92844399-lvtn-1-2012-2

7/31/2019 92844399-LVTN-1-2012-2

1/74

Lun vn tt nghip GVHD: Nguyn Tun Hng

i

MC LC

GII THIU ............................................................................................................................................1

NHIM V LUN VN ........................................................................................................................2

Chng 1..................................................................................................................................................3

L THUYT IU KHIN M ............................................................................................................3

1.1 Gii thiu v Logic M..................................................................................................................3

1.1.1 Tp hp m............................................................................................................................4

nh ngha : .....................................................................................................................................4

ngha : ...........................................................................................................................................4

1.1.2 Cc tnh cht v c im c bn ca tp m: ......................................................................5

a. cao v dng chnh tc ca tp m: .......................................................................................5

b.Min xc nh ca tp m: ...........................................................................................................5

c. Min gi tr ca bin : ..................................................................................................................6

d. Cc dng hm ph thuc : ...........................................................................................................6

1.2 Cc ton t m..............................................................................................................................9

1.2.1 Cc ton tc bn ca Zadeh trn tp m.............................................................................9

a. Giao hai tp m: .........................................................................................................................9

b. Hp hai tp m: ........................................................................................................................10

c. B ca mt tp m: ...................................................................................................................10

1.2.2 Cc ton tb trn tp m: .................................................................................................11

a. Ton tproduct and : .................................................................................................................11

b. Ton tbounded sum or : ..........................................................................................................11

1.3 B t m(fuzzy hedge) ...............................................................................................................12

1.3.1 Sdng cc Hedge : .............................................................................................................12

1.3.2 Xp xmt vng m: ............................................................................................................12

1.3.3 Gii hn mt vng m: .........................................................................................................13

1.3.4 Lm mnh v lm gim tnh cht ca tp m.......................................................................13

7/31/2019 92844399-LVTN-1-2012-2

2/74


ii

1.3.5 Lm tng hay gim tnh mca tp m: .............................................................................14

1.4 Bin ngn ng .............................................................................................................................15

1.5 Mnh m................................................................................................................................15

1.6 X l m.....................................................................................................................................17

1.6.1 Cc php tng quan ............................................................................................................17

1.6.2 Cc lut hp thnh m: ........................................................................................................18

1.7 Gii m........................................................................................................................................20

1.7.1 Phng php im trng tm ...............................................................................................20

1.7.2 Phng php cc i ............................................................................................................21

1.7.3 Phng php cao .............................................................................................................22

1.8 H m..........................................................................................................................................23

1.8.1. H mc bn .......................................................................................................................23

1.8.2 Cc bc xy dng mt h mc bn : ................................................................................24

Xy dng cc lut iu khin : ...............................................................................................25

1.8.3 nh ngha cc tp mcho cc bin ....................................................................................25

1.8.4. c tnh vo ra ca h mc bn .......................................................................................26

1.8.5. Tng hp h mtl.............................................................................................................26

Chng 2................................................................................................................................................28

PHNG PHP PID ZIEGLER NICHOLS ........................................................................................28

2.1 Hm truyn l in v m hnh ca ziegler-nichols .....................................................................28

2.2. Thit k PID stheo phng php ZIEGLER-NICHOLS: ........................................................29

Chng 3................................................................................................................................................34

XY DNG BIU KHIN PID M .............................................................................................34

3.1 Thit k h m..............................................................................................................................34

3.1.1 Sai lch nhit : ...................................................................................................................34

3.1.2 Tc tng gim nhit : ...................................................................................................35

3.2 Thit k h lut .............................................................................................................................38

3.2.1 H lut ...................................................................................................................................38

7/31/2019 92844399-LVTN-1-2012-2

3/74


iii

3.2.2 Chn lut v gii m.............................................................................................................41

Chng 4................................................................................................................................................45

THIT K V THI CNG M HNH .................................................................................................45

4.1 Cc cm bin s dng trong Lun Vn ........................................................................................45

4.1.1 Cm bin nhit Thermocouple .........................................................................................45

4.1.2 Cm bin o mc cht lng...................................................................................................45

4.2 Cc phn t chp hnh .................................................................................................................46

4.2.1 Van iu khin .......................................................................................................................46

4.2.2 ng c khuy trn ...............................................................................................................48

4.2.3 Rle in t..........................................................................................................................49

Chng 5................................................................................................................................................51

THIT K V THC HIN PHN MM ..........................................................................................51

5.1 Quy trnh iu khin .....................................................................................................................51

5.2 Lu gii thut ..........................................................................................................................52

5.2.1 Lu hot ng ca h thng .............................................................................................52

5.2.2 Lu gii thut PID ...........................................................................................................53

5.2.3Lu gii thut PID m.....................................................................................................54

5.3 Cc phn mm lp trnh cho PLC Schneider Premium ....................................................................56

5.4 Thit k giao din gim st v iu khin vi SCADA ...................................................................59

Chng 6................................................................................................................................................63

KT QU THC HIN ........................................................................................................................63

6.1 Giao din chng trnh iu khin v gim st ............................................................................63

6.2 Qu trnh o c th nghim ........................................................................................................64

6.3 iu khin nhit l nhit bng phng php PID ...................................................................67

6.4 iu khin nhit l nhit bng phng php PID fuzzy .........................................................68

KT LUN V HNG PHT TRIN ............................................................................................ 69

Kt lun ..................................................................................................................................... 69

Hng pht trin ....................................................................................................................... 69

7/31/2019 92844399-LVTN-1-2012-2

4/74


iv

TI LIU THAM KHO..................................................................................................................... 70

7/31/2019 92844399-LVTN-1-2012-2

5/74


1

GII THIU

Fuzzy logic tri qua mt thi gian di t khi ln u c quan tm trong lnh vc

k thut khi tin s Lotf Zadeh nh hng vo nm 1965. T, Fuzzy l ti c tptrung nghin cu ca cc nh ton hc, khoa hc v cc ks khp ni trn th gii.

n cui thp nin 90 k thut fuzzy logic t c mt s thnh tu ng k. T khi

ra i, l thuyt m c pht trin v ng dng rng ri. Mt s sn phm ng dng

biu khin m xut hin nh my git, my iu ha v nhiu sn phm khc.

Trong phm vi iu khin khin, biu khin PID l phng php iu khin ti u.

Tuy nhin, biu khin PID pht huy ht u im ca n th c tnh ca i tng

phi bit r rng. iu ny khng phi lc no cng thc hin c trong thc t. Do ,trong mt s trng hp biu khin kinh in ch mang tnh cht n nh ch khng

mang tnh cht ti u. Vy ta cn a them tnh ti u vo biu khin kinh in h

thng lm vic tt hn.

Mt dng kt hp gia iu khin kinh in v iu khin ti u l biu khin PID

m. u im ca biu khin ny l khnng t chnh nh li thng s ca biu

khin cho ph hp vi im lm vic ca i tng.

Vic tch hp biu khin PID mtrn cc hvi iu khin trnn quen thuc.

Nhng vic xy dng biu khin PID mtrn PLC Premium vn l iu kh th v.

PLC Premium vi vic h trnhiu ngn ng lp trnh nh FBD, LD, SFC, IL, ST gip

cho vic lp trnh d dng.Vi mc ch nhm mrng phm vi ng dng ca PLC

Premium to ng lc em thc hin ti Tch hp biu khin PID mvo

PLC Premium.

Cng do gii hn ca ti, trnh v thi gian nn chc chn khng trnh khi

nhng thiu st. Em mong nhn c s ch dn gp qu bu ca cc Thy C ti

c hon thin hn.

7/31/2019 92844399-LVTN-1-2012-2

6/74


2

NHIM V LUN VN

thc hin ti ny trc ht phi hiu r tp lnh ca PLC Premium, phi c c

sl thuyt viu khin mv cao hn l PID m. Cc chng mc trong lun vn

c xy dng chun by cho vic tch hp biu khin PID mtrong PLCPremium. Cc chng lun vn bao gm :

Chng 1 : L thuyt iu khin m, cc php ton trn tp m, lut hp thnh m,

tng hp cc phng php xy dng lut hp thnh mv a ra cc phng php gii

m.

Chng 2 : Phng php PID theo ZIEGLER NICHOLS. Bao gm cch tnh hm

truyn v cch tnh cc tham s PID theo ZIEGLER NICHOLS.

Chng 3 : Xy dng b iu khin PID m. Chng ny s gii thiu 1 cch chi tit

v cch thit k cc tp m, cc h lut v cch gii m.

Chng 4 : Thit k v thi cng L phn ng Ha cht. Chng ny bao gm vic gii

thiu cc cm bin, van iu khin s dng trong Lun vn.

Chng 5 : Thit k v thc hin phn mm. Chng ny bao gm cc s gii thut,

cch s dng cc phn mm Unity Pro, Vijeo Citect.

Chng 6 : Kt qu thc nghim. Chng ny bao gm qu trnh thc nghim, so snh

kt qu gia 2 phng php PID v PID m.

7/31/2019 92844399-LVTN-1-2012-2

7/74


3

Chng 1

L THUYT IU KHIN M

1.1 Gii thiu v Logic M

Cc cng c c in m ta dng xy dng cc php nh x gia th gii thc v

cc m hnh u t trn c s logic hai-gi-tr Boolean. Cch xy dng nh vy th hin

mt s thiu cht ch : mt i tng ch c th c hai kh nng hoc l phn t ca tp hp

ang xt hoc khng, m khng d tr cho trng hp ca cc i tng c mt phn tnh

cht ca tp hp ang xt.

Th d: khi quy nh trong thnh ph xe gn my c tc nhanh gy nguy him l

xe c tc v thuc tp hp A : {v50km/h} , ta khng th cho rng mt xe chy tc

49,9km/h l hon ton khng nguy him theo nh l thuyt tp hp c in.

Hu ht cc hin tng m ta bt gp hng ngy u khng hon ton r rng, c ngha lchng lun c mt mc m h no trong vic din t tnh cht ca chng.

Th d: khi nim nhit NNGl mt khi nim m. Ta khng th ch ra c

chnh xc mt im nhit m ti khngNNG, v khi ta tng nhit ln mt n v

th nhit li c xem l NNG.

Trong nhiu trng hp, cng mt khi nim s c nhiu mc m trong cc thi

im v ng cnh khc nhau.

Th d: khi nim NNGca mt cn phng cn iu ha nhit s khng honton ging vi khi nim NNGca mt l nhit cn iu khin lm vic tm nhit

hng trm C.

Kiu logic hai-gi-tr rt hiu qu v thnh cng trong vic gii quyt cc bi ton

c nh ngha r rng. Tuy nhin, thc t tn ti mt lp cc khi nim khng thch hp

vi cch tip cn nh vy.

Mun s dng cc khi nim ny mt cch hiu qu hn trong m hnh ta cn tm

hiu mt cng c, l logic m v t c s trn n l gii thut iu khin m.

7/31/2019 92844399-LVTN-1-2012-2

8/74


4

1.1.1 Tp hp m

nh ngha :

Tp mF xc nh trn tp kinh in M l mt tp m mi phn t ca n l

mt cp cc gi tr (x, mF(x)) trong xM v mFl nh x :mF : M [0,1]

tp kinh in M c gi l c sca tp m F.

nh x mFc gi l hm ph thucca tp m F.

ngha :

Tp m F l hm nh x mi gi tr x c th l phn t ca mt tp kinh in M

sang mt s nm gia 0 v 1 ch ra mc ph thuc tht s ca n vo tp M. ph thuc bng 0 c ngha l x khng thuc tp M, ph thuc bng 1 c ngha

l x hon ton l i din cho tp hp M. Khi mF(x) tng dn th ph thuc ca x

tng dn. iu ny to ra mt ng cong qua cc phn t ca tp hp.

Mt tp m bao gm 3 thnh phn :

Min lm vic [x1,x2] gm cc s thc tng dn nm trn trc honh.

on [0,1] trn trc tung th hin ph thuc ca tp m.

ng cong hm s mF(x) xc nh ph thuc tng ng ca cc phn t ca

tp m.

x

mF(x)

1

x1 x2

0

7/31/2019 92844399-LVTN-1-2012-2

9/74


5

1.1.2 Cc tnh cht v c im c bn ca tp m:

a. cao v dng chnh tc ca tp m:

caoca mt tp m l gi tr cc i ph thuc ca cc phn t tp m.

Tp m dng chnh tckhi c t nht mt phn t c ph thuc l 1. V d nh

trong hai tp m hnh trn ta thy tp m A l dng chnh tc.

Trong cc m hnh b iu khin m, tt c cc tp m c s u phi dng chnh tc nhm

khng lm suy gim ng ra.Tp m c a v dng chnh tc bng cch iu chnh li tt c gi tr ph

thuc mt cch t l quanh gi tr ph thuc cc i.

Th d: tp m B trn c a v dng chnh tc nh sau :

b.Min xc nh ca tp m:

Trong thc t tp cc phn t c ph thuc ln hn 0 ca tp m thng khng tri

di ht min lm vic ca n. Nh v d di y, min lm vic ca tp m l on [x1,x2] ,

1

0,75

0

1

0,75

00

(a). Tp mA c cao l 1 (b). Tp mB c cao l 0,75

7/31/2019 92844399-LVTN-1-2012-2

10/74


6

tuy nhin ng cong thc s bt u x3v t n ph thuc ton phn x4. Ta gi

on [x3,x4] l min xc nhca tp m.

c. Min gi tr ca bin :

Mt bin m hnh thng c c trng bi nhiu tp m vi min xc nh c phn

chng ln nhau.

Th d: ta c bin NHIT gm cc tp m LNH, MT, M, NNG.

Min gi tr ca binl tp hp tt c cc gi tr c th c ca bin. V d i vibin NHIT trn min gi tr l on [x1,x6] .

d. Cc dng hm ph thuc :

Dng tuyn tnh :

y l dng tp m n gin nht, thng c chn khi m t cc khi nim cha bit

hay cha hiu r rng.

x

mF(x)

1

0

x3 x4 x2x1

1

0

MT M NNG

x1 x2 x3 x4

LNH

7/31/2019 92844399-LVTN-1-2012-2

11/74


7

Dng ng cong S :

Mt tp m dng ng cong S c 3 thng s l cc gi tr a, b, g c ph thuc

tng ng l 0, 0.5 v1.

ph thuc ti im x c tnh bi cng thc sau :

xkhi

xkhix

xkhix

xkhi

xS

1

)/()(21

)/()(2

0

),,;(2

2

Dng ng cong hnh chung :

Dng ng cong hnh chung c trng cho cc s m (xp x mt gi tr trung tm),

bao gm 2 ng cong dng S tng v S gim.

1

0

1

0

Tp mtuyn tnh tng Tp mtuyn tnh gim

b

0.5

1

0

x

7/31/2019 92844399-LVTN-1-2012-2

12/74


8

T 2 tp m dng ng cong S ta suy ra ph thuc ti im x ca tp m dng ng

cong hnh chung nh sau :

xkhixS

xkhixSx

),2/,;(1

),2/,;(),;(

Dng hnh tam gic, hnh thang v hnh vai :

Cng vi s gia tng ca cc b vi iu khin 8 bit v 16 bit, dng tp m chun hnh

chung c thay bng cc dng tp m hnh tam gic v hnh thang do yu cu tit kim b

nh vn hn ch ca cc b vi iu khin.

Dng hnh thang :

Dng tam gic :

a g

0

1

b

x

b

0.5

1

0x

1

0

a

xA xB

b

x

7/31/2019 92844399-LVTN-1-2012-2

13/74


9

xkhi

xkhix

xkhix

xkhi

xT

0

)/()(

)/()(

0

),,;(

Dng hnh vai :

Thng thng vng gia ca bin m hnh c c trng bng cc tp m c dng hnh

tam gic v n lin quan ti cc khi nim tng v gim. Tuy nhin vng bin ca bin

khi nim khng b thay i.

Th d: xt bin NHIT gm cc tp m LNH, MT, M, NNG nh hnh v

Khi ta t n NNG th tt c nhit cao hn s lun l NNG.

Khi ta t n LNH th tt c nhit thp hn s lun l LNH.

Do ta c 2 tp m NNG v LNH c dng hnh vai.

1.2 Cc ton tm

1.2.1 Cc ton tc bn ca Zadeh trn tp m

a. Giao hai tp m:

A B = min(mA[x],mB[y])

1

0

MT M NNG

x1 x2 x3 x4

LNH

x5 x6

7/31/2019 92844399-LVTN-1-2012-2

14/74


10

b. Hp hai tp m:

A B = max(mA[x],mB[y])

c. B ca mt tp m:~A = 1 - mA[x]

A A BB

P P QQ

A~A

7/31/2019 92844399-LVTN-1-2012-2

15/74


11

1.2.2 Cc ton tb trn tp m:

Trong khi xy dng cc m hnh m, c nhng trng hp ngi ta thy cn thit

phi nh ngha cc cc ton t khc thay th cho cc ton t c bn AND, OR, NOT ca

Zadeh. Cc ton t ny c gi l cc ton t b.

Tn gi Giao Hp

Zadeh min(mA[x],mB[y]) max(mA[x],mB[y])

Mean (mA[x]+mB[y]) /2(2*min(mA[x],mB[y])+

+4*max(mA[x],mB[y])) /6

Mean2 Mean mean

Mean1/2

Mean1/2 mean1/2

Product (mA[x]*mB[y]) (mA[x]+mB[y])(mA[x]*mB[y])Bounded Sum max(0, mA[x]+mB[y]-1) min(1, mA[x]+mB[y])

Khi i vo xem xt cc h m phn sau ta s s dng 2 ton t b lproduct and

vbounded sum or trong cc php lin h v tng quan m.

a. Ton tproduct and :

gproduct and = mA[x]*mB[y]

Ton t product andkhng thay i cc c tnh min/max ca ton t giao c bn

ca Zadeh.

gproduct and(0, mA[x]) = 0

gproduct and(1, mA[x]) = mA[x]

Ngoi ra ton t product andc thm 1 tnh cht l tng tc hon ton ngha l n

thay i vi mi cp gi tr (mA[x],mB[y]). Tnh cht ny cn thit khi m t cc trng thi

m bin i theo thi gian.

b. Ton tbounded sum or :

gbounded sum or = min(1, mA[x]+mB[y])

Khi s dng ton tbounded sum orc hai vng m tham gia u ng gp vo kt

qu cui cng cho d 1 trong chng c ph thuc nh hn (s b b qua khi s dng ton

t hp c bn ca Zadeh).

7/31/2019 92844399-LVTN-1-2012-2

16/74


12

1.3 B tm(fuzzy hedge)

Hedgel b t thm vo trc tn camt tp m nhm thay i v b sung tnh cht

ca tp m . Hedgethay i hnh dng ca tp m, thay i hm ph thuc v do to ra

mt tp m mi. Hedgekhong, xp x, gn vicn dng chuyn mt s thc thnh mttp m c gi l s m.

1.3.1 Sdng cc Hedge :

Ta c th s dng cng lc nhiuHedge thm vo mt tp m.

Th d :

chc chn khng rt cao

c gii thch nh sau :chc chn (khng (rt cao))

1.3.2 Xp x mt vng m:

xp x mt vng m (bao gm c vic chuyn mt s thc thnh mt tp m) ta s

dng ccHedgekhong, xp x, gn vi . Cc Hedge ny c tc dng hi m rng vng m.

Th d : xt tp m tui TRUNG NIN v tp m xp x ca n l tp m KHONG TRUNG NIN.

TRUNG NIN KHONG TRUNG NIN

7/31/2019 92844399-LVTN-1-2012-2

17/74


13

1.3.3 Gii hn mt vng m:

C 2Hedgedng gii hn mt vng m l trn v di

Th d :

1.3.4 Lm mnh v lm gim tnh cht ca tp m

Hedgertdng tng mnh tnh cht ca tp m. iu ny c thc hin bngcch gim ph thuc ca mi gi tr trong min lm vic ngoi tr cc gi tr c ph

thuc l 0 hay 1.

Th d: xt tp m CAO v RT CAO

TRUNG NIN TRN TRUNG NIN

TRUNG NINDI TRUNG NIN

7/31/2019 92844399-LVTN-1-2012-2

18/74


14

Hedgehidng gim mnh tnh cht ca tp m. iu ny c thc hin bng

cch tng ph thuc ca mi gi tr trong min lm vic ngoi tr cc gi tr c ph

thuc l 0 hay 1.

Th d: xt tp m CAO v HI CAO

1.3.5 Lm tng hay gim tnh mca tp m:

Hedgechc chndng gim tnh m ca tp m. iu ny c thc hin bng

cch tng ph thuc cacc gi tr c ph thuc ln hn 0.5 v gim ca cc gi tr c

ph thuc nh hn 0.5

Th d: xt tp m CAO v CHC CHN CAO

RT CAOCAO

HI CAO CAO

CHC CHN CAO CAO

7/31/2019 92844399-LVTN-1-2012-2

19/74


15

Hedge nhn chung dng tng tnh m ca tp m. iu ny c thc hin bng cch

gim ph thuc ca cc gi tr c ph thuc ln hn 0.5 v tng ph thuc ca cc

gi tr c ph thuc nh hn 0.5

Th d: xt tp m CAO v NHN CHUNG CAO

1.4 Bin ngn ng

Cc b iu khin m thao tc trn cc bin ngn ng. Mi bin ngn ng l i din

ca mt khng gian m. Cu trc ca mt bin ngn ng nh sau :

Lvar {q1qn} {h1hn} fs

q : cc t ch tn sut nh thng, lun lun

h : ccHedge nh rt, hi kho st trong phn trc

fs : tp m trung tm

Th d :

cao, thp

rt cao, hithp

thng cao, lun lun thp

thngrt cao, lun lun hithp

1.5 Mnh m

Mt b iu khin m bao gm mt chui cc mnh m. Mt mnh thit lp

mt mi quan h gia min lm vic v mt khng gian m.

NHN CHUNG CAO CAO

7/31/2019 92844399-LVTN-1-2012-2

20/74


16

Mt mnh n gin c dng :

x l A

x : gi tr v hng thuc min lm vic

A :bin ngn ng

mA (xA)

Qu trnh m t gi tr r x=x1tm ra ph thuc mA(x1) c gi l qu trnh m

ha. Trong trng hp c nhiu bin ngn ng qu trnh m hal tm ra mt vect bao

gm nhiu ph thuc.

Th d: xt bin NHIT gm cc tp m LNH,MT,M,NNG.

M habin nhit :

5.0

5.0

0

0

45

0

0

75.0

25.0

1500

CC

(x)

(x)(x)(x)

x

nong

am

mat

lanh

Mnh m c iu kin :

Nu y l B th x l A

x,y : gi tr v hng thuc min lm vic

A,B : bin ngn ng

C th gii thch mnh ny nh sau :

x l phn t ca A ty theo mc y l phn t ca B

1

0

0.25

0.75

0.5

150C 450C

MT M NNGLNH

x

7/31/2019 92844399-LVTN-1-2012-2

21/74


17

1.6 Xl m

1.6.1 Cc php tng quan

Xt mt mnh c iu kin sau :

Nu y l B th x l A

Cc php tng quan qui nh vng m kt qu c to ra nh th no t gi tr ca

mnh iu kin v bin ngn ng mnh kt qu.

Cc php tng quan l c s cho cc lut hp thnh c s dng trong b iu

khin m.

C 2 php tng quan l : tng quan ti thiu v tng quan tch.

a.Tng quan ti thiu :

y l phng php tng quan thng c dng nht, thc hin bng cch b i

phn c ph thuc ln hn gi tr ca mnh iu kin trn min m c trng bi bin

ngn ng mnh kt qu.

Th d: xt mnh c iu kin sau :

Nu nhit THP th cng sut l LN

Php tng quan ti thiu to ra cc on nm ngang trn min m kt qu dn n

mt mt mt phn thng tin. Tuy nhin php tng quan ny tng i n gin v cho php

gii m d dng hn.

Nhit Cng sut l

THP LN

7/31/2019 92844399-LVTN-1-2012-2

22/74


18

b. Tng quan tch :

Phng php ny thng cho kt qu tt hn, c thc hin bng cch nhn hm

ph thuc ca min m c trng bi bin ngn ng mnh kt qu vi gi tr ca mnh

iu kin.

Lc ny dng ca min m c bo ton, thng tin khng b mt mt, tuy nhin vic

gii m kh khn hn.

Th d: vn xt mnh c iu kin trn :

Nu nhit THP th cng sut l LN

so snh kt qu gia 2 php tng quan.

1.6.2 Cc lut hp thnh m:

Trong mt b iu khin m, cc mnh c x l song song to ra mt khng

gian kt qu cha thng tin t tt c cc mnh . Cc lut hp thnh qui nh cch thc

tng quan v tng hp cc khng gian m t s tc ng qua li gia cc mnh ca h.

Tng ng vi 2 php tng quan ti thiu v tng quan tch ta c cc lut hp thnh

nh sau :

Tng quan ti thiu : lut hp thnh Max-Min, Sum-Min

Tng quan tch : lut hp thnh Max-Prod, Sum-Prod

Hai lut hp thnh m thng dng l lut hp thnh Max-Min v lut hp thnh Sum-

Min.

a. Lut hp thnh Max-Min :Gi s h gm n mnh :

Nhit Cng sut l

THP LN

7/31/2019 92844399-LVTN-1-2012-2

23/74


19

Nu y l B1 th x l A1

Nu y l B2 th x l A2

............................................

Nu y l Bn th x l An

Cc min m kt qu c thc hin bng php tng quan ti thiu. Sau min

m bin ra c cp nht bng cch hp cc min m ny theo ton t OR c bn ca Zadeh.

Th d: xt l nhit c iu khin bi 2 lut sau :

Nu nhit THP th % cng sut l LN

Nu nhit TRUNG BNH th % cng sut l TRUNG BNH

Bin vo nhit gm 2 tp m : THP v TRUNG BNH.

Bin ra % cng sut lgm 2 tp m : TRUNG BNH v LN.

Tin hnh m ha bin vo nhit ta thu c vect gm 2 phn t l 2 ph

thuc ca nhit vt l t vo 2 tp m trn.

(t)

(t)t

BNHTRUNG

THAP

V d, m ha gi tr nhit t1=200C ta c :

0.250.75

C200

S dng phptng quan ti thiu ta thu c 2 min m kt qu nh sau :

0.75

0.25

THP TRUNG BNH

Nhit % cng sut l

TRUNG BNH LN

200C

7/31/2019 92844399-LVTN-1-2012-2

24/74


20

Sau min m bin ra thu c bng cch hp 2 min m ny theo ton t OR c bn ca

Zadeh nh sau :

b. Lut hp thnh Sum-Min :

Cc min m kt qu vn c thc hin bng php tng quan ti thiu. Tuy nhin

min m bin ra c cp nht bng cch thc hin ton t b bounded sum or thay cho

ton t OR c bn ca Zadeh.

Th d: vn xt th d trn nhng p dng lut hp thnh Sum-Min ta c kt qu nh sau :

1.7 Gii m

Qu trnh x l m to mt min m bin ra. Gii m l tm ra mt gi tr vt l (gi

tr r) c trng cho thng tin cha trong min m .

1.7.1 Phng php im trng tm

Phng php ny c p dng khi min m bin ra l mt min lin thng. Gi tr r ca

bin ra l honh ca im trng tm ca min m bin ra.

% cng sut l

TRUNG BNH LN

% cng sut l

TRUNG BNH LN1

7/31/2019 92844399-LVTN-1-2012-2

25/74


21

Cng thc xc nh x' theo phng php im trng tm nh sau :

trong : l l min xc nhca tp m A

l

dx*(x)

dx*(x)*xx'

A

lA

1.7.2 Phng php cc i

Gi tr r ca bin ra l im c ph thuc ln nht.

Trong trng hp cc im c ph thuc ln nht tri di trn mt on thng nm ngang

[x1;x2] gi tr r ca bin ra l trung im ca on [x1;x2] nh hnh v :

x' x

mA

l

x' x

mA

7/31/2019 92844399-LVTN-1-2012-2

26/74


22

1.7.3 Phng php cao

Tp m dng Singleton l mt dng n gin ha cho php x l m v gii m c

d dng hn, thng c dng trong cc h thng dng vi iu khin, c tch hptrong tp lnh ca MCU 68HC12 ca hng Motorola.

Mi tp m kt qu ca cc mnh iu kin c thay bng mt on thng

(x,m(x)) vi m(x) l cao ca tp m tng ng.

Th d: xt bin NHIT gm cc tp m LNH,MT,M,NNG.

Phng php caochnh l p dng gii m theo phng php im trng tm i

vi cc tp m bin ra dng Singleton.

Do cc tp m ca min m bin ra khng chng lp ln nhau nn khi gii m cng

vic tnh tch phn rt mt thi gian c thay bng vic tnh tng s hc nh sau :

x1 x

mA

x2x'

1

0x1 x2 x3 x4 x5 x6

MT M NNGLNH

7/31/2019 92844399-LVTN-1-2012-2

27/74


23

n

1i

i

n

i

ii

H

H*x

x'1

trong : xil v tr cc singleton

Hil cao ca cc singleton tng ngn l s tp m bin ra

1.8 H m

1.8.1. H mc bn

Mt h m c bn bao gm 3 thnh phn chnh :

Khu m ha

Thit b thc hin lut hp thnh m (x l m)

Khu gii m.

Khu mhac nhim v chuyn i mt gi tr r u vo x0thnh mt vecto m

gm cc ph thuc ca gi tr r theo cc tp m nh ngha trc.

Khu x l mx l vecto m v cho ra tp m B' ca bin ra.

Khu gii mc nhim v chuyn i tp m B' thnh mt gi tr r y' c trng cho

thng tin cha trong tp m .

Do h m c bn ch c kh nng x l cc gi tr tn hiu hin thi nn n thuc

nhm cc b iu khin tnh. Tuy vy vi vic ghp thm cc khu ng hc cn thit nh vi

phn, tch phn, ta s c c mt b iu khin m c kh nng x l cc bi ton ng.

Nguyn tc tng hp biu khin mhon ton da vo nhng phng php ton

hc trn c snh ngha cc bin ngn ng vo/ra v s la chn nhng lut iu khin. Do

cc biu khin mc khnng x l cc gi tr vo/ra biu din di dng du phy ng

X L M GII MM HA

x1

xn

m B' y'

7/31/2019 92844399-LVTN-1-2012-2

28/74


24

vi chnh xc cao nn chng hon ton p ng c cc yu cu ca mt bi ton iu

khin r rng v chnh xc.

Biu khin mhot ng ch yu da vo kinh nghim thit k cc lut iu

khin, trin khai cc mnh hp thnh xy dng m hnh lut hp thnh .

1.8.2 Cc bc xy dng mt h mc bn :

Xc nh cc bin vo v ra.

nh ngha cc tp m cho cc bin vo v ra.

Xy dng cc lut iukhin (cc mnh m).

Chn lut hp thnh.

Chn phng php gii m.

Ti u h thng.

nh ngha cc bin vo/ra:

Cc bin vo l cc bin iu khin cc qu trnh bn trong ca b iu khin m, cc

bin ra dng iu khin i tng .

Sau khi xc cc bin vo/ra ta cn phi xc nh min gi tr cho tng bin cng nh

n v ca tng bin.

nh ngha cc tp m cho cc bin :

Do cc tp m chnh l i tng thao tc ca cc lut iu khin nn ta phi nh

ngha cc tp m trc khi xy dng cc lut iu khin. Mt khc do dng tp m phn nh

mi lin h gia gi tr cc d kin v ngha ca chng -> khu quan trng trong vic tng

hp b iu khin m.

H M C BN

Vi phn

Tch phn

x(t) y'(t)

7/31/2019 92844399-LVTN-1-2012-2

29/74


25

- xc nh tp m cn:

- Min gi tr vt l cho cc bin ngn ng vo/ra.

- S lng tp m(gi tr ngn ng).

- Xc nh hm lin thuc:

Cch thc hin l bt u bng cc dng hm lin thuc bit trc v m hnh ha

n cho n khi nhn c b iu khin m lm vic nh mong mun.

Trong nhiu trng hp dng hm lin thuc hnh tam gic cho ktqu khng km g

dng hm lin thuc phc tp hn l dng hnh chung, do b iu khin m t khi nhy vi

s thay i hnh dng tp m. iu ny lm cho h m kh bn vng v d thch nghi, l

mt thuc tnh quan trng khi m hnh ln u c kho st.

Xy dng cc lut iu khin :

y l bc tng hp cc hiu bit cng nh chin lc iu khin i tng di

dng mt tp cc lut iu khin.V cng l bc kh khn nht do hat ng ca b iu

khin hon ton da trn cc lut iu khin. Cc lut iu khin c thit lp da trn cc

mnh hp thnh.

Chn thit b hp thnh :

Thit b thc hin lut hp thnh trong b iu khin m l thit b hp thnh. C th

chn thit b hp thnh theo nguyn tc Max_Min, Max_Prod trin khai php hoc khi

thit lp lut hp thnh chung:

R=R1or R2or Rn

Chn nguyn l gii m:

Gii m hay r ha, ty theo cch chn la phng php gii m m phc tp v

trng thi lm vic ca c h thng cng b nh hng .

1.8.3 nh ngha cc tp mcho cc bin

a. chng lp

bin i nhiu tp m ring l thnh mt b mt lin tc, cc tp m ln cn phi

c chng lp ln nhau. Kinh nghim cho thy chng lp tt nht thng trong khong

25% 50%.

Th d: Cc tp m ln cn c chng lp 50% :

7/31/2019 92844399-LVTN-1-2012-2

30/74


26

b. La chn dng hm lin thuc

Cch thc hin l bt u bng cc dng hm lin thuc bit trc v m hnh ha

n cho n khi nhn c b iu khin m lm vic nh mong mun.Trong nhiu trng hp dng hm lin thuc hnh tam gic cho kt qu khng km g

dng hm lin thuc phc tp hn l dng hnh chung, do b iu khin m t khi nhy vi

s thay i hnh dng tp m. iu ny lm cho h m kh bn vng v d thch nghi, l

mt thuc tnh quan trng khi m hnh ln u c kho st.

1.8.4. c tnh vo ra ca h mc bn

Nh ni h m c bn thc cht l mt b iu khin tnh nn quan h truyn t

hon ton c m t y bng ng c tnh y(x) gi l c tnh vo raca h m.

c tnh vo ra ca mt h m c bnc th l tuyn tnh hoc phi tuyn.

Nu c tnh vo ra tuyn tnhhoc tuyn tnh tng on ta c h m t l.

Ngc li nu ta c mt ng c tnh iu khin mong mun, ta cng c th t

tng hp c h m tng ng.

1.8.5. Tng hp h mt l

H m t l c ng c tnh vo ra tuyn tnh tng on xc nh bi cc im nt(xk,yk) nh hnh v :

7/31/2019 92844399-LVTN-1-2012-2

31/74


27

Thut ton tng hp h m t l nh sau :

1. Xc nh cc im nt (xk,yk) ca ng c tnh.

2. nh ngha n tp m u vo Akc hm lin thuc mAk(x) dng hnh tam gic vi

nh l im xkv min xc nh l khong [xk-1,xk+1] trong x0 , xn+1l nhng im

bt k tha mn x0xn.

3. Xc nh n tp m u ra Bkbiu din di dng Singleton ti cc im ykv c

cao l 1.

4. nh ngha tp n lut iu khin Rkdng :

Rk : NU x=AkTH y=Bk

5. p dng lut hp thnh Max-Min.

6.

S dng nguyn l cao gii m.Nguyn tc tng hp biu khin mhon ton da vo nhng phng php ton

hc trn c snh ngha cc bin ngn ng vo/ra v s la chn nhng lut iu khin. Do

cc biu khin mc khnng x l cc gi tr vo/ra biu din di dng du phy ng

vi chnh xc cao nn chng hon ton p ng c cc yu cu ca mt bi ton iu

khin r rng v chnh xc.

Biu khin mhot ng ch yu da vo kinh nghim thit k cc lut iu

khin, trin khai cc mnh hp thnh xy dng m hnh lut hp thnh .

x1 x2 x3

xnxn-2

y2

yn

yn-1

y1

y1

y

x

yn-2

xn-1

7/31/2019 92844399-LVTN-1-2012-2

32/74


28

Chng 2

PHNG PHP PID ZIEGLER NICHOLS

2.1 Hm truyn l in v m hnh ca ziegler-nichols

L nhit c u vo l in p cung cp cho dy t ( hay cng sut cung cp ) v ng

ra l nhit ca sn phm cn nung hay nhit vng s dng . thnh lp hm truyn l

nhit ta phi kho st phng trnh vi phn m t cc quan h nhit - nng lng cc b

phn , y l bi ton phc tp nu mun chnh xc .

Mt cch gn ng , ta c thxem mi trng nung l ng cht , ng nhit . Nh

vy phng trnh cn bng nng lng cho ta : in nng cung cp sc dng b vo

nng lng nhit truyn ra bn ngoi v nng nhit mi trng nung . T tnh c

hm truyn l lc s l bc nht :

Trong :

K : L h s t l cho bit quan h vo ra ch xc lp .

T : Thi hng nhit th hin qun tnh ca h thng .

M hnh hm truyn ny cho thy qu trnh qu vi u vo hm nc c dng hm

m ch l gn ng , thc t h thng c bc cao hn nhng qu trnh qu u vo hm

nc vn khng vt l, nh hnh sau :

7/31/2019 92844399-LVTN-1-2012-2

33/74


29

Theo Ziegler-Nichols th mt h thng nh vy c th biu din di dng hm

truyn sau :

T1 : Thi gian tr (Thi gian khng nhy ca l nhit )

T2 : Thi gian qun tnh ca l nhit .

* Cc hng s thi gian c tnh trn th .

Khai trin Taylor ca e-T1sta c :

2.2. Thit k PID stheo phng php ZIEGLER-NICHOLS:

Phng php ny thng p dng cho i tng c qun tnh ln nh l nhit c

m t bng hm truyn t :

Trong :

K : H s khuch i ca i tng l nhit .

7/31/2019 92844399-LVTN-1-2012-2

34/74


30

T1: Hng s thi gian khng nhy ca l nhit .

T2: Hng s thi gian qun tnh nht ca l .

K , T1 , T2c xc nh bng phng php thc nghim .

PID ca Ziegler-Nichols c dng :

D s CTi s

Td s( ) (*

* ) 11

Vi CT

K T

1 2 2

1

, *

*Ti = 2T1 Td = 0,5T1

H stng ng vi h s khuch i t l

Kp = C

Ki =C

T1

Kd = C*Td

Hiu chnh PI ca Ziegler-Nichols l :

D(s) = C(1+1

Ti s*)

vi C =0 9 2

1

,*

K

T

T

Hiu chnh khuch i t l P :

D(s) = C

vi C=1 1

2K

T

T*

i vi h lin tc hiu chnh PID c dng tng qut l :

Gc(s) = Kp +Ki

s+ Kd*s

Chuyn sang h ri rc s dng h bin i Z i vi khu vi phn :

7/31/2019 92844399-LVTN-1-2012-2

35/74


31

Zdf t

dt TZ F z

T

z

zkT

( )( ) ( ) *

11

1 11

Hm truyn khu vi phn : G z Kd z

T zD ( )

*

1

Trong phng trnh vi phn chuyn sang sai phn dng :

df t

dt Tf kT f k T

t kT

( ){ ( [( ) ]}

1

1

C 3 phng php tnh tch phn :

f[(k-1)T]

f(t) B F

E C f(kT)

A D

(k-1)T kT t

- Cch 1 : Tch phn theo hnh thang ABCD

- Cch 2 : Tch phn theo hnh ch nht li v pha sau ABFD

- Cch 3 :Tch phn theo hnh ch nht tin vpha trc AECD

Theo cch 1 :

u(kT) = u(k-1)T + T/ 2{f(kT) + f[(k-1)T]}

GI(z) = KiU z

F z

KiT z

z

( )

( )*

2

1

1

Theo cch 2 :

7/31/2019 92844399-LVTN-1-2012-2

36/74


32

u(kT) = u(k-1)T + Tf[(k-1)T]

G KiU z

F z

Ki Tz

zI

( )

( )

*

1

Theo cch 3:

u(kT) = u[(k-1)T] + Tf(kT)

Tng qut theo cch 1 hm truyn b lc PID theo z l :

Gc z Kp Kd z

z

KiT z

z( ) *

1

2

1

1

Dng tng qut k hiu tn hiu vo biu khin l f(t), tn hiu ra l u(t) .

Trng hp b iu khin PID c mc knh sai s th tn hiu vo b iu

khin l sai lch e(t ) sinh ra trong h thng hi tip. i vi trng hp ny tn hiu iu

khin c dng :

ng thi ta cng c :

1)(

)()(

z

zK

zF

zUKzG ipi

2

])1[()(])1[()()()(

)1(

0

TkekTeTKedtK

T

TkekTeKkTeKkTu i

Tk

idp

Tk

idp edtKT

TkeTkeKTkeKTku

)1(

0

])2[(])1[(])1[(])1[(

7/31/2019 92844399-LVTN-1-2012-2

37/74


33

T hai biu thc trn ta c :

T cng thc trn ta thy : tn hiu iu khin u c th tnh c ti mi thi im

nu ta bit c gi tr cc thng s ca biu chnh : Kp, Ki , Kd xc nh c , m iu

ny c th gii quyt c t thc nghim v qua cc cng thc ca Ziegler Nichols

trnh by .

TkuTkeT

KdTK

T

KKTke

TK

T

KKkTe

TkuTkekTe

TK

T

TkekekTeKTkekTeKTkukTu

idp

idp

i

dp

122

21

2

12

1

1221])1[()(

7/31/2019 92844399-LVTN-1-2012-2

38/74


34

Chng 3

XY DNG BIU KHIN PID M

3.1 Thit k h m

Nguyn tc tng hp mt biu khin mhon ton da vo nhng phng php

ton hc trn c snh ngha cc bin ngn ng vo/ra v s la chn nhng lut iukhin. Do thit k biu khin mtrc tin ta snh ngha cc bin ngn ng

vo/ra.

i lng vo ca biu khin mchnh l sai lch nhit v tc tng gimnhit .

i lng ra ca biu khin ml 3 gi trtng i ca 3 thng s Kp, Ki, Kdca biu khin PID.

3.1.1 Sai lch nhit :c nh ngha nh l sai khc gia nhit t v nhit hin ti o c, k

hiu l ET.

ET = nhit t nhit o [C]

Mong mun ca chng ta l iu khin n 90C nn min xc nh ca bin s lkhong [-90C,+90C].

Trong min xc nh , ta nh ngha 5tp m :ET = {m nhiu, m va, m t, bng khng,dng t,dng va, dng nhiu}

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

Tuy nhin, tp trung hn trong khong sai lch nh, ta khng phn b u 7 tp mny trn khong [-90C,+90C] m ch phn b u trong khong [-6C, +6C].

0 2 4 6

90

-2-4-6

-90 C

ZE P1 P2 P3N1N2N3

Cc tp mca bin ET

7/31/2019 92844399-LVTN-1-2012-2

39/74


35

3.1.2 Tc tng gim nhit :

L gi tr tng hay gim ca nhit hin ti so vi nhit trc trong khongthi gian ly mu, k hiu l DET.

DET=(nhit hin ti nhit trc)/thi gian ly mu[C/s]

i tng iu khin l mt in tr un ncc qun tnh tng i ln, trongkhong thi gian ly mu l 2giy ch tng hay gim ti a 1,3C nn ta nh ngha DET vimin xc nh l [-2,+2].

Cng nh ngha cho bin DET c 7 tp m vi tn gi nh trn, nh ngha trongkhong [-2;+2].

Gi tr ng ra l 3 bin kp, kd, l 3 gi trtng i i din cho 3 thng s ca b

iu khin PID l Kp, Ki , Kd.

O

Cc tham s Kp, Ki, Kd ca biu khin PID c chnh nh da trn c sphn

tch tn hiu cho v tn hiu ra ca h thng, chnh xc hn l sai lch et(t) v o hm

ca sai lch de/dt ca h sai lch. C nhiu phng php chnh nh cc thng s cho biu

khin PID nh chnh nh qua phm hm mc tiu, chnh nh trc tip, song phng n n

0 0 5 1.0 1.5 2-0.5-0.4-0.8-1.2[C]/T[s]

ZEP11 P21 P31N11N21N31

Cc tp mca bin DET

B chnh

nh m

Thit b

chnh nh

Biu

khin PID

i tngxy

e(t), te.

-

7/31/2019 92844399-LVTN-1-2012-2

40/74


36

gin hn cl phng php chnh nh mtheo Zhao, Tomizuka v Isaka. Vi gi thit l

cc tham s Kp, Kd b chn tc l : KPmaxminmaxmin

,,, DDDPP KKKKK .

Zhao, Tomizuka v Isaka chun ha cc tham s nh sau :

c 0 kp, kd 1

Nh vy b chnh nh msc 2 u vo v 3 u ra l kp, kd,

Bin ngn ngkp theo nh ngha trn min xc nh l [0,1]. Ta nh ngha cho bin

kp c 5 tp ml :

minmax

min

minmax

min

,DD

DD

D

PP

PP

PKK

KKk

KK

KKk

0.5 0.75 10.250Kp

UZ LMS

B chnh

nh m1

B chnh

nh m2

B chnh

nh m3

kp

kd

et

det

7/31/2019 92844399-LVTN-1-2012-2

41/74


37

Hnh 4.1 : Biu din lut chnh nh Kp trong khng gian

Bin ngn ngkd theo nh ngha trn cung c min xc nh l [0,1]. Ta cng nh ngha

cho bin kd c 5 tp ml :

Hnh 4.2 : Biu din lut chnh nh Kd trong khng gian

0 0.25 0.750.5 1

Z M US L

kd

7/31/2019 92844399-LVTN-1-2012-2

42/74


38

Bin ngn ngc nh ngha l t s= Ti/Td.Ta nh ngha cho bin nm

trong khong [1 10] vi 5 tp ml L1, L2, L3, L4, L5.

Hnh 4.1 : Biu din lut chnh nh Ki trong khng gian

3.2 Thit k h lut

3.2.1 H lut

H thng gm 5 bin ngn ng u vo i vi ET v 5 bin ngn ng cho bin

DET nn mi h lut cho kp, kd l gm 5 x 5 = 25 lut If then

0

L2L1 L3

L4 L5

41 2 3 5

7/31/2019 92844399-LVTN-1-2012-2

43/74


39

H lut cho kp:

kpDET

N31 N21 N11 ZE1 P11 P21 P31

ET

N3 U U U U U U UN2 L L L L L L LN1 M M M M M M MZE Z Z Z Z Z Z ZP1 M M M M M M MP2 L L L L L L LP3 U U U U U U U

Hnh 4.4 : Lut hp thnh Kp

H lut cho kd :

kdDET

N31 N21 N11 ZE1 P11 P21 P31

ET

N3 Z Z Z Z Z Z ZN2 M M M M M M MN1 L L L L L L LZE U U U U U U UP1 L L L L L L LP2 M M M M M M MP3 Z Z Z Z Z Z Z

7/31/2019 92844399-LVTN-1-2012-2

44/74


40

Hnh 4.5 : Lut hp thnh Kd

H lut cho :

DETN31 N21 N11 ZE1 P11 P21 P31

ET

N3 L1 L1 L1 L1 L1 L1 L1N2 L3 L2 L2 L1 L2 L2 L3N1 L4 L3 L2 L1 L2 L3 L4

ZE L5 L4 L3 L2 L3 L4 L5P1 L4 L3 L2 L1 L2 L3 L4P2 L3 L2 L2 L1 L2 L2 L3P3 L1 L1 L1 L1 L1 L1 L1

Hnh 4.6 : Lut hp thnh

7/31/2019 92844399-LVTN-1-2012-2

45/74


41

3.2.2 Chn lut v gii m

Chn lut hp thnh theo quy tc MaxMin.

Gii mtheo phng php cao.

Gi s ti mt thi im no ET = 2.5, DET = 0.4

Khi :

(ET) = {0, 0, 0, 0 ,0.75, 0.25 , 0}

(DET) = {0, 0, 0, 0.2 , 0.8 , 0, 0}

Xt vi h lut cho kp

p dng lut MaxMin cho ta :

0.2M 0.75M

0.2L

0.25L

Gii mtheo phng php cao ta c :

Min

Min

Max0.75M

Min

Min

Max

0.25L

7/31/2019 92844399-LVTN-1-2012-2

46/74


42

Hnh 4.7 : Gii mkp bng pp trng tm trn Matlab

Xt vi h lut cho kd


0.2L 0.75L

0.2M

0.25M


Hnh 4.8 : Gii mkd bng pp trng tm trn Matlab

Min

Min

Max0.75L

Min

Min

Max

0.25M

7/31/2019 92844399-LVTN-1-2012-2

47/74


43

Xt vi h lut cho


0.2L1

0.2L1

0.75L2 0.25L2


Hnh 4.9 : Gii m bng pp trng tm trn Matlab

Min

Min

Max0.2L1

Min

Min

Max0.75L2

7/31/2019 92844399-LVTN-1-2012-2

48/74


44

Gi s biu khin PID c cc thng s theo ZeiglerNichols c Kp = 66.25 , Kd = 331.25

Ki = 3.3125.

Ta chn Kpmax = 80, Kpmin = 50

Kdmax = 360 , Kdmin = 300

Khi , gi tr Kp, Ki, Kd do biu khin mt chnh nh s l :

Kp = kp * ( KpmaxKpmin ) + Kpmin

= 0.5625 * ( 8050 ) + 50 = 66.875

Kd = kd * ( KdmaxKdmin ) + Kdmin

= 0.6875 * ( 360300 ) + 300 = 341.25

Trong thut ton PID cc thng s Kp, Ki, Kd c cc chc nng khc nhau. Xt bi

ton trn, Khi ET = 2.5 v DET = 0.4, tc l nhit o gn bng nhit t v nhit ang

tng. Hi vo xc lp, khi ta cn tng Kp , Ki gim sai s xc lp, ng thi tng Kd

gim thi gian xc lp v gim vt l.

7/31/2019 92844399-LVTN-1-2012-2

49/74


45

Chng 4

THIT K V THI CNG M HNH

4.1 Cc cm bin sdng trong Lun Vn

4.1.1 Cm bin nhit Thermocouple

V nguyn tc th ngi ta hon ton c th to ra mt thermocouple cho gi tr ra bt

k bi v c rt nhiu t hp ca hai trong s cc kim loi v hp kim hin c.

Tuy nhin c mt thermocouple dng c cho o lng th ngi ta phi xt n

cc vn nh : tuyn tnh, tm o, nhy, v do ch c mt s loi dng trong

thc t nh sau :

Loi J :kt hp gia st vi constantan, trong st l cc dng v constantan l

cc m. H s Seebeck l 51V/C 20C.

Loi T : kt hp gia ng vi constantan, trong ng l cc dng v constantanl cc m. H s Seebeck l 40V/C 20C.

Loi K : kt hp gia chromel vi alumel, trong chromel l cc dng v alumel

l cc m. H s Seebeck l 40V/C 20C.

Loi E : kt hp gia chromel vi constantan, trong chromel l cc dng v

constantan l cc m. H s Seebeck l 62V/C 20C.

Loi S, R, B : dng hp kim gia platinum v rhodium, c 3 loi : S) cc dng dng

dy 90% platinum v 10% rhodium, cc m l dy thun platinum. R) cc dng dng dy

87% platinum v 13% rhodium, cc m dng dy thun platinum. B) cc dng dng dy

70% platinum v 30% rhodium, cc m dng dy 94% platinum v 6% rhodium. H s

Seebeck l 7V/C 20C.

4.1.2 Cm bin o mc cht lng

Trong phm vi ti ny em chn cch dng phao o mc cht lng trong cc bnhcha

7/31/2019 92844399-LVTN-1-2012-2

50/74


46

u im:

- R, d thit k v ch to.

Nhc im:

- Tm o hp.

- chnh xc v n nh khng cao.

Hnh 5.1 Cm bin Phao dng trong ti

Nguyn l hot ng:

Thit b gm mt phao gn vo bin tr thng qua mt cn bng kim loi, gn thit b

vo bn o mc cht lng, khi mc cht lng thay i, phao thay i theo dn n gi tr bin

tr thay i. Trong phm vi ti ny tn hiu cn c v dng p DC (0 10v). Do hai

u ca bin tr c ni vi ngun p DC c nh 10v, u cn li c a v knh analog

ca PLC.

- Dy xanh dng l dy max.

- Dy vng l dy ngun.

- Dy xanh l l dy a vo knh Analog ca PLC.

4.2 Cc phn tchp hnh

4.2.1 Van iu khin

Van l thit b dng trong vic vn chuyn lu cht dng lng, rn, st v kh. Van

c s dng nh l mt phn trn h thng ng ng vn chuyn v iu khin lu cht

theo mun ca chng ta.

V cn bn van c chia lm hai loi:

7/31/2019 92844399-LVTN-1-2012-2

51/74


47

- Loi iu khin bng tay (Manual valve)

- Loi iu khin bng in,kh...(control valve)

Manual valve ta c th thy nhiu trong cc h thng nc sinh hot hng ngy nhng

size nh. Control valve c s dng nhiu trong cc ngnh cng nghip, nht l lc du, hocht, nh my in... control valve cng c th iu khin bng tay thng qua Handwheel.

Size ca control valve c th t 1 ti 40.

Van iu khin dng trong ti lun vn l van solenoid.

Hnh 5.2 Van in dng trong ti

Cu to van

Van c cc thnh phn c bn sau:

-Thn van: y l phn chnh yu nht ca van, n c th l 01 phn c c hay l

t 02 phn lp ghp li vi nhau. Thn van sc lp vi ng ng thng qua vic ni ren,

ni bch, kp, hoc hn trc tip vo ng ng.

-Cht van, ti van: y l phn lin kt gia a van v phn vn hnh tc ng ngngt v iu khin van

-a van: y l phn c gn vo ti van v sc tc ng xoay hoc di chuyn

ln xung khi chng ta tc ng iu khin vo ti van.

-Tay vn: c t an cui ti van, phn trn thn van. Tay van c iu khin

bng tay, v-lng hoc bng biu khin (kh nn, in, thy lc).

-Cc phn khc: m van (bonnet), c m van (bolted bonnet), kp ni cc phn van

(yoke bonnet), cc phn m/ lt/ ron (gland/packing/seal).tt c phn ny kt hpcc phnchnh to nn mt van hon chnh.

7/31/2019 92844399-LVTN-1-2012-2

52/74


48

Nguyn l hot ng ca van

Van c iu khin bng cun dy . trng thi bnh thng van ng, khi cun dy

c kch bi p 24VDC s sinh ra lc ht ht tip im m van.

4.2.2 ng c khuy trn

ng c dng quay cnh qut trn ca bnh trn. C nhiu loi ng c khc nhau,

vic phn loi ng c tu thuc vo ngun cp cho ng c, b chnh vn tc, tc quay

v cng sut.

Do qui m bn trn kh nh v yu cu tc quay ca cnh qut trn khng qu

nhanh, do ta cn dng ng c c tc va phi. c tc quay ca ng c nh

mong mun, ta c th s dng b iu khin tc cho ng c.

Thng s ca ng c

- ng c DC

- S dng ngun 24v

- Tc quay 3000v/p.

Hnh 5.3 ng c dng trong ti

7/31/2019 92844399-LVTN-1-2012-2

53/74


49

4.2.3 Rle in t

Rle in t c cc b phn chnh l mch t, cun dy, tip im, v. Mch tc

ch to t vt liu st t gm 2 phn, phn tnh hnh ch l phn ng l tm ghp hnh ch

U. Phn ng ni lin kt c kh vi tip im ng.

im khc bit c bn gia rle in t v contactor l rle in t ch c mt loi

tip im iu khin c ththng ng hoc thng m, khng c hp p h quang, v

khng c l xo nn tip im m s dng thanh ng lai tip im to lc nn.

Phn loi

Theo cun ht : cun ht mt chiu v cun ht xoay chiu.

Theo dong in qua tip im : r le m chiu , rle xoay chiu. Theo slng cp tip im : 2 cp tip im, 3 cp tip im

Theo cu trc chn : chn trn, chn dt.

Theo cm rle : trn, vung.

Nguyn l hot ng

Khi c dng in chy qua cun dy s sinh ra lc ht in t ht tm ng v pha

li. Lc ht in t c gi tr t l thun vi bnh phng dng in v t l nghch vi

khong cch khe hmch t : .Khi dng in trong cun dy nhhn dng tc ng i < Itd th lc ht in t nh

hn lc ko l xo F < Flx, tm ng ng yn.

Khi i > Itd th lc ht in t ln hn ko l xo F > Flx, tm ng b ht v pha lm

cho khe hmch t nh nht, tc l ht v pha phn tnh. Khi khe hmch t nh, lc ht

cng tng, tm ng c ht dt khot v pha phn tnh v tip im ng cng vo

tip im tnh.

Khi dng in trong cun dy gim I < Itd lc l xo s thng lc ht in t. L xo

ko tm ng ra khi phn tnh, khe hmch ttng, lc in t cng gim, l xo ko dt

khot tm ng v, tip im ng ri khi tip im tnh.

Cc thng scbn

in p nh mc cun ht l in p cp cho cun ht lm vic ch lu di.

in p ny c th l 9V, 12V, 24V, 110V, 440V mt chiu v 24V, 110V, 220V,

440V xoay chiu. in p ny ghi trn cun ht.

7/31/2019 92844399-LVTN-1-2012-2

54/74


50

in p nh mc : in p lm vic lu di ca mch in m rle khng ch, in

p nh mc c th l 24V, 110V, 220V, 440V mt chiu v 24V, 110V, 127V, 220V,

380V, 500V xoay chiu.

Dng in nh mc : dng in di hn qua tip im ca rle m khng lm tip

im hng.

Tui thc kh : c tnh bng s ln ng ngt, thng l vi trm ngn ln ng

ngt khng in v 1 trm ngn ln ng ngt c dng nh mc.

in p cch in : in p thcch in.

Thi gian tc ng : l khong thi gian k tlc dng in vt qu gi trtc ng

n lc phn ng c ht hon ton vo phn tnh, thng vo khong t 2- 20ms.

Tn stc ng : l s ln tc ng trong mt n v thi gian.

7/31/2019 92844399-LVTN-1-2012-2

55/74


51

Chng 5

THIT K V THC HIN PHN MM5.1 Quy trnh iu khin

i tng iu khin m ti mun hng n l mt quy trnh iu khin ha cht

trong l phn ng ha hc. Trong mc ch quan trng l iu khin cho l phn ng

mt nhit n nh, m hiu sut ca phn ng t c l tt nht. Phn ng Friedel-

Craft alkyl havi vic to ra cht 4- methylacetophenone l mt phn ng ph hp vi m

hnh thit k, cng nh yu cu viu khin nhit trong l phn ng.

Hai ha cht tham gia phn ng s ln lt c a vo l phn ng. Sau hn

hp trong l phn ng sc khuy trn. Nhit ca l phn ng sc duy tr gi tr

mong mun bng cch iu chnh cng sut ca nhit in tr. Trong qu trnh gia nhit cho

l phn ng, cht xc tc AlCl3 sc cho t t vo.

i vi cc i tng c m hnh ton phc tp nh trn, vic xc nh m hnh ton

ca n trnn kh khn . V th s dng phng php PID iu khin i tng trnn

khng chnh xc. PID ml phng php iu khin m cc thng s Kp, Ki, Kd c th

t chnh nh theo tng giai on. Ngay c khi c nhiu, biu khin PID mvn c kh

nng tiu khin i tng theo 1 gi trn nh, xc lp nh trc khi gp nhiu.

7/31/2019 92844399-LVTN-1-2012-2

56/74


52

5.2 Lu gii thut

5.2.1 Lu hot ng ca h thng

Khi ng h thng

Nhp cc gi tr t SP chocc bnh cha A, B, C

H_B_PV H_B_SPH_A_PV H_A_SP H_C_PV H_C_SP

Van A m Van B m Van C m

ng van Ang van B ng van C

ng c khuy

END STEP1

S

SS

7/31/2019 92844399-LVTN-1-2012-2

57/74


53

5.2.2 Lu gii thut PID

Start PID

Nhp cc thng s Kp, Ki, Kd

Udk > 0

Tnh e(0) =Nhit t -Nhit hin ti

Nhp thng s Nhit t

Tnh A0 = Kp + Kd/T + Ki * T/2;A1 = - Kp2* Kd/T + Ki* T/2;

A2 = Kd/T

Gn e(-2) = e(-1) = 0; u(-1) = 0;

Tnh Udk = A0 * e(0) + A1* e(-1) + A2 * e (-2)

Udk < Udkmax

Udk = 0

Udk =Udkmax

Xut xung PWM : Ton = T * Udk/Udkmax;Toff = T - Ton

e(-2) = e(-1);e(-1) = e (0);u(-1) = Udk

END

S

S

7/31/2019 92844399-LVTN-1-2012-2

58/74


54

5.2.3 Lu gii thut PID m

X l m

Tnh ph thuc Ai(ET)

Tnh ph thuc Bj(DET)

Tm lut iu khin

Lut hp thnh Max Min

Cp nht min m bin ra

Ht Lut

Lut iu khin k tip

Gii m

No

Yes

7/31/2019 92844399-LVTN-1-2012-2

59/74

7/31/2019 92844399-LVTN-1-2012-2

60/74


56

5.3 Cc phn mm lp trnh cho PLC Schneider Premium

PLC thuc h Premium l mt trong nhng PLC c cu hnh mnh nht hin nay.

y ta xt n PLC TSX P57 3634M ca h TSX Premium thuc hng Schneider. H TSX

Premium ny ng dng cho iu khin lp trnh loi trung v phc tp c cu to bng

nhng module lp ghp nhau cho php rt d mrng v thay i theo tng chc nng ng

dng. Mt h thng iu khin PLC c xy dng da trn cc RACK c lien kt qua

Bus-x kt ni. Trn mi Rack c th b tr nhiu module c chc nng khc nhau,bao gm:

module ngun,module processor, module giao tip vo ra, module I/O TOR, module analog

ng vo, module analog ng ra

Sau y, ta s ln lt gii thiu cc module s dng trong lun vn :

Module ngun : TSX PSY 2600. y l module ngun cung cp VAC c

kch cchun, c 3 n hin th l OK, BAT, 24.

Module vi xl : TSX P57 3634M.y l module vi x l c b nhRam

192kb v c khe cm PCMCIA cho card mrng b nh, c khe cm

PCMCIA cho card truyn thng. C 5 n hin th l RUN, ERR, I/O,

TERR, FIP.

Module giao tip u vo TSX DEY 08D2.

Module giao tip u ra TSX DSY 08T2.

Module AnalogTSX AEY 414.y l module c cc cng ly mu tn hiu

vo l Analog, bin i thnh tn hiu Digital cho PLC phn tch v x l. C

4 knh Analog, phn gii t12 n 16 bit, thi gian chuyn i l

1ms/knh.

5.3.1 Gii thiu v phn mm Unity Pro

y l phn mm lp trnh iu khin cho PLC ca hng Schneider. Di y l mt

sbc c bn c thc hin trong lun vn.

7/31/2019 92844399-LVTN-1-2012-2

61/74


57

Bc 1 : To Project mi trn Unity Pro vi PAC TSX P573634M, v cu

hnh cc Rack/Module nh nu phn trn.

Bc 2 : To Ethernet.

Sau cu hnh a ch IP cho PLC. y,ta chn a ch IP l 192.168.1.41.

Sau ta Set Address

Bc 3 : Vo mc Variables & FB instances/Elementary Variables to cc

bin s dng trong chng trnh.

Bc 4 : Vo mc Program/Tasks/MAST/Sections to 1 section mi v 1

ngn ng lp trnh tin hnh lp trnh.

7/31/2019 92844399-LVTN-1-2012-2

62/74


58

Tm tt cch chn v phn b bin dng trong chng trnh

Danh sch cc bin ni

STT Tn bin a ch Ni dung1 Valve_A %M1

Cc bin dng iu khin ng mvan2 Valve_B %M23 Valve_C %M34 Valve_Reactor %M45 Motor %M5 Bin iu khin ng c6 Start %M6 Bin cho php h thng hot ng7 Stop %M7 Bin dng ton h th ng8 Run %M10 Bin hin th h th ng hot ng9 Ong_A %M11

Bin hin thi trng thi trong cc ng dn

10 Ong_B %M12

11 Ong_C %M1312 Ong_D %M1413 RTD %M15 Bin hin th th nhit 14 start_PIDfuzzyscada %M16 Bin hot ng ca ch PID fuzzy15 start_PIDscada %M17 Bin hot ng ca ch PID16 Tank_A_level_SP %MW1

Bin hin th gi trt mc cht lng ca3 bnh

17 Tank_B_level_SP %MW218 Tank_C_level_SP %MW319 Tank_A_level_PV %MW5

Bin hin th gi tro hin ti mc chtlng ca 3 bnh

20 Tank_B_level_PV %MW6

21 Tank_C_level_PV %MW722 Temp_SP %MW9 Bin hin thi gi trt ca nhit 23 Kpscada %MW11

Bin hin th thng s Kp, Ki, Kd ca bPID fuzzy

24 Kdscada %MW1325 Kiscada %MW1526 tamETscada %MW17 Bin hin th t m sai lch nhit (SLN)27 tamDETscada %MW19 Bin hin th tm ca o hm SLN28 KdPIDscada %MW21

Bin hin th gi trt ca 3 thng s Kp,Ki, Kd ca b PID

29 KiPIDscada %MW2330 KpPIDscada %MW2531 Temp_PV %MW27 Bin hin th gi tro c ca nhit

Danh sch cc bin ng ra

STT Tn bin a ch Ni dung1 vanA %Q0.3.1

Bin iu khin ng mvan2 vanB %Q0.3.03 vanC %Q0.3.44 vanD %Q0.3.55 khuay %Q0.3.2 Bin iu khin ng c6 OUT %Q0.3.6 Bin iu khin nhit in tr(PIDfuzzy)7 OUTPID %Q0.3.7 Bin iu khin nhit in tr(PID)

Danh sch cc bin Analog ng vo

7/31/2019 92844399-LVTN-1-2012-2

63/74


59

STT Tn bin a ch Ni dung1 Docao_binhA %ch0.4.0 Cm bin mc cho bnh A2 Docao_binhB %ch0.4.1 Cm bin mc cho bnh B3 Docao_binhC %ch0.4.2 Cm bin mc cho bnh C4 Temperature %ch0.4.3 Cm bin nhit

Ngoi ra cn c cc bin dng cho qu trnh tnh ton cc thng s dnh cho gii thut

PID cng nh PID m.

5.4 Thit k giao din gim st v iu khin vi SCADA

Vijeo Citectmt phn mm gim st c pht trin vi s hp tc ca Citect Pty

Ltd (mt cng ty con ca Schneider).Vijeo Citect c 3 chng trnh chnh, bao gm: Citect

Explorer, Citect Graphics Builder, Citect Project Editor.

Di y l cc bc c bn thchin trong phn mm Vijeo Citect phc v cho lun vn.

Bc 1: i vi chng trnh Citect Explorer, ta to 1 project mi. Sau

vo Graphic/pages to 1 trang mi.

Bc 2: i vi chng trnh Citect Project Editor. y l ni cu hnh

cc Board, Port, khai bo Cluster, Servers, Tags.

Bc 3: i vi chng trnh Citect Graphics Builder. y l ni to cc

trang ha, giao din hin thcc s h thng phc vcho iu khincng nh gim st.

Trn y l mt s khi nim c bn vPLC Premium cng nh cc phn mm phc

v chnh cho Lun Vn. chng 5, ta si su vo vn ny hn na.

5.4.1 Cu hnh truyn thng cho h thng

Sau khi to 1 project mi ti Citect Explore, ta vo Citect project Editor chn mc

Communication tin hnh cu hnh board, port, khai bo cluster, khai bo cc I/O server,

cc Trend server.

7/31/2019 92844399-LVTN-1-2012-2

64/74


60

Hnh 6.1 Cu hnh Board

Hnh 6.2 Cu hnh ports ch m phng

Hnh 6.3 Cu hnh ports ch Runtime

7/31/2019 92844399-LVTN-1-2012-2

65/74


61

Hnh 6.4 To Cluster, I/O server v Trend Server

5.4.2 Danh sch cc Tag sdng trong h thng

c im ca nhng bin ny l c a ch trng vi cc bin bn Unity Pro. Mc

ch l to ra mi lin h gia 2 phn mm, thun li cho vic dng phn mm ny iu

khin cc bin bn phn mm kia v ngc li. trong Lun vn ny, ti t tn bin cng

nh tn a ch trng vi bn Unity Pro tin cho vic qun l cng nh lp trnh.

STT Tn bin a ch Kiu1 Valve_A %M1 DIGITAL2 Valve_B %M2 DIGITAL3 Valve_C %M3 DIGITAL4 Valve_Reactor %M4 DIGITAL5 Motor %M5 DIGITAL6 Start %M6 DIGITAL7 Stop %M7 DIGITAL8 Run %M10 DIGITAL9 Ong_A %M11 DIGITAL

10 Ong_B %M12 DIGITAL

11 Ong_C %M13 DIGITAL12 Ong_D %M14 DIGITAL

7/31/2019 92844399-LVTN-1-2012-2

66/74


62

13 RTD %M1514 start_PIDfuzzyscada %M16 DIGITAL15 start_PIDscada %M17 DIGITAL16 Tank_A_level_SP %MW1 INT17 Tank_B_level_SP %MW2 INT

18 Tank_C_level_SP %MW3 INT19 Tank_A_level_PV %MW5 INT20 Tank_B_level_PV %MW6 INT21 Tank_C_level_PV %MW7 INT22 Temp_SP %MW9 REAL23 Kpscada %MW11 REAL24 Kdscada %MW13 REAL25 Kiscada %MW15 REAL26 tamETscada %MW17 REAL27 tamDETscada %MW19 REAL

28 KdPIDscada %MW21 REAL29 KiPIDscada %MW23 REAL30 KpPIDscada %MW25 REAL31 Temp_PV %MW27 REAL

7/31/2019 92844399-LVTN-1-2012-2

67/74


63

Chng 6

KT QU THC HIN

6.1 Giao din chng trnh iu khin v gim st

Gii thiu v cch s dng v iu khin phn mm.

Trc ht ta phi nhp 3 thng s gi trt cho 3 cm bin mc ca 3 bnh A,

B, C. Sau nhn vo nt Start, h thng s hot ng. Lc ny cc van A, B, C scm, nc t 3 bnh A, B, C sc vo bnh phn ng. n khi gi tro t hin

ti nhhn hoc bng vi gi trt, ln lt 3 van A, B, C sc ng. Lc ny

ng c khuy s bt u hot ng.

Tip theo, ta s tin hnh chn 1 trong 2 cch iu khin nhit .

ch PID fuzzy, chng ta s tin hnh chn Nhit t v tm ca sai

lch nhit ET v tm ca o hm sai lch nhit DET. Sau nhn vo buton

PID fuzzy. H thng iu khin nhit s hot ng.

chPID , chng ta cng tin hnh chn nhit t v cc thng s Kp,

Ki, Kd ca bPID. Sau nhn vo button PID. H thng iu khin nhit s hot

ng.

Hnh 7.1 Giao din h thng trn SCADA

7/31/2019 92844399-LVTN-1-2012-2

68/74

7/31/2019 92844399-LVTN-1-2012-2

69/74


65

Hnh 7.2 th nhit ca p ng vng h

p dng phng php ZIEGLER-NICHOLS :

Ta xc nh c cc thng s sau :

L = 225 (s)

T = 1230 (s)

Suy ra, hm truyn ca l nhit c dng nh sau :

Da vo hm truyn ta c th thy, l nhit c thi gian tr kh cao. V vy nhit

ca h thng c th xc lp ti nhit ta mong mun th cng phi mt mt khong thi

gian tng i di.

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

c tuyn vng h

7/31/2019 92844399-LVTN-1-2012-2

70/74


66

Cc thng s ca biu khin PID sc tnh theo phng php p ng nc ca

ZIEGLER-NICHOLS

Vi

Nh vy, Thng s Kp, Ti, Td ca h thng l nhit ny s l :

Ti = 2 * L = 2 * 225 = 450

Td = L/2 = 225/2 = 112.5

M phng trn Matlab vi thng s Kp, Ti, Td va tm

Hnh 7.3 : M phng thng sPID ca h thng

7/31/2019 92844399-LVTN-1-2012-2

71/74


67

Nhn xt : nhn vo p ng m phng ca h thng khi iu khin PID ta thy thi gian

nhit xc lp l 2500 giy. vt lPOT ca h thng l khong 22% . Sai sxc lp bng 0.

6.3 iu khin nhit l nhit bng phng php PID

Ta tin hnh nhp cc thng s PID va tm vo phn mm Scada

Hnh 7.4 Nhp thng sPID vo phn mm

Vi Nhit t l :

Hnh 7.5 th nhit khi iu khin bng PID

7/31/2019 92844399-LVTN-1-2012-2

72/74


68

Nhn xt : vt ll 6.7 % .

Thi gian xc lp l 48 pht 15 giy = 2895 giy

Thi gian ln 16 pht 25 giy = 985 giy

Sai sxc lp l

6.4 iu khin nhit l nhit bng phng php PID fuzzy

Ta tin hnh nhp thng s l tm ca sai lch nhit v tm ca o hm sai lch

nhit cho h thng.

y ta chn tm ET l , tm DET l Cc thng sKpmax, Kpmin, Kdmax, Kdmin c nhp vo code ca chng trnh.

y ta chn Kpmax = 20, Kpmin = 10; Kdmax = 1000, Kdmin = 800;

Hnh 7.7 th nhit khi iu khin bng PID fuzzy

Nhn xt : vt ll 7.16%.

Thi gian ln l 16 pht 45 giy = 1005 giy

Thi gian xc lp l 39 ph 50 giy = 2390 giy

Sai sxc lp l 0.4 C

7/31/2019 92844399-LVTN-1-2012-2

73/74


69

KT LUN V HNG PHT TRIN

Kt lun

So vi Phng php PID thng, Phng php PID mc sai s xc lp t hn cng

nh thi gian xc lp nhanh hn. V thi gian ln v vt lc2 phng php l tng

ng nhau.

Ngoi ra cn 1 u im ni bt ca PID mso vi PID thng l khnng t chnh

nh cc h s Kp, Ki, Kd. Khi xy ra nhiu, phng php PID ms t chnh li cc thng

s cho ph hp vi vic iu khin cc i tng

Hng pht trin

trong ti ny, m hnh chdng m phng cho vic iu khin ha cht trong

l phn ng. V vy, ti t c ng dng thc tin cn sa cha m hnh cho ph hp

vi yu cu iu khin ha cht. Bao gm vic thay i thnh ha cht tht v kim sot l

phn ng mt cch cht ch nhm to ra mt h thng an ton cho ngi s dng.

Ngoi ra, cng cn to 1 lut hp thnh cho Kp, Ki, Kd t c thi gian xc lp

nhanh hn, vt l v sai s xc lp t hn na.

7/31/2019 92844399-LVTN-1-2012-2

74/74


TI LIU THAM KHO

1. L thuyt iu khin hin i - Nguyn ThPhng H

2. L thuyt iu khin m- Dng Minh Tr & Nguyn Don Phc3. Fuzzy LogicRobert Fuller

4. Fuzzy Logic with Engineer ApplicationTimothy J.Ross & McGraw Hill

5. Tng ho qu trnh cng ngh - Trng nh Chu

6. Ti liu ging dy SCADA - Trng nh Chu

Ngoi ra cn c cc ti liu trn mng.

92844399-lvtn-1-2012-2

Documents