input (promt)

tn bin = input (promt, s)

c) Gii thch:

tn bin, l ni lu gi tr ngp vo.


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promt: chui k t mun nhp vo.

s: cho bit gi tr nhp vo l nhiu k t.

5. Lnh IF ELSEIF ELSE

a) Cng dng:

Thc hin lnh khi tha iu kin.b) C php:

if biu thc lun l 1

thc hin cng vic 1;

elseif biu thc lun l 2

thc hin cng vic 2;

else

thc hin cng vic 3;

end

c) Gii thch:

Khi biu thc lun k 1 ng th thc hin cng vic 1 tng t cho biu thc lun l 2.Nu c hai biu thc sai th thc hin cng vic sau lnh else.

Biu thc lun l l cc php so snh ==, , =

cng vic chnh l cc lnh cn thi hnh, c th c nhiu lnh, kt thc lnh phi c du ;

6. Lnh MENU

a) Cng dng:

To menu chn chc nng.

b) C php:tn bin = menu (Tn menu,chc nng1,chc nng2, . , chc nng n)

c) Gii thch:

tn menu: l tiu ca menu.

tn bin: l ni ct gi tr nhn c sau khi chn chc nng ca menu.

Chc nng 1, 2, .,n:khi chn chc nng no th tn bin c gi tr l s th t ca chcnng .

7. Lnh PAUSE

a) Cng dng:

Dng chng trnh theo mun.b) C php:

pause on

pause off

pause (n)

c) Gii thch:


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pause on: dng chng trnh, v ch nhn 1 phm bt k (tr cc phm iu khin) chngtrnh thc hin tip.

pause off: tt chc nng pause.

pause (n): dng chng trnh ti n giy.

d) V d:

for n = 1 : 3;

disp(Press any key to continue)

pause

end

Press any key to continue



8. Lnh WHILE

a) Cng dng:

Dng thc hin 1 cng vic cn lp i lp li theo mt quy lut, vi s b c lp khngxc nh, ph thuc vo biu thc lun l.

b) C php:

while biu thc lun l

thc hin cng vic;

end

c) Gii thch:

Biu thc lun l l cc php so snh = =, , =

Cng vic chnh l cc lnh cn thi hnh, c th c nhiu lnh, kt thc lnh phi c du ;

Khi thc hin xong cng vic th quay ln kim tra li biu thc lun l, nu vn cnng th tip tc thc hin, nu sai th kt thc.

V. TP LNH X L CHUI1. Lnh ABS

a) Cng dng:

To vector n c gi tr ca mi phn t l s th t tng ng vi k t trong bng mASCII.

Ly tr tuyt i ca mt s m.b) C php:

n = ABS(s)

x = ABS(a)

c) Gii thch:

n: tn vector.

s: chui k t, hoc l tn bin cha chui k t.


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a: s m, hoc l tn bin cha s m.

x: tr tuyt i ca a.

2. Lnh BLANKS

a) Cng dng:

To khong trng gia hai hay nhiu chui k t theo mong mun.

b) C php:[S1 BLANKS(b1) S2 BLANKS(b2) BLANKS(bn) Sn]

c) Gii thch:

S1, S2, Sn: cc chui k t.

b1, b2: s khong trng.

3. Lnh DEC2HEX

a) Cng dng:

i con s ca h 10 sang h 16.

b) C php:

s = dec2hex(n)

c) Gii thch:

s: bin cha chui k s ca h 16

n: con s nguyn h 10.

4. Lnh HEX2DEC

a) Cng dng:

i chui k s ca h 16 sang con s ca h 10.

b) C php:

n = hex2dec(s)c) Gii thch:

n: con s ca h 10.

s: chui k s h 16.

5. Lnh INT2STR

a) Cng dng:

Chuyn s nguyn sang dng chui.

Chuyn cc k t trong mt chui sang s th t tng ng trong bng m ASCII.

b) C php:kq = INT

c) Gii thch:

kq: bin STR(n)cha kt qu.

n: tn bin cn chuyn.

Nu n l s nguyn th kq l chui k s.

Nu n l chui k t th kq l s tng ng trong bng m ASCII


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6. Lnh ISSTR

a) Cng dng:

Kim tra ni dung bin c phi l chui k t khng.

b) C php:

kq = isstr(n)

c) Gii thch:kq: bin cha kt qu.

n: tn bin cn kim tra.

kq = 1 nu n l chui k t.

0 nu n khng l chui k t.

7. Lnh LOWER

a) Cng dng:

Cho ra chui k t vit thng.

b) C php:

b = lower(s)

c) Gii thch:

b: bin cha kt qu.

s: tn bin cha chui k t hay chui k t.

8. Lnh NUM2STR

a) Cng dng:

Chuyn s thc sang dng chui.

Chuyn cc k t trong mt chui sang s th t tng ng trong bng m ASCII.

b) C php:kq = num2tr(n)

c) Gii thch:

kq: bin cha kt qu.

n: tn bin cn chuyn.

Nu n l s thc th kq l s tng ng trong bng m ASCII.

9. Lnh SETSTR

a) Cng dng:

Cho ra k t t

ng ng vi s th t trong bng m ASCII.b) C php:

x = Set Str(n)

c) Gii thch:

x: bin cha k t tng ng (thuc bng m ASCII).

n: s nguyn (0 n 255).


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10. Lnh STR2MAT

a) Cng dng:

To ma trn c cc phn t dng chui.

b) C php:

s = str2mat(s1, s2, )

c) Gii thch:s: tn ma trn kt qu.

s1, s2: chui k t.

11. Lnh STR2NUM

a) Cng dng:

Chuyn chui (dng s) sang s thc.

b) C php:

n = str2num(s)

c) Gii thch:

s: chui dng s.

n: s thc.

12. Lnh STRCMP

a) Cng dng:

So snh 2 chui k t.

b) C php:

l = strcmp(s1, s2)

c) Gii thch:

l: bin cha kt qu.s1, s2: chui cn so snh.

13. Lnh UPPER

a) Cng dng:

Cho ra chui vit hoa.

b) C php:

b = upper

c) Gii thch:

b: bin cha kt qu.s: tn bin cha chui k t.


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VI. CC HM TON HC C BN1. Mt s hm lng gic:

a) C php:

kq = hlg(x)

b) Gii thch:

kq: tn bin cha kt qu.

x: n v radian.

hlg: tn hm lng gic.

Tn hm lnggic

Gii thch

sin

cos

tanasin

atan

sinh

cosh

tanh

Tnh gi tr sine

Tnh gi tr cosine

Tnh gi tr tangentNghch o ca sine

Nghch o ca tangent

Tnh gi tr hyperbolic sine

Tnh gi tr hyperbolic cosine

Tnh ga tr hyperbolic tangent

2. Lnh ANGLE

a) Cng dng:

Tnh gc pha ca s phc.b) C php:

p = angle(z)

c) Gii thch:

p: tn bin cha kt qu, n v radians

z: s phc

3. Lnh CEIL

a) Cng dng:

Lm trn s v pha s nguyn ln hn.b) C php:

y = ceil(x)

c) Gii thch:

y: s sau khi c lm trn.

x: s cn c lm trn.


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4. Lnh CONJ

a) Cng dng:

Tnh lng lin hip ca s phc.

b) C php:

y = conj(z)

c) Gii thch:y: tn bin cha lng lin hip

z: s phc

5. Lnh EXP

a) Cng dng:

Tnh gi tr ex.

b) C php:

y = exp(x)

6. Lnh FIX

a) Cng dng:

Lm trn s v pha zero.

b) C php:

y = fix(x)

c) Gii thch:

y: s sau khi c lm trn.

x: s cn c lm trn.

7. Lnh FLOOR

a) Cng dng:

Lm trn s v pha s nguyn nh hn.

b) C php:

y = floor(x)

c) Gii thch:

y: s sau khi c lm trn .

x: s cn c lm trn

8. Lnh IMAG

a) Cng dng:Ly phn o ca s phc.

b) C php:

y = imag(z)

9. Lnh LOG

a) Cng dng:

Tm logarithm c s e.


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b) C php:

y = log(x)

10. Lnh LOG2

a) Cng dng:

Tm logarithm c s 2.

b) C php:y = log2(x)

11. Lnh LOG10

a) Cng dng:

Tm logarithm c s 10.

b) C php:

y = log10(x)

12. Lnh REAL

a) Cng dng:

Ly phn thc ca s phc.

b) C php:

y = real(z)

13. Lnh REM

a) Cng dng:

Cho phn d ca php chia.

b) C php:

r = rem(a,b)

c) Gii thch:

r: bin cha kt qu

a, b: s chia v s b chia

14. Lnh ROUND

a) Cng dng:

Lm trn s sao cho gn s nguyn nht.

b) C php:

y = round(x)

15. Lnh SIGN

a) Cng dng:

Xt du s thc.

b) C php:

y = sign(x)

c) Gii thch:


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x: s thc cn xt du.

y: kt qu tr v.

y x

0 s 0

1 s dng

-1 s m

VII. TP LNH THAO TC TRN MA TRN1. Cng, tr, nhn, chia tng phn t ca ma trn vi hng s

a) C php:

Ma trn kt qu = ma trn [+] [-] [.] [/] hng s.2. Lnh DET

a) Cng dng:

Dng tnh nh thc ca ma trn.

3. Lnh DIAG

a) Cng dng:

To ma trn mi v x l ng cho theo quy c.

b) C php:

v = diag(x)

v = diag(x,k)

c) Gii thch:

x: l vector c n phn t.

v: l ma trn c to ra t x theo quy tc: s hng bng s ct v cc phn t ca x nmtrn ng cho ca v.

k: tham s nh dng cho v, s hng v ct ca v = n + abs(k).

Nu k = 0 ng cho ca v chnh l cc phn t ca x

Nu k > 0 cc phn t ca x nm pha trn ng cho v

Nu k < 0 cc phn t ca x nm pha di ng cho v

4. Lnh EYE

a) Cng dng:

To ma trn n v.

b) C php:

y = eye(n)

y = eye(n,m)


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c) Gii thch:

n: to ma trn c n hng, n ct.

m, n: to ma trn c m hng, n ct.

5. Lnh FLIPLR

a) Cng dng:

Chuyn cc phn t ca cc ma trn theo th t ct ngc li.b) C php:

b = fliplr(a)

c) Gii thch:

b: tn ma trn c chuyn i.

a: tn ma trn cn chuyn i.

6. Lnh FLIPUD

a) Cng dng:

Chuyn cc phn t ca ma trn theo th t hng ngc li.

b) C php:

b = flipud(a)

c) Gii thch:

b: tn ma trn c chuyn i.

a: tn ma trn cn chuyn i.

7. Lnh INV

a) Cng dng:

Tm ma trn nghch o.

b) C php:Ma trn nghch o = inv (ma trn)

8. Lnh to ma trn

a) Cng dng:

Dng to 1 ma trn gm c n hng v m ct.

b) C php:

Tn ma trn = [a11 a12a1m ; a21 a22 a2m ;;]

c) Gii thch:

a11, a12, a1m l cc gi tr ti hng 1 ct 1 n cc gi tr ti hng 1 ct m, c n du (;) l cn hng.

9. Lnh to vector n

a) Cng dng:

Lnh ny dng to 1 vector n gm c n phn t.

b) C php 1:

Tn vector = [pt1 pt2 pt3 ptn]


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c) Gii thch:

pt1 pt2 ptn: l cc s thc.

d) C php 2:

Tn vector = gt:csc:gtkt

e) Gii thch:

gt: l gi tr bt u ca vector.csc: cp s cng.

gtkt: gi tr kt thc.

10. Lnh LINSPACE

a) Cng dng:

To vector c gi tr ngu nhin gii hn trong khong nh trc.

b) C php:

y = linspace(x1, x2)

y = linspace(x1, x2, n)

c) Gii thch:

y: tn ca vector.

x1, x2: gii hn gi tr ln nht v nh nht ca vector y.

n: s phn t ca vector y.

Nu khng c gi tr n th mc nh n = 100.

11. Ma trn chuyn v

a) Cng dng:

Ma trn chuyn v = ma trn ang c.

b) C php:To 1 ma trn chuyn v t 1 ma trn ang c.

12. Lnh MAGIC

a) Cng dng:

To 1 ma trn vung c tng ca cc phn t trong 1 hng, 1 ct hoc trn ng chobng nhau.

b) C php:

Tn ma trn = magic(n)

c) Gii thch:

n: kch thc ma trn.

Gi tr ca mi phn t trong ma trn l mt dy s nguyn lin tc t 1 n 2n.

Tng cc hng, ct v cc ng cho u bng nhau.

13. Nhn ma trn

a) Cng dng:

Ma trn kt qu = ma trn 1* ma trn 2.


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14. Lnh ONES

a) Cng dng:

To ma trn m gi tr ca cc phn t l 1.

b) C php:

y = ones(n)

y = ones(m,n)c) Gii thch:

y = tn ma trn.

n: to ma trn c n hng


15. Lnh PASCAL

a) Cng dng:

To ma trn theo quy lun tam gic Pascal.

b) C php:

pascal (n)

c) Gii thch:

n: l s hng (ct)

16. Lnh RAND

a) Cng dng:

To ma trn m kt m gi tr ca cc phn t l ngu nhin.

b) C php:

y = rand(n)

y = rand(m,n)c) Gii thch:

y: tn ma trn.

n: to ma trn c n hng, n ct.


Gi tr ca c c phn t nm trong khong [0 1]

17. Lnh RESHAPE

a) Cng dng:

nh dng li kch thc ma trn.

b) C php:

b = reshape(a,m,n)

c) Gii thch:

b: ma trn c nh dng li.

a: ma trn cn c nh dng.

m, n: s hng v s ct ca b.

Ma trn a phi c s phn t l: m*n.


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18. Lnh ROT90

a) Cng dng:

Xoay ma trn 900.

b) C php:

b = rot90(a)

c) Gii thch:b: ma trn c xoay 900

a: ma trn cn xoay.

19. Lnh TRACE

a) Cng dng:

Tnh tng cc phn t ca ng cho ma trn.

b) C php:

d = trace(a)

c) Gii thch:

d: bin cha kt qu.

a: tn ma trn.

20.Lnh TRIL

a) Cng dng:

Ly phn na di ma trn theo hnh.

b) C php:

I = tril(x)

I = tril(x,k)

c) Gii thch:I: tn ma trn kt qu.

k: tham s.

Nu k = o ly t ng cho tr xung.

Nu k = n ly t ng cho tr ln n n v.

Nu k = -n ly t ng cho tr xung n n v.

21. Lnh TRIU

a) Cng dng:

Ly phn na trn ma trn theo hnh tam gic.b) C php:

I = triu(x)

I = triu(x,k)

c) Gii thch:

I: tn ma trn kt qa.

k: tham s


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Nu k = 0 ly t ng cho tr ln.

Nu k = n ly t ng cho tr xung n n v.

Nu k = -n ly t ng cho tr ln n n v.

22. Lnh ZEROS

a) Cng dng:

To ma trn m gi tr ca cc phn tb) C php:

y = zeros(n)

y = zeros(m,n)

c) Gii thch:

y: tn ma trn.

n: to ma trn c n hng v n ct.


16. Lnh SQRT

a) Cng dng:

Tnh cn bc hai.

b) C php:

y = sqrt(x)

VII. TP LNH HA1. Lnh AXES

a) Cng dng:

t cc trc ta ti v tr nh trc.b) C php:

axes(propertyname, propertyvalue )

c) Gii thch:

Tng ng vi mt propertyname i km vi 1 propertyvalue.

1. position,[left, bottom, width, height]: nh v tr v kch thc ca trc.

left: khong cch t mp tri ca s n trc ng.

bottom: khong cch t mp di ca s n trc ngang.

width: chiu di ca trc ngang.

height: chiu cao trc ng.

Ghi ch:

Lun ly im [0,0] lm gc ta .

Trc ngang v trc ng c gi tr trong khong [0 1] v chia theo t l thch hp


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2. Lnh AXIS

a) Cng dng:

Chia li trc ta .b) C php:

axis([xmin xmax ymin ymax])

axis([xmin xmax ymin ymax zmin zmax])

axis on

axis off

c) Gii thch:

xmin, ymin, zmin: l gi tr nh nht ca cc trc x, y, z.

xmax, ymax, zmax: l gi tr ln nht ca cc trc x, y, z.

on: cho hin th trc ta .

off: khng cho hin th trc ta .

3. Lnh BAR

a) Cng dng:

V th dng ct.b) C php:

bar(x,y)

c) Gii thch:

V gi tr x theo gi tr y.

d) V d:

x = -pi:0.2:pi;

bar(x,sin(x));

grid on

title(Do thi ham sin(x) dang thanh)

xlabel(truc x (rad))

ylabel(y = sin(x))


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4. Lnh CLA

a) Cng dng:Xa tt c cc i tng nh: ng th, tn thnhng khng xa trc ta .b) C php:

cla

5. Lnh CLF

a) Cng dng:

Xa hnh nh ( th) hin ti.b) C php:

clf

6. Lnh CLOSEa) Cng dng:

ng hnh nh ( th) hin ti.b) C php:

close

7. Lnh COLORMAP

a) Cng dng:

To mu sc cho th trong khng gian 3 chiu.b) C php:

colormap(map)colormap(default)

c) Gii thch:

Colormap l s trn ln ca 3 mu c bn: red, green, blue. Ty theo t l ca 3 mu cbn m cho ra cc mu sc khc nhau.

default: mu c c l mu mc nh.

map: bin cha cc thng s sau:


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Map mu c c

Bone gray + blue

Cool cyan + magenta

Flag red + white + blue + black

Gray gray

Hot black + red + yellow + white

Pink pink

8. Lnh FIGURE

a) Cng dng:

To mi hnh nh ( th).

b) C php:figure

9. Lnh GCA

a) Cng dng:

To cc c tnh cho trc.b) C php:

h = gca

c) Gii thch:

h: l bin gn cho lnh cga.

Cc c tnh ca trc gm c:

C php Gii thch

Set(gca,XScale,log,Yscale,linear)

nh n v trn trc ta : trc x cn v l log v trc y c n v tuyntnh.

Set(gca,Xgrid,on,YGrid',nomal)

To li cho th: trc x c to li vtrc y khng to li.

Set(gca,XDir',reverse,YDir,normal)

i trc ta : i trc x v pha idin, trc y gi nguyn.

Set(gca,XColor',red,Ycolor,yellow)

t mu cho li th: t li trc xmu , li trc y mu vng.

Gm c cc mu: yellow, magenta,cyan, red, green, blue, white, black.


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10. Lnh GRID

a) Cng dng:

To li ta .

b) C php:

grid on

grid offc) Gii thch:

on: hin th li ta .

off: khng hin th li ta .11. Lnh PLOT

a) Cng dng:

V th tuyn tnh trong khng gian 2 chiu.b) C php:

plot(x,y)

plot(x,y,linetype)c) Gii thch:

x,y: v gi tr x theo gi tr y.

linetype: kiu phn t to nn nt v bao gm 3 thnh phn:

- Thnh phn th nht l cc k t ch mu sc:

K t Mu

y Vng

m ti

c L

r

g Lc

b Lam

w Trng

k en


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- Thnh phn th hai l cc k t ch nt v ca th:

K t Loi nt v

- ng lin nt

: ng chm chm

-. ng gch chm

-- ng nt t on

- Thnh phn th ba l cc k t ch loi im nh du gm:., o, x, +, *

d) V d:

V th hm y = sin(x) vi th mu lam, ng lin nt v nh du cc im cchn bng du *, trc x thay i t 0 ti 2, mi bc thay i l /8

x = 0:pi/8:2*pi;

y = sin(x);

plot(x,y, b-* )

ylabel(y = sin(x))

xlabel(Truc x)

title(Do thi ham y = sin(x))

grid on


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12. Lnh SUBPLOT

a) Cng dng:

To cc trc trong mt phn ca ca s ha.b) C php:

subplot(m,n,p)

subplot(mnp)

c) Gii thch:

subplot(m,n,p) hoc subplot(mnp)thnh ca s ha thnh mn vng v nhiu thtrn cng mt ca s.

m: s hng c chia.

n: s ct c chia

p: s th t vng chn v th.

Nu khai bo p > mn th s xut hin mt thng bo li.

d) V d:

Chia ca s ha thnh 23 vng v hin th trc ca c 6 vng.subplot(231)

subplot(232)

subplot(233)

subplot(234)

subplot(235)

subplot(236)


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13. Lnh SEMILOGX, SEMILOGY

a) Cng dng:

V th theo logarith.b) C php:

semylogx(x,y)

semylogx(x,y,linetype)

semylogy(x,y)

semylogy(x,y,linetype)

c) Gii thch:

semylogx v semylogy ging nh lnh plot nhng ch khc mt iu l lnh ny v ththeo trc logarith. Do , ta c th s dng tt c cc loi linetype ca lnh plot.

d) V d:

V th hm y = x2 3x + 2 theo trc logarith ca x.

x = 0:100;

y = x.^2-3*x+2;semylogx(x,y,b)

grid on

14. Lnh POLAR

a) Cng dng:

V th trong h trc ta cc.b) C php:

polar(theta,rno)


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c) Gii thch:


d) V d:

t = -pi:0.01:pi;

polar(t, sin(t))

V ta thu c dng th sau:

15. Lnh SET

a) Cng dng:

Thit lp cc c tnh cht cho i tng no .b) C php:

set(h, propertyname, propertyvalue,)

c) Gii thch:h: bin cha i tng.

PropertyName v PropertyValue c cho trong bng sau:

C php PropertyName PropertyValue Gii thch

Set(h,Marker,+) Marker -, --, :, -. , o, , +, * Chn kiu phn t

Set(h,LineWidth,1) LineWidth 1, 2, 3, dy nt v

Set(h,MarkerSize,9) MarkerSize 1, 2, 3, Kch th

c cc im tonn h

Set(h,color,cyan) Color yellow,magenta,ed,green,blue,

cyan,white,black

Chn mu cho i tngh


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d) V d:

a = [1 2 3 4 5 4 3 4 5 6];

h = plot(a)

set(h,color,black)

16. Lnh STAIRS

a) Cng dng:

V th dng bc thang.b) C php:

stairs(x,y)

c) Gii thch:


d) V d:

x = -pi:0.2:pi;

stairs(x,sin(x))

xlabeL(Truc x)ylabel(y = stairs(x,sin(x))

grid on


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17. Lnh TITLE

a) Cng dng:

t tiu cho th.b) C php:

title(text)

c) Gii thch:

text: tn tiu .

18. Lnh XLABEL, YLABEL, ZLABEL

a) Cng dng:t tn cho trc X, Y, Z.

b) C php:

xlabel(nx)

ylabel(ny)

zlabel(nz)

c) Gii thch:

nx, ny, nz: tn trc x, y, z19. Lnh WHITEBG

a) Cng dng:

Thay i mu nn ca ca s ha.b) C php:

whitebg

whitebg(color)

c) Gii thch:

whitebg chuyn i qua li mu nn ca s ha gia trng v en.


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whitebg(color) chuyn mu nn ca s ha thnh mu ca bin color.

color c th l cc mu: yellow (vng), magenta ( ti), cyan (l), red (), green (lc), blue(lam), white (trng), black (en).

MATLAB cn v c cc th nh sau :


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VII. V GIN BODE, NyQuist, Nichols

L THUYT:

Gin Bode gm hai th: th logarith bin ca hm truyn v gc pha theo

logarith tn s. (mt n v trc honh gi l mt decade).

Bin : G(j)dB = 20 log10G(j) (2.22)

Pha : = G(j) (hay arg G(j)) (2.23)

Gin Bode ca cc khu c bn:

* Khu khuch i:

Hm truyn t G(s) = K

Gin Bode L() = 20 lgM() = 20 lgK l 1 ng thng song song vi trc honh.

* Khu qun tnh bc 1:

Hm truyn t G(s) =1Ts

K+

Biu Bode L() = 20 lgM() = 20 lgK 20lg 1T 22 + c dc gim

20dB/decade

* Khu vi phn bc 1:

Hm truyn t G(s) = K(Ts + 1)

Gin Bode L() = 20 lgM() = 20 lgK + 20lg 1T 22 + c dc tng20dB/decade

* Khu tch phn:

Hm truyn t G(s) =s

K

Gin Bode L() = 20 lgM() = 20 lgK 20lg

* Khu bc 2:

Hm truyn t G(s) =22

2

2 nn

n

ss

++

Gin Bode L() = -20lg ( ) 222222 41 tt +

V d

V gin Bode h thng hi tip n v ca hm truyn vng h sau:


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G(s) =)s1.01(s

10

+

>> num = 10;

>> den = [0.1 1 0];

>> bode(num,den)Kt qu:

Frequency (rad/sec)

Phase(deg);Magnitude(dB)

Bode Diagrams

-40

-20

0

20

40

10-1

100

101

102

-160

-140

-120

-100

H thng gm 1 khu khuch i bng 10, mt khu tch phn v mt khu qun tnh bc 1

Tn s gy: 10.

| G(jw)|dB = 20dB 20log

Ti tn s = 1rad/sec | G(jw)|dB = 20dB v dc 20dB/decade (do khu tch phn).

dc 20dB/decade tip tc cho n khi gp tn s ct = 10rad/sec, ti tn s ny ta cngthm 20dB/decade (do khu qun tnh bc nht) v to ra dc -40dB/dec.


G(s) =)1000)(10)(1(

)100(105

++++

sss

s


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>> num = 100000*[1 100];

>> den = [1 1011 11010 10000];

>> bode(num,den)

Kt qu:

Frequency (rad/sec)


Bode Diagrams

-50

0

50

10-1

100

101

102

103

104

-150

-100

-50

H thng gm mt khu khuch i 105, mt khu vi phn bc nht v 3 khu qun tnh bc 1.

Tn s gy: 1,10,100,1000.

| G(jw)|dB|w = 0 = 60dBTi tn s gy = 1rad/sec c li 60dB v dc 20dB/decade (v khu qun tnh bc 1). dc 20dB/decade c tip tc n khi gp tn s gy = 10rad/sec ti y ta cng thm -20dB/decade(v khu qun tnh bc 1), to ra dc 40dB/dec. dc - 20dB tn s =100rad/dec (do khu vi phn bc 1). Ti tn s gy = 100rad/sec tng 20dB (v khu vi phnbc 1). To ra dc c dc -20dB.

Ti tn s gy = 1000rad/sec gim 20dB (v khu qun tnh bc 1). To ra dc - 40dB.


G(s) =2)s1.01(s

10

+

>> num = 10;

>> den = [0.01 0.2 1 0 ];


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>> bode(num,den)

Kt qu:

Frequency (rad/sec)


Bode Diagrams

-60

-40

-20

0

20

40

10-1

100

101

102

-250

-200

-150

-100

H thng gm mt khu khuch i 10, mt khu tch phn v 1 thnh phn cc kp.

Tn s gy: 10.

| G(jw)|dB = 20dB 20log

Tn s gy nh nht = 0.1 rad/sec ti tn s ny c li 40dB v dc 20dB (do khu tchphn). dc ny tip tc cho ti tn s gy kp = 10. tn s ny s gim 40dB/decade, tora dc 60dB/dec.


G(s) =)100s)(1s(s

)10s(102

+++

>> num = 100*[1 10];

>> den = [1 101 100 0];>> bode(num,den)

Kt qu:


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Frequency (rad/sec)


Bode Diagrams

-50

0

50

10-2

10-1

100

101

102

103

-160

-140

-120

-100

H thng gm mt khu khuch i 100, mt khu tch phn v 2 khu qun tnh bc 1, 1 khu viphn.

Tn s gy: 1,10,100

| G(jw)|dB|w = 0 = 20log10 20log

Ta ch xt trc tn s gy nh nht 1decade. Ti tn s gy = 0.1rad/sec c li 40dB v dc 20dB/dec, dc 20dB/dec tip tc cho n khi gp tn s gy = 1rad/sec, ta cng thm

20dB/dec (v khu qun tnh bc 1) v to ra dc 40dB/dec. Ti tn s =10 s tng20dB/dec (v khu vi phn) to ra dc 20dB/dec, dc 20db/dec c tip tc cho nkhi gp tn s gy = 100rad/sec s gim 20dB/dec (v khu qun tnh bc 1) s to dc 40dB/decade.

Bi 5: Bi ny trch t trang 11-21 sch Control System Toollbox

V gin bode ca h thng hi tip SISO c hm sau:

S2+01.s+7.5

H(s) = -----------------------

S2+0.12s3+9s2

>> g=tf([1 0.1 7.5],[1 0.12 9 0 0]);

>> bode(g)


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Frequency (rad/sec)

Phase(deg);M

agnitude(dB)

Bode Diagrams

-4 0

-2 0

0

20

40

From: U(1)

10 -1 10 0 10 1-200

-150

-100

-5 0

0

To:Y(1)

Biu Nichols

L thuyt

Cng dng: xc nh n nh v p ng tn s vng kn ca h thng hi tip ta s dngbiu Nichols. S n nh c nh gi t ng cong v mi quan h ca li theo c tnhpha ca hm truyn vng h. ng thi p ng tn s vng kn ca h thng cng c xcnh bng cch s dng ng cong bin v di pha vng kn khng i ph ln ngcong bin pha vng h.

C php

[mod,phase,puls]= nichols(A,B,C,D);

[mod,phase,puls]= nichols(A,B,C,D,ui);

[mod,phase]= nichols(A,B,C,D,ui,w);

mod,phase,puls]= nichols(num,den);

[mod,phase]= nichols(num,den,w);

Nhng cu trc trn cho ln l nhng gi tr t nhin, pha l v vect ca im tn s lrad/s. S tn ti ca im tn s m p ng tn s c nh gi bng vect w, v ui l bin khaibo vi h thng nhiu ng vo

Ch :

+ Khi s dng lnh nichols vi cu trc khng c bin ng ra th ta c biu nichols

+ Lnh nichols lun lun cho pha trong khong [-3600,00]


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V biu nichols cho h thng c hm truyn sau:

( )32

1ss

1s7s30)s(G

+

++=

Cc bc thc hin:

>> num=30*[1 7 1];

>> den=[poly([-1 -1 -1]) 0];

>> hold on, plot(-180,0,'*r'), hold on;

>> nichols(num,den)

Tr v biu nichols vi im ti hn critical point

(-1800 ,0) c biu din nh hnh sau:

V BIU NYQUYST V KHO ST N NH

DNG GIN BODE

L thuyt

+ H thng n nh trng thi h, s n nh trng thi kn nu biu Nyquist

khng bao im (-1+i0) trn mt phng phc.


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+ H thng khng n nh trng thi h, s n nh trng thi kn nu biu Nyquist

bao im (-1+i0)p ln ngc chiu kim ng h (p l s cc GH nm phi mt phng

phc).

Cu trc lnh:

>> num = [nhp cc h s ca t s theo chiu gim dn ca s m].

>> den = [nhp cc h s ca mu s theo chiu gim dn ca s m].

>> nyquist(num,den)

V biu Nyquyist ca h thng c hm truyn sau:

GH(s) =st1

k

(vi k =10, t =1)

>> num = 10;

>> den = [-1 1];>> nyquist(num,den)

Kt qu:

Real Axis

Imaginary

Axis

Nyquist Diagrams

0 2 4 6 8 10

-5

-4

-3

-2

-1

0

1

2

3

4

5

Nhn xt: hm truyn vng h c 1 cc nm bn phi mt phng phc. Biu Nyquist khng

bao im A (-1+j0).

im 1 k hiu (+) nm trn trc thc m (Real Axis), im 0 nm trn trc o (ImaginaryAxis).

Kt lun: h khng n nh.

* Dng lnh margin tm bin d tr v pha d tr.

>> num = 10;

>> den = [-1 1];

(A)


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>> margin(num,den);

Frequency (rad/sec)


Bode Diagrams

0

5

10

15

20

Gm = 0 dB, Pm = 0 (unstable closed loop)

100

20

40

60

80

Kt lun:

d tr bin (Gm = 0 dB).

d tr pha (Pm = 0).

Warning: Closed loop is unstable (h vng kn khng n nh).


GH(s) =( )st1sk

(k = 10, t = 1)

>> num = 10;

>> den = [-1 1 0];

>> nyquist(num,den)

Ta thu c d th sau:


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Real Axi s

Imagin

aryAxis

Nyquist Diagram s

0 2 4 6 8 10

-1000

-800

-600

-400

-200

0

200

400

600

800

1000

Nhn xt:hm truyn vng h c 1 cc nm bn phi mt phng phc v 1 cc nm ti gc ta. Biu Nyquist khng bao im A (-1+j0).

im 1 k hiu (+) nm trn trc thc m (Real Axis) , im 0 nm trn trc o (ImaginaryAxis).



>> num = 10;

>> den = [-1 1 0];

>>margin(num,den)

Frequency (rad/sec)


Bode Diagrams

-20

0

20

40

60


10-1

100

-80

-60

-40

-20

Kt lun:


d tr pha (Pm = 0).

(A)


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Warning: Closed loop is unstable (h vng kn khng n nh).


GH(s) =( )( )1st1st

k

21 ++(k =10, t1 = 1, t2 = 2)

>> num = 10;

>> den = [2 3 1];>> nyquist(num,den)

Real Axis

ImaginaryAxis

Nyquist Diagram s

0 2 4 6 8 10

-6

-4

-2

0

2

4

6

Nhn xt:hm truyn vng h c 2 cc nm bn tri mt phng phc. Biu Nyquist khngbao im A (-1+j0).

im 1 k hiu (+) nm trn trc thc m (Real Axis) , im 0 nm trn trc o (Imaginary

Axis).Kt lun: h thng n nh.


>> num = 10;

>> den = [2 3 1];

>> margin(num,den)

Ta thu c dng th sau:

(A)


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60

Frequency (rad/sec)

Phase(deg

);Magnitude(dB)

Bode Diagrams

-20

-10

0

10

20

Gm = In f, Pm=38.94 deg. (at 2.095 rad/sec)

100

-150

-100

-50

Kt lun: h thng n nh.

d tr bin (Gm = ).

d tr pha (Pm = 38.94), ti tn s ct bin 2.095 rad/sec.


GH(s) =( )( )1st1sts

k

21 ++ (k = 10 t1=1, t2 =2)

>>num = 10;

>> den = [2 3 1 0];

>> nyquist(num,den)

Real Axis

ImaginaryAxis

Nyquist Diagrams

-30 -25 -20 -15 -10 -5

-1000

-800

-600

-400

-200

0

200

400

600

800

1000

Nhn xt:hm truyn vng h c 2 cc nm bn tri mt phng phc v 1 cc zero. Biu Nyquist bao im A(-1+j0).

(A)


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>> num = 10;

>> den = [2 3 1 0];>>margin(num,den)

Frequency (rad/sec)


Bode Diagrams

-40

-20

0

20

40

60


10-1

100

-250

-200

-150

-100

Kt lun: h thng khng n nh.


d tr pha (Pm = 0)


GH(s) = ( )( )( )1st1st1stsk

321 +++ ( t1 =1, t2 = 2, t3 = 3, k = 10)

>> num = 10;

>> den = [6 11 6 1 0];

>> nyquist(num,den)

Real Axi s

ImaginaryAxis

Nyquist Diagram s

-60 -50 -40 -30 -20 -10 0

-1000

-800

-600

-400

-200

0

200

400

600

800

1000

(A)


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Nhn xt:hm truyn vng h c 3 cc nm bn tri mt phng phc v 1 cc zero. Biu Nyquist bao im A (-1+i0).




>> num = 10;

>> den = [6 11 6 1 0];

>> margin(num,den)

Frequency (rad/sec)


Bode Diagrams

-50

0

50


10-2

10-1

100

-300

-200

-100

Kt lun: h thng khng n nh.


d tr pha (Pm = 0).

NHM LNH V QU O NGHIM

(Roots Locus)

1. Lnh PZMAPa) Cng dng:

V biu cc-zero ca h thng.

b) C php:

[p,z]= pzmap(num,den)

[p,z]= pzmap(a,b,c,d)



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c) Gii thch:

Lnh pzmap v biu cc-zero ca h LTI. i vi h SISO th cc cc v zero cahmtruyn c v.

Nu b qua cc i s ng ra th lnh pzmap s v ra biu cc-zero trn mn hnh.

pzmap l phng tin tm ra cc cc v zero tuyn t ca h MIMO.

pzmap(a,b,c,d) v cc cc v zero ca h khng gian trng thi trong mt phng phc. i vicc h thng MIMO, lnh s v tt c cc zero truyn t t tt c cc ng vo ti tt c cc ngra. Trong mt phng phc, cc cc c biu din bng du cn cc zero c biu din bngdu o.

pzmap(num,den) v cc cc v zero ca hm truyn trong mt phng phc. Vector num v dencha cc h s t s v mu s theo chiu gim dn s m ca s.

pzmap(p,z) v cc cc v zero trong mt phng phc. Vector ct p cha ta cc cc v vectorct z cha ta cc zero trong mt phng phc. Lnh ny v cc cc v zero c tnh sntrong mt phng phc.

Nu gi li cc i s ng ra th :

[p,z]= pzmap(num,den)



to ra cc ma trn p v z trong p cha cc cc cn z cha cc zero.

d) V d: (Trch trang 11-174 sch Control system Toolbox)

V cc cc v zero ca h lin tc c hm truyn :

32

152)(

2

2

++++

=ss

sssH

num = [2 5 1];

den = [1 2 3];pzmap(num,den)

title(Bieu do cuc-zero)


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2. Lnh RLOCFIND

a) Cng dng:

Tm li qu o nghim vi tp hp nghim cho trc.

b) C php:

[k,poles]= rlocfind(a,b,c,d)

[k,poles]= rlocfind(num,den)[k,poles]= rlocfind(a,b,c,d,p)

[k,poles]= rlocfind(num,den,p)

c) Gii thch:

Lnh rlocfind to ra li qu o nghim kt hp vi cc cc trn quo nghim. Lnhrlocfind c dng cho h SISO lin tc v gin on.

[k,poles]= rlocfind(a,b,c,d) to ra du x trong ca s ha m ta dng chn mt imtrn qu o nghim c sn. li ca im ny c to ra trong k v cc cc ng vi liny nm trong poles. s dng lnh ny th qu o nghim phi c sn trong ca s ha.

[k,poles]= rlocfind(num,den) to ra du x trong ca s ha m ta dng chn mtim trn qu o nghim ca h thng c hm truyn G = num/den trong c num v dencha cc h s a thc theo chiu gim dn s m ca s hoc z.

[k,poles]= rlocfind(a,b,c,d,p) hoc [k,poles]= rlocfind(num,den,p) to ra vector li k vvector cc cc kt hp pole vi mi thnh phn trong mi vector ng vi mi nghim trong p.

d) V d:

Xc nh li hi tip cc cc vng kn ca h thng c h s tt dn = 0.707 v chm truyn :

32

152)(

2

2

++++

=ss

sssH

num = [2 5 1];den = [1 2 3];

+) V qu o nghim:

rlocus(num,den); title(Do loi quy dao nghiem);

+ )Tm li ti im c chn:

rlocfind(num,den);

Sau khi nhp xong lnh, trn mn hnh ca Matlab s xut hin dng ch:

Select a point in the graphics window

v trn hnh v c th

c ta ko chut v chn imta c qu o nghim:


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3. Lnh RLOCUS

a) Cng dng:

Tm qu o nghim Evans.

b) C php:

r = rlocus(num,den)

r = rlocus(num,den,k)

r = rlocus(a,b,c,d)

r = rlocus(a,b,c,d,k)

c) Gii thch:Lnh rlocus tm qu o nghim Evans ca h SISO. Qu o nghim c dng

nghin cu nh hng ca vic thay i li hi tip ln v tr cc ca h thng, cung cp ccthng tin v p ng thi gian v p ng tn s. i vi i tng iu khin c hm truynG(s) v khu b chnh hi tip k*f(s), hm truyn vng kn l :

)(

)(

)()(1

)()(

sq

sg

sfskg

sgsh =

+=

Nu b qua cc i s ng ra th lnh rlocus s v ra qu o trn mn hnh. Lnh rlocusdng cho c h lin tc v gin on.

r = rlocus(num,den) v qu o nghim ca hm truyn :

q(s) = 1 + k)(

)(

sden

snum= 0

vi vector li k c xc nh t ng. Vector num v den ch ra h t s v mu s theo chiugim dn s ca s hoc z.

)(......)2()1(

)(......)2()1(

)(

)(21

21

nddensdensden

nnnumsnumsnum

sden

snumndnd

nnnn

++++++

=


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r = rlocus(a,b,c,d) v ra qu o nghim ca h khng gian trng ti SISO lin tc vgin on vi vector li c xc nh t ng

r = rlocus(num,den,k) hoc r = rlocus(a,b,c,d,k) v ra qu o nghim vi vector li kdo ngi s dng xc nh. Vector k cha cc gi tr v li m nghim h vng kn c tnh.

Nu s dng cc i s ng ra th :

[r,k] = rlocus(num,den)

[r,k] = rlocus(num,den,k)

[r,k] = rlocus(a,b,c,d)

[r,k] = rlocus(a,b,c,d,k)

to ra ma trn ng ra cha cc nghim v vector li k. Ma trn r c length(k) hng v(length(den) 1) ct, ng ra cha v tr cc nghim phc. Mi hng trong ma trn tng ng vimt li trong vector k. Qu o nghim c th c v bng lnh plot(r,x).

d) V d: Tm v v qu o nghim ca h thng c hm truyn :

32

152)(

2

2

++++

=ss

sssH

+) Xc nh hm truyn :

>>num = [2 5 1];

>>den = [1 2 3];

+ )V qu o nghim :

>>rlocus(num,den)

title(Quy dao nghiem)


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4. Lnh SGRID

a) Cng dng:

To li cho qu o nghim v biu cc-zero lin tc.

b) C php:

sgrid

sgrid(new)sgrid(z,wn)

sgrid(z,wn,new)

c) Gii thch:

Lnh sgrid to li cho qu o nghim v biu cc-zero lin tc trong mt phng s. ngli v l cc ng hng s t s tt dn () v tn s t nhin (n). ng t s tt dn c vt 0 ti 1 theo tng nc l 0.1.

sgrid(new) xa mn hnh ha trc khi v v thit lp trng thi hold on qu o nghimhay biu cc-zero c v ln li bng cc lnh :

sgrid(new)

rlocus(num,den) hoc pzmap(num,den)

sgrid(z,wn) v cc ng hng s t l tt dn c ch nh trong vector z v v ng tn s tnhin c ch nh trong vector wn.

sgrid(z,wn,new) xa mn hnh ha trc khi v cc ng t s tt dn v tn s t nhinc ch nh trong vector z v wn. Trng thi hold on c thit lp.

d) V d:V li trong mt phng s trn qu o nghim ca h thng c hm truyn :

>>num = [2 5 1]; % ta c th thay i 2 dng num=, den= thnh dng lnh sau:

>>den = [1 2 3]; % H(s)=tf([2 5 1],[1 2 3]);

>>rlocus(num,den)

title(Quy dao nghiem)

sgrid


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5. Lnh ZGRID

a) Cng dng:

V li t l tt dn v tn s t nhin cho qu o nghim gin on.

b) C php:

zgrid

zgrid(new)zgrid(z,wn)

zgrid(z,wn,new)

c) Gii thch:

Lnh zgrid to li qu o cho nghim hoc biu cc-zero trong mt phng z. Cc nghng s t l tt dn () v tn s t nhin chun ha s c v. c thay i t 0 ti 1 theotng nc thay i l 0.1 v tn s t nhin c v t 0 ti vi tng nc thay i l /.

zgrid(new) xa mn hnh ha trc khi v li v thit lp trng thi hold on quo nghim hoc biu cc-zero c v ln li s dng cc lnh :

zgrid('new')rlocus(num,den) hoc pzmap(num,den)

zgrid(z,wn) v hng s tt dn c ch nh trong vector z v v hng s tn s t nhin cho cctn s chun ha c ch nh trong vector wn. Cc tn s chun ha c th c v bng lnhzgrid(z,wn/Ts) vi tn s l thi gian ly mu.

zgrid(z,wn,new) xa mn hnh ha trc khi v t s tt dn v tn s t nhin c ch nhtrong vector z v wn. Trng thi hold on c thit lp.

zgrid([ ],[ ]) s v ra vng trn n v.

d) V d:V li trong mt phng cho qu o nghim ca h thng c hm truyn :

8.06.1

5.14.32

)( 2

2

++

= szzz

zH

>>num = [2 -3.4 1.5];

>>den = [1 -1.6 0.8];

>>axis(square)

>>zgrid(new)

>>rlocus(num,den)

title(Ve luoi cho quy dao nghiem)


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CC BI TPV QU O NGHIMV d: Cho hm truyn sau:

KGH =)5s)(4s(s

k

++vi k = 2

>> num = 2;

>> den = [1 9 20 0];

>> rlocus(num,den)

-7 -6 -5 -4 -3 -2 -1 0 1 2-10

-8

-6

-4

-2

0

2

4

6

8

10

Real Axis

ImagAxis

T th cho ta:

1. im cc: 0 ,-4,-5.2. Qu o nghim c 3 nhnh.3. im zero v cng ( ).4. im tch c xc nh bng cch t ca s MATLAB ta nhp:

>> num = 2;

>> den = [1 9 20 0];>> rlocus(num,den);

>> rlocfind(num,den)

Sau khi nhp lnh th trn ca s lnh s xut hin hng ch:

Select a point in the graphics window (hy chn 1 im trn th minh ha).Trn th s c thc cho ta chn im ko r chut chn im cn chn.

selected_point = -1.4516


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im tch c gi tr: -1.4516

Giao im ca qu o nghim vi trc o (tng t nh tm im tch): +4.472j, -4.472j.

T gi tr ti giao im ca qu o nghim vi trc o ta th vo phng trnh c trng:

F(s) = s3+9s2+20s+k = 0

F(jw) = -jw3-9w2+20jw+k = 0

kgh = 180Kt lun: h thng s n nh khi 0 < k < 180

V d: Cho hm truyn nh sau:

( )( )2s1s4s

)s(G++

+=

Vit theo cu trc sau ta c c th biu din qu o nghim:

>> num=[1 4];

>> den=conv([1 1],[1 2])

>> rlocus(num,den)

Kt qu nhhnh sau:


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V d: Cho hm truyn sau:KGH =

2s

)1ts(k +(k = 1, t = 1)

>> num = [1 1];

>>den = [1 0 0];

>> rlocus(num,den)

-3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Real Axis

Imag

Axis

1. im cc: 02. Qu o nghim c 2 nhnh

3. im zero , -1

4. im tch c c xc nh bng cch t ca s MATLAB ta nhp:

num = [1 1];

den = [1 0 0];

rlocus(num,den);

rlocfind(num,den)

Sau khi nhp lnh th trn ca s lnh s xut hin hng ch:

Select a point in the graphics window (hy chn 1 im trn th minh ha).Trn th s c thc cho ta chn im ko r chut chn im cn chn.

selected_point = -2

im tch c gi tr: -2.

Kt lun: h thng bin n nh.


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V d: Trch t trang 5-19 sch Control System Toolbox

Bi ny tng hp cc lnh:

>> h=tf([4 8.4 30.8 60],[1 4.12 17.4 30.8 60]);

>> subplot(221)

>> bode(h)

>> subplot(222)>> step(h)

>> subplot(223)

>> pzmap(h)

>> subplot(224)

>> plot(rand(1,100)

>> plot(rand(1,100))

Kt qu ta thu c dng thi sau:

Frequency (rad/sec)

Phase(deg);M

agnitude(dB)

Bode Diagrams

-2 0

0

20

From: U(1)

10 -1 10 0 10 1-100

0

10 0

To:Y(1)

Time (sec.)

Amplitude

Step Response

0 2 4 6 8 10 120

0.5

1

1.5

From: U(1)

To:Y(1)

Real Axis

ImagAxis

Pole-zero map

-3 -2 -1 0 1-4

-2

0

2

4

0 50 1000

0. 2

0. 4

0. 6

0. 8

1bai tong hop


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Phn IIIKhi qut v Simulink

1.Khi ng Simulink: khi ng vo Matlab, sau c hai cch vo ca s Simulink

Cch 1: vo trc tip Simulink bng cch nhp chut vo biu tng trong menu caMatlab

Cch 2: g lnh Simulink/ Enter ()

2. c im ca Simulink

Simulink phn bit (khng ph thuc vo th vin con) hai loi khi chc nng: khi o (virtual) v khi thc (notvirtual). Cc khi thc ng vai tr quyt nh khi chy m phng mhnh Simulink. Vic thm hay bt mt khi thc s thay i c tnh ng hc ca h thng angc m hnh Simulink m t. C th nu nhiu v d v khi thc nh: khi tch phn Integratorhay khi hm truyn t Tranfer Fcn ca th vin Continuous, khi Sum hay khi Product cath vin con Math. Ngc li, cc khi o khng c kh nng thay i c tnh ca h thng,

chng ch c nhim v thay i din mo ho ca m hnh Simulink. chnh la cc khinh Mux, Demucx hay Enable thuc th vin con Signal v System. Mt s chc nng mang ctnh o hay thc tu thuc theo v tr hay cch thc s dng chng trong m hnh Simulink, ccm hnh c xp vo loi o c iu kin .

3. Cc thao tc c bn s dng trong Simulink

Simulink gn nh ch c th s dng c nh chut. Bng cch nhy kp phm chuttri vo mt trong s cc th vin con thuc ca s th vin chnh Library ta s thu c mt cas mi c cha cc khi thuc th vin con . Hoc cng c th thu c kt qu tng t bngcch nhy kp chut tri nhnh ca th vin con, nm phn bn phi ca ca s truy cpLibrary Browser. T cc khi cha trong th vin con ta c th xy dng c lu tn hiumong mun. to nh dng (Format) v son tho ta c cc kh nng sau y:

Copy (sao chp ): bng cch gp v th Drag &Drop nh phm chut phi ta c thchp mt khi t th vin ( cng c th t mt th vin khc)

Move (di chuyn): ta c th d dng di chuyn mt khi trong phm vi ca s ca khi nh phm chut tri.

nh du : bng cch nhy phm chut tri vo khi ta co th nh du, la chn tngkhi, hoc ko chut nh du nhiu khi mt lc.

Delete (xo) : c th xo cc khi v cc ng ni b nh du bng cch gi lnhmenu Edit / Clear . Bng menu Eit / Undu hoc t hp phm Ctrl + Z ta c th cu vn li ngtc xo va thc hin.

H thng con: bng cch nh du nhiu khi c quan h chc nng, sau gom chngli thng qua menu Edit / Creat Subsystem, ta c th to ra mt h thng con mi.

Ni hai khi : dng phm chut tri nhy vo u ra ca mt khi, sau di mi tn cachut ti u vo cn ni. Sau khi th ngn tay khi phm chut, ng ni t ng c tao ra.C th r nhnh tn hiu bng cch nhy phm chut phi vo mt ng ni c c sn ko ngni mi xut hin ti u vo cn ni.

Di chuyn ng ni: lu tn hiu thong v d theo di, nhiu khi ta phi dichuyn, b tr li v tr cc. Sau khi nh ngn tay khi phm chut, ng ni t dng c to ra


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c th r nhnh tn hiu bng cch nhy phm chut phi vo mt ng ni c sn v ko ngni mi xut hin ti u vo cn ni.

Di chuyn ng ni: lu tn hiu thong v d theo di, nhiu khi ta phi dichuyn, b tr li cc ng ni. Khi nhy chn bng chut tri ta c th di chuyn tu ccim gc hoc di chuyn song song on thng ca ng ni.

Ch th kch c v dng d liu ca tn hiu: lnh chn qua menu Format/ Signaldimensions s hin th kch c ca tn hiu tn hiu i qua ng ni. Lnh menu Format / Portdata types ch th thm loi d liu ca tn hiu qua ng ni.

nh dng (Format) cho mt khi: sau khi nhy phm chut phi vo mt khi, ca snh dng khi s m ra. Ti mc Format ta c th la chn kiu v kch c ch, cng nh v trca tn khi, c th lt hoc xoay khi. Hai mc Foreground Color v Background Color chophp ta t ch mu bao quanh cng nhmu nn ca khi.

nh dng cho ng ni: sau khi nhy phm chut phi vo mt ng ni, ca snh dng ng(ca c ng dn ti ng ni ) s m ra. Ti y ta c cc lnh cho phpct b, copy hoc delete ng ni

Hp i thoi (Dialog Box) v c tnh ca khi (Block Properties): hoc i theo menuca ca s m phng Edit/Block Properties, hoc chn mc Block Properties ca ca s nhdng khi, ta s thu c hp i thoi cho php t mt vi tham s tng qut v c tnh cakhi.

Hp i thoi v c tnh ca tn hiu (Signal properties): c th ti c hp thoinh Signal properties ca mt ng ni hoc bng cch nhy chut nh du trn ca s mphng, sau i theo menu Edit/ Signal properties, hoc chn mc Signal properties t ca snh dng ng. Trong hp i thoi ta c th t tn cho ng ni hoc nhp mt on vnbn m t. Tuy nhin, t tn cho ng ni cng cn c cch khc n gin hn: nhy kpphm chut tri vo ng ni ta s t ng ti c ch nhp vn bn.

II. Tn hiu v cc loi d liu

1. Lm vic vi tn hiu

i vi Simulink, khi nim tn hiu nhm ch vo d liu xut hin u ra ca cc khichc nng trong qu trnh m phng: cc d liu chy dc theo ng ni t u ra ca khichc nng ny ti u vo ca cc khi chc nng khc m khng tn thi gian. Tn hiu trongkhun kh Matlab c nhng c im ring do ngi s dng xc nh.

Trong Simulink ta phn bit ba loi kch c tn hiu:

Tn hiu n( Scalar). Vector tn hiu: cn c gi l tn hiu 1-D, v kch c ca tn hiu c xc nh theo

hai chiu [m x n]. C vector hng [1 x n] v vector ct [m x 1] cng thuc v phm tr ma trntn hiu. i khi, v d: lc khai bo nh dng, ma trn cng c gi l mng

Khi to mt cu trc Simulink, cc khi o s to nn cc ng tn hiu o, duy nht nhmmc ch lm cho s cu trc ch nn ri mt, ngi s dng d qun l hn. Tn hiu oc th coi l s tp hp hnh nh ca nhiu tn hiu o, khng o, hay hn hp c hai loi. Trongqu trnh m phng, Simulink s dng mt th tc tn Signal properties nhn bit: nhng tnhiu thc no c ghp vo tn hiu o. Din t mt cch khc: nhng khi chc nng noc ghp thc s u cui ca tn hiu


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2. Lm vic vi cc loi s liu

Bn cnh cc c im c gii thiu, mi tn hiu thuc s cu trc Simulink uc gn mt loi s liu nht nh, v quyt nh n dung lng b nh dnh cho mt tnhiu. Simulink cng h tr tt c cc loi s liu ca Matlab

Double: chnh xc cao, du phy ng Sigle: chnh xc va, du phy ng Boolean (0 hoc 1, logic, c Simulink s l nhuint8)Loi s mc nh sn ca Simulink l Double. Trong qu trnh m phng, Simulink s kim

tra xem vic o gia cc loi s liu c ng hay khng nhm loi tr cc kt qu sai lm c thxy ra.

Kh nng khai bo, xc nh loi s liu ca tn hiu cng nh ca tham s thuc cc khichc nng trong Simulink l c bit c ngha, nu ta d nh to ra t m hnh Simulink mchy cho cc ng dng thi gian thc. Nhu cu v b nh v tc tnh ton ph thuc vo lois liu c ta chn


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III. Thvin ca Simulink1.Thvin Sources

Trong th vin ny bao gm cc ngun pht tn hiu, cc khi cho php nhp s liu tmt File, hay t Matlab Workspace. Sau y ta ln lt im qua ngha tng khi.

a. Constant: khi ny to nn mt hng s ( khng ph thuc thi gian) thc hoc phc.Hng s c th l vecter hay ma trn. Ta c th khai bo tham s constsnt value lvecter hng hay ct vi kch c [nx1] hay [1 x n] di dng ma trn

b. Step v Ramp: nh hai khi ny ta c th to nn cc tn hiu dng bc thang hay dngdc tuyn tnh dng kch thch cc m hnh Simulink. Trong hp thoi Block Parameters cakhi Step ta c th khai bo gi tr u- gi tr cui v c thi im bt u ca tn hiu bcnhy. i vi Ramp ta c th khai bo dc, thi im m gi tr xut pht ca tn hiu ura.

(Ch : hai khi Step v Ramp khng ch to ra mt tn hiu m c th to ra mt tp cc tnhiu c x l di dng vector hoc ma trn. )

V d:

c. Signal Generator v Pulse GeneratorNh Signal Generator ta to ra cc dng tn hiu kch thch khc nhau.

Cung cp cho 4 dng sng khc nhau (ging nh mypht sng)

+ Sng Sin+ Sng vung (Square)+ Sng rng ca (Sawtood)+ Sng ngu nhin (Random)

Vi Pulse Generator to chui xung hnh ch nht. Bin v tn s c th khai bo ty. i vi Pulse Generator ta cn c kh nng chn t l cho b rng xung( tnh bng phn trmcho c chu k)


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d. Repeating sequenceKhi ny cho php ta to nn mt tn hiu tun hon ty . Tham s Time values phi l mt

vecter thi gian vi cc gi tr n iu tng.Vecter bin ra Output values phi c kch c (chiu di) ph hp vi chiu di ca tham s Timevalues.Gi tr ln nht ca vecter thi gian quyt nh chu k lp li ca vecter bin ra.

e. Sine WaveKhi ny c s dng to tn hiu hnh Sin cho c hai loi m hnh: lin tc (tham s

Sample time = 0)v gin on (tham s sample time = 1)

Mn hnh ci t thng s cho khi Sine Wave

f. From WorkspaceKhi From Workspace c nhim v ly s liu t ca s Matlab Workspace cung cp

cho m hnh Simulink. Cc s liu ly vo phi c dng ca biu thc Matlab, khai bo ti dngData.


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g. From FileBng khi From File ta c th ly s liu t mt MAT-File c sn. MAT-File c th l kt

qu ca mt ln m phng trc , c to nn v ct i nh khi To file trong s Simulink

2. Thvin SinksTh vin ny bao gm cc khi xut chun ca Simulink. Ngoi kh nng hin th n

gin bng s, cn c cc khi dao ng k biu din cc tn hiu ph thuc thi gian hay biu

din hai tn hiu trn h ta XY.a. Scope

Nh khi Scope ta c th hin th cc tn hiu ca qu trnh m phng. Khi nhn vont Properties, hp thoi Scope Properties (c im ca Scope) s m ra. Chngeneral ta c th t ch cho cc trc. Khi t Number of axes > 1, ca s Scope sc nhiu th con ging tng t nh lnh Subplot ca Matlab. Nu in mt s c

th vo time range, th s ch c biu din ti thi im do gi tr ca s xc nh.

Ca s ca Scope sau khi m:

b. XY Graph

Khi ny biu din hai tn hiu u vo trn h ta XY di dng ha Matlabu vo th nht (bn trn). ng vi trc X u th hai ng vi trc Y.


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c. To WorkspaceKhi To Workspace gi s liu u vo ca khi ti mi trng Matlab Workspace di

dng mng (Array), Stracture hay Stracture with time v ly chui k t khai ti variable name t tn cho tp s liu c ghi.

d. To FileKhi ny gip ta ct tp s liu (mng hay ma trn) u vo ca khi cng vi vct

thi gian di dng Mat- File. Array nh dng ging nh nh dng m khi From File cn, vvy s liu do To File ct c th c From File c trc tip m khng cn phi x l g.V d: hai tn hiu hnh Sin v tn hiu hnh rng ca c hin th c lp, ng thi trn h ta XY, c thit lp nhhnh bn.

3. Thvin MathTh vin ny c mt s khi c chc nng ghp ton hc cc tn hiu khc nhau, c

nhng khi n gin ch nhm cng hay nhn tn hiu cn c cc hm phc tp nh lng gicv logicSau y ta xt chc nng ca mt s khi quan trng trong th vin ny.

a. SumTn hiu ra ca khi Sum l tng ca cc tn hiu u vo (V d nh tn hiu u vo l cc

tn hiu hnh Sin th tn hiu u ra cng l cc tn hiu hnh Sin). Khi Sum cng c th tnh tngtng phn t( v d tn hiu vo gm hai tn hiu: Sin(x)

v [5 9 3] th tn hiu ra s c dng [Sin(x)+5 Sin(x)+9 Sin(x)+3])


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b. Product v Dot ProductKh i Product th c hi n php nhn tng phn t hay nhn ma trn cng nh php chiagia cc tn hiu vo (dng 1-D hay 2- D) ca khi v d: nu mt khi Product c thams Number of Inputs = */*, vi ba tn hiu vo l 5, sinx v[4 4 5 6] khi y tn hiu u ra c dng [20/Sinx 20/sinx 25/Sinx 30/Sinx].Khi Dot Product tnh tch v hng ca cc Vector u vo. Gi tr u ra ca khitng ng vi lnh Matlab y = Sum(conj(u1)*u2).

c. Math Function v Trigonometric FunctionC hai khi ny u c th x l tn hiu 2-D. Khi Math Function c mt lng lncc hm ton c chun b sn cho php ta la chn theo nhu cu s dng. Cnkhi Trigonometric Function c tt c cc hm lng gic quan trng.

d. Gain v Slider GainKhi Gain c tc dng khuych i tn hiu u vo (nh dng 1-D hay 2-D) bngbiu thc khai bo ti Gain. Biu thc ch c th l mt bin hay mt s bin.Bin phi tn ti trong mi trng Matlab Workspace th khi y Simulink mi tnh

ton

c vi bin.

Khi Slider Gain cho php thay i h s khuych i v hng trong qu trnh m phng.

4. Thvin Constinuousa.Integrator

Khi Integrator ly tch phn tn hiu u vo ca khi. Gi tr ban u c khai bohoc trc tip ti hp thoi Block Parameters hoc thng qua chn gi tr Internal ti Initialcondition Source sau in gi tr ban u vo dng vit ca Initial condition. u ra cakhi Integrator c th c mt tn hiu bn ngoi lp v mt gi tr ban u bin trng thi cakhi. Bin trng thi ca khi thc cht ng nht v gi tr vi bin u ra nhng vi Simulinktnh hai bin (bin ra v bin trng thi) ti nhng thi im t nhiu c khc nhau. Nu mhnh Simulink cha cc bin trng thi chnh lch nhau v kch c gi tr, khi y nn khai botham s Absolute Tolerance ring r thm cho tng khi Integrator ca m hnh, mc d khaibo Absolute Tolerance chung ti hp thoi Simulation Parameters. Vic khai bo thm s buc

Simulink bo m ng gi tr sai s yu cu i vi tng khi.


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b. DerivativeKhi ny cho php ta tnh o hm tn hiu u vo. Tn hiu tm c u ra c

dng u/t vi l bin thin ca i lng cn tnh k t bc tch phn lin trc . Gi trca ra ban u l 0

c. Transfer Fcn v Zero-PoleKhi Transfer Fcn cho php c th m hnh ha hm truyn t ca mt h tuyn tnh.

Tham s ca khi l cc h s ca a thc t s v mu s, khai bo theo th t s m ca sgim dn. Bc ca mu s phi ln hoc bng bc ca t s. V d: nu nhp cho t s [5 7 3 1]v mu s [6 8 3 2 1] khi s to ra hm truyn t:

W(s) =( )( ) 12386

1375234

23

+++++++

=ssss

sss

su

sy

Khi Zero Pole s to nn t cc tham s Zeros, Poles v Gain mt hm truyn t didng h s ha theo im khng, im cc.


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d. Transport Delay v Variable Transport DelayKhi Trasnport Delay lm tr tn hiu vo khong thi gian 0 khai bo ti Time Delay

trc khi xut ti u ra. Ch n khi thi gian m phng bt u vt qu thi gian tr (so vilc bt u m phng), khi Transport Delay mi xut gi tr khai ti Initial Input ti u ra.

Bng khi Variable Transport Delay c th iu khin tr tn hiu mt cch rt linh hot:tn hiu cha thi gian tr c a ti u vo th hai (u vo pha di) ca khi. Ti Maxmum Delay ta phi khai mt gi tr tr ti a, c tc dng gii hn (chn trn) gi tr ca tnhiu iu khin thi gian tr.

5. Thvin Tablesa. Lookup TableKhi ny to tn hiu ra t tn hiu vo trn c s thng tin ct trong mt bng tra (Vector

of input values x Vector of output values). Nu gi tr hin ti ca tn hiu vo trng vi mt gitr thuc Vector of input values, gi tr tng ng trong bng thuc Vevtor of output values sc a ti u ra. Nu gi tr ca tn hiu vo nm gia hai gi tr thuc Vector of outputvalues, Simulink thc hin ni suy hai gi tr tng ng ca Vector of output values. Nu gi trca tn hiu vo b hn / ln hn gi tr u tin / gi tr cui cng ca Vector of input values,


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Simulink s thc hin ngoi suy hai ga tr u tin / cui cng ca Vector of output values.Vector of input values c th l mt Vector hng hay mt Vector ct.

b. Lookup Table (2-D)1Khi ny cho php to nn mt bng tra hai chiu. Bng tham s Table ta khai bo mtma trn ct cc tn hiu u ra. Mun tm c gi tr a ti u ra ta cn bit Row tm hngv Column tm ct ca trong gi tr ma trn. Tn hiu t u vo pha trn c so viRow tn hiu t u vo pha di c so vi Column.

II. p dng Simulink vo thit k v phn tchTrong vic kho st nhng ng dng ta th xy s m phng cho h dao