Điều khiển nhiệt độ dùng mờ thích nghi

LVTN: ieu Khien Nhiet o Dung M Thch Nghi

GVHD: Ts Nguyen Thien Thanh 1 SVTH: Nguyen Phng Thao

CHNG 0: M AU

on ngi che tao ra dung cu e s dung cho muc ch cua ho

ong thi cung ngh en viec ieu khien chung theo y muon cua

mnh. Khai niem hoi tiep la khai niem het sc quan trong e ieu

khien dung cu. ng dung au tien het sc co y ngha la ieu khien toc o

ong c hi nc c James Watts phat minh 1769. Khi cac d an mi

vi nhieu au vao va nhieu au ra ngay cang tr nen phc tap hn th s

mo ta he thong ieu khien oi hoi mot so lng ln cac phng trnh kem

theo. Ly thuyet ieu khien co ien mot vao mot ra hoan toan khong co

gia tr vi he thong a vao a ra. T nam 1960, ly thuyet hien ai c

phat trien e thch ng vi mc o phc tap ngay cang tang cua cac d an

va nhng quy tac oi hoi tnh chnh xac, tai trong, gia thanh c dung

trong quan oi, khong gian va trong cong nghiep. S phat trien nay c

tang toc bi may tnh so v kha nang lap trnh giai quyet ong thi nhieu

phng trnh.

Ky thuat ieu khien da tren phng trnh toan hoc. Tuy nhien,

chung ta thng oi mat vi nhng d an hoa hoc, may moc va nhieu he

thong khac can c ieu khien, th viec mo ta ac tnh cua chung thong

qua cac phng trnh toan hoc la het sc kho khan v mc o phc tap qua

ln. Ngay ca nhng chuyen gia e hoan thanh viec ieu khien, ho phai

van dung, chat ep kien thc t nhng kinh nghiem lau dai e a ra nhng

phng phap, luat ieu khien thong qua ngon ng trc giac t nhien. Kien

thc ( b quyet ) c trnh bay vi ngon ng trc giac t nhien th c

giai thch mot cach de dang, de hieu bang nhan thc thong thng va do

o de nh. Trong nhieu trng hp, ngon ng trc giac t nhien co mot

ranh gii m ho ve ng ngha, no c e cap nh nhng so hang ngon

ng m va c at tnh hoa bi ham lien thuoc. Y tng thiet ke bo ieu

khien m ra i.

Vay dung m cho ta nhng li iem g?

C



Mot phng phap thiet ke khac n gian hn, nhanh gon hn

e anh gia tai sao phng phap m c ban lai co sc hap dan at an

tng trong ng dung ieu khien , chung ta hay xem v du ve thiet ke ien

hnh:

Hnh tren minh hoa yeu cau cua cac bc tuan t e phat trien bo ieu

khien dung phng phap thong thng va phng phap m.

Dung phng phap thong thng th bc au tien la phai hieu c tnh

chat vat ly cua he thong va yeu cau ieu khien cua no. Da tren s hieu

biet o, bc th hai se phat trien mot mo hnh gom chng trnh, cam

bien, phan t chap hanh. Bc th ba la ap dung ly thuyet ieu khien

tuyen tnh e lam ro nhng chc nang n gian cua bo ieu khien chang

han nh cac thong so cua bo ieu khien PID. Bc th t la xay dng luat

Tnh chat vat ly

Yeu cau ieu khien

Tnh chat vat ly

Yeu cau ieu khien

Xay dng

mo hnh tuyen tnh

Xay dng luat cho

bo ieu khien

Xac nh bo ieu khien

n gian

Mo phong thiet ke

a phu hp cha?

Thiet ke bo ieu khien

bang luat m

Mo phong thiet ke

a phu hp cha?

Ky thuat thiet ke thong thng Ky thuat thiet ke m c ban



cho bo ieu khien n gian. Va bc cuoi cung la mo phong thiet ke bao

gom ca nhng anh hng phi tuyen, nhieu va s thay oi cua cac thong

so. Neu viec thc hien khong thoa man ta can xac minh lai mo hnh cua

he thong, thiet ke lai bo ieu khien, viet lai luat ieu khien va th lai.

Vi logic m, bc au tien la hieu va at tnh hoa hanh vi cua he thong

bang nhng kien thc kinh nghiem tch luy. Bc th hai la trc tiep thiet

ke luat ieu khien trong moi quan he gia cac so hang vao/ra. Bc cuoi

cung la mo phong va tm sai sot cua khau thiet ke. Neu phan thc hien

khong thoa man chung ta ch can xac minh lai luat m va th lai.

Mac du hai phng phap thiet ke co nhieu iem tng ong, nhng

phng phap m c ban n gian chu ky thiet ke mot cach ang ke. Ket

qua nay co y ngha ve li nhuan chang han nh giam c thi gian phat

trien, thiet ke n gian va nhanh chong em ra th trng.

Logic m giam i viec thiet ke cac tien trnh phat trien cua

chu ky.

Vi phng phap thiet ke m, nhng bc dung trc ay b loai bo bt.

Hn the na trong qua trnh tm sai sot va chnh nh chu ky, ta co the thay

oi bang cac luat c xac minh n gian thay v thiet ke lai bo ieu

khien. Vi luat m ta co the thay c ng dung thay v chng trnh kho

khan. Ket qua cho thay dung logic m giam ang ke toan bo tien trnh

phat trien cua chu ky.

Logic m n gian hoa viec thiet ke phc tap.

Logic m cho phep ta mo ta he thong phc tap bang kien thc va kinh

nghiem thong qua luat m. No khong oi hoi bat ky mo hnh he thong nao

hay cac phng trnh toan hoc nam vai tro chu ao trong moi quan he

vao/ra. Luat m de hoc, de dung ngay khi ban khong phai la chuyen gia.

Mot cach ien hnh, no ch dung vai luat e mo ta he thong ma le ra phai

oi hoi nhieu dong vi phan mem thong thng.Ket qua la logic m het

sc co y ngha trong viec n gian hoa thiet ke phc tap.

Giai quyet ieu khien phi tuyen tot hn.

He thong trong cuoc song hang ngay cua chung ta eu la he phi tuyen.

Nhng phng phap thiet ke thong thng dung phng phap xap x e

nam bat phi tuyen. Cach chon la ien hnh la tuyen tnh, tuyen tnh tng

oan, tra bang. Ky thuat xap x tuyen tnh th hoan toan n gian,tuy

nhien no co khuynh hng gii han phan ieu khien va phan ln thc thi



cho nhng ng dung chac chan. Ky thuat tuyen tnh tng oan th lam viec

tot hn mac du keo dai phan thc thi v no oi hoi phai thiet ke nhieu

oan tuyen tnh cua bo ieu khien. Ky thuat tra bang co the cai tien hieu

suat ieu khien, nhng rat kho khan e tm sai sot va chnh nh. Hn the

na oi vi he thong phc tap ton tai he so nhan au vao th viec tra bang

la khong thc te hoac qua at e thc thi v no oi hoi mot bo nh qua

ln.

Logic m cho ra mot cach giai quyet khac oi vi ieu khien phi tuyen

bi v no gan gui hn vi the gii thc ben ngoai. Phi tuyen c nam bat

bi luat, ham lien thuoc va qua trnh suy dien cai ma rat co ket qua trong

cai tien thc thi, thc hien n gian va giam dc gia thanh thiet ke.

Logic m cai tien viec thc hien ieu khien.

Nhieu ap dung logic m mang lai ket qua tot hn trong ieu khien tuyen

tnh, tuyen tnh tng oan, hay ky thuat tra bang. V du nh mot van e

ien hnh gan vi ieu khien co ien la thi gian ap ng cua bo ieu

khien vi o vot lo. Cho v du ve he thong ieu khien nhiet o mot vao

n gian c minh hoa sau:

ng tuyen tnh au tien xap x ng cong mong muon cho ra ap ng

cham va khong co vot lo, no ch ra rang nhiet o phong th qua lanh cho

mot khoang thi gian. ng tuyen tnh th hai co ap ng nhanh hn

nhng co vot lo va sau o la dao ong, no ch ra rang nhiet o khong on

nh trong mot khoang thi gian.

Vi logic m, ta co the dung luat, ham lien thuoc e xap x bat c ham

nao cho en chnh xac bat ky nhiet o nao. Da vao hnh minh hoa, ta co

the xap x ng cong mong muon cho bo ieu khien nhiet o bang cach



dung 4 iem( 4 luat ). Chung ta co the them luat vao e tang o chnh xac

cua viec xap x. Nhng luat th n gian hn e thc thi va de dang tm sai

sot va chnh nh chung hn ky thuat tuyen tnh tng oan hay ky thuat tra

bang.

If temperature is cold then force is high.

If temperature is cool then force is medium.

If temperature is warm then force is low.

If temperature is hot then force is zero.

Nhng luat nay khong giong nh nhng bang tra bi v luat m lam gian

oan hnh dang cua ham phi tuyen. Viec ket hp bo nh yeu cau viec at

nhan va suy dien m th t hn ang ke so vi bang tra, at biet oi vi

nhng he thong a vao. Ket qua la toc o x ly co the c cai tien.

Tom lai ieu khien m co nhieu iem manh trong viec thiet ke he thong ieu khien cac oi tng phc tap, cac oi tng ma viec mo ta mo

hnh oi tng la cc ky kho khan, la cho phep thiet ke he thong n gian,

tiet kiem nhieu cong sc, thi gian, giam c gia thanh Ben canh nhng iem manh tren khi s dung logic m e thiet ke bo ieu

khien gap mot so han che trong viec toi u hoa he thong la do no oi hoi

phai co kinh nghiem va nghe thuat thiet ke he thong.

e khac phuc nhng nhc iem nay, ngi ta ket hp logic m vi

mang neuron. Mang neuron, mot he thong x ly thong tin ay ha



hen,chng minh kha nang hoc, truy cap thong tin trong bo lu tr va tong

quat hoa t viec huan luyen mo hnh hay d lieu. Mang neuron nhan tao

la lnh vc va khoa hoc va ky thuat, trong o khoa hoc c nh ngha

nh la kien thc co cau truc va ky thuat chnh la khoa hoc ng dung. V ky

thuat n le khong giai quyet toi u nhng bai toan ma bc hien tai luon

la ket qua cua cac bc trc o. Cong nghe mang neuron nhan tao hnh

thanh, no thay the cho cac giai phap tnh toan truyen thong va a ra mot

vai kha nang e tiep can nhieu van e hien tai khong giai quyet c.

Mang neuron c ng dung rong rai trong cac nganh ky thuat nh: ky

thuat ieu khien, ien t vien thong, he thong ien va cong nghe thong

tin. Trong ky thuat ieu khien mang neuron nhan tao c ng dung e

nhan dang, d bao va nhan dang cac he thong ong. Trong ien t vien

thong mang neuron nhan tao c ng dung e nhan dang d bao va ieu

khien ca c tram bien apS phat trien cua mang neuron, mot lnh vc cua tr tue nhan tao, cho ta nhng thanh qua ang ke trong viec thiet ke he

thong co kha nang hoc nhng hanh vi ma ta mong muon. Nhng mang

neuron lai co khuyet iem la kho giai thch ro rang cac hoat ong cua he.

S ket hp gia logic m va mang neuron la s ket hp hai u iem de

thiet ke va de toi u cho ta at c ket qua tot nhat ma ta mong

muon.Bo ieu khien m thch nghi ra i. Bo ieu khien ma trong qua

trnh lam viec co kha nang chnh nh thong so cua no cho phu hp vi s

thay oi cua oi tng c goi la bo ieu khien thch nghi. Bo ieu khien

m co kha nang chnh nh lai cac thong so cua bo ieu khien cho phu

hp vi oi tng cha biet ro a a he thch nghi tr thanh he ieu

khien thong minh. o chnh la bo ieu khien m thch nghi.



CHNG 1: TAP M

1.1 TAP M VA CAC PHEP TOAN TREN TAP M.

1.1.1 Tap m:

Trong khai niem tap hp kinh ien, viec xay dng cac phep anh xa

va cac mo hnh eu at tren c s logic hai gia tr Boolean. Tc la ham

phu thuoc F(x) nh ngha tren tap F ch co hai gia tr la 1 neu x thuoc F va la 0 neu x khong thuoc F. Kieu logic hai gia tr nay to ra rat hieu qua

va thanh cong trong viec giai quyet cac bai toan c nh ngha ro rang.

Tuy nhien trong thc te thng ton tai mot tap hp ma o phu thuoc

cua cac phan t trong tap hp co gia tr trong khoang [0,1]. T o khai

niem tap m ra i.

nh ngha: Tap m F xac nh tren tap kinh ien M la mot tap ma moi phan t cua no la mot cap cac gia tr (x, F(x) ) trong o x thuoc

M va F la anh xa: F : M [0,1]

Anh xa F c goi la ham lien thuoc cua tap m F.

Tap kinh ien M c goi la c s cua tap m F.

Ham lien thuoc cua cac tap m: Ham lien thuoc e tnh o phu thuoc cua mot phan t x nao o, co

hai cach: tnh trc tiep( neu F(x) cho trc di dang cong thc tng

minh ) hoac tra bang( neu F(x) cho di dang bang ).

Cac dang ham phu thuoc:

1. Dang tuyen tnh :

ay la dang tap m n gian nhat, thng c chon khi mo ta

cac khai niem cha biet hay cha hieu ro rang.



2. Dang ng cong S :

Mot tap m dang ng cong S co 3 thong so la cac gia tr , ,

co o phu thuoc tng ng la 0, 0.5 va1. Dang ng cong S thng

c dung e at trng cho ng cong phan bo chuan. A la iem

uon.

o phu thuoc tai iem x c tnh bi cong thc sau :

xkhi

xkhix

xkhix

xkhi

xS

1

)/()(21

)/()(2

0

),,;(2

2

Trong ky thuat ieu khien m thong thng cac ham lien thuoc

kieu S hay c thay gan ung bang mot ham tuyen tnh tng oan.

0.5

1

0

x

A

1

0

Tap m tuyen tnh tang Tap m tuyen tnh giam

1

0



3.Dang ng cong hnh chuong :

Dang ng cong hnh chuong ac trng cho cac so m (xap x

mot gia tr trung tam), bao gom 2 ng cong dang S tang va S giam.

o rong hay hep cua mien khao sat cung nh o doc cua dang

hnh chuong tuy theo tnh chat cua hien tng c mo ta, cung nh

quyet nh cua ngi thiet ke.

T hai tap m dang ng cong S ta suy ra o phu thuoc tai

iem x cua tap m dang ng cong hnh chuong nh sau :

xkhixS

xkhixSx

),2/,;(1

),2/,;(),;(

4. Dang hnh tam giac, hnh thang va hnh vai :

Cung vi s gia tang cua cac bo vi ieu khien 8 bit va 16 bit,

dang tap m chuan hnh chuong c thay bang cac dang tap m

hnh tam giac va hnh thang do yeu cau tiet kiem bo nh von han che

cua cac bo vi ieu khien.

0.5

x

1

0



Dang hnh thang :

Dang tam giac :

xkhi

xkhix

xkhix

xkhi

xT

0

)/()(

)/()(

0

),,;(

Dang hnh vai :

Thong thng vung gia cua bien mo hnh c ac trng bang

cac tap m co dang hnh tam giac v no lien quan ti cac khai niem

tang va giam. Tuy nhien vung bien cua bien khai niem khong b

thay oi. Luc nay can phai dung dang hnh vai e mo ta tnh chat cua

bien bien.

0

1

x

1

0

xA xB

x



V du: Xet bien Nhiet o gom cac tap m LANH, MAT, TRUNG

BNH, AM, NONG nh hnh ve:

Khi ta at en NONG th tat ca nhiet o cao hn se la luon NONG.

Khi nhiet o cha at en LANH th nhiet o thap hn se la LANH.

Do o ta co hai tap m NONG, LANH dang hnh vai.

Cac tnh chat va at iem c ban cua tap m: 1.o cao va dang chnh tac cua tap m

o cao cua tap m F ( nh ngha tren c s M ) la gia tr

H = sup F(x) la gia tr cc ai o phu thuoc cua cac phan t tap m xM

0

1

edge floor

1

0

edge floor

Hnh vai trai Hnh vai phai

Lanh Mat

Trung

bnh Am Nong

X1 X2 X3 X4 X5 X6

1



Mot tap m co t nhat mot phan t co o phu thuoc bang 1

c goi la tap m chnh tac, tc la H=1 va neu H < 1 la tap m

khong chnh tac.

Trong cac mo hnh bo ieu khien m, tat ca cac tap m c s

eu phai dang chnh tac nham khong lam suy giam ngo ra.

Tap m c a ve dang chnh tac bang cach ieu chnh lai tat

ca gia tr o phu thuoc mot cach t le quanh gia tr o phu thuoc cc

ai.

2.Mien xac nh cua tap m:

Mien xac nh cua tap m F ( nh ngha tren c U ), c ky

hieu bi S la tap con cua M thoa man:

S = { x M / F(x) > 0 }

3.Mien tin cay cua tap m:

Mien tin cay cua tap m F ( nh ngha tren c s U ), c ky

hieu bi T, la tap con cua M thoa man:

T = { x M / F(x) = 1 }

1

0,75

0 0

(a). Tap m A co o cao la 1 (b). Tap m B co o cao la 0,75



Minh hoa ve mien xac nh va mien tin cay cua mot tap m.

Cac phep toan tren tap m : Cac phep toan tren tap m c xay dng thong qua cac ham

lien thuoc tng t nh cac phep toan tren tap hp kinh ien :

Phep toan bang nhau: Cho A va B la hai tap hp m trong khong

gian M, A va B c goi la bang nhau neu va ch neu:

A(x) = B(x) cho tat ca x thuoc M

Phep hp hai tap m :Hp cua hai tap m A va B co cung c s M

la mot tap m cung xac nh tren c s M vi ham lien thuoc:

AUB(x) = MAX { A(x), B(x) }

Tong quat: Hp cua tap m A co ham lien thuoc A(x) ( nh

ngha tren c s M ) vi tap m B co ham lien thuoc B(y) ( nh ngha tren c s N) la mot tap m xac nh tren c s MxN vi ham

lien thuoc :

AUB(x,y) = MAX { A(x,y) , B(x,y) }

trong o :

A(x,y) = A(x) vi moi y N va

B(x,y) = B(y) vi moi x M.

0

1

Mien tin cay

Mien xac nh

x



Phep giao hai tap m :Giao cua hai tap m A va B co cung c s

M la mot tap m cung xac nh tren c s M vi ham lien thuoc :

AB(x) = MIN { A(x), B(x) }

Tong quat: Giao cua tap m A co ham lien thuoc A(x) ( nh

ngha tren co c s M ) vi tap m B co ham lien thuoc B(y) (nh ngha tren co c s N) la mot tap m xac nh tren c s MxN co

ham lien thuoc :

AB(x,y) = MIN { A(x,y), B(x.y) }

trong o :

A(x,y) = A(x) vi moi y N va

B(x,y) = B(y) vi moi x M

AB A B

AB A B



Phep bu cua mot tap m :Bu cua tap m A co c s M va ham lien

thuoc A(x) la mot tap m Ac

xac nh tren cung co c s M vi ham

lien thuoc :

( ) 1 ( )C AA x x

Tch catesian : Cho A1, A2, , An la cac tap m trong M1, M2, ,

Mn. Tch Catesian cua cac tap m A1, A2,, An la mot tap m trong khong gian tch M1.M2.M3Mn vi ham lien thuoc cua no c nh

ngha bi :

1 2 1 2... 1 2( ) { ( ), ( ),..., ( )}

n nA xA x xA A A A nx MIN x x x

cho tat ca x1, x2 ,,xn thuoc M.

Tch ai so : Tch ai so cua 2 tap m A va B vi cac ham lien

thuoc A(x) va B(x) la mot tap m ma ham lien thuoc cua noA.B(x) c cho bi :

A.B(x) = A(x).B(x)

1.2 QUAN HE M VA CAC PHEP TOAN TREN QUAN HE M:

1.2.1 Quan he m:

Khong gian tch: Cho xX va yY , khong gian cua tch X va Y c nh ngha la:

XxY= { (x,y)| xX va yY }.

A AC



Quan he ro: Cho R la tap con cua khong gian tch XxY, R c goi la quan he ro neu Rc nh ngha bang ham at tnh cua no sao cho:

1 ( , )

0 ( , )( , )khi x y R

R khi x y RX x y

Neu X co kch thc M va Y co kch thc N th quan he nay co the c

bieu dien di dang ma tran MxN.

Quan he m: Cho R la tap con cua khong gian tch XxY, Rc goi la quan he m gia hai khong gian X va Y, neu R c nh ngha bang ham

lien thuoc cua no sao cho R(x,y) co the lay bat ky gia tr nao trong khoang [0,1].

Neu X co kch thc M, Y co kch thc N th quan he nay co the

c bieu dien di dang ma tran MxN.

1.Thuat toan xay dng quan he m R:

Cho menh e hp thanh mot ieu kien R: AB

Neu =A th =B,

trong o so chieu cua R phu thuoc vao so iem lay mau cua A(x)

va B(y) khi ri rac cac ham lien thuoc tap m A va B.

Chang han vi n iem x1, x2 , ,xn cua ham A(x) va m iem mau

y1, y2,, ym cua ham B(y) th luat hp thanh R la mot ma tran n hang, m cot nh sau:

1 1 1 11 1

1 1

( , ) ( , )

( , ) ( , )

R R m n

R n R n m n nm

x y x y r r

R

x y x y r r

Cho menh e hp thanh nhieu ieu kien R: 1 2 ... nA A A B

Neu 1 =A1 va 2 =A2 va n =An th =B bao gom n menh e

ieu kien. Lien ket VA trong menh e ieu kien chnh la phep giao



cac tap m A1, A2, ,An vi nhau. Va ket qua cua phep giao se la o thoa man H.

o thoa man H = MIN 1 21 2( ), ( ),..., ( )

nA A A nc c c vi cac

vector gia tr au vao:

1

n

c

x

c

trong o ci , i = 1n la mot trong cac iem

mau mien xac nh cua ( )iA ix .

Khong nh luat hp thanh co mot menh e ieu kien luat hp

thanh cua menh e vi n ieu kien khong the bieu dien di dang

ma tran c na ma thanh mot li trong khong gian n+1 chieu.

Xet mot menh e hp thanh hai ieu kien sau:

Neu = A va = B th = C

R: A B C

Ri rac hoa cac ham lien thuoc:

A(x) c ri rac hoa tai 5 iem , x{0,2; ..; 0.6}

B(x) c ri rac hoa tai 5 iem , x{0,3; ..; 0.7}

A(x) c ri rac hoa tai 5 iem , x{0,2; ..; 1.0}

1

0.5

A(x)

0.2 0.4 0.6 0.3 0.5 0.7 0.2 0.4 0.6 0.8 1

B(y) C(z)

x y

z



Lap R gom cac ham lien thuoc cho tng vector gia tr au vao:

V du nh cap iem (x=0.3, y=0.5)

o thoa man H se la : H = MIN{A(x= 0.3), B(y= 0.5)}

= MIN{0.5; 1.0} = 0.5

va R(0.3; 0.5) = {0; 0.5; 0.5; 0.5; 0}

Nh vay tren khong gian R3

th R se la mot li ba chieu, trong o tai

moi iem nut tren li la mot gia tr cua R(x,y).

Cho nhieu menh e hp thanh: Cho p menh e hp thanh gom:

R1 : 1 =A1 th =B1 hoac

R2 : =A2 th =B2 hoac

Rp : p =Ap th =Bp ,

trong oA1, A2,, Ap co cung c s X ; B1, B2,, Bp co cung c s Y.

Quan he R se la hoi cua tat ca cac luat hp thanh con:

1 2 ... pR R R R

1.2.2 Cac phep toan tren quan he m:

Neu P va Q la hai quan he m tren khong gian XxY va YxZ th

quanhe m tren khong gian XxZ o la s hp thanh cua hai quan he m P

va Q, c viet la : oR PQ , trong o ky hieu o la toan t hp thanh.

Co ba loai toan t hp thanh m thong dung nhat o la MAX_MIN,

MAX_PROD, MIN_MAX.

Neu toan t hp thanh la toan t MAX_MIN th ham lien thuoc

cua quan he m R c nh ngha bi:

( , ) ( , ) _ [ ( , ), ( , )]R PoQ P Qx z x z MAX MIN x y y z

Neu toan t hp thanh la toan t MIN_MAX th ham lien thuoc

cua quan he m R c nh ngha bi:



( , ) ( , ) _ [ ( , ), ( , )]R PoQ P Qx z x z MIN MAX x y y z

Neu toan t hp thanh la toan t MAX_PROD th ham lien

thuoc cua quan he m R c nh ngha bi:

( , ) ( , ) [ ( , ) ( , )]R PoQ P Qx z x z MAX x y y z

trong o: P(x,y) la ham lien thuoc cua P

Q(y,z) la ham lien thuoc cua Q.

1.2.3 Phng trnh quan he m:

Cho A la tap m trong khong gian X va R la quan he m trong khong

gian tch XxY.Tap m au ra B trong khong gian Y c bieu dien bang

quan he m o la:AoR=B, trong o ky hieu o la toan t hp thanh. Neu toan t hp thanh nay la MAX_MIN, th ham lien thuoc cua tap m B o

la: ( ) _ [ ( ), ( , )]B A Ry MAX MIN x x y

1.3 CAC PHNG PHAP HOA M VA GIAI M:

1.3.1 M hoa:

Hoa m la qua trnh lam m mot ai lng ro, ngha la dung nhng

ham phu thuoc cua cac bien ngon ng e tnh mc o phu thuoc cho tng

tap m oi vi mot gia tr cu the au vao. M hoa la bc au tien trong

qua trnh tnh toan cua he m. Ket qua cua no c dung lam au vao e

tnh cac luat m.

Bien ngon ng: La phan chu ao trong cac he thong dung logic m. Bien ngon ng c xac nh thong qua tap cac gia tr m cua no. Bien

ngon ng co hai mien gia tr khac nhau:

Mien cac gia tr ngon ng

Mien cac gia tr vat ly( mien cac gia tr ro ) .

V du : Trong ai lng nhiet o, gia tr c nhac en di dang ngon

ng :

-rat nong

-hi nong



-trung bnh

-hi lanh

-rat lanh

Moi gia tr ngon ng o cua bien nhiet o c xac nh bang mot

tap m nh ngha tren c s la tap cac so thc dng ch gia tr vat ly x

(n v o) cua bien nhiet o . Ham lien thuoc tng ng cua chung c

ky hieu bang :

Vi x V la mien cac gia tr vat ly ( mien gia tr ro), ta co c

mot vector gom cac o phu thuoc cua x nh sau :

-rat nong(x)

-hi nong(x)

-trung bnh (x) =

-hi lanh (x)

-rat lanh (x)

Anh xa nay c goi la qua trnh Fuzzy hoa cua gia tr ro x.

Tnh o phu thuoc: T cac gia tr ro au vao ta suy ra o phu thuoc cua tap m theo ham phu thuoc. Cac loai ham phu thuoc thong dung: dang

ch Z, dang ch S, dang tam giac, dang hnh thang.

rat nong(x)

hi nong(x)

trung binh(x)

hi lanh (x)

rat lanh (x)



Dang ch Z Dang tam giac Dang hnh thang Dang ch S

a.Tnh o phu thuoc theo ham dang ch Z:

Ham dang ch Z c ac trng bi hai iem x1, x2 .

- Neu ai lng can tnh o phu thuoc nho hn x1 th o phu thuoc la

mot.

- Neu ai lng can tnh o phu thuoc ln hn x1 nhng nho hn x2 th o phu thuoc theo ham doc xuong.

- Neu ai lng can tnh o phu thuoc ln hn x2 th o phu thuoc la

khong.

1

11 2

1 2

2

1

( ) 1

0

khix x

x xx khix x x

x x

khix x

b.Tnh o phu thuoc theo ham dang tam giac:

Ham dang Tam Giac c ac trng bi ba iem x1, x2, x3 .


khong.

- Neu ai lng can tnh o phu thuoc ln hn x1 nhng nho hn x2 th o phu thuoc theo ham doc len.

X1

X2





khong.

1

11 2

1 2

22 3

2 3

3

0

( )

1

0

khix x

x xkhix x x

x xx

x xkhix x x

x x

khix x

c.Tnh o phu thuoc theo ham dang hnh thang:

Ham dang Hnh Thang c ac trng bi bon iem x1, x2, x3, x4 .


khong.


- Neu ai lng can tnh o phu thuoc ln hn x2 nhng nho hn x3 th o phu thuoc la 1.



khong.

X1 X3

X2



1

11 2

1 2

2 3

33 4

3 4

4

0

( ) 1

1

0

khix x

x xkhix x x

x x

x khix x x

x xkhix x x

x x

khix x

d.Tnh o phu thuoc theo ham dang ch Z:

Ham dang ch Z c ac trng bi hai iem x1, x2 .

- Neu ai lng can tnh o phu thuoc nho hn x1 th o phu thuoc

lakhong.



mot.

1

11 2

1 2

2

0

( )

1

khix x

x xx khix x x

x x

khix x

1.3.2 Giai m:

Qua trnh x ly m tao mot mien m bien ra. Giai m la tm ra mot

gia tr vat ly (gia tr ro) ac trng cho thong tin cha trong mien m o.

X1

X3 X2

X4

X1

X2



1. Phng phap iem trong tam :

Phng phap nay c ap dung khi mien m bien ra la mot

mien lien thong. Gia tr ro cua bien ra la hoanh o cua iem trong

tam cua mien m bien ra.

Cong thc xac nh x' theo phng phap iem trong tam nh sau :

trong o : l la mien xac nh cua tap m A

l

dx*(x)

dx*(x)*x

x'

A

l

A

2. Phng phap cc ai :

Gia tr ro cua bien ra la iem co o phu thuoc ln nhat.

x x'

A

l



Trong trng hp cac iem co o phu thuoc ln nhat trai dai

tren mot oan thang nam ngang [x1;x2] gia tr ro cua bien ra la trung

iem cua oan [x1;x2] nh hnh ve :

3. Phng phap o cao :

Tap m dang Singleton la mot dang n gian hoa cho phep x

ly m va giai m c de dang hn, thng c dung trong cac he

thong dung vi ieu khien, a c tch hp trong tap lenh cua MCU

68HC12 cua hang Motorola.

Moi tap m ket qua cua cac menh e ieu kien c thay bang

mot oan thang (x,(x)) vi (x) la o cao cua tap m tng ng.

A

x' x

x1 x

A

x2 x'



Th du : xet bien NHIET O gom cac tap m

LANH,MAT,AM,NONG.

Phng phap o cao chnh la ap dung giai m theo phng

phap iem trong tam oi vi cac tap m bien ra dang Singleton.

Do cac tap m cua mien m bien ra khong chong lap len nhau

nen khi giai m cong viec tnh tch phan rat mat thi gian a c

thay bang viec tnh tong so hoc nh sau :

n

1i

i

n

i

ii

H

H*x

x'1

trong o: xi la v tr cac singleton

Hi la o cao cua cac singleton tng ng

n la so tap m bien ra

1

0

x1 x2 x3 x4 x5 x6

MAT AM NONG LANH



CHNG 2: LOGIC M

2.1 LOGIC RO VA LOGIC M

2.1.1 Logic ro: : [0,1]T u U la logic hai ch so 0 va 1.

c bieu dien thong qua hai gia tr 0, 1 tc la ung hay sai. ieu o

co ngha la vi mot s viec ch co the co hai trang thai co hay khong ma

thoi.

Cho hai e xuat P va Q, cac gia tr chan ly cua e xuat nay c cho

nh sau:

Neu , ( ) 1;x A T P mat khac T(P)=0.

Neu , ( ) 1;x B T Q mat khac T(Q)=0.

Cac phep toan trong logic ro: Phep toan hp:

:P Q x A hoac x B

V the ( ) max{ ( ), ( )}T P Q T P T Q

Phep toan giao:

:P Q x A va x B

V the ( ) min{ ( ), ( )}T P Q T P T Q

Phep toan phu nh:

Neu T(P)=1 th T( ~P )=0;

Neu T(P)=0 th T( ~P )=1;

Phep toan keo theo:

(PQ): x A hoac x B

V the ( ) ( )T P Q T P Q



Phep toan tng ng:

1 ( ) ( )( ) : ( )

0 ( ) ( )

khiT P T QP Q T P Q

khiT P T Q

Tuy nhien, trong thc te ta thng bat gap mot s viec ma khong ch

mieu ta bang hai trang thai ung hay sai . Cac ngng cua cac trang thai

nhieu khi khong ro rang, chang han nh: gan ung, ung t, sai t, sai

nhieu Do o logic m ra i.

2.1.2 Logic m:

Logic m la s m rong cua logic ro hay con goi la logic nhieu ch

so, v gia tr chan ly cua mot e xuat trong khong gian co the lay gia tr

bat ky trong khoang [0,1] ma khong b gii han bi hai ch so 0 va 1. Gia

s e xuat P trong tap m A, th gia tr chan ly trong e xuat P c ky

hieu la T(P), co the c cho bi ( ) ( )AT P x , trong o 0 ( ) 1A x .

Neu nh ngha gia tr chan ly cua e xuat P trong tap m A o la:

TN(P)={0,..,i/(N-1),.1}

trong o N la so nguyen va 0 i N .

Trong logic ro N=2(hai ch so) va i=0, do o T2(P) = {0,1}

Trong logic m N=nhieu ch so cu the nh sau:

- N = 3, i= 1, th T3(P)= {0, , 1} ng vi {False, Maybe, True}

- N= 4, i= 1, 2 th T4(P)= {0, 1/3, 2/3, 1} ng vi {False,

Almost_False, Almost_True, True}

- N=5, i= 1, 2, 3 th T5(P)={0, 1/4, 2/4, , 1} ng vi {False,

Almost_False, Maybe, Almost_True, True}

Cac phep toan trong logic m: Phep toan phu nh:

( ) 1 ( )T notP T P

Phep toan hp:

P Q : x is A or B ( ) max{ ( ), ( )}T P Q T P T Q



Phep toan giao:

P Q : x is A and B ( ) min{ ( ), ( )}T P Q T P T Q

Phep toan suy dien:

PQ : x is A then x is B

( ) ( ) max{ ( ), ( )}T P Q T notP Q T notP T Q

2.2 C S TRI THC M:

C s tri thc m c bieu dien thong qua luat.

Luat hp thanh m.

Hau het cac he thong hoat ong da tren nen tang logic m eu dung

luat e bieu dien moi quan he gia cac bien ngon ng va e rut ra hanh

ong tng ng vi moi au vao.

Mot luat bao gom 2 phan :

- Phan ieu kien ( phan if ) : co the gom nhieu ieu kien ket hp vi

nhau bang cac lien t And, Or menh e ieu kien.

- Phan ket luan ( phan then ) : menh e ket luan.

Menh e hp thanh :

Cho 2 bien ngon ng , . Neu:

- nhan gia tr (m) A co ham lien thuoc A(x)

- nhan gia tr (m) A co ham lien thuoc B(y)

Th 2 bieu thc :

= A

= B c goi la 2 menh e p, q.

Menh e hp thanh p => q hoan toan tng ng vi luat ieu khien (

menh e hp thanh 1 ieu kien):

Neu = A th = B

Trong o : p : menh e ieu kien

q : menh e ket luan



Ham lien thuoc cua menh e hp thanh anh xa A(xo) B(y) c goi la ham lien thuoc cua luat hp thanh vi B la mot tap m cung c s vi B, bieu dien he so thoa man menh e q cua y.

Nguyen tac Mamdani : o phu thuoc cua ket luan khong c ln hn o phu thuoc cua ieu kien

Xac nh ham lien thuoc sau cho menh e hp thanh A B

1) A==>B(x,y) = MIN { A(x), B(y) } cong thc MAX MIN

2) A==>B(x,y) = A(x).B(y) cong thc MAX PROD

Tong quat : C s tri thc m uc thiet ke dui dang n luat m IF-

THEN nh sau:

If A11 . . . . . .A1i . . . . . . . A1n Then B11 . . . . . B1j . . . . . . B1m

If A21 . . . . . .A2i . . . . . . . A2n Then B21 . . . . . B2j . . . . . . B2m

. . . . . . . .

If Ak1 . . . . . .Aki . . . . . . . Akn Then Bk1 . . . . . Bkj . . . . . . Bkm

If AN1 . . . . . ANi . . . . . . . ANn Then BN1 . . . . . BNj . . . . . . BNm

Neu he co nhieu au vao va nhieu au ra th 2, 2m n ,

Neu he co nhieu au vao va mot au ra th 1, 2m n .

Neu luat co dang If x is A1 and A2 . . . . . and AL Then y is BS, ta co

the viet lai : If AS Then BS

Trong o, 1 2.......S LA A A A va ham lien thuoc cua no c cho bi:

1 2( ) min{ ( ), ( ),..... ( )}

S LA A A Ax x x x

Neu luat co dang If x is A1 or A2 . . . . . or AL Then y is BS, ta co the

viet lai : If AS Then BS

Trong o, 1 2.......S LA A A A va ham lien thuoc cua no c cho bi :

1 2( ) max{ ( ), ( ),..... ( )}

S LA A A Ax x x x



2.3 KY NGHE SUY DIEN M BANG TAY:

Neu luat co dang If x is A Then y is B, no tng ng vi quan he

m ( ) ( )R A B notA Y va ham lien thuoc cua quan he nay c

nh ngha bi: ( , ) {[ ( ) ( )],[1 ( )]}R A B Ax y max x y x

Do o, neu biet tap m A, ta co the xac nh tap m au ra B s dung

cong thc: ' ' ' [( ) ( )]B A R A A B notA Y

Neu luat co dang If x is A Then y is B Else y is C th no tng

ng vi quan he m ( ) ( )R A B notA C va ham lien thuoc cua

quan he nay c nh ngha bi:

( , ) ( ) ( ) , 1 ( ) ( )R A B A Cx y max x y x y Tng t, neu biet c tien ieu kien A, th ta co the tnh c tap m

B thong qua cong thc ' ' 'B A R A A B notA C

Trong o o la toan t hp thanh Max_Min hay Max_Prod.

2.3 S suy dien m nh ky thuat o th (Cach xac nh tap m

au ra B bang may):

Ly giai xap x m la phng phap tnh tap m au ra bang tay neu

biet tap m au vao va quan he m. Neu a phng phap nay vao may

se ton rat nhieu thi gian tnh toan cac ma tran va vector, va neu kch

thc cua cac ma tran va vector ln se ton rat nhieu bo nh. V le o, mot

phng phap xap x m khac c a ra cho may tnh toan e xac nh

tap m au ra o la phng phap suy dien m nh ky thuat o th c

trnh bay sau. Cho hai luat m o la:

Luat 1: If x1 is A11 and x2 is A12 Then y is B1

Luat 2: If x1 is A21 and x2 is A22 Then y is B2

Trng hp 1: Cac au vao x1, x2 la cac gia tr ro s dung phep toan hp thanh Max_Min.

Cng o ban cua luat 1 c cho bi:

11 12 11 121 1 2 1 2( ) ( ) min ( ), ( )A A A Ax x x x



Do o,tap m au ra B1 cua luat 1 c xac nh bang ham lien thuoc cua no o la:

1 1 1' 1 1( ) ( ) min , ( )B B By y y


21 22 21 222 1 2 1 2( ) ( ) min ( ), ( )A A A Ax x x x

Do o,tap m au ra B2 cua luat 2 c xac nh bang ham lien thuoc cua no o la:

2 2 2' 2 2( ) ( ) min , ( )B B By y y

Tap m au ra B cua he thong la s hp nhau cua cac tap m au ra B1

va B2 o la:

1 2' ' 'B B B

vi ham lien thuoc cua no:

x1 x2 y

A11 A12 B1

B1

x1 x2 y

A21 A22 B2

B2



1 2'( ) ' '

max ( ), ( )B y B By y

Ket qua tap m au ra B cua he thong dc mo ta hnh:

Trng hp 2: Cac au vao x1 va x2 la cac gia tr ro (crisp) va s dung phep toan suy dien Max_Prod.


11 12 11 121 1 2 1 2( ) ( ) min ( ), ( )A A A Ax x x x

Do o,tap m au ra B1 cua luat 1 c xac nh bang ham lien thuoc

cua no o la:

1 1' 1( ) ( )B By y


21 22 21 222 1 2 1 2( ) ( ) min ( ), ( )A A A Ax x x x

Do o,tap m au ra B2 cua luat 2 c xac nh bang ham lien thuoc

cua no o la:

y

B

x1 x2 y

A11 A12 B1

B1



2 2' 2( ) ( )B By y

Tap m au ra B cua he thong la s hp nhau cua cac tap m au ra B1 va B2 o la:

1 2' ' 'B B B

vi ham lien thuoc cua no:

1 2'( ) ' '

max ( ), ( )B y B By y

Ket qua tap m au ra B cua he thong c mo ta hnh:

x1 x2 y

A21 A22 B2

B2

y

B



CHNG 3: THIET KE PHAN CNG

HE THONG O NHIET O

Phan tren a gii thieu ve bo ieu khien m, sau ay la phan ket noi

gia bo ieu khien vi oi tng lo nhiet thong qua mach ong lc (mach

kch cong suat cho lo), cap nhiet ien (TC lay thong so nhiet o lo) va

mach gia cong chuyen oi so lieu can thiet e a ve bo ieu khien x ly.

Thiet ke he thong ieu khien nhiet o thong qua lo ien :

3.1 Mach ong lc:

Vi quan tnh lo nhiet kha ln ngi ta thng ong ngat nguon e

thay oi cong suat at vao lo thay v ieu khien ien ap. Do o t mach

ieu khien se xuat ra xung co o rong thay oi trong khoang thi gian T

nhat nh e thay oi cong suat cung cap cho lo .

Bo ieu

khien

Mach

ong lc

Cap nhiet

ien

Mach gia cong

chuyen oi

Lo ien

Nhiet

o at

Nhiet

do lo

Sai soE

Bo ieu

khien

T0

T



Nh vay trong thi gian T0 lo ong, T-T0 lo tat. ng vi s thay oi

cua T0 t 0 en T th cong suat cung cap Pcc = (T0/T).Pmax thay oi t 0

en Pmax.

Mach ong lc dung Opto_Triac ong ngat nguon ien li cung cap

cho lo :

Trong thi gian Ton C815 tch cc mc cao kch dan diod cua

Opto_Triac lam Diod phat quang kch dan Triac nen lo c cap nguon

trong suot khoang thi gian nay .

Hoat ong cua mach kch lo:

Transistor BJT thng lam viec 2 che o:

- Khuech ai.

- ong ngat.

che o khuech ai: Transistor hoat ong vung tch cc, tng

ng vi cac gia tr lam viec uCE > uCESAT va dong iC phu thuoc vao

tai va dong i B.

He so khuech ai tnh cua dong c nh ngha tai mot iem lam

viec IC, IB bi he thc hFE = IC / IB khi UCE = hang so.

Q3

Opto_Triac

R_LO

1 2

D2

LED

12

R9

1K

C815

13

2

+12V

OPTOTRIAC

MACH KICH LO

~220V



che o ong ngat: Transistor hoat ong vung bao hoa, la vung

nam gia ng thang gii han mat phang va gii han bao hoa.

Trong vung nay, ta xac nh gia tr hieu ien the nho nhat

uCE=uCESAT ng vi IC cho trc va uCB >0, uCB = 0 . Transistor se

ong, dong iC dan va ien the uCE at gia tr uCESAT nho khong ang

ke(khoang 1-2 V ), luc nay transistor trang thai bao hoa.

Nh vay e tao mach kch cho lo ta phai tao ra dong iB u ln e

uCE 0.

Luc o, tren ien cc B, E la ien ap ieu khien, cac ien cc C,

E c s dung lam cong tac ong m mach cong suat.

- ong: VCE > 0

IB > 0

- Ngat: IB =< 0

Khi transistor ong, dong IC se phu thuoc tai, ng vi nguon cung

cap la 12V, ap tren LED khoang 2V, UCE khoang 0.2V, ap qua Opto

4-5 V ap tren ien tr 1K t 3-5 V va dong khoang 3-6 mA u

kch dan cho Triac hoat ong ong lo.

3.2 Cam bien:

Nh chung ta a biet nhiet o la ai lng gia tang khong tuyen tnh

viec nhan hay chia nhiet o se khong co mot y ngha ro rang nao. Do o

e co the xac nh gia tr chnh xac cua nhiet o la van e khong n

gian. Tuy vay nhieu ai lng vat ly phu thuoc nhiet o nh : s gian n

cua chat kh, long, ran, s truyen nhiet, o nong cua cac chat tinh khiet, va

s thay oi mau sac theo nhiet o . . . . Da vao nhng ac iem tren ma

ngi ta che tao ra cac loai cam bien nhiet o vi kha nang chuyen oi

nhiet o thanh cac gia tr ap, dong,ien tr, . . . va cung tuy theo cau tao

cua chung ma ta co cac loai cam bien nhiet o khac nhau.

3.2.1 Cac loai cam bien hien tai

Tuy theo lnh vc o va ieu kien thc te ma co the chon mot

trong bon loai cam bien : thermocouple, RTD, thermistor, va IC ban

dan. Moi loai co u iem va khuyet iem rieng cua no.



1.Cap nhiet ien:

Dong nhiet sinh ra v tr tiep xuc do s chenh lech nhiet o.

u iem

n gian.

Re tien.

ap ng nhanh.

Tam thay oi rong hn nhieu so vi nhiet ke ien tr.

La thanh phan tch cc, t cung cap cong suat.

Khong can dong ien chay qua do vay khong co hieu ng ot

nong.

Khuyet iem

Phi tuyen.

Thi gian on nh lau.

ien ap cung cap thap.

oi hoi ien ap tham chieu.

Kem on nh nhat.

Kem nhay nhat.

ng dung:

ng dung rong rai trong o nhiet o cua cac chat ran, long,

kh.

o nhiet o be mat cua vat.

2.RTD (resistance temperature detector)

o nhiet o theo s thay oi ien tr

u iem

On nh nhat.

Chnh xac nhat.

Tuyen tnh hn thermocouple.

Khuyet iem

Mac tien.

Can phai cung cap nguon dong.

Lng thay oi R nho.



ien tr tuyet oi thap.

T gia tang nhiet.

3.Thermistor

u iem

Ngo ra co gia tr ln.

Nhanh.

o hai day.

Khuyet iem

Phi tuyen.

Gii han tam o nhiet.

De v.

Can phai cung cap nguon dong.

T gia tang nhiet.

4.IC cam bien

u iem

Tuyen tnh nhat.

Ngo ra co gia tr cao nhat.

Re tien.

Khuyet iem

Nhiet o o di 200C.

Can cung cap nguon cho cam bien.

Do cam bien nhiet s dung trong luan van la cam bien nhiet

chuyen oi thanh tn hieu ien nen ta ch khao sat hai loai cam bien o

la cap nhiet ien va nhiet ien tr.



3.2.2 Cap nhiet ien

Cap nhiet ien la cam bien nhiet n gian c cau tao bi hai day

dan kim loai a, b khac nhau c noi vi nhau bi hai moi han co nhiet

o T1 , T2 .

Khi gia nhiet mot au noi th se co dong ien chay trong mach o.

Neu mach b h mot au th hieu ien the mach h (hieu ien the

Seebeck) la mot ham cua nhiet o moi noi va thanh phan cau thanh nen

hai kim loai.

Khi nhiet o thay oi mot lng nho th hieu ien the Seebeck cung

thay oi tuyen tnh theo :

eAB = T vi la he so Seebeck

Neu nhiet o moi noi T1 bang khong va nhiet o moi noi T2 bang T

th suat ien ong tao ra bi cap nhiet ien c tnh nh sau:

2 31 1

2 2E AT BT CT

Trong o: A, B, C la cac hang so phu thuoc vat lieu che tao.

Khi dung cap nhiet ien th gia tr hieu ien the thu c b anh

hng bi hai loai nhiet o : nhiet o can o va nhiet o tham chieu. Cach

gan 0C cho nhiet o tham chieu thng ch lam trong th nghiem e rut ra

cac gia tr cua thermocouple va a vao bang tra. Tuy nhien khi a vao

Kim loai B

Kim loai A Kim loai A

Kim loai B

Kim loai A

eAB

+

-



s dung thc te th nhiet o tham chieu la nhiet o moi trng, mot ai

lng khong co nh, thay oi theo tng a iem va thi gian. Do o e

tang tnh chnh xac cua phep o ta phai bu nhiet cho au t do cua cap

nhiet ien.

Cac phng phap bo chnh nhiet:

- Nhung au t do vao nc a ang tan.

- Chon sau di at 1m en 2m la ni c xem nh co nhiet o on

nh.

- Dung mach bu nhiet.

- Dung day bu: dung mot oan day bu co vat lieu giong nh cap

nhiet ien, moi loai cap nhiet ien c trang b mot cap day dan

rieng biet. Nhiem vu cua day bu la ieu hoa cac ai lng dao

ong nhiet o tai iem o va gi cho au t do duy tr c nhiet

o quy nh.

Mat khac e am bao o on nh cua suat ien ong, phai an nh

nhiet o s dung cao nhat cho cap nhiet co tnh en cac ieu kien thc

te. Day cang nho th nhiet o cc ai cang thap.

Cac loai cap nhiet ien:

Tuy theo cau tao nen hai day dan ma ta co cac loai cap nhiet ien

sau:

- Loai J : ket hp gia sat vi constantan, trong o sat la cc dng

va constantan la cc am. He so Seebeck la 51V/C 20C.

- Loai T : ket hp gia ong vi constantan, trong o ong la cc

dng va constantan la cc am. He so Seebeck la 40V/C 20C.

- Loai K : ket hp gia chromel vi alumel, trong o chromel la cc

dng va alumel la cc am. He so Seebeck la 40V/C 20C.

- Loai E : ket hp gia chromel vi constantan, trong o chromel la

cc dng va constantan la cc am. He so Seebeck la 62V/C

20C.

- Loai S, R, B : dung hp kim gia platinum va rhodium, co 3 loai.

S): cc dng dung day 90% platinum va 10% rhodium, cc am la



day thuan platinum. R): cc dng dung day 87% platinum va 13%

rhodium, cc am dung day thuan platinum. B): cc dng dung day

70% platinum va 30% rhodium, cc am dung day 94% platinum va

6% rhodium. He so Seebeck la 7V/C 20C.

3.2.3 Nhiet ien tr:

Nh a noi tren, khi nhiet o thay oi tac ong len ien tr se

lam thay oi gia tr cua ien tr. Li dung tnh chat nay ngi ta xac

nh thong so nhiet o thong qua gia tr ien tr o c.

Trong trng hp tong quat, gia tr cua mot ien tr phu thuoc

nhiet o nh sau:

0 0( ) ( )R T R F T T

vi R0 la ien tr o c nhiet o T0 va F la ham at trng bi

vat lieu.

Vi vat lieu la kim loai ta co ham sau:

2 3

0( ) (1 )R T R AT BT CT

trong o T o bang 0

C va T0 la nhiet o o 00

C.

Vi vat lieu la hon hp cua cac oxt ban dan (nhiet ien tr ) ta co ham sau:

0

0

1 1( ) .expR T R B

T T

trong o T o bang K (nhiet o tuyet oi ).

Khi nhiet o bien thien T nho ma cam bien co the nhan biet

c ta noi o la o nhay nhiet R .

1.

( )R

dR

R T dT



o nhay cua nhiet ien tr rat cao, khoang 10 lan ln hn so vi

o nhay cua ien tr kim loai cho phep ng dung chung e phat hien

nhng bien thien rat nho cua nhiet o (t 10-4

en 10-3

K ). Mat khac

kch thc nhiet ien tr lai nho gon cho phep o nhiet o tng

iem,ong thi do nhiet dung nho nen toc o hoi ap ln.

3.3 Mach gia cong:

Mach gia cong can thc hien 3 chc nang sau: bu nhiet cho au t do,

khuech ai, va tao ien ap ra la 0V khi o 00

C. Xet mach sau:

U1, U2, U3 (dung OP07 cho offset thap) ong vai tro mot bo em

ien ap ly tng : co tr khang vao rat ln va tr khang ra rat nho,

khong e cac au vao anh hng lan nhau.

ien ap ra tren thermocouple :

V3 = S(Td Ta) = S.Td S.Ta

Vi : Td la nhiet o can o.

Ta la nhiet o moi trng.

S la o nhay cua thermocouple (40V/C).

Nh vay la gia tr ien ap ra tren cap nhiet ien ngoai nhiem vu

mang thong tin cua nhiet o can o con b anh hng bi nhiet o moi

trng.

e loai tr anh hng tren, ta can phai co mot khoi tao ra ien ap

theo nhiet o moi trng nhng co dau ngc lai dung IC cam bien

LM335A.

IC LM335A la loai cam bien nhiet o ban dan, co o nhay la

10mV/K. Ap tao ra do LM335A cam bien c la :

V2 = K.Ta [K] = K(273 + Ta) [C]

= K.273 + K.Ta = C + KTa (C = K.273)

vi K = 10mV/K; C = 2,73V

co the triet tieu anh hng cua Ta, nhng lai tao ra mot mc ien

ap la 2,73V 0C nen can phai co mot khoi e tr 2,73V nham tao ien

ap au ra la 0V 0C.

Bien tr R12 chnh la thanh phan bu tr ien ap 2,73V nh a noi

tren.



U4 (dung OP07) ong vai tro bo cong co khuech ai, ien ap ra cuoi

cung la :

2 3 3 24 44 1

1 2 3 1

2 34 41

1 2 3 1

1

2.731

out

d a a

R V RVR RV V

R R R R

R ST ST R KTR RV

R R R R

Khong b anh hng cua nhiet o moi trng :

2 3

2

3

0

10250

40

a aR ST R KT

R K mV

R S V

(1)

Triet tieu ien ap tnh (2,73V) :

3 341

1 2 3 2 3

311

4 2 3

2.73 2.73

2.73 1

R RRV

R R R R R

RRV

R R R

(2)

Sau khi a triet tieu nhiet o moi trng va ien ap tnh, khi o, ien ap ra

V4 la :

24

2 3

. 4(1 )

1

dout

R ST RV

R R R

Ta chon o tang cua 10

C la 10mV, th ng vi Td =1 , th V4out

se la 10mV. Hay o nhay cua mach se la 10mV/ 0

C.



2 44

2 3 1

2 4

2 3 1

2 4

3 1

. .11 10

1 250

250

out

R S RV mV K

R R R

K R R

S R R R

R R

R R

Neu ta chon:

3 1

2 4

100

250 100 25000 25

R R

R R K

(*)

th t (*) ta suy ra cach chnh V1 phng trnh (2) nh sau:

1

1 12.73 1 10.92

250 1 250V mV

Cac tu C14, C15, C16 chon gia tr 10F e chong nhieu.

Lu y :

1. Cac bien tr nen dung loai bien tr tinh chnh (hay bien tr o lng) co

cau tao gom nhieu vong day ien tr xoan ben trong (chnh nhieu vong

mi het gia tr), tranh dung bien tr thong thng rat kho chnh va khong

on nh (khi va cham nhe b thay oi gia tr).

2. Cac OPAMP dung loai OP07 hoac tng ng, co mc offset thap e

phu hp vi cac ai lng o co gia tr nho, cac chan 1 va 8 dung e chnh

offset khong dung trong thiet ke nay.

*Hoat ong cua OPAMP:

Op_amp ly tng co 3 at tnh can thiet c xem nh chuan e anh

gia hoat ong cua Op_Amp:

1.o li ap vong h A0L la xac nh am.

2.ien tr vao R

gia cong 1 va 2 la rat ln. Do o dong vao la zero.

3.ien tr ra R0 la zero. Thong thng hieu ien the ra phu thuoc vao tai.



Khuech ai OP_Amp chang qua la s la s khac biet 1 2dv v v gia

hai tn hieu vao. o li vong ap

0OL

L

vA

v

.

Cong 1 la cong vao ao vi hieu ien the v1.

Cong 2 la cong vao khong ao vi hieu ien the v2.

Mach khuech ai khong ao:

Tn hieu vao tai cong khong ao. Khi v2 dng, v0 dng va dong

dng. Hieu ien the v1=iR1 uc cung cap cho cong ao nh hoi tiep hieu

Rd

+

+

+

+

+

+VCC

-VCC

vd

v1

v0

v2

0V

S o cau tao cua Op_Amp

+VCC

-VCC

Rd

+

+ +

+

+ vd

v1

v0

v2

0V

R2

R1 i



ien the am. khuech ai khong ao nay dong vao cong khong ao la

zero, do o 1 20;dv v v .o li ien ap la: v0/v2 . Vi dong vao

Op_Amp la zero, nen dong qua R2, R1 phai giong nhau. Ta co:

0 1 2

2 1

0 0 2

2 1 1

1

v v v

R v

v v RAv

v v R

Chu y: Neu Op_Amp khong ly tng, ien tr vao Op_Amp c tnh

nh sau:

2 22

1 1

(1 )in d OLv R

Z R R Av R

ien tr nay rat ln co the len en 1210 .

Khuech ai vi he so bang 1:

Bo khuech ai mot tang n khong ao pha vi he so khuech ai

bang 1. Co ien tr vao rat ln va ien tr ra rat nho, ap vao va ap ra

c xem nh khong oi. Dung mach nay lam au vao cua mach phoi hp

tr khang se lam giam anh hng nhieu.

+VCC

-VCC

Rd

+

+ +

+

+ vd

v1

v0

v2

0V

i



CHNG 4: BO IEU KHIEN M

IEU KHIEN NHIET O C BAN

4.1 Bo ieu khien m c ban:

Cac thanh phan c ban cua bo ieu khien m bao gom khau m hoa,

thiet b thc hien luat hp thanh va khau giai m. Mot bo ieu khien m

ch gom ba thanh phan nh vay co ten goi la bo ieu khien m c ban.

- Khau m hoa co nhiem vu chuyen oi mot gia tr ro au vao x0

thanh mot vecto gom cac o phu thuoc cua gia tr ro o theo cac

tap m a nh ngha trc.

- Khau x ly m x ly vecto va cho ra tap m B' cua bien ra.

- Khau giai m co nhiem vu chuyen oi tap m B' thanh mot gia

tr ro y' ac trng cho thong tin cha trong tap m o.

Do he m c ban ch co kha nang x ly cac gia tr tn hieu hien thi

nen no thuoc nhom cac bo ieu khien tnh. Tuy vay vi viec ghep them

cac khau ong hoc can thiet nh vi phan, tch phan, ta se co c mot bo ieu khien m co kha nang x ly cac bai toan ong.

y'(t)

X LY

M

GIAI

M

M

HOA

x1

xn

B' y'

Bo ieu khien m c ban

HE M C BAN

Vi phan

x(t)



4.2 Nguyen ly ieu khien m:

Nguyen tac tong hp bo ieu khien m hoan toan da vao nhng

phng phap toan hoc tren c s nh ngha cac bien ngon ng vao/ra va

s la chon nhng luat ieu khien. Do cac bo ieu khien m co kha nang

x ly cac gia tr vao/ra bieu dien di dang dau phay ong vi o chnh

xac cao nen chung hoan toan ap ng c cac yeu cau cua mot bai toan

ieu khien ro rang va chnh xac.

Bo ieu khien m hoat ong chu yeu da vao kinh nghiem e thiet

ke cac luat ieu khien, trien khai cac menh e hp thanh xay dng mo

hnh luat hp thanh .

4.3 Cac bc xay dng mot he m c ban :

Xac nh cac bien vao va ra.

nh ngha cac tap m cho cac bien vao va ra.

Xay dng cac luat ieu khien (cac menh e m).

Chon luat hp thanh.

Chon phng phap giai m.

Toi u he thong.

1. nh ngha cac bien vao/ra:

Cac bien vao la cac bien ieu khien cac qua trnh ben trong cua

bo ieu khien m, cac bien ra dung e ieu khien oi tng .

Sau khi xac cac bien vao/ra ta can phai xac nh mien gia tr cho

tng bien cung nh n v cua tng bien.



2. nh ngha cac tap m cho cac bien :

Do cac tap m chnh la oi tng thao tac cua cac luat ieu

khien nen ta phai nh ngha cac tap m trc khi xay dng cac luat

ieu khien. Mat khac do dang tap m phan anh moi lien he gia gia

tr cac d kien va y ngha cua chung -> khau quan trong trong viec

tong hp bo ieu khien m.

e xac nh tap m can:

Mien gia tr vat ly cho cac bien ngon ng vao/ra.

So lng tap m(gia tr ngon ng).

Xac nh ham lien thuoc:

Cach thc hien la bat au bang cac dang ham lien thuoc a biet

trc va mo hnh hoa no cho en khi nhan c bo ieu khien m

lam viec nh mong muon.

Trong nhieu trng hp dang ham lien thuoc hnh tam giac cho

ket qua khong kem g dang ham lien thuoc phc tap hn la dang hnh

chuong, do bo ieu khien m t khi nhay vi s thay oi hnh dang

tap m. ieu nay lam cho he m kha ben vng va de thch nghi, o

la mot thuoc tnh quan trong khi mo hnh lan au c khao sat.

3. Xay dng cac luat ieu khien :

ay la bc tong hp cac hieu biet cung nh chien lc ieu

khien oi tng di dang mot tap cac luat ieu khien.Va cung la

bc kho khan nhat do hoat ong cua bo ieu khien hoan toan da

tren cac luat ieu khien. Cac luat ieu khien c thiet lap da tren

cac menh e hp thanh.

4. Chon thiet b hp thanh :

Thiet b thc hien luat hp thanh trong bo ieu khien m la thiet

b hp thanh. Co the chon thiet b hp thanh theo nguyen tac

Max_Min, Max_Prod e trien khai phep hoac khi thiet lap luat hp

thanh chung:

R=R1or R2 or Rn

5. Chon nguyen ly giai m:



Giai m hay ro hoa, tuy theo cach chon la phng phap giai

m ma o phc tap va trang thai lam viec cua ca he thong cung b

anh hng .

4.4 Thiet ke:

Thiet ke bo ieu khien m co mo hnh nh sau:

Nguyen tac tong hp mot bo ieu khien m hoan toan da vao nhng

phng phap toan hoc tren c s nh ngha cac bien ngon ng vao/ra va

s la chon nhng luat ieu khien. Do o e thiet ke bo ieu khien m

trc tien ta se nh ngha cac bien ngon ng vao/ra.

Cac bien ngon ng vao/ra va tap m:

ai lng vao cua bo ieu khien m chnh la sai lech nhiet o va

toc o tang giam nhiet.

1. Sai lech nhiet o:

c nh ngha nh la o sai khac gia nhiet o at va nhiet

o hien tai o c, ky hieu la ET.

ET = nhiet o at nhiet o o [C]

ET

DET

Thiet b hp thanh M hoa Giai m

y

Cau truc bo m ieu khien nhiet o



Mong muon cua chung ta la ieu khien en 128C nen mien

xac nh cua bien se la khoang [-128C,+128C].

Trong mien xac nh o, ta nh ngha 7 tap m :

ET = {am nhieu, am va, am t, bang khong, dng t, dng va,

dng nhieu}

hay ET = {NB, NM, NS, ZE, PS, PM, PB}

Tuy nhien, e tap trung hn trong khoang sai lech nho, ta

khong phan bo eu 7 tap m nay tren khoang [-128C,+128C]

ma ch phan bo eu trong khoang [-12C, +12C].

2. Toc o tang giam nhiet o:

La gia tr tang hay giam cua nhiet o hien tai so vi nhiet o

trc o trong khoang thi gian lay mau, ky hieu la DET.

DET=(nhiet o hien tai nhiet o trc)/thi gian lay mau[C/s]

oi tng ieu khien la mot lo nng dan dung co o quan

tnh tng oi ln, trong khoang thi gian lay mau la 3 giay ch

tang hay giam toi a 1,3C nen ta nh ngha DET vi mien xac

nh la [-2,+2].

Cung nh ngha cho bien DET co 7 tap m vi ten goi nh

tren, nh ngha trong khoang [-2;+2].

0 3 6 9 128 -3 -6 -9 -128 [C]

ZE PS PM PB NS NM NB

12 -12

Cac tap m cua bien ET



ai lng ra cua bo ieu khien m chnh la phan tram cong suat

kch cho lo nhiet ( %P ).

- Bien OUT vi 7 tap m dang singleton.

%P = {V1, V2, V3, V4, V5, V6, V7}

- Bien OUT vi 7 tap m dang tam giac.

%P = {V1, V2, V3, V4, V5, V6, V7}

0 0,5 1.0 1.5 2 -0.5 -1 -1.5 -2 [C]/T[s]

ZE PS PM PB NS NM NB

Cac tap m cua bien DET

60 80 40 20 10 0 %P

V1 V2 V3 V4 V5 V6 V7

100

Cac tap m bien ra P



Thiet ke he luat:

Gom 7x7 = 49 luat s khi ban au da tren nhng nhan nh ve

oi tng.

DET

NB NM NS ZE PS PM PB

ET

NB V1 V1 V1 V1 V1 V1 V1

NM V1 V1 V1 V1 V1 V1 V1

NS V1 V1 V1 V1 V1 V1 V1

ZE V1 V1 V1 V1 V1 V1 V1

PS V2 V2 V2 V3 V3 V4 V4

PM V3 V4 V4 V5 V5 V6 V7

PB V6 V6 V7 V7 V7 V7 V7

60 80 100 40 20 10 0 %P

V5 V6 V7 V1 V4 V3 V2

Cac tap m cua bien ra P



4.5 Giai thuat ieu khien:

Sai

Sai

Sai

ung

Nhap Tat

Bat au

ETcu:=Tat 280C

To:=nhiet o hien

tai

ETmi:=Tat - To

DET:=ETmi - ETcu

ETmi = 12

?

X ly m

%P:=0

%P:=100

0 < %P < 100

Ton:=%P*T

Toff:=T Ton

Etcu:=ETmi

Dng?

Ket thuc

ung

ung



Tnh o phu thuoc Bj(DET)

Luat hp thanh

MaxMin : R = min[Ai(ET); Bj(DET)]

MaxProd : R = Ai(ET)* Bj(DET)

Tm luat ieu khien

Cap nhat mien m bien ra

Het luat ?

ung

Sai

Tnh o phu thuoc Ai(ET)

X ly m

Giai m

Luat ieu khien

ke tiep



CHNG 5:

5.1 Qua Trnh Phat Trien:

Mang neuron c xem nh mot mo hnh toan hoc n gian cua bo

nao con ngi, co chc nang x ly song song. Trai vi may tnh hoat ong

da tren chng trnh do con ngi viet san, mang neuron hoat ong da

tren nhng g con ngi day no trc o.

Mang neuron co the hoc cac ket hp mi, cac chc nang mi hay

nhan biet cac mau mi. Mac du may tnh co the thc hien nhng viec hien

tai vi o chnh xac va toc o cao, nhng mang neuron ha hen mot the

mi trong lnh vc x ly thong tin.

5.2 Mang Neuron La G ?

Mang Neuron, mot he thong x ly thong tin ay ha hen, chng minh

kha nang hoc, truy cap thong tin trong bo lu tr va tong quat hoa t viec

huan luyen mo hnh hay d lieu.

La mang c xay dng bang cach sao chep lai cac nguyen ly to

chc cua he neuron con ngi. Bo oc con ngi la mot he neuron gom co

1010

en 1012

neuron c to chc co cau truc vao khoang 200 mo hnh

khac nhau di dang nhieu lp.

Bo oc con ngi, mot bo may phc tap va het sc tinh vi vi kha

nang x ly mot cach nhp nhang, ong bo co s lien ket chat che vi cac

phan t x ly ma khong mot he thong nao b kp. Mo hnh mang neuron a

c thuc ay bang s nhan nh la tr oc con ngi tnh toan theo cach

khac han so vi may tnh. T o con ngi a ra mang neuron nham hieu

nhng li giai cua tr oc ve cac lnh vc nh nhan dang hnh anh, tieng noi

va ap dung nhng lnh vc o vao may tnh. Sau nhieu nghien cu, ngi

ta a ra nhan xet sau :



ieu quan trong chnh la cach x ly song song ch khong phai toc o

tnh toan cua bo nao.

Mac du cha hieu cach mo ta cac y tng cua bo nao nen cha the bat

chc hoan toan, nhng ta co the thay rang bo nao s dung nhng phan

t tnh toan co toc o cham nhng c lien ket vi nhau.

Hoat ong cua he than kinh c chia thanh 3 giai oan :

Con ngi nhan c kch thch t ben ngoai thong qua cac giac quan.

S kch thch nay c chuyen oi thanh xung ien va c chuyen

en nao.

Bo nao lien tuc thu nhan thong tin, x ly, anh gia va so sanh chung

vi nhng thong tin ang lu tr e a ra cac quyet nh thch hp.

Nhng menh lenh a ra sau khi bo nao x ly c truyen en cac bo

phan chap hanh nh tay chan cho hanh ong hay li cho tieng noi di dang xung ien. Bo phan thi hanh bien oi xung ien a en

thanh hanh ong.

Mac du cac neuron co hnh dang va kch thc khac nhau nhng ve can

ban, co the chia thanh 3 phan :

Synapse kch thch

Synapse han che

Dendrite

soma



au vao dendrities: co nhiem vu nhan tat ca thong tin t ben

ngoai.

Than neuron: la phan t x ly co chc nang thu thap tat ca thong

tin en t cac au vao dentries, tnh toan va a ra quyet nh ngo

ra axon.

au ra axon: Axon la mot thiet b phi tuyen tao ra xung ien ap

c goi la the nang kch hoat, ton tai trong khoang 10-3

giay co tac

dung gi tn hieu i.

Moi neuron co mot mc kch hoat, nam trong tam gia gia tr ln

nhat va gia tr nho nhat. Viec gia tang hay giam mc kch hoat cua neuron

nay oi vi neuron khac c thc hien thong qua cac synapse bam tren

dendrite. Gia tr cua cng o synapse c goi la he so trong lng. Neu

la synapse kch thch, mc kch hoat t neron gi lam gia tang mc kch

hoat cua neuron nhan. Con neu la synapse han che th mc kch hoat t

neuron gi se lam giam mc kch hoat cua neuron nhan. Mc kch hoat tai

neuron nhan at en mot gia tr ngng nao o se kch thch au ra,

truyen tren axon en cac neuron khac, cuoi axon co khoang 10000

synapse. Cac synapse khong ch khac nhau tac dung kch thch hay han

che ma con khac nhau mc kch hoat.

Trong thi gian he tiep xuc mot vai oi tng, mot so phan t cam

bien b tac ong, cng o ket noi cua mot so neuron thch hp trong he

se c gia tang nham cung cap toan bo thong tin ve oi tng ma he

ang tiep xuc va sau o a ra mot so quyet nh lp neuron au ra e

ieu khien mot vai phan t c. Qua trnh tiep xuc oi tng, a ra quyet

nh va ieu khien phan t c c goi la qua trnh hoc va cng o ket

noi cua mot so neuron thch hp c gia tang trong thi gian he tiep xuc

oi tng c goi la luat hoc. Trong mot vai trng hp, he co chuan

oan sai, he co the ieu chnh e co mot chuan oan ung bang cach he

co the cap nhat he so trong lng ket noi gia cac neuron thch hp sao

cho he co mot chuan oan ung.

Cong viec c ban cua mot neuron nhan tao la cong cac mc kch hoat

au vao roi tao mot mc tac ong au ra neu tong cac mc kch hoat

au vao ln hn mot gia tr ngng nao o.



Co kha nhieu mo hnh toan hoc cho neuron. ay trnh bay mo hnh

thong dung nhat, dung mot ham truyen ket noi cac au vao e tao au ra:

- Phng tien ket noi la tong co trong so, trong o trong so ai dien

cho o manh yeu cua synapse.

- Synapse kch thch co trong so dng va synapse han che co trong

so am.

- Gia tr ngng c them vao e bieu dien mc o kch hoat cua

neuron.

- Dong tn hieu t au vao xi c xem nh dong mot chieu c

bieu dien bi mui ten. Tn hieu ra c cho theo quan he :

n

i

ii

T xwfxwfxwfy1

,

vi w = (w1, w2, , wn)T

Rn la vector trong so. Ham f(wTx) c

goi la ham kch hoat hay ham truyen.

Trong bieu thc co e cap en gia tr ngng nh la mot gia tr

anh gia s ket hp cua cac mc kch hoat au vao. Hoan toan co the

chuyen gia tr ngng vao tch vo hng wx bang cach xem no nh mot

au vao co trong so bang 1.

au vao

au ra

Ham truyen

n

i

ii xwf0

Ham tac ong

f

Y



w1x1 + . . . + wnxn > w1x1 + . . . + wnxn + (-1). > 0

o la ly do tai sao thng ngi ta cho gia tr ngng bang 0 trong bieu

thc.

5.3 Cac Thanh Phan C Ban Cua Mang Neuron Nhan Tao Gom:

Phan t x ly, mo hnh ket noi va viec huan luyen mang.

5.3.1 Phan t x ly:

Mot mang neuron nhan tao c ket noi bang nhieu than neuron, moi

ket noi cua chung la mot thanh phan t x ly. Moi phan t x ly nay co

nhieu au vao va mot au ra. e ket hp vi cac au vao cua moi phan t

x ly th i o la mot ham tong hp fi co chc nang tong hp tat ca thong

tin ben ngoai hoac t nhieu phan t x ly khac gi en va e ket hp vi

au ra cua moi phan t x ly th i o la mot ham tac ong hay con goi la

ham truyen a(fi ).

Ham tong hp: Ket hp tat ca thong tin t au vao cua phan t x ly

th i, vi xj la au vao t moi trng hoac au ra cua phan t x ly th

j, wij la he so trong lng ket noi gia xj va phan t x ly th i, i la

gia tr ngng cua phan t x ly th i. Ham tong hp c nh ngha

mot trong cac dang sau:

+Ham tong hp tuyen tnh :

1

m

i ij j i

j

f w x

+Ham tong hp phi tuyen bac 2:

y

w1 wn

x1 xn

0

y

w1 wn

x1 xn

-1

. . . . . .



2

1

m

ji ij i

j

f w x

+Ham hnh cau:

2 2

1

( )m

i j ij i

j

f x w

vi p va wij la ban kn va tam cua hnh cau.

Ham tac ong: ket hp au ra cua phan t x ly th i, con goi la ham

truyen at .

+Ham bac thang n v:

1, 0( )

0, 0

fa f

f

+Ham ngng hay con goi la ham doc:

1, 0( ) sgn( )

1, 0

fa f f

f

+Ham Ramp:

1, 1

( ) ,0 1

0, 0

f

a f f f

f

+Ham Unipolar sigmoid:

1( )

1 fa f

e

+Ham Bipolar sigmoid:

2( ) 1

1 fa f

e

vi >0 c s dung e xac nh bc lien tuc cua ham tac



ong khi ma ham tong hp fi tien gan en zero.

5.3.2 Mo hnh ket noi cua mang neuron nhan tao:

Mo hnh ket noi cua mang neuron nhan tao c chia lam 2 loai:

Mang nuoi tien (FeedForward network): au ra cua lp neuron trc

chnh la au vao cua lp neuron sau.

Mang nuoi lui (FeedBack neywork): au ra c nh hng lui ve

lam au vao cho cac neuron cung lp hoac lp trc o.

Mo hnh mang neuron nuoi tien mot lp gom: m au vao, n au

ra, va khong co lp neuron an.

Mo hnh mang nuoi tien nhieu lp gom: m au vao, n au ra, va

cac lp neuron an.

x1

xm yn

y2

y1

x2

x1

x2

xm

y1

y2

yn



Mo hnh mang neuron nuoi lui mot lp gom: lp neuron au

vao, lp neuron au ra, khong co lp neuron an.

Lp neuron au vao ban au c nhan t moi trng, sau o

th c nhan t s hoi tiep cua lp neuron au ra.

Mo hnh mang nuoi lui nhieu lp gom: lp neuron au vao, t

nhat 1 lp neuron an, lp neuron au ra.

x1

x2

xm

y1

y2

yn

x1

x2

xm

y1

y2

yn



Ban au mang nhan cac au vao t moi trng va thong qua

viec huan luyen mang lp neuron au ra chnh la lp neuron

au vao mang.

5.3.3 Luat Hoc Thong So Tong Quat Cho Cac Mang Neuron

Nhan Tao:

Viec huan luyen mang e co c au ra mong muon da tren hai

cach hoc sau:

Hoc thong so: la phng phap hoc bang cach cap nhat cac he so trong

lng ket noi.

Hoc cau truc: la phng phap hoc bang cach thay oi ben trong cau

truc mang gom cac phan t x ly, va mo hnh ket noi.

Phng phap hoc thong so: Co 3 che o hoc:

Hoc giam sat: Chu yeu tm c ma tran he so trong lng e

au ra cua mang xap x au ra mong muon vi mot sai so chap

nhan c. Noi cach khac mang c cung cap au vao, ra mong

muon. Mang huan luyen khi nhan thong so au vao, cho ket qua

au ra cua mang c so sanh vi au ra mong muon----->phat

sinh sai so. Sai so nay c dung e ieu chnh lai he so trong

lng cua mang.

X( au vao) Y (au ra thc s )

d (au ra

Tn hieu mong muon

sai so c )

Hoc cung co: La hoc giam sat thieu thong tin chi tiet san co ve

au ra cho moi au vao. cach hoc nay thong tin hoi tiep ch cho

biet au ra trang thai tot hay xau t o a ra cach ieu chnh

Mang

neuron

W

Khau phat sinh

tn hieu sai so



he so trong lng cho thch hp vi mong muon au ra lan ke

tiep se tot hn.


Tn hieu Tn hieu

nhan nh cu cung co

Hoc khong giam sat: Khong co bat ky mot thong tin nao t moi

trng giup cho viec nhan nh au ra cua mang la ung hay sai.

Do o mang se t ieu chnh bang cach hoi tiep t au ra thc s

cua mang.


Qua tham khao ba che o hoc c ban tren, ta xem xet mot cau truc

huan luyen tong quat cho phan t x ly th i trong mot mang neuron nhan

tao c mo ta hnh sau:

Mang

neuron

W

Mang

neuron

W

Khau phat sinh

tn hieu nhan nh

Learning

Signal

Generator

x2

xj

xm-1 xm-1

xm=-1

wi1

wi2

wij

wim-1

wim=

wi

X

i th neuron

di

yi

r



Vi xj , j = 1,2,...m la cac au vao, la gia tr ngng c a vao

trong viec hoc bang cach xem no nh la he so trong lng cua au

vao xm = -1.

Neu wi (t) la vector he so trong lng, X(t) la vector cac mau au

vao, va r la tn hieu hoc tai bc hoc th t, va la mot so dng c goi

la hang so hoc c dung e xac nh toc o hoc th luat hoc he so trong

lng tong quat trong cac mang neuron nhan tao c nh ngha nh

sau:

wi(t) = r X(t)

Vi wi(t) = wi(t+1) wi(t): s gia tang cua vector he so trong lng Do vay ta co the cap nhat he so trong lng cho bc ke tiep nh sau:

wi(t+1) = wi (t) + r X(t)

oi vi 3 che o hoc ta co cac cach xac nh tn hieu hoc r khac nhau.

Hoc giam sat: do a biet c au ra mong muon, ta co the tnh sai so

gia au ra mong muon va au ra thc s cua mang. Tn hieu sai so

nay dung e xac nh tn hieu hoc cua mang

r = fr (wi ,X,di ) = Tn hieu sai lech = di yi

==>wij = (di yi )xj vi i=1,2,...n; j=1,2,...m

Hoc cung co: do co tn hieu cung co di , nen tn hieu hoc cua mang:

r = fr (wi ,X,di ) = Tn hieu cung co = di

==>wij = di xj vi i=1,2,...n; j=1,2,...m

Hoc khong giam sat: do khong co tn hieu au ra mong muon, nen

au ra thc s cua mang c dung e xac nh tn hieu hoc:

r = fr (wi ,X ) = Tn hieu ra thc s cua mang = yi

==>wij = yi xj vi i=1,2,...n; j=1,2,...m (luat hoc Hebbian)



Neu hoc trong thi gian lien tuc, th s dung phng trnh sau e

cai tien vector he so trong lng tai thi iem ( t+1 ):

( )( )i

dw trX t

dt

5.4 Mot So Luat Hoc Va Giai Thuat Hoc BP:

5.4.1 Luat hoc perceptron:

Luat hoc perceptron, chu yeu da tren mo hnh perceptron ch gom

mot neuron duy nhat, dung ham ngng tuyen tnh lam ham truyen nen

c dung cho viec nhan dang va phan oi tng thanh hai loai ma thoi

c xem nh tieu bieu cho nguyen ly sa sai theo giai thuat lan truyen

ngc sai lech.

Mo ta giai thuat:

Luat hoc chu yeu c s dung trong giai thuat nay chnh la cach

hoc giam sat. Vi cach hoc nay mang neuron nhan tao c cung cap

vi mot day au vao, au ra mong muon: (x(k)

, d(k)

).

Tap au vao: ( ) ( ) ( ) ( )

1 2, ,...,T

k k k k

mx x x x ,m so au vao.

Tap mau au ra mong muon: ( ) ( ) ( ) ( )

1 2, ,...,T

k k k k

nd d d d , n so au

ra.

Chung ta mong muon au ra thc s cua mang sau khi c hoc xong

se can bang vi mau au ra mong muon:

( ) ( ) ( ) ( )1

mk T k k k

i i ij j i

j

y a w x a w x d

Va 1 2, ,...,TT

i i i imw w w w la vector he so trong lng c s dung

cho viec huan luyen mang.

au ra mong

muon

au ra thc

s

w11

w21 d1

y1

e1

x1

x2



Mau Perceptron n gian co ham tac ong chnh la ham dau, va gia tr

au ra mong muon ch co 2 gia tr la +1, -1 ma thoi.

Qua trnh truyen tien: ( ) ( )sgn( )k T ki iy w x .

Sau o he se cap nhat lai he so trong lng thong qua sai so gia au ra

mong muon va au ra thc s:

2 ,

sgn0,

i j i iT

ij i i j

i i

d x y dw d w x x

y d

vi 0, la he so hoc.

T phng trnh nay ta thay rang gia tr ra cua mang neuron bang

gia tr ra mong muon, di = yi , khi w khong thay oi. Khi o qua trnh

hoc ket thuc.

5.4.2 Giai thuat hoc delta:

Luat hoc delta da tren tnh chat cua ao ham ma nen tang la

phng thc giam nen co the dung cho ham truyen bat ky (tuyen tnh

hay ban tuyen tnh).



1. ao ham:

nh ngha : ao ham cua

ham so f tai mot iem x thuoc

mien xac nh, ky hieu la

)(xf , c cho bi :

n

n

xx xx

xfxfxf

n

)()(lim)(

Neu )(xf > 0 th ta noi rang f tang tai x, neu )(xf < 0 th ta noi

rang f giam tai x, con neu )(xf = 0 th ham f co mot cc tr tai x.

Phng trnh ng thang d i qua iem (x0

,f(x0

)) c cho bi :

)()( 0

0

0

xfxx

xfy

)()()( 000 xfxxxfy

goi x1 la giao iem cua d va truc hoanh, the th x

1 la nghiem

phng trnh :

0)()()( 000 xfxxxf

suy ra

)(

)(0

001

xf

xfxx

Tong quat, ta co :

)(

)(1n

nnn

xf

xfxx

Qua trnh tren c goi la phng thc giam. Ap dung ieu nay cho

trong so w, ta thay vong lap ke wn+1

phai thoa tnh chat :

Hng giam



f(wn+1

) < f(wn)

tc la gia tr cua f tai wn+1

nho hn gia tr trc o tai wn

.

Trong luat hoc sa sai, moi phep lap theo phng thc giam se tm

hng giam tai wn

e vi mot > 0 nho bat ky sao cho :

)())(( nnn wfwfwf

at wn+1

la vector

)(1 nnn wfww

at f : Rn

R la mot ham thc va at e Rn vi 1e la mot hng

cho trc. ao ham cua f theo hng e tai w c nh ngha nh sau :

t

wftewfwf

te

)()(lim)(

0

Neu

T

ithu

e )0..,.1.,..0(

tc e la mot hng c s trong khong gian vector th thay v )(wfe , ta

viet ) (w f i , c nh ngha bi :

t

wwwfwtwwfwf nini

ti

),...,,...,(),...,,...,(lim)( 11

0

gradient cua f tai w, ky hieu la )(wf , c nh ngha :



T

n wfwfwf ))(),...,(()( 1

2. Mo ta luat hoc delta:

Xet mot neuron s dung au ra la ham tuyen tnh, the th vector

trong so tm c trong giai thuat hoc se la mot ng thang (trng

hp khong gian hai chieu). ieu nay co ngha la luat hoc cho ham

truyen tuyen tnh ch co the xap x mot ham tuyen tnh ma thoi.

Tuy nhien, neu ham truyen la phi tuyen th kho co the co mot xap x

tot. o la ly do tai sao ngi ta dung ham kch hoat ban tuyen tnh.

au ra cua neuron :

o() = f(wT

x)

Cung nh luat hoc perceptron, luat hoc delta can mot tap d lieu mau

cho qua trnh

He lay xk

lam au vao, tao ra ket qua ok

cua rieng no roi so sanh vi

ket qua mong muon yk

. Sai lech cua mau th k c tnh theo :

22 ))((2

1)(

2

1xwfyoyE Tkkkk

Sai lech cua tat cac cac mau :

K

K

k

k EEEEE

...211

Luat hoc se thay oi w theo hng lam cc tieu hoa sai lech bang cach

s dung phep lap :

)(wEww k

vi

)())(())((2

1)( 2 xwfxwfyxwfy

dw

dwE TTkTkk

3. Mot so ham truyen va ao ham cua no:



Bieu thc tren cho thay trong luat hoc delta, ta can phai tnh ao

ham cua ham truyen. Sau ay la mot so ham truyen hay dung va ao

ham cua no :

Ham dang ch S lng cc :

))(1(2

1

))exp(1(

)exp(2)(1

)exp(1

2)( 2

2tf

t

ttf

ttf

Ham dang ch S n cc :

))(1)(())exp(1(

)exp()(

)exp(1

1)(

2tftf

t

ttf

ttf

4. Tom tat giai thuat:

Cho trc K mau d lieu :

1 1{( , ),..., ( , )}k kx d x d

vi ),...,( 1k

n

kk xxx va dk R, k = 1,,K.



Do tnh chat khong tuyen tnh cua ham truyen ma giai thuat kho co

the dng ung ngha (gia tr tao ra bi mang neuron bang ung gia tr

mong muon hay sai lech = 0). Do o ngi ta thiet lap tieu chuan dng

theo mot gia tr sai lech Emax cho phep nao o : khi sai lech E nho hn

hoac bang Emax th dng.

Trong thc te ngi ta con co mot tieu chuan dng theo so lan lap:

khi at en mot so lan lap xac nh th dng.

Bc 1 : chon trc gia tr > 0 va Emax > 0.

Bc 2 : khi tao ngau nhien w, bat au vi mau th nhat k = 1 va

gan sai lech E = 0.

Bc 3 : bat au qua trnh hoc, gan x = xk, y = dk. au ra cua mang

neuron tnh theo :

= o() = f(wTx)

Bc 4 : cap nhat trong so

)(wEww k

Bc 5 : tnh sai lech bang cach cong them sai lech hien tai

2)(

2

1oyEE

Bc 6 : neu k < K th k = k + 1 va tr lai Bc 3. Neu khong th qua

Bc 7.

Bc 7 : ket thuc chu ky hoc. Neu E Emax th ket thuc qua trnh hoc.

Con neu E > Emax th gan E = 0 va bat au mot chu ky hoc mi bang

cach tr lai Bc 3.

5.4.3 Giai thuat hoc truyen lui BP:

Giai thuat truyen lui (Back propagation Alogorithm ) hay con goi

la giai thuat hoc BP la mot trong cac giai thuat quan trong nhat trong

lch s phat trien cua cac mang neuron nhan tao. Giai thuat c s

dung e huan luyen cac mang nuoi tien nhieu lp vi cac phan t x ly

trong mang co ham tac ong la ham phi tuyen. Mang nuoi tien nhieu

lp c ket hp vi giai thuat truyen lui con c goi la mang truyen



lui. Giai thuat van hanh theo hai luong d lieu sau: hng truyen tien

dung cac mau huan luyen truyen t lp neuron au vao en lp neuron

au ra va cho ket qua thc s Ok (hoac Y

k

) cua lp neuron au ra, sau

o hng truyen lui se s dung sai lech gia au ra mong muon vi au

ra thc s cua mang lam tn hieu vao i ngc t lp neuron au ra en

lp neuron au vao e cap nhat he so trong lng ket noi trong mang.

Ham tong hp cho moi phan t x ly th q cua lp neuron an la:

1

m

q qj j

j

net v x

va au ra cua no: q qz a net Ham tong hp cho moi phan t x ly th i cua lp neuron au ra la:

1

m

i iq q

j

net w z

va au ra cua no: i iy a net

o sai lech gia gia tr tao ra cua mang neuron vi gia tr mong muon

cho mot mau d lieu hoc c cho bi :

x1

x2

xm

vqj wiq

y1

y2

yn

xj (j=1,..,m) , vqj zq (q=1,..,l) , wiq yi (i=1,..,n)



21( ) ( )2

i i iE w d y

o sai lech tong the c tnh bang cach lay tong cua cac o sai lech :

1

( ) ( )K

i

k

E w E w

V the he so trong lng gia lp neuron au ra va lp neuron an co the

c cap nhat bang mot lng :

/iq iqw E w

S dung luat chain cho ( / iqE w ), ta co:

/ / /iq i i i i iw E y y net net wq

trong o:

/

/ ( )

/

i i i

i i i

i iq q

E y d y

y net a net

net w z

Do o ta co the viet lai:

iq i i i q oi qw d y a net z z

Trong o: oi la tn hieu sai lech cua neuron th I trong lp neuron au

ra cua mang.

Tn hieu sai lech

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