Điều khiển và giám sát lò nhiệt

8/21/2019 iu khin v gim st l nhit

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LUAN VAN TOT NGHIEP IEU KHIEN & GIAM SAT LO NHIET

GVHD : BUI THANH HUYEN & 1 & SVTH :NGUYEN MINH TAM

PHAN 1GII THIEUCAC OI TNGLIEN QUAN


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CHNG 1 :GII THIEU HE THONGIEU KHIEN NHIET OVA NHIEM VU LUAN VAN

1.1. Gii thieu ve nhiet o va phng phap ieu khien :Nhiet o la mot ai lng vat ly hien dien khap ni va trong nhieu lnh

vc, trong cong nghiep cung nh trong sinh hoat. Nhiet o tr nen la moi quantam hang au cho cac nha thiet ke may va ieu khien nhiet o tr thanh mottrong nhng muc tieu cua nganh ieu Khien T ong. Trong nhieu lnh vc cuanen kinh te, van e o va kiem soat nhiet o la mot qua trnh khong the thieuc, nhat la trong cong nghiep. o nhiet o trong cong nghiep luon gan lienvi quy trnh cong nghe cua san xuat , viec o va kiem soat nhiet o tot quyetnh rat nhieu en chat lng cua san pham trong cac nganh cong nghiep thcpham, luyen kim, xi mang, gom s, cong nghiep che tao ong c ot trong...

Tuy theo tnh chat , yeu cau cua qua trnh ma no oi hoi cac phngphap ieu khien thch hp. Tnh on nh va chnh xac cua nhiet o cung coi hoi ay at ra cac van e can phai giai quyet.

Mot ieu thc s can thiet la ta phai khao sat ky oi tng cung capnhiet ma ta can phai ieu khien e dan en mo hnh toan hoc cu the. T ochung ta se giai quyet bai toan ieu khien tren c s ly thuyet a nghien cusan . He thong ieu khien nhiet o co the phan lam hai loai : he thong ieukhien hoi tiep (feedback control system) va he thong ieu khien tuan t

(sequence control system) . ieu khien hoi tiep thng c xac nh va giam sat ket qua ieu khien ,

so sanh no vi yeu cau thc thi (v du iem at) va t ong ieu chnh ung .

ieu khien tuan t thc hien tng bc ieu khien tuy theo hoat ong ieukhien trc khi xac nh tuan t .


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Mot he thong muon chnh xac can phai thc hien hoi tiep tn hieu ve sosanh vi tn hieu vao va ra se c gi en bo ieu khien hieu chnh au ra .He thong ieu khien hoi tiep co nhieu u iem nen thng c thay trong cac

he thong t ong .Cac phng phap ieu khien khac nhau nhng nguyen tac ieu khien la

giong nhau . Mot he thong ieu khien nhiet o da tren nguyen tac he thonghoi tiep co dang tong quat nh hnh di ay :

ay la mot he thong hoi tiep qua bo cam bien cho tn hieu o lng nhieto ve so sanh vi gia tr at , sai lech gia tn hieu at va o se c a ti boieu khien tao tn hieu ieu khien cong suat cap cho bo phan gia nhiet . Nhvay cac phng phap ieu khien khac nhau ve ban chat la do cac bo ieu khienkhac nhau tao nen .

1.2.Nhiem vu luan van :1.2.1.Nhiem vu cua luan van la tm hieu thc hien cac muc tieu sau :

1. S dung PLC SIEMENS S7-300 ieu khien lo nhiet bang phngphap m lai

2. Giam sat ieu khien va thu thap d lieu hoat ong cua lo nhiet sdung phan mem WinCC (Windows Control Center)

1.2.2.Pham vi ieu khien : do trong khuon kho gii han cua luan van nen em ch giihan trong pham vi nh sau :

oi tng : PLC S7-300 (CPU 314IFM), modun AI SM331chuyen dung co kha nang oc trc tiep tn hieu t cac cam biennh Thermocoup, PT... va lo nhiet dan dung

Cam bien : Thermocoup TC loai K co o nhay nhiet 40V/10C

X Bo ieu khien Bo phan gia nhiet

Cam bien nhiet o

Gia tr at Nhiet o


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Phng tien ieu khien : OP (Operation Panel), tuy nhien cthay the bang PC ( Personal Computer ) vi he ieu hanhWindows 98

Giao tiep may tnh : thong qua phan mem WInCC cua cong tySIEMENS Bo ieu khien m va PID : tch hp trong PLC S7-300 cua congty SIEMENS

Chng trnh ieu khien : soan thao bang phan mem Step7 cuacong ty SIEMENS


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CHNG 2 : GII THIEU PLC SIEMEN VA PHAN MEMSTEP71. GII THIEU PLC

PLC (Programmable Logic Control): thiet b ieu khien logic kha trnh laloai thiet b cho phep thc hien linh hoat cac thuat toan ieu khien logic thongqua mot ngon ng lap trnh, thay cho viec phai the hien thuat toan o bangmach logic.

1.1. Vai net ve lch s cua PLC:PLC bat au phat trien t nam 1968 e ap ng mot yeu cau cua hang

Hydraumatic Division of General Motors (GM). Thi gian nay, GM thng matnhieu thi gian e thay the he thong ieu khien da tren relay moi khi can hieuchnh hay thay oi mau ma cua xe hi. e giam chi ph cao ve viec noi lai day,ky thuat ieu khien cua GM goi he thong ien t co s linh ong cua may tnh,co the lap trnh va bao dng bi cac ky s va cac chuyen gia trong x nghiep.No cung co the chu ng c bui ban cua khong kh, s rung, nhieu ien, oam va nhiet o cao trong cac moi trng cong nghiep.

PLC au tien c lap at vao nam 1969 va thanh cong nhanh chong.Nhng chc nang giong nh relay c thay the, tham ch nhng PLC au tien

cung co o tin cay hn he thong relay, ly do la thanh phan ien t cua no ngian so vi cac phan chuyen ong cua cac relay ien c. No chiem t khonggian hn cac counters, timers va cac thanh phan ieu khien khac ma no thaythe. Kha nang lap trnh lai cua no rat ln khi co s thay oi ve ke hoach ieukhien.

Co le cha khoa ln nhat e PLC co the chap nhan c trong congnghiep la ngon ng lap trnh au tien da tren gian o hnh thang (ladderdiagram) va cac ky hieu thng dung cua th ien.

Hau het cac nhan vien trong x nghiep c huan luyen theo mc logic hnh

thang nen ho de dang chap nhan no trong PLC. Thc ra mc logic hnh thang co vai trochung trong viec lap trnh va sa cha, cho du ngon ng lap trnh tan tien hn a cphat trien.

1.2 . ac iem cua PLC :Mot he ieu khien c goi la ieu khien lap trnh c khi cac ngo ra

va cac ngo vao c noi ket vi nhau thong qua mot bo ieu khien co the laptrnh c. Chc nang cua mot he ieu khien c chuyen oi thanh mot


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chng trnh va c nap vao bo ieu khien. Bo ieu khien da theo chngtrnh nay e thc hien qua trnh ieu khien cac ngo ra va cac thong so ngo vao.

Chung ta co nen dung mot ngon ng co the lap trnh ? Trong nhng nam1970 va au thap ky 80 nhieu ky s, nha ieu hanh san xuat va nhng ngi

thiet ke he thong a ton nhieu thi gian e tranh luan ve e tai nay song songo la chi ph cho PLC. Ngay nay, ngi ta chap nhan PLC v no tr nen kinh teva co hieu qua trong he thong ieu khien can t ba en bon relay hay nhieu hntrong khi o chi ph cho mot PLC nho ch vai tram dollars. Cac nha san xuat athieu suat va chat lng len hang au nen chi ph tr nen khong quan trong.

Vi s phat trien manh me cua ky thuat may tnh nhng chung ta vandung PLC e ieu khien may trong cong nghiep la v:

Mot PLC n gian co the dung trong nhieu lnh vc congnghiep, t viec ieu khien lap i lap lai mot tac vu n giannao o cho en viec ieu khien e chay ch mot tac vu phctap.

Cac chng trnh ieu khien co the c thay oi mot cach dedang, cai tien e phu hp vi hoat ong mi.

Chng trnh ieu khien co the de dang nap vao nhieu PLC, dedang trao oi chng trnh.

Thi gian ap ng nhanh tr thanh mot tieu chuan oi vi PLC.ieu nay la can thiet bi v trong ieu khien cong nghiep, cac

tn hieu t cac cam bien thay oi rat nhanh. Trong PLC co san cac bo em, bo nh th co the s dung vi

nhieu o chnh xac khac nhau, khi trong qua trnh ieu khienco can them.

Co the chap nhan c ve tnh kinh te khi PLC c s dungtrong cac he thong ieu khien co 4 relay hay nhieu hn.

Khi dung PLC co the giao tiep vi cac thiet b nh en LED 7oan, bo chon nhan ( thumbwheels), cac chc nang ve x ly tn

hieu analog, x ly tn hieu tan so cao... Cho phep co the hien th o hoa tren mot he thong. Truyen thong: Nhng hoat ong giao tiep vi nhng PLC khac

hay mang may tnh giup cho viec thu thap d lieu va trao oithong tin c de dang.


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Cac thiet ke au tien la nham thay the cho phan cng cac relay day noiva cac logic thi gian. Tuy nhien, ben canh o viec oi hoi tang cng dunglng nh va tnh de dang cho PLC ma van am bao c toc o x ly cungnh gia ca...

Chnh nhng ieu nay a gay ra s quan tam sau sac en viec s dungPLC trong cong nghiep. Cac tap lenh nhanh chong i t cac lenh logic n gianen cac lenh em, nh thi, thanh ghi dch... sau o la cac chc nang lam toantren cac may ln... S phat trien cua may tnh dan en cac bo PLC co dunglng nh ln hn, so lng I/O nhieu hn. PLC s dung bo nh co the lap trnhc e lu tr cac lenh va thc thi cac chc nang ac biet gom co ieu khienON/OFF, nh thi, em, th t, so hoc va x ly d lieu. Vi moi he ieu khien,cac tn hieu au vao, au ra c noi vao PLC. PLC hoat ong bang cach kiemtra lai tn hieu cac lenh (a c lap trnh trong bo nh), sau o ghi ket qua vao

ngo ra a en cac thiet b ieu khien.Trong PLC, phan cng CPU va chng trnh la hai n v c ban choqua trnh ieu khien hoac x ly he thong. Chc nang ma bo ieu khien can thchien se c xac nh bi mot chng trnh. Chng trnh nay c nap san vaobo nh cua PLC, PLC se thc hien viec ieu khien da vao chng trnh nay.Nh vay neu muon thay oi hay m rong chc nang cua quy trnh cong nghe, tach can thay oi chng trnh ben trong bo nh cua PLC. Viec thay oi hay mrong chc nang se c thc hien mot cach de dang ma khong can mot s canthiep mang tnh vat ly nao so vi cac bo ieu khien dung day noi va relay.

Nhieu PLC giup gia tang s canh tranh. Cac qua trnh thng s dungPLC bao gom: ong goi, ong chai va van chuyen, x ly vat lieu, van hanhmay, phat nang lng, nhng he thong ieu khien xay dng, he thong bao ve,day chuyen t ong, ve ng va x ly nc. PLC ng dung trong nhieu nganhcong nghiep bao gom thc an va o uong, chuyen ong t ong, hoa hoc, nha,bot giay va giay, dc va vat lieu. Thc ra, bat ky mot ng dung nao can enien eu co the s dung PLC.

So sanh PLC vi mot so he thong khac:Ch tieu sosanh

R-le Mach so May tnh PLCGia thanh tngchc nang Kha thap Thap Cao ThapKch thc vatly Ln Rat gon Kha gon Rat gonToc o ieukhien Cham Rat nhanh Kha nhanh Nhanh


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Kha nangchong nhieu Xuat sac Tot Kha tot TotLap at Mat thi gianthiet ke va lapat

Mat thi gianthiet ke Mat nhieuthi gian laptrnh

Lap trnhva lap atn gianKha nang ieukhien tac vuphc tap

Khong Co Co CoDe thay oiieu khien Rat kho Kho Kho n gianCong tac baotr Kem-co ratnhieu cong tac Kem- neu ICc han Kem- co ratnhieu machien t

chuyendung

Tot- cacmodulec tieuchuan hoa

1.3. Mot vai u iem cua PLC trong t ong:u iem :

- Thi gian lap at cong trnh ngan gon.

- De dang thay oi ma khong ton that tai chnh.

- Co the tnh toan c chnh xac gia thanh.

- Can t thi gian huan luyen.

- De dang thay oi thiet ke nh phan mem.

- ng dung trong pham vi rong.

- De bao tr, cac ch th ra vao giup x ly s co de hn vanhanh hn.

-o tin cay cao.

-

Chuan hoa c phan cng ieu khien.

- Thch ng trong moi trng khac nghiet: nhiet o, o am,ien ap dao ong, tieng on

.

1 3 1 ieu khien giam sat:


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- Thay cho ieu khien Relay.

- Thi gian em.

- Thay cho cac panels ieu khien mach in.

- ieu khien t ong va ban t ong bang tay,cac may va cac

qua trnh.

1 3 2 ieu khien day:Cac phep toan so hoc.

- Cung cap thong tin.

-ieu khien lien tuc: nhiet o, ap suat...

-ieu khien P.I.D.

-ieu khien ong c chap hanh.

-ieu khien ong c bc.

1 3 3 ieu khien mem deo:-ieu khien qua trnh va bao ong.

- Phat hien loi vaieu hanh.

- Ghep noi qua may tnh.

- Ghep noi vi may in.

- Mang t ong hoa x nghiep.

- Mang cuc bo.- Mang m rong.

1.4. Cau truc cua mot PLC :

- Mot he thong lap trnh c ban phai gom co hai phan: khoi x lytrung tam (CPU: Central Processing Unit) va he thong giao tiep vao/ra (I/O)

Hnh 1.4.a-S o khoi cua he thong ieu khien lap trnh

CENTRALPROCESSING

UNIT

INPUT

OUTPUT


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- Khoi ieu khien trung tam (CPU) gom 3 phan: bo x ly, he thongbo nh va he thong nguon cung cap

Hnh 1.4.b-S o khoi tong quat cua CPU

2. Gii thieu PLC SIEMEN2.1. Cau truc , chc nang1- Cac khoi cua S7-300- Khoi tn hieu (SM)

+ Khoi ngo vao digital: 24V DC, 120/230V AC+ Khoi ngo ra digital: 24V DC, ngat t+ Khoi ngo vao analog: Ap, dong, ien tr, cap nhiet+ Khoi ngo vao digital: 24V DC, Ap, dong

- Khoi giao tiep (IM): Khoi IM360/IM365 va IM365 dung e noinhieu cau hnh. Chung ieu khien thanh ghi cua he thong.

- Khoi gia lap (DM): Khoi DM 370 d phong cac khoi tn hieu chac ch nh. Chang han nh danh cho cho cac khoi trong tng lai se lap at.- Khoi chc nang (FM): The hien nhng chc nang ac biet sau

+ em+ nh v+ ieu khien hoi tiep

- X ly lien lac (CP): Cung cap nhng tien nghi lien lac sau+ Noi iem iem+ Mang PROFIBUS

+ Ethernet cong nghiep- Phu tung: Cac thanh noi va bo phan noi pha trc mat2.2- Cac thanh phan c ban cua S7-300- Dan nhap: Bang ke cac thiet b cau hnh S7-300

Bo phan Nhiem vuRanh trt La gia cua S7-300

Processcor Memory

PowerSupply


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Nguon cung cap (PS) Bien oi ap khu vc (120/230V) ra 24V DC la aplam viec cua S7-300

Vi x ly (CPU) Thc hien chng trnh cua ngi dung phu kien:khoi nh, pin lu tr

Khoi giao tiep (IM) Ket noi cac thanh d lieu gia cac gia (day)Khoi tn hieu (SM)(Digital/Analog)

Lam thch nghi vinhieu mc x ly cua S7-300.Phu kien: noi thanh ghi, noi pha trc

Khoi chc nang (FM) Thc hien nhiem vu nh v, ieu khien hoi tiepv.v

X ly truyen thong(CP)

e noi cac bo phan PLC vi nhau. Phu kien: cap,phan mem, khoi giao tiep

- Ray: Nguon cung cap, CPU, IM, va 8 loai khoi khac c gan

chat vao thanh ray.- Nguon:+ Nguon cung cap co nhieu kieu: 2A, 5A, en 10A ap 24V.

Nguon ap cung cap la lpai cach ly, co bao ve ngan mach, ap on nh khi khongtai. Co LED bao trang thai h hong. en LED nhap nhay khi ngan mach.

+ Ban lu y nut oi ien ap s cap 120V va 230V.- Khoi vi x ly: CPU co nhng thanh phan sau ay mat trc:

+ Bao trang thai va bao loi+ Cong tac chuyen oi cach van hanh vi 4 chon la

+ Moi noi nguon cung cap 24V+ Phan giao tiep nhieu iem MPI e noi vi cac thiet b laptrnh hay PLC khac

+ Hoc cha pin (khong co oi vi CPU312/FM)+ Hoc cha khoi nh (khong co oi vi CPU312/FM, 314/FM)

- Khoi giao tiep: Co the sap xep cau hnh theo nhieu kieu.- Khoi tn hieu: Nhng khoi nay c chon tuy theo day ien ap s

dung va ien ap ngo ra. Co bo noi bus ieu khien cho moi khoi, va cac vong noicac bus d lieu pha sau. Tn hieu x ly bo noi pha trc.

- Noi lien ket: Ban can co cap e noi CPU trc tiep vi may laptrnh.- Cap: Cap PROFIBUS va cap noi can co e noi nhieu PLC vi

nhau.- FM: Nhng khoi chc nang thay the cac khoi IP.- CP: Bo x ly truyen thong danh cho he thong bus d lieu cua

PROFIBUS.


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2.3- Kha nang m rong cua S7-300- o m rong toi a: cho phep m rong en 32 khoi, nhieu nhat la

8 khoi tren moi gia (chong). Khong co qui luat ve so ranh ang ky cho cac khoitn hieu, cac khoi chc nang, va cac bo x ly truyen thong. Ngha la chung co

the chiem bat ky ranh.- Khoi giao tiep (IM):+ Khoi giao tiep (IM 360/361) c dung e hoi tiep thanh ghi

d lieu gia. Bo IMS la khoi gi, va bo IMR la khoi nhan. Cac khoi giao tiepphai dung ung ranh ch nh.

+ Neu can, nguon cung cap phai gan them gia m rong.+ Co loai khoi giao tiep ten IM 365 la dang tiet kiem dung cho

cau hnh kieu xep 2 khoi. (Khong dung cho nguon them; khong noi CP).- Phan oan noi bo:

+ Co vai khoi chc nang, chang han khoi FM NC, co the phaich nh cong I/O cho chung. Khoi FM co vung I/O rieng, va khoi nay co thetruy cap vung I/O nhanh chong. Vung I/O nay la phan oan noi bo.

+ Mot phan oan noi bo co the cau hnh cho tng ranh, CPUkhong the truy cap I/O.

- So ranh+ Ranh 1 en 3:ch nh thng trcRanh 1: PS (nguon cung cap), neu coRanh 2: CPU (vi x ly), neu coRanh 3: IM (khoi giao tiep), neu co+ Ranh 4 en 11 (t do ch nh): SM, FM, CP co the cam vao

bat c ranh nao- Khoang cach: cac loai cap vi o dai sau c dung cho cac

kieu sap xep cau hnh+ Cau hnh 2 chong vi IM 365 toi a 1m+ Cau hnh nhieu chong vi IM 360/361 toi a 10m.

2.4. Cau truc phan cngCac thanh phan trong cau truc cua S7-300

1. Gia chuan DIN: Nguon cung cap CPU, IM va nhieu nhatla 8 module co kha nang lap at tren mot gia.

2. Nguon cung cap: co kha nang vi dong ra 2A, 5A, 10A vaien ap ra 24V DC. ien ap ra phai cach biet, bao ve khi ngan mach va on nhnh khi lam viec khong tai. Mot en bao nguon lam viec che o bnh thng


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va en nhap nhay khi qua tai. Co the chon cong tac, chon li ien cung cap120V hay 230V AC.

3. Bo x ly trung tam: CPU c lap rap vi cac phan t at mat trc cua thiet b sau ay:

- en bao trang thai va bao loi.- Cong tac chon che o lam viec 4 v tr.- Cho noi cho nguon 24V.- Cong MPI cho thiet b lap trnh hoac cho ghep noi vi mot

PLC khac.- Ngan ng pin (khong co oi vi CPU 312).- Ranh at mot module (khong co oi vi CPU 312).

4. Module giao dien:tao kha nang ghep noi nhieu cau hnh.5. Module tn hieu: c la chon theo mien gii han cua tn

hieu vao va ra. Moi module co them mot bus noi e tao ra kha nang m rongtiep cac tn hieu o c noi bang au day cua bo noi.6. Cable noi (Cap): au day trc tiep vi thiet b lap trnh can co

mot cable danh cho may lap trnh PG... Neu noi mot vai PLC vi nhau trongmot mang can phai co cable profibus va bo noi cable.

7. FM: module chc nang thay cho cho module IP.8. CP: Bo x ly truyen thong danh cho he profibus.2.5. Modul m rong:c chia thanh 5 loai

1. PS (power supply): module nguon nuoi. Co 3 loai 2A, 5A, 10A2. SM (signal module): module m rong cong tn hieu vao ra. Bao

gom:- DI (digital input): module m rong cac cong vao so. So cac

cong vao so co the la 8, 16 hoac 32 tuy thuoc vao tng loai module.- DO (digital output): module m rong cac cong ra so. So cac

cong ra so co the la 8, 16 hoac 32 tuy thuoc vao tng loai module.- DI/DO: module m rong cac cong vao/ra so. So cac cong

vao/ra so co the la 8, 16 hoac 32 tuy thuoc vao tng loai module.- AI (analog input): module m rong cac cong vao tng t.

Chung chnh la bo chuyen oi so 12 bits (AD) tc la moi tn hieu tng t cchuyen thanh mot tn hieu so (nguyen) co o dai 12 bits. So cac cong vao tngt co the la 2/4 hoac 8 tuy tng loai module.

- AO (analog output): module m rong cac cong ra tng t.Chung chnh la bo chuyen oi so 12 bits (AD) tc la moi tn hieu tng t cchuyen thanh mot tn hieu so (nguyen) co o dai 12 bits. So cac cong ratng tco the la 2/4 hoac 8 tuy tng loai module.


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- AI/AO:module m rong cac cong vao/ra tng t. So cac congtng t co the la 4 vao/ 4 ra hoac 4 vao/2 ra tuy loai module.

3. IM (interface module): module ghep noi. ay la loai modulechuyen dung co nhiem vu noi tng nhom cac module m rong lai vi nhau

thanh mot khoi va c quan ly chung bi mot module CPU. Thong thng cacmodule m rong c ga lien vi nhau tren mot thanh goi la rack. Tren moirack ch co the ga c nhieu nhat 8 module m rong (khong ke module CPU,module nguon nuoi). Mot module CPU S7-300 co the lam viec trc tiep cvi nhieu nhat 8 rack va cac rack nay phai c noi vi nhau bang module IM.

4. FM (function module): module chc nang ieu khien rieng. Vdu module ieu khien ong c bc, ong c serco...

5. CP (communication module): module phuc vu truyen thongtrong mang gia cac PLC vi nhau hoac gia PLC vi may tnh.

CHNG 3 :TAP LENH S7-300Tham khao phu luc

CHNG 4. CHNG TRNH FCPA4.1 Chuan b mot Project cho viec khai bao bo ieu khien m bang FCPAChng trnh FCPA (Fuzzy Control Parameter Assinment) la phanmem ho trviec tao lap bo ieu khien m cho PLC Simatic S7-300 theo tng bc nh atrnh bayTrc het ta phai cai at FCPA tren may tnh ca nhan.Viec cai at thanh congFCPA oi hoi :- co t nhat 1Mbytes con trong trong o cng .


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- Chay di he ieu hanh Window 95/98 hoac NT.Toan bo chng trnh goc cua FCPA gom 2 phan Fuzzy/Toolva Fuzzy/FBvidung lng tong cong 2,27MB.e cai dat ,ta goi tep Setup .exe cuaFuzzy/Toolva cua Fuzzy/FBt Window va thc hien nhng ch dan hien trenSau khi a c cai dat, phan chnh cua FCPA se c tch hp trong Step7di th muc S7WRFUZ, cac cong cu ho tr khac c a vao th vien cuaphan mem Step7 cung nh ProjectFuzConEx. Xem hnh minh hoa

Bo ieu khien m c tong hp viFCPA co dang mot khoi d lieu (DB) cho

Project ng dung. Khoi DB tao bi FCPAse c goi la khoi DB mva c s dungcung viFB Fuzzy Controlco trong ProjectFuzConEx khi cai at chng trnhFuzzy/FB vi ten mac nh la FB30. Bivay trc khi s dung FCPA e tao lap DBm cho Project ng dung, bat buoc Projectng dung a phai co FB Fuzzy Control. Hnh 1: th vien cua FuzCon

V du Project ng dung cua ta co ten la FuzCon. Trc khi s dung FCPA etao lap khoi DB m cho Project ng dung FuzCon, ta phai sao chep FB FuzzyControl co ten mac nh FB30 t Project FuzConEx sang Project FuzCon. Cothe thay oi ten FB30 neu nh trong Project ng dung cua ta a co mot FB trungten.


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Hnh 2 : copy FB30 t v du FuzConEx sang Project hien hanh

4.2 Tao DB m Sau khi a chuan b mot Projct ng dung cho bo ieu khien m (Project co

cha FB Fuzzy Control), ta co the bat au s dung FCPA e tao lap DB m chobo ieu khien m va khoi DB m nay phai nam trong cung mot th muc vi FBFuzzy Control cua Project ng dung . e vao FCPA ta thc hien lenh goi t

Window theo th t.Start simatic step7 Fuzzy Control Parameter Assignmentkhi o tren man hnh se xuathien ca so

Do khoi DB m phainam trong mot Poject nao onen khi kch vao mot trong haibieu tng, FCPA se yeu cau tacho biet ten Project cha khoi

DB m o. Chang han khi kchvao bieu tng tao DB m miva khoi DB m c tao ra nayse phai nam trong Project coten FuzCon th ta phai cho FCPA Hnh 3: tap m s dung trong chng trnhbiet ten se c at cho khoi DB m,(vd DB2) va ten cua Project la FuzCon. Caso man hnh khai bao cac d lieu o co dang nh sau (Hnh 3)

Bien ngonng auvao

Bien ngonng au ra

Luat

hpthanh


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Sau khi a cho ay u ten Project, ten khoi DB m, ta an phm OK.Chng trnhFCPA se kiem tra lai trong Project FuzCon thc s a co khoi ham FuzzyControl hay cha bang thong bao liet ke tat ca cac khoi ham a co trong Projectng dung. Ta phai chon trongbang danh muc c liet ke ra o khoi ham Fuzzy

Control a c lay t Project FuzConExsang.An phm OK e xac nhan va ta bat au cong viec tong hp bo ieu khienm vi phan mem FCPA.

Trong luan van, tap m c xay dng vi hai au vao ET, DET va baau ra Kr, Kp va An_pha. ET la tn hieu sai lech t bo ieu khien va tr at,DET la ao ham sai lech. Kr, Kp, An-pha la cac tham so tnh toan c theophng phap Zhao Tomizuka va Isaka (xem them phan ly thuyet ieu khienm)

4.3.Khai bao so bien ngon ng vao raNeu tao mot DB m mi th sau khi an phmOK xac nhan khoi FB Fuzzy Control, chngtrnh FCPA se hoi so cac bien ngon ng vao/racua bo ieu khien m bang hop hoi thoai

Viet ten bo ieu khien m (neu muon)va so cac bien ngon ng vao ra vao nhng otng ng. Han che cua FCPA la:

-Ch tao lap c nhng bo ieu khienm vi toi a 8 bien vao. Hnh 4 : khai bao bien ngon ngvao/ra

-Ch tao lap c bo ieu khien vi toi a 4 bien ra.An phm OK e xac nhan cac gia tr va cho. Nhng bien ngon ng au vao

se co ten mac nh Input01, Input02,va Output01, Output02lan lt la tenmac nh cua bien ngon ng au ra.

Sau khi an OK, tren man hnh se xuat hien ca so soan thao tiep gia tr ngonng cua tng bien vao/ra cung nh luat hp thanh cua bo ieu khien m

4.4. Soan thao gia tr cho tng bien (ngon ng ) au vaoCac gia tr cua moi bien ngon ng au vao c goi la bien ngon ng. V

ban chat cua gia tr ngon ng la tap m, nen e soan thao gia tr ngon ng chomot bien ngon ng ta can phai:

1. Khai bao so cac gia tr ngon ng (tap m) cua bien.2. Soan thao tap nen cung nh ham thuoc cho tng gia tr ngon ng.


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e vao che o soan thao gia tr ngon ng (tap m) cho mot bien au vao naoo ta nhay kep phm chuot trai tai bieu tng cua bien o. V du e soan thaogia tr cho bien vao Input01, ta nhay kep vao bieu tng cua(a uc anh dautren man hnh ).Khi o ca so soan thao hien ra:

Khai bao so cac gia tr ngon ng(tap m): e khai bao so cac tap m cho bienInput01, ta ch can kch chuot vao phm Insertroi viet so cac tap m can co vaoo tng ng trong ca so hien ra (toi a la 7):Tiep theo ta an phm OK. So cac tap m toi a ma FCPA cho phep khai bao la7. Cac tap m c khai bao se mac nh:

-Co ten lan lt la n-big, n-small, zero, p-small, p-big.-Co ham thuoc hnh tam giac c chia eu tren tap nen.

Sau khi an phm OK, FCPA se in ra man hnh ca so soan thao ham thuoc chomoi tap m nh sau:

* Cu the trong luan van :a. Ham thuoc cho bien ET :

b. Ham thuoc cho bien DET :


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c. Ham thuoc cho bien Kr va Kp :


20/127



d. Ham thuoc cho bien An_pha :


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Sa oi ham thuoc: Muon sa oi ham thuoc mac nh cho tap m nao, ta kchhoat tap m o bang cach ghi trc tiep ten tap vao o cha ten tap m hoac anphm va chon ten tap m trong bang danh muc hien ra. Ham thuoc cua tap mc chon se chuyen sang mau o bao trang thai tch cc cua no.

Viec sa oi ham thuoc ong ngha vi viec oi dang (Singleton, tam giac hayhnh thang) va mien xac nh. Co 2 cach sa nh sau:1. -Cach th nhat: Chon nh cua ham thuoc can sa bang cach a

chuot vao nh o va an phm chuot trai FCPA se bao nh a ctch cc bang mot vanh khuyen nho quanh nh o, v du nh hnhdi th nh C la nh a c tch cc. Gi nguyen phm chuot roikeo nh o sang phai hoac sang trai e thay oi toa o cua nh.

2. -Cach th hai: Sa trc tiep bang cach ghi toa o mi vao cac otrong ca so Point.

Nh vay muon co ham thuoc hnh tam giac, ta cho nh B trung vi nh C (hainh co cung toa o). e co dang singleton ta cho A trung vi D, B trung vi C.

Sau khi a soan thao hay sa oi xong tat ca cac gia tr cua mot bien vao, taan phm OK e ket thuc, FCPA se quay lai man hnh ban au.

4.5. Soan thao gia tr cho tng bien (ngon ng) au raTng t nh a khai bao hay sa oi cho gia tr bien vao, viec khai bao

cac gia tr (tap m) cho bien ra cung c bat au bang cach nhay kep phmchuot trai tai bieu tng cua bien au ra. Muon soan thao hay sa oi gia trngon ng(tap m) cho mot bien au ra nao o ta nhay kep phm chuot trai taibieu tng cua phm o.

V du e soan thao gia tr cho bien ra Output01, ta nhay kep vao bieu tngcua no. Khi o ca so soan thao se hien ra. Tiep tuc ta kch chuot vao phmInserte khai bao so cac tap m cho bien Output01.

Chu y la FCPA ch cho phep khai bao toi a 9 gia tr cho moi bien ra.Sau khi khai bao xong so cac gia tr (tap m )cho bien ra Output01 ta nhan

phm OK vao man hnh soan thao. Khac vi bien ngon ng au vao, gia tr(tapm) cua cac ra ch co duy nhat mot dang singleton.

Muon sa oi gia tr ngon ng nao ta tch cc no bang cach chon ten tap mcua gia tr o trong bang danh muc hien ra khi an phm . FCPA se bao trang

thai tch cc cau ham thuoc cua tap m c chon bang cach chuyen no sangmau o va them mot hnh khuyen chnh gia.

e sa oi ham thuoc dang singleton n gian ta ch can sa oi toa o cuano bang cach a con tro vao hnh khuyen, gi phm chuot trai roi keo sangphai/trai, hoac trc tiep ghi toa o mi vao o Point cua ca so man hnh soanthao.


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Luat hp thanh cua cac bien ngon ng Kr, Kp,An_pha c xay dng theo phng phapZhao Tomizuka va Isaka

4.6.Soan thao luat hp thanh :Sau khi khai bao xong bien ngon ng vao/ra va cac gia tr(tap m) cho chungchang han nh ta a khai bao mbien vao Input, ,Inputm v cac gia tr Amva s bien ra Output 1=Bn1,, output s vi cac gia tr Bi1 ,, Bisbc tiep theo la

ta xay dng luat hp thanh. e vao che o xay dng luat hp thanh co cau truc.R1: Neu Input 1=A11va va Input 1= A1mth Output 1= B11 vava

Outputs =B1sR2: Neu Input 1=A21va va Inputm =A2mth Output 1= B21vava

Outputs=B2s:Rn: Neu Input 1=An1 vava Inputm=Anm th Output 1= Bn1 vava

Outputs=Bns

ta nhay kep phm trai cua chuot tai o if then:e soan thao tng menh e hp thanh. An phm insert e chen them se la motcot gom cac o trong. So cac o trong nay c qui nh bi so cac bien ngon ngvao ra ma ta a khai bao t trc. Moi o trong ng vi mot bien ngon ng. Tieptheo, neu ta nhay chuot tai o trong cua bien ngon ng nao, tren man hnh sehien ra bang cac gia tr(tap m) cua bien ngon ng o e ta chon. V du manhnh soan pha tren, menh e hp thanh th nhat ma ta va soan thao bang cachchon gia tr cho no t bang cac gia tr chnh la:

Neu Intput01=n-big va Intput02=n-big th Output01=p_big.Sau khi khai bao xong ay u cac menh e hp thanh, man hnh soan thao

luat hp thanh se co dang nh sau:


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trong o, do b khong che ve kch thc ca so man hnh, so cac menh e hpthanh nhieu nhat co the c hien th la 9. tuy nhien ta co the xem cac menh ehp thanh khac bang cach dch chuyen phm hien th nh chuot.

4.7. Chon ong c suy dien

FCPA ch cung cap mot ong c suy dien la max-MIN nen ta khong co khanang chon mot ong c suy dien khac.4.8. Chon phng phap giai m

FCPA cung ch cung cap mot phng phap giai m duy nhat la phng phapiem trong tam. Bi vay trenman hnh soan thao bo ieu khien cua FCPAkhong co phm la chon phng phap giai m.

4.9. Quan sat quan he vao ra cua bo ieu khien mCung vi viec khai bao xong luat hp thanh ta a ket thuc qua trnh soan thao

mot bo ieu khien m. An phm OK e ket thuc qua trnh soan thao va tr ve

ca so man hnh chnh cua FCPA. V du sau khi khai bao mot bo ieu khien mco 3 au vao, 2 au ra vi luat hp thanh gom 13 menh e hp va an phm OK,FCPA se quay tr ve man hnh chnh.* Quan sat mot cach trc quan quan he vao ra cua bo ieu khien m va soan

thao ta chon Debug3D Graphic Display, khi o tren man hnh xuat hien o thmo ta quan he vao/ra cua bo ieu khien m nh sau:a. Kr :

b. Kp :


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c. An_pha :

Ngoai ra, ta con co the s dung chng trnh FCPA e mo phong tn hieu vao rava cac moi quan he cua bo ieu khien m (hnh)


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Bang cach thiet lap gia tr cho cac tap m ta co the quan sat trang thai va gia trhien thi cua Kr, Kp, An_pha (hnh )

S dung DB m vi FB30(fuzzy control)Cac tham bien hnh thc cua F B30Bo ieu khien m c soan thao xong can phai c cat gi vao Project

bang lenh filesave. No se c lu tr vao Project di dang mot khoi DBma ta a at ten. Khoi d lieu m nay c s dung cung vi khoi ham FB30a c lay t Project FuzConEx trong th vien cua Simatic Manager khi caiat chng trnh Fuzzy/FB. Bi vay khi s dung khoi d lieu m ta phai ket thucFCPA bang lenh File Exitva quay tr lai Simatic Managere viet lenh sdung theo cau truc:Cu phap CALL FB30 , DBxTrong o DBx la ten khoi d lieu m. Khoi FB30 (ten hnh thc Fuzzy Control)co 8 bien au vao INPUT 1INPUT 8kieu so thc, 5 bien ra gom OUTPUT1OUTPUT 4cung kieu so thc vaINFOkieu byte. Khi thc hien lenh goi khoiFB30 nh tren, toan bo 8 bien hnh thc au vao va 5 bien au ra hien tren manhnh ch ta truyen tham tr:CALL FB 30 , DBxINPUT 1 :=INPUT 2 :=INPUT 3 :=

INPUT 4 :=INPUT 5 :=INPUT 6 :=INPUT 7 :=INPUT 8 :=OUTPUT 1:=OUTPUT 2:=OUTPUT 3:=OUTPUT 4:=INFO :=V du, xet lai bai toan ieu khien cau truc a c e cap ti muc 5.1.1. Goiten koi d lieu m vi hai bien vao ,mot bien ra vva luat hp thanh nh amo ta c soan thaobang FCPA la DB2 th khi s dung ta dung lenh:

CALL FB 30 , DBxINPUT 1 := MD0 // Gia tr tn hieu o gocINPUT 2 := MD4 // Gia tr tn hieu o toc o goc


27/127



INPUT 3 := // Khong s dungINPUT 4 := // _INPUT 5 := // _INPUT 6 := // _INPUT 8 := // _INPUT 7 := // _OUTPUT 1:= MD8 // Gia tr hieu ieu khien ong cOUTPUT 2:= // Khong s dungOUTPUT 3:= // _OUTPUT 4:= // _INFO := // Thanh ghi bao trang thai

Neu nh trc o gia tr tn hieu o goc a c ghi vao trong o nh MD0, giatr o toc o thay oi goc c ghi vao MD4. Tn hieu ieu khien ong c se

c FB30 truyen vao o nh MD8.Thanh ghi bao trang thai lam viec cua FB30Gia tr tra ve co ten INFOvi kch thc mot byte la ma bao trang thai thc

hien cong viec cua khoi ham FB30.No c quy nh nh sau:B1600 Khoi ham FB30 a c thc hien bnh thng.B1601 Khoi ham FB30 khong c thc hien. Gia tr tra ve au ra

van la nhng gia tr cu.B1611 Khong tm thay khoi DB m a ch th. Co the khoi DB m

nay a khong c o vao CPU.B1621 Khoi d lieu DB m c goi theo ham FB30 khong cung kch

thc ve bien vao ra. Chang han nh khoi DB m a c soan thao cho 4 bienvao va 2 bien ra, nhng khi goi cung vi FB30 lai khai bao 5 bien vao va 2 bienra.

Lien quan ti ma B1601 bao FB30 khong lam viec la noi dung t kep coten START_STOPtrong DB m a c soan thao bang FCPA. T kep nay cotac dungnh mot bien ieu kien e thc hien lenh CALL FB30, DBx:

-Neu START_STOP = W160000 lenh se c thc hien.-Ngc lai khi START_STOP W160000 th lenh se khong c

thc hien.

CHNG 5 :MODULE MEM PID


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Nhieu nam trc ay, bo ieu khien PID c coi la bo ieu khien ly tng oivi cac oi tng co mo hnh lien tuc. Bo PID thc s la bo ieu khien ong maviec thay oi cac tham so cua bo ieu khien co kha nang lam thay oi ac tnhong va tnh cua he thong ieu khien t ong.

Bo ieu khien PID thc chat la thiet b ieu khien thc hien luat ieu khienc mo ta bang phng trnh sau :

)()(1

)()(

'

0

teTdeT

tektu Dl

p

Trong o )(te la tn hieu vao, )(tu la tn hieu ra cua bo ieu khien, pk la he so

khuyech ai cua luat ieu khien ty le, lT hang so thi gian tch phan va DT lahang so thi gian vi phan.

oi vi he thong co o d tr on nh ln, neu muon tang o chnh xac ieukhien ta ch tang he so khuech ai cua luat ieu khien ty le

He thong se khong co sai lech tnh khi tn hieu vao la ham bac thang n v vahang so thi gian tch phan lT c chon khac khong. Luat ieu khien tch phancon goi la ieu khien cham sau v sai so ieu khien c tch luy cho en khi uln th quyet nh ieu khien mi c a ra.

Tang kha nang tac ong nhanh cua he, giam bt thi gian qua ieu chnh bang

cach thay oi hang so thi gian cua luat ieu khien vi phan. Luat ieu khien viphan con c goi la ieu khien vt trc.

Luat ieu khien trong phng trnh (5.1) thng c bieu hien di dang hamtruyen at nh sau :

)1)(1(1

1)( 21 pTpTp

kpT

pTkpW DD

iD

l

pDK

(5.2)

)(tu )(te PID

oi tngieu khien

Hnh 1 : ieu khien vi bo ieu khien PID


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T nam 1975 tr lai ay, do s phat trien khong ngng cua ky thuat ien t vaky thuat vi x ly, cac PID so ngay cang c s dung rong rai trong congnghiep, PID so c mo ta qua phng trnh vi sai phan sau :

22111 kkkkk erereruu o

Hoac bang ham truyen at gian oan

1

2

2

1

10

1)(

z

zrzrrzW

Vi bo ieu khien PID, ngi s dung de dang tch hp cac luat ieu khien

khac nh luat ieu khien ty le (luat P), ieu khien ty letch phan (luat PI), luatieu khien ty levi phan (luat PD). Bo ieu khien PID luon la mot phan tkhong the thay the c trong cac qua trnh t ong khong che nhiet o, mc,toc o ..Ngay ca khi ly thuyet ieu khien t ong hien ai c ng dung vaoviec thiet ke, cac bo ieu khien nh bo ieu khien m, bo ieu khien n ron ,bo ieu khien ben vng th viec ket hp gia cac phng phap ieu khien hienai va bo ieu khien PID kinh ien van em lai nhng hieu qua bat ng makhong bo ieu khien nao co kha nang em lai.

Mot trong nhng ng dung cua bo ieu khien PID trong ieu khien thch nghi vaieu khien m la thng xuyen phai chnh lai cac tham so cua no cho phu hpvi s thay oi khong biet trc cua oi tng cung nh cua moi trngnhamam bao c cac ch tieu chat lng a e ra cho he thong. Neu nh ta a tong hoa c cong viec thay oi tham so nay th bo ieu khien PID o se lamot bo ieu khien ben vng vi moi tac ong cua nhieu noi cung nh nhieungoai len he thong [3]. ay chnh la phng phap ieu khien c ng dungtrong luan van : ieu khien m laiPhan ly thuyet ve PID so c trnh bay kha chi tiet trong ly thuyet ve PID

phan sau, nen trong phan nay ch khai quat mot so net chnh

Cung chnh v vay ma cac thiet b ieu khien qua trnh nh DCS DisbutedControl system, PLC Progerammable Logic Control, PCS Process Controlsystem cua cac hang san xuat thiet b t ong tren the gii khong the thieu cmodule ieu khien PID hoac cng hoac mem.


30/127



e s dung tot cac module nay, ngi thiet ke phai nam c cac phng phapchon luat ieu khien va cac tham so cho bo ieu khien.

5.1 Xac nh tham so cho bo ieu khien PIDLuat ieu khien thng c chon tren c s a xac nh c mo hnh toanhoc cua oi tng va phai phu hp vi oi tng cung nh thoa man cac yeucau bai toan thiet ke [7], [15].

Trong trng hp mo hnh toan hoc cua oi tng khong xac nh c co thechon luat ieu khien va cac tham so cua bo ieu khien theo phng phap thcnghiem. Tuy nhien, e tien hanh c phng phap thc nghiem, he thong phai

am bao thoa man them mot so ieu kien.5.1.1 Phng phap ReinichPhng phap thiet ke thuat ieu khien cua Reinisch da tren c s mo hnh toanhoc cua oi tng a xac nh mot cach tng minh. Mo hnh ong hoc cua oitng c a ve hai dang c ban sau:

1) Dang khau nguyen ham vi mo hnh ac trng :

)...1(

)1(

)1(

)1()(

1

1

n

n

pT

dtn

i

i

pT

dtpapap

ebpk

pT

ebpkpW

tt

(5.5)

Vi iT la cac so thc thoa man 0...21 nTTT va hang so thi gian tre tT , lamot so thc hien hu han khong am. Khong mat tnh tong quat neu ta giathiet

1T , hang so thi gian ln nhat va

2T la hang so thi gian ln th hai.

Neu 30 Th , th bo ieu khien thch hp se la P hoac PI. Trong trng hp40 Th , ngi ta lai thng hay chon bo ieu khien PD hoac PID.

Dang khau ong hoc co thanh phan tch phan


31/127



)...1(

)1(

)1(

)1()(

1

1

n

n

pT

idtn

i

i

pT

idtpapap

ebpk

pT

ebpkpW

tt

(5.6)

vi nhng ieu kien han che giong nh cua (5.5)

e thuan li cho viec thiet ke he thong vi luat ieu khien I cho oi tng dang1 va khong co luat ieu khien I cho oi tng dang 2, Reinisch a a hamtruyen phai co cua he h ve dang gan ung nh sau :

)2

21

01(

1)(

pcpcpTpW

(5.7)

vi hai trng hp phan biet 02 c va 02 c .Tham so T c tnh bi :

idtkk cho oi tng dang 1iidt

k cho oi tng dang 2

va 1c c xac nh t cac tham so cua oi tng sau :

1c = 1

1

TbTn

i

i

= tTba 1

Tham so Ki cua bo ieu khien PID se c xac nh t T theo (5,8). Cac thamso 21, vv TT , con lai th c tnh n gian la 11 TTv va 22 TTv .

ieu khien oi tng dang 1

e chon T cho oi tng dang 1 ta i t o qua ieu chnh cc ai mong muonmax thong qua he so chnh nh =( max ) theo cong thc :

1

11

1

CKKCT

dt

(5.10)

1) Cho trng hp (5.7) co c2=0, he so chnh nh c tnh theo

max

2

max

2

ln

ln4

(5.11)


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2) Cho trng hp (5.7) co c20 th = a+ cvi a va c xac nh t max theobang ben, hang so co the c xac nh theo cac cach :

a)2

1

2

c

c neu ieu khien c s dung la 1 (5.12 )

b) 21

2

cc neu ieu khien c s dung la P hoac PI (5.13)

c)2

1

2

c

c neu ieu khien c s dung la PD hoac PID (5.14)

trong o

d)211

''

111

'

1111 ,, TTccTccTbac (5.15)

e)

'

12

'

112

'

2

2

1

1122 ,2 cTcTcc

T

babTac (5.16)

V du 1 : Cho mot oi tng thuoc dang 1 (theo phng trnh (5.5) vi mohnh

pp epp

epp

pW 662 )41)(101(

1

4041

1

Hay thiet ke luat ieu khien va chon tham so sao cho o qua ieu chnhmax khong vt qua 10%.

e ieu khien oi tng tren ta co the s dung cac bo ieu khien I, P hoacPI.Theo nh bang tren th yeu cau max %10 dan en a=1,4 va c=1. Hn naoi tng co cac tham so sTsasabkdt 4,40,14,0,1 1

2

21 va T=6. Bivay theo (5.15) va (5.16) th

.74,98,198,6,10,20 2''22'

2

2

2

''

1

'

11 scscscscscsc Suy ra co the conhng gia tr sau :

= 495,02

1

2 c

c neu bo ieu khien c s dung la I.

= 98,02

1

2 c

c neu bo ieu khien c s dung la P hoac PI.

Gia s rang ta s dung bo ieu khien I. Vay th do ca =1,9 nen t(5.10) co 03,01k va 21 pp TT = 0.


33/127



Neu bo ieu khien ma ta s dung lai la PI th cac tham so can xac nh cuabo ieu khien la

1k va

1pT . T 38,2 ca ta suy ra c

05,01k va 0,10 21 TpsTp

ieu khien oi tng dang 2u iem cua phng phap Reiniseh la ngay ca trong trng hp oi tng cothanh phan tch phan (dang 2), cac gia tr can thiet cho cong viec tnh toantham so bo ieu khien nh ''2

'

22

''

1

'

1,1 ,,,, cccccc cung c tnh giong nh cho oitng dang 1.oi vi van e ieu khien oi tng dang 2, Reiniseh e xuat s dung boieu khien P hoac PD (khong co I) va do o theo cong thc ham truyen at(5.2) cua bo ieu khien th ch con hai tham so pk va pT phai xac nh.

Vi nhng gia tr trung gian ''2'

22

''

1

'

1,1 ,,,, cccccc , tnh theo (5.12) : (5.16), ta co :

a)2

1

2

c

c neu bo ieu khien c s dung la P

b)2

1

'

2

c

c neu bo ieu khien c s dung la PD.

T o suy ra :

1)ack

kidt

p

1

1 cho bo ieu khien P.

2)ack

kidt

p ''

1

1 va 1TTp cho bo ieu khien PD.

Trong o ca va a, c c tnh t o qua ieu chnh cc ai mong muon

max theo bang a cho trang 210.

V du 2 : Tm bo ieu khien cho oi tng thuoc dang 2 vi mo hnh

p

p

epp

pW 62 )40141(

1)(

e %.10max Giong nh v du 1, cac gia tr trung gian la2'

2

2'

2

2

2

''

1

'

11 74,98,198,6,10,20 scscscscscsc . Bi vay neu chon bo ieukhien PD th


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45,305,22''

1

''

2 hayc

c

va do o

,05,0pk 10pT

5.1.2 Phng phap thc nghiemTrong trng hp khong the xay dng mo hnh cho oi tng th phng phapthiet ke thch hp la phng phap thc nghiem. Thc nghiem ch co the tienhanh neu he thong am bao ieu kien : khi a trang thai lam viec cua he en

bien gii on nh th moi gia tr cua cac tn hieu trong he thong eu phai namtrong gii han cho phep.

Phng phap Zlegier va NichoisTrc khi tien hanh thc nghiem he thong phai c lap at theo s o hnh5.1, bao gom oi tng va bo ieu khien theo luat PID. Sau khi lap at xong,thc nghiem c tien hanh theo cac bc sau :

1) Cho he thong lam viec bien gii on nhieu khien oi tng theo luat P, tc la cho 0pT va 1T

Tang he so khuech ai pk cua luat ieu khien P cho en khi he thong bien

gii on nh. Xac nh he so pthk va chu ky giao ong ti han dao ong

Trong nhieu trng hp , viec xac nh chu ky dao ong rieng gap kho khan vakhong am bao o chnh xac th phng phap gii thieu sau ay se khac phucnhc iem o.

Phng phap Jassen va OffereinThc nghiem theo phng phap nay c tien hanh theo cac bc sau ay :

1) Cho he thong lam viec bien gii on nh


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ieu khien o i tng theo luat P( 0pT va 1T )

Tang he so khuech ai pk cua luat ieu khien P cho en khi he thong bien

gii on nh. Xac nh he so pthk va chu ky giao ong ti han dao ong.

2) Chon luat ieu khien va tnh toan tham so t pthk , thT theo bang sauLuat ieukhien ph

p

k

k

ph

p

T

T

th

D

T

T

Luat P 0,5Luat PI 0,45 0,8Luat PID 0,6 0,5 0,12

Trong nhieu trng hp, viec xac nh chu ky dao ong rieng gap kho khan vakhong am bao o chnh xac th phng phap gii thieu sau ay se khac phucnhc iem o.

Phng phap Jassen va Offerein1) Cho he thong lam viec bien gii on nh

ieu khien oi tng theo luat 0( pTP va )1 T

Xac nh he so pthk 2) Chon tham so cho luat PI

Cho he lam viec vi luat PI va vi he so pk =0,45 pthk , 1T tuy chon.Giam hang so thi gian tch phan

1T cho en khi he thong lam viec bien gii

on nh. Xac nh hang so thi gian tch phan tthT che o nay.Chon

1T = 3 lthT

3) Chon luat ieu khien PID

Cho he thong lam viec theo luat PID vi pk = pthk ( du nho), DT va 1T tuychon.Tang hang so thi gian vi phan cho en khi he thong at c qua ieu chnhcc ai ln nhat maxmax .Xac nh DMAXT

Chon DMAXP TT3

1 va

1T = 4,5 DT


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Giam pk cho en khi he thong at c ac tnh ong hoc mong muon.

5.2 Module mem PID5.2.1 Nhng module PID mem co trong co trong step7Phan mem Step7 cung cap cac module mem PID e ieu khien cac oi tng

co mo hnh lien tuc nh lo, ong c, mc au ra cua oi tng c a vaoau vao cua bo ieu khien qua cac cong vao tng t cua cac module vao tngt cua cac Simatic S7-300/400. Tn hieu ra cua bo ieu khien co nhieu dang vac a en cac c cau chap hanh qua cac module vao ra khac nhau nh:

- qua cac cong ra tng t cua module ra tng t (AO) hoac- qua cac cong ra so cua module ra so (DO), hoac- qua cac cong phat xung ra toc o cao.

Phu thuoc vao c cau chap hanh, ngi s dung co the chon c module memPID tng thch. Ba module PID c tch hp trong phan mem Step7 phu hpvi ba kieu c cau chap hanh neu tren, o la:

1 ieu khien lien tuc vi module mem FB41 ( ten hnh th CONT_ C).2 ieu khien bc vi module mem FB42 (ten hnh thc CONT _ S)3 ieu khien kieu phat xung vi khoi ham ho tr FB43 ( ten hnh thc

CONT_S)Moi module mem PID eu co mot khoi lng d lieu rieng (DB) e lu gi cacd lieu phuc vu cho chng trnh tnh toan thc hien luat ieu khien. Cac khoi

ham FB cua module mem PID eu cap nhat c nhng khoi d kieu nay moithi iem.Module mem FB PULSEGEN c s dung ket hp vi module mem FBCONT _ C nham tao ra bo ieu khien co tn hieu ra dang xung toc o cao thchng vi nhng c cau chap hanh kieu ty le.Mot bo ieu khien PID mem c hoan thien thong qua cac khoi ham FB nhieuchc nang tao ra tnh linh hoat cao trong thiet ke. Ngi s dung co the choncac chc nang nay hoac loai bo cac chc nang khong can cho mot he thong.Cac chc nang c ban khac nh x ly tn hieu chu ao, tn hieu qua trnh va tnh

toan cac bien khac cung vi bo ieu khien PID cung c tch hp san trongmot module ieu khien mem.Mot ieu can chu y la nhng module PID mem khong toan nang ti mc co theng dung c vao moi bai toan ieu khien. ac tnh ieu khien va toc o x lycua module PID mem phu thuoc vao loai CPU c chon e giai quyet baitoan ieu khien. Do khi x ky mot mach vong ieu khien ngi ta phai thchien cong viec trch mau tn hieu au vao cho mach vong ieu khien o (lien


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quan en tn hieu bao ngat theo chu ky thi gian OB30 OB38), nen can phaico s tng thch gia so mach vong ieu khien PID va kha nang cung nh toco tnh toan cua CPU. Neu bai toan ieu khien yeu cau tan suat cap nhat cangcao th so dong ieu khien phai cang giam. Ch nhng bai toan co so vong

ieu khien t ngi ta mi co the s dung cac bo module PID mem co tan suattruy nhap cao.Tat ca cac module PID mem eu cung cap nhieu giai phap la chon luat ieukhien trong khi thiet ke e o ieu khien phu hp c vi oi tng nh : luatieu khien ty le (luat P), luat ieu khien ty le vi phan ( luat PD), luat ieukhien ty le tch phan ( luat PI). Chat lng cua he thong phu thuoc vao cactham so cua bo ieu khien do o, ieu kien bat buoc e am bao thanh congtrong thiet ke la ngi s dung phai co mo hnh oi tng chnh xac. o cungchnh la nhc iem c ban cua cac phng phap ieu khien kinh ien.

Cac ai lng vat ly cua oi tng va ac tnh cua bo ieu khien quyet nhac tnh ong cua he thong trong qua trnh ieu khien va ch b thay oi rat t sovi thiet ke. Ch co the at c chat lng ieu khien tot neu nh ngi thietke chon thuat ieu khien va thi gian trch mau phu hp vi oi tng.Hoan toan co the thiet ke bo ieu khien (cau truc ,tham so , goi module memPID trong chng trnh he thong ) ma khong can lap trnh. Tuy nhien muon lamc nh vay phai nam c phan mem Step7.

5.2.2Khai bao tham so va cac bien cua module mem PID

Ngi thiet ke co the khai bao tham so va cac bien cho bo ieu khien trong motd lieu a phng (instance data block ) bang cach s dung giao dien cuamodule mem PID. e vao chng trnh khai bao tham so kho thc hien .Star Simatic Step7 PID Control ParameteAssignmentTrong hop hoi thoai au tien,ngi thiet ke co the m khoi d kieu (DB ) atch hp san cho FB14 :con- C, FB42 CON_S hoac m mot khoi d lieu mihoan toan. Rieng FB43 PULSEGEN khong the thc hien chon tham so vabien qua giao dien, trong trng hp nay ngi thiet ke phai s dung cong cu

cua STEP7 e thiet lap tham so va khai bao bien cho bo ieu khien .oi vi CPU 314 IFM co the thiet lap tham so va bien cho module mem SFB41hoac SFB42 bang cach nhap trc tiep mot khoi d lieu bat ky va chon no lamkhoi lng d lieu cuc bo cho nhng module nay.5 3 ieu khien lien tuc vi FB41 CONT C5.3.1Gii thieu chung ve FB41


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S o cau truc cua module mem FB41 CONT- C c minh hoa trong hnh5.2

FB41 CONT C c s dung e ieu khien cac qua trnh ky thuat vi cacbien au vao va au ra tng t tren c s thiet b kha trnh Simatic. Trong khi

thiet lap tham so, co the tch cc hoac khong tch cc mot so thanh phan chcnang cua bo ieu khien PID cho phu hp vi cac oi tng.Co the s dung module mem PID nh mot bo ieu khien vi tn hieu chu aoat cng (fixed setpoint) hoac thiet ke mot he thong ieu khien nhieu machvong theo kieu ieu khien cascade. Nhng chc nang ieu khien c thiet ketren c s cua thuat ieu khien PID cua bo ieu khien mau vi tn hieu tngt.

Hnh 2 : Cau truc cua modun mem FB41 ONT_


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Module mem PID bao gom tn hieu chu ao SP=INT, tn hieu ra cua cac oitng PV_PER, tn hieu gia e mo phong tn hieu ra cua oi tng PV_IN, cacbien trung gian trong qua trnh thc hien luat va thuat ieu khien PID nhPVPER-ON, P-SEL, D_SEL, Man-ON.

Tn hieu ra cua CRP-IN = PV-PER x 27648100 Chuan hoa :Chc nang cua ham chuan hoa PV NORM tn hieu ra cua oi tngla chuan hoa tn hieu ra cua ham CRP-IN theo cong thc :

Tn hieu ra cua PV_NORM = ( Tn hieu ra cua Crp-IN) x PV- FAC- OFF

Hai tham tr khong che day gia tr cho phep cua PV_NORM la PV_FAC vaPV_OFF. Mac nh PV_FAC cua ham PV_NORM co gia tr bang 1 va PV_ OFFco gia tr bang 0.Loc nhieu tac ong trong lan can iem lam viec : Tn hieu sai lech la hieu giatn hieu chu ao va tn hieu ra cua oi tng.No c tao ra t ngay trong FB41va la dau vao cua khoi DEADBAND co tac dung loc nhng dao ong nho xungquanh gia tr xac lap. Neu khong muon s dung DEADBAND hoac vi oitng ma co the bo qua s anh hng cua nhieu trong lan can iem lam viec tachon DEAD- W =0

5 3 2 Chon luat ieu khien tren Module FB41 CONT- C

Hnh 5.3 mo ta thuat PID c thiet ke theo kieu song song cua ba thuat ieukhien n le: ty le (P), tch phan (I) va vi phan (D) theo s o cau truc tronghnh 5.2(sau khoi DEADBAND). Chnh v cau truc song song nh vay nen ta cothe thong qua cac tham tr P_SEL, I-SEL hay D_SEL ma tch hp c cac thuat

Hnh 3 : Thuat ieu khien PID


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ieu khien khac nhau t bo ieu khien mau nay nh thuat ieu khien P, PI, PD,PID.

5.3.3 at gia trPhan mem cho phep chon che o t ong (automatic mode ) hoac che o bangtay. che o bang tay cac che o cua cac bien c chon bang tay. Bo tchphan (INT) t thiet lap che o LNM-LNM-P-DISV va bo vi phan (DIF) t ongve 0. ieu o am bao cho viec chuyen che o t thiet lap gia tr bang tay veche o t ong khong gay mot bien oi nao oi vi cac bien a c thiet lapgia tr bang tay.Cung co the at gii han cho cac gia tr c thiet lap bang tay nh hamLMNLIMIT. Mot bt c se co mot gia tr logic bang 1 khi bien vao co gia tr

vt qua gii han a chon. Ham LMN- NORM se chuan hoa tn hieu ra cuaham LMNlimit theo cong thc:

LMN = (TN HIEU CUA LMNLIMIT )*LMN-FAC + LMN-OFF

Mac nh LMN_FAC co gia tr bang bang 1, con LMN_OFF co gia tr bang 0.Cac gia tr at bang tay co the theo mot cach bieu dien rieng. Ham CRP-OUTco chc nang bien oi t kieu bieu dien so thc dau phay ong sang kieu bieudien rieng theo cong thc:

LMN-PER = LMN *100

27648

Ngoai ra nhieu co the c loc trc bang cach a quan au vao DISV.

5.3.4 Khi ong va thong bao loiFB41 CON- C co mot chng trnh con phuc vu cho viec khi tao lai hoantoan he thong. Chng trnh nay c c goi khi tn hieu vao COM-RST co

gia tr logic bang 1.Trong khi khi tao, luat ieu khien tch phan c t ong thiet lap vi gia trkhi tao I_ITVAL. Neu luat ieu khien c goi theo ngat thi gian, no se luonluon lam viec vi gia tr nay. Tat ca au ra khac c at gia tr mac nh.Khoi FB41 CON- C khong co kha nang t kiem tra loi ben trong cua modulemem PID. Ma bao loi RET-VAL khong c s dung.


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5.3.5 Tham bien hnh thc au vaoKhoi FB41 Con C co 26 tham bien hnh thc au vao nh sau:

Ten bien KieudlieuPham vigii han Gia trmac nh Mo ta chc nang

COM-RST BOOL FALSE COMPLETE RESTARTKhoi co chc nang khi tao lai hethong hoan toan khi au vao

complete restart c thiet lap giatr logic TRUE.

MAN-ON BOOL TRUE MANUAL VALUE ONkhi au vao manual value on cogia tr logic TRUE mach vong ieukhien se b ngat, cac gia tr se cthiet lap bang tay.

PVPER-ON BOOL FALSE PROCESS VARIABLE

PERIPHERAL ONKhi oc bien qua trnh t cac congvao/ ra, au vao PV_PER phai cnoi vi cong vao /ra va au vaoprocess variable peripheral on cogia tr logic TRUE.

P-SEL BOOL TRUE PROPORTIONAL ACTION ONHoat ong cua bo ieu khien PIDco the tch cc hoac khong tch cctng phan rieng trong thuat ieukhien PID. Thuat ieu khien ty lec kch hoat khi gia tr TRUEc thiet lap tai cong vaoproportional action on

I-SEL BOOL TRUE INTERGER ACTION ONHoat ong cua bo ieu khien PID


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co the tch cc hoac khong tch cctng phan rieng trong thuat ieukhien PID. Thuat ieu khien ty lec kch hoat khi gia tr logic

TRUE c thiet lap tai cong vaoProportional action on INT-HOLD

BOOL FALSE INTERGAR ACTION HOLDau ra cua bo ieu khien tch phanco the b ong lanh ( khong cs dung) khi thiet lap gia tr logicTRUE cho au vao intergralaction hold.

I-ITL-ON BOOL FALSE INTIALIZATION OF INTERGRAL

ACTIONau ra cua bo ieu khien tch phanco the c noi vao cong vaoI_ITL_VAL neu nh cong vaointialization of intergral action cogia tr logic TRUE.

D-SEL BOOL FALSE DERIVATE ACTION ONHoat ong cua bo ieu khien PIDco the tch cc hoac khong tch cc

tng phan rieng trong thuat ieukhien PID. Thuat ieu khien viphan c kch hoat khi gia trTRUE c thiet lap tai cong vaoderivate action on

CYCLE TIME 1ms T#1s SAMPLING TIMEThi gian lay mau la khoang thigian khong oi gia cac lan khoic cap nhat.

SP-INT REAL -100.0 .100.0%hoac gia trvat ly.

0.0 INTERNAL SEPOINTau vao internal sepoint c sdung e thiet lap tn hieu chu ao (tn hieu mau)

PV-IN REAL -100.0100.0%hoac gia tr

0.0 PROCESS VARIABLE INGa tr khi tao co the at au vaoprocess variable in hoac t bien


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vat ly. qua trnh c bieu dien di dangso thc dau phay ong.

PV-PER WORD

W#16 #0000

PROCESS VARIBLE ERIPHERALBien qua trnh c noi vi CPU

thong qua cong vao tng t.MAN REAL -100.0..100.0%hoac gia trvat ly.

0.0 MANUAL VALUECong vao manual value c sdung e at gia tr bang cac hamgiao dien.

GAIN REAL 2.0 PROPORTONAL GAINau vao proportionall gain c sdung e thiet lap he so ty le cho boieu khien theo luat ty le.

TI TIME CYCLE T # 20s RESET TIMECong vao reset time c thietlap hang so thi gian tch phan chobo ieu khien vi phan

TD TIME

CYCLE T # 10s DERIVATE TIMECong vao Derivate time s dunge thiet lap hang so thi gian viphan cho bo ieu khien vi phan.

TM-LAG Time CYCLE T # 2s TIME LAG OF DERIVATE

ACTIONThi gian tch cc cua luat ieukhien vi phan c chon thong quacong vao time lag of derivateaction.

DEADB- W REAL 0.0(%)hoac gia trvat ly.

0.0 DEAD BAND WIDTHMot vung kem nhay c s dunge x ly tn hieu sai lech. o rongcua vung kem nhay c at thong

qua cong vao dead band width.LMN-HLM

REAL LMN_LLM(%) hoacgia tr vatly.

100.0 MANIPULATED VALUE HIGHLIMIT.Gia tr han che c thiet lap bangtay qua cong vao Manipulatedvalue high limit.

LMN-LLN REAL -100 0.0 MANIPULATED VALUE LOW


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..LMN-LLN(%) hoacgia tr vatly.

LIMITGa tr han che di c thiet lapbang tay qua cong vaomanipulated value low limit.

PV-FAC REAL 1.0 PROCESS VARIBLEFACTORBien qua trnh c nhan vi vimot he so cho phu hp vi pham viquy nh cua bien nay.Gia tr buc chon thong qua cong vaoprocess variablefactor

PV-OFF REAL 1.0 PROCESS VARIBLE OFFSET

Bien qua trnh c cong vi motlng bu cho phu hp vi pham viquy nh cua bien nay. Gia tr buc thong qua cong vao processvariable offset

LMN-FAC REAL 1.0 MANIPULATED VALUE OFFSETGia tr gii han c nhan oi vimot he so cho phu hp vi pham viquy nh cua bien qua trnh.He so

nay c at qua cong vaomanipulated value offset.LMN-OFF REAL 0.0 MANIPULATED VALUE OFFSET

Ga tr gii han c cong them motlng bu cho phu hp vi pham viquy nh cua bien qua trnh. Gia trbu c at qua cong vao

I-ITLVAL REAL -100.0 100.0(%)

hoac gia trvat ly.

0.0 INTIALIZATION VALUE OF THEINTERGRAL ACTION.

Ga tr au ra cua bo ieu khien tchphan co c thiet lap thong quacong vao of the integral action.

DISV REAL -100.0 100.0(%)hoac gia trvat ly.

0.0 DISTURBANCE VARIBLEKhi ieu khien he thong bangphng phap feedforward th motgia tr bu nhieu c at thong qua


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cong vao disturbance variable.

5.3 Tham bien hnh thc au rakhoi FB41 CON C co tham bien hnh thc au ra nh sau :

Ten bien Kieu d lieu Mac nh Mo taLMN REAL 0.0 MAINPULATED VALUE

Gia tr ra c thiet lap bang taythong qua cong ra manipulatedvalue

LMN- PER WORD W#16#0000 MANIPULATED VALUEPERIPHERALGia tr au ra thiet lap bang tay theokieu bieu dien phu hp vi cac congvao/ ra tng t c chon qua congra manipulated value peripheral

QLMN-HLM BOOL FALSE LOW LIMIT OF MANIPULATEDVALUE REACHEDCong ra low limit of manipulated

value reached thong bao gia tr cuabien qua trnh nho hn gia tr giihan di .

LMN-P REAL 0.0 PROPORTIONAL COMPONENTTn hieu ra cua bo ieu khien ty lec xuat ra cong ra proportionalcomponent.

LMN-I Real 0.0 INTEGRAL COMPONENTTn hieu ra cua bo ieu khien tch

phan c xuat qua cong raintegral component.LMN-D REAL 0.0 DERIVATIVE COMPONENT

Tn hieu ra cua bo ieu khien viphan c xuat qua cong raDerivative component

PV REAL 0.0 PROCESS VALUE


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Tn hieu qua trnh c xuat quacong ra process value.

ER REAL 0.0 ERROR SIGNALTn hieu sai lech c xuat qua

cong ra error signal

5.4. Khoi ham tao xung FB43 PULSEGEN:5.4.1. Gii thieu chung ve FB43PULSEGEN:FB43 "PULSEGEN" c dung e thiet ke mot bo ieu khien PID vi tn hieu

au ra dang xung. Mot mnh no khong phai la bo ieu khien PID. FB43 "PULSEGEN"khong co giao dien e thiet lap tham so nen phai dung cac cong cu cua STEP 7.

Bo ieu khien PID hai hoac ba v tr vi bo tao xung theo nguyen tacieu bien co the c thiet ke bang FB43 "PULSEGEN". Khoi ham FB43"PULSEGEN" thng c s dung cung vi bo ieu khien lien tuc CONT_C(Hnh 1).

Hnh 1Khoi ham PULSEGEN chuyen oi tn hieu au vao INV (au ra LMNcua module mem PID) bang cach ieu bien tn hieu xung lien tuc thanh mot day

xung co chu ky co nh va o rong tng ng vi o ln cua tn hieu au vao.Chu ky cua mot xung ty le vi gia tr bien au vao. Chu ky PER_TM chnh la

chu ky cua CONT_C ch khong phai la thi gian x ly cua FB "PULSEGEN". Chu kyPER_TM c xac nh sau vai chu ky x ly cua FB "PULSEGEN" So lan kch hoat


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FB "PULSEGEN" trong mot chu ky PER_TM chnh la thc o o chnh xac cua quatrnh ieu bien.

Hnh 2: Qua trnh ieu bien cua FB43 PULSEGENMot bien au vao la: 30% va 10 lan kch hoat FB "PULSEGEN" tren mot

PER_TM ngha la :- Gia tr xuat QPOS bang 1 trong ba lan kch hoat au tien cua FB

"PULSEGEN" (30% trong 10 lan kch hoat).- Gia tr xuat QPOS bang 0 trong 7 lan hch hoat sau cua FB

"PULSEGEN" (70% trong 10 lan kch hoat ).

Hnh 3: S o cau truc nguyen ly cua PULSEGEN

Vi ty le mau la 1:10 ( ty le gia so lan kch hoat CONT_C va so lan kchhoat PULSEGEN ) th o chnh xac cua gia tr c thiet lap bang tay trong v


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du nay la 10%, noi cach khac, tap cac gia tr au vao INV ch co the c gialap bang mot bo tao xung vi gia tr au ra QPOS trong cac bc la 10%.o chnh xac tang khi so lan kch hoat FB "PULSEGEN" trong mot lan kchhoat CONT_C tang. Khi PULSEGEN c kch hoat, v du nhieu hn 100 lan so

vi CONT_C, th 1% day gia tr c thiet lap bang tay.Chu y:Tan so kch hoat phai c lap trnh bi ngi dung.

Che o t ong ong bo hoa: che nay, xung au ra co the c ong bo hoa vi khoi thay oi gia tr bienau vao INV (v du nh CONT_C). Khi o, mot thay oi cua bien au vao selam thay oi xung au ra. Bo tao xung lng gia o ln cua INV cac khoangthi gian PER_TM tng ng va chuyen oi no thanh tn hieu xung co o rong

tng ng. Neu INV thay oi ma khoi kch hoat khong phai la khoi au tienhay hai khoi cuoi cung cua chu ky th qua trnh ong bo c thc hien. (Hnh2). Neu muon tat che o ong bo th at gia tr logic 0 cho tham tr SYN_ON

Hnh 4: ong bo hoa au chu ky


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5.4.2. at gia tr:Phan mem cho phep chon cac thuat ieu khien PID hai hoac ba v tr haybipolar or monopolar two-step tuy vao cac tham so c thiet lap cho bo tao

xung. Bang di ay liet ke cac che o:

Bang 1

che o ba v tr, tn hieu hanh ong co the nhan 3 trang thai : heat, off, cool.Tn hieu nay do tn hieu so au ra la QPOS_P hay QNEG_P quyet nh. Bang 2la mot v du cua ieu khien nhiet o.

Bang 2e tn c o rong cua xung FB43 "PULSEGEN" da vao o ln cua tn hieuau vao. ac iem cua o th bieu dien o rong xung phu thuoc vao tham bienP_B_TM (minimum pulse hay minimum break time) va he so ty le (Hnh 3).


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Hnh 3: o th dang oi xng cua bo ieu khien ba v tr (he so ty le 1)Thng th he so ty le la 1. Gia tr tuyet oi cua INV nho th tao ra mot xung coo rong nho hn P_B_TM, va gia tr tuyet oi cua INV ln hn th tao xung co

o rong ln hn theo cong thc sau:Pulse duration = INV/100*PER_TMHe so ty le RATIOFAC se lam thay oi o rong xung am va ca xung dng. Vdu nh trong x ly nhiet o, RATIOFAC cho phep ieu khien thi gian nong vathi gian lanh cua thiet b la khac nhau. He so nay cung anh hng enP_B_TM. Neu he so ty le < 1 th ngha la gia tr ngng cua cac xung am sec nhan vi he so ty le.Ratio factor 1:Duration of the negative pulse = (INV/100)*PER_TMDuration of the positive pulse = (INV/100)*(PER_TM/RATIOFAC)

che o hai v tr, ch co tn hieu xung dng QPOS_P cua PULSEGEN miieu khien tat hay m. che o nay, phan mem cho phep chon hai day gia trnhap bang tay: lng cc va n cc.

Hnh 4 : o th dang cua bo ieu khien hai v trTrong che at tr bang tay, (MAN_ON = TRUE), hai tn hieu xuat cua bo ieukhien PID hai hoac ba v tr co the c thiet lap thong qua cac tham bienPOS_P_ON va NEG_P_ON ma khong phu thuoc vao INV (Bang 3).


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Bang 3 : Cac gia tr cua tham bien1.3/ Khi ong va thong bao loi:Trong khi khi tao lai he thong, tat ca cac tn hieu xuat c at bang 0.Khoi FB43 "PULSEGEN" khong co kha nang t kiem tra loi. Ma bao loi

RET_VAL khong c s dung.1.4/ Tham bien hnh thc au vao:Khoi FB43 "PULSEGEN" co 12 tham bien hnh thc au vao nh sau:

Ten bien Kieud lieu Pham vi giihan Gia tr macnh Mo ta chungINV REAL -

100.0100.00.0 INPUT VARIABLE

Mot gia tr tn hieu tuan

t a vao tham so auvao input value

PER_TM TIME >=20*CYCLE

T#1s PERIOD TIMETham so au vao periodtime la mot chu ky conh trong qua trnh ieubien.

P_B_TM TIME >=CYCLE T#50ms MINIMUM PULSE/BREAKTIME

Tham bien nhap vao, giatr xung toi thieu.

RATIOFAC

REAL 0.1 ...10.0 1.0 RATIO FACTORHe so ty le, nham mucch thay oi o rong cuaxung am hay xung dng.


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STEP3_ON

BOOL TRUE THREE STEP CONTROLONTham bien nhap e tatm che o ba vi tr. che

o nay, ca hai tn hieuxuat eu hoat ong.ST2BI_ON

BOOL FALSE TWO STEP CONTROLFOR BIPOLARMANIPULATED VALUERANGE ON

MAN_ON BOOL FALSE MANUAL MODE ONKhi thiet lap tham sonhap nay la mannualmode on th cac tn hieuxuat co the c ieukhien bang tay.

POS_P_ON

BOOL FALSE POSITIVE PULSE ON che o at tr bang taycua bo ieu khien ba vtr, tn hieu xuat QPOS_Pco the c thiet lap tham so nhap la positivepulse on. che o at trbang tay cua bo ieukhien hai haiv tr,QNEG_P luon c thietlap ngc vi QPOS_P.

NEG_P_ON

BOOL FALSE NEGATIVE PULSE ON che o at tr bang taycua bo ieu khien ba vtr, tn hieu xuat QNEG_Pco the c thiet lap tham so nhap la negativepulse on. che o at trbang tay cua bo ieukhien hai hai v tr,QNEG_P luon c thiet


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lap ngc vi QPOS_P.SYN_ON BOOL TRUE SYNCHRONIZATION

ONKhi thiet lap tham so

nhap synchronizationon, xung au ra co thec ong bo hoa vikhoi thay oi gia tr bienau vao INV. Khi o, motthay oi cua bien au vaose lam thay oi xung aura.

COM_RS

T

BOOL FALSE COMPLETE RESTART

Module mem c khitao lai hoan toan khi cong vao complete startco gia tr logic bang 1.

CYCLE TIME >= 1ms T#10ms SAMPLING TIMEKhoang thi gian gi caclan goi khoi phai co nh.Thi gian trch mau(sampling time) c thiet

lap qua cong vaosampling time.

1.5/ Tham bien hnh thc au ra:Khoi FB43 "PULSEGEN" co 2 tham bien hnh thc au ra nh sau:

Tenbien Kieu dlieu Pham vigii han Gia trmac nh Mo ta chungQPOS_P BOOL FALSE OUTPUT POSITIVE PULSE

Tham bien au ra output positivepulse c thiet lap khi xuat ramot xung(positive pulse). Trongche o 2 v tr, tham bien nay luonco gia tr TRUE, QNEG_P luon cogia tr ngc vi QPOS_P


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QNEG_P

BOOL FALSE OUTPUT POSITIVE PULSETham bien au ra output positivepulse c thiet lap khi xuat ramot xung(negative pulse). Trong

che o 2 v tr, tham bien nay luonco gia tr TRUE, QNEG_P luon cogia tr ngc vi QPOS_P


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PHAN 2C S LY THUYET


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CHNG 1LY THUYET IEU KHIEN M

1.1. M au.Cac cong cu co ien ma ta dung e xay dng cac phep anh xa gia the giithc va cac mo hnh eu at tren c s logic hai-gia-tr Boolean. Cach xaydng nh vay the hien mot s thieu chat che : mot oi tng ch co the co haikha nang hoac la phan t cua tap hp ang xet hoac khong, ma khong d trucho trng hp cua cac oi tng co mot phan tnh chat cua tap hp ang xet.Th du: khi quy nh trong thanh pho xe gan may co toc o nhanh gay nguyhiem la xe co toc o v thuoc tap hp A : {v50km/h} , ta khong the cho rangmot xe chay toc o 49,9km/h la hoan toan khong nguy hiem theo nh lythuyet tap hp co ien.Hau het cac hien tng ma ta bat gap hang ngay eu khong hoan toan rorang, co ngha la chung luon co mot mc o m ho nao o trong viec dien tatnh chat cua chung.Th du : khai niem nhiet o NONGla mot khai niem m. Ta khong the ch rac chnh xac mot iem nhiet o ma tai o khongNONG, va khi ta tangnhiet o len mot n v th nhiet o lai c xem la NONG.Trong nhieu trng hp, cung mot khai niem se co nhieu mc o m trongcac thi iem va ng canh khac nhau.Th du : khai niem NONGcua mot can phong can ieu hoa nhiet o se khonghoan toan giong vi khai niem NONGcua mot lo nhiet can ieu khien lamviec tam nhiet o hang tram o C.Kieu logic hai-gia-tr rat hieu qua va thanh cong trong viec giai quyet cac baitoan c nh ngha ro rang. Tuy nhien, thc te ton tai mot lp cac khai

niem khong thch hp vi cach tiep can nh vay.Muon s dung cac khai niem nay mot cach hieu qua hn trong mo hnh ta cantm hieu mot cong cu, o la logic m va at c s tren no la giai thuat ieukhien m.

1.2. Tap hp m.1.2..1. nh ngha :Tap mF 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 xM va Fla anh xa :


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F: M [0,1] tap kinh ien M c goi la c scua tap m F. anh xa Fc goi la ham phu thuoccua tap m F.

1.2.2. Y ngha :Tap m F la ham anh xa moi gia tr x co the la phan t cua mot tap kinh ienM sang mot so nam gia 0 va 1 e ch ra mc o phu thuoc that s cua no vaotap M. o phu thuoc bang 0 co ngha la x khong thuoc tap M, ophu thuocbang 1 co ngha la x hoan toan la ai dien cho tap hp M. Khi F(x) tang danth o phu thuoc cua x tang dan. ieu nay tao ra mot ng cong qua cacphan t cua tap hp.

Mot tap m bao gom 3 thanh phan : Mien lam viec [x1,x2] gom cac so thc tang dan nam tren truc hoanh. oan [0,1] tren truc tung the hien o phu thuoc cua tap m. ng cong ham so F(x) xac nh o phu thuoc tng ng cua cac phan

t cua tap m.

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

o caocua mot tap m la gia tr cc ai o phu thuoc cua cac phan t tapm.

x

F(x)

1

x1 x2

0

1

0,75


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Tap m dang chnh tackhi co t nhat mot phan t co o phu thuoc la 1. Vdu nh trong hai tap m hnh tren ta thay tap m A la dang chnh tac.Trong cac mo hnh bo ieu khien m, tat ca cac tap m c s eu phai dangchnh 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 ophu thuoc mot cach t le quanh gia tr o phu thuoc cc ai.Th du: tap m B tren c a ve dang chnh tac nh sau :

2. Mien xac nh cua tap m :

Trong thc te tap cac phan t co o phu thuoc ln hn 0 cua tap m thngkhong trai dai het mien lam viec cua no. Nh v du di ay, mien lam vieccua tap m la oan [x1,x2] , tuy nhien ng cong thc s bat au x3va aten o phu thuoc toan phan x4. Ta goi oan [x3,x4] la mien xac nhcuatap m.

1

0,75

0

x

F(x)

1


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3. Mien gia tr cua bien :

Mot bien mo hnh thng c ac trng bi nhieu tap m vi mien xac nhco phan chong len nhau.Th du : ta co bien NHIET O gom cac tap m LANH, MAT, AM, NONG.

Mien gia tr cua bien la tap hp tat ca cac gia tr co the co cua bien. V du

oi vi bien NHIET O tren mien gia tr la oan [x1,x6] .1.2.4. 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 niemcha biet hay cha hieu ro rang.

1

0

MAT AM NONG

x1 x2 x3 x4

LANH

x5 x6

1 1


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

xkhi

xkhix

xkhix

xkhi

xS

1

)/()(21

)/()(2

0

),,;(2

2

3. Dang ng cong hnh chuong :Dang ng cong hnh chuong ac trng cho cac so m (xap x mot gia trtrung tam), bao gom 2 ng cong dang S tang va S giam.

0.5

1

0

x

0 5

1


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T 2 tap m dang ng cong S ta suy ra o phu thuoc tai iem x cua tap mdang 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 mchuan hnh chuong c thay bang cac dang tap m hnh tam giac va hnhthang do yeu cau tiet kiem bo nh von han che cua cac bo vi ieu khien.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 codang 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.

0

1

x

1

0

xA xB

x


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Th du : xet bien NHIET O gom cac tap m LANH, MAT, AM, NONG nhhnh ve

Khi ta a at en NONG th tat ca nhiet o cao hn se luon la NONG.Khi ta a at en LANH th tat ca nhiet o thap hn se luon la LANH.Do o ta co 2 tap m NONG va LANH co dang hnh vai.

1.3. Cac toan t m.1.3.1. Cac toan t c ban cua Zadeh tren tap m :1. Giao hai tap m :

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

2. Hp hai tap m :

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

1

0

MAT AM NONG

x1 x2 x3 x4

LANH

x5 x6

A A BB

A A BB


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3. Bu cua mot tap m :

~A = 1 - A[x]

1.3.2. Cac toan t bu tren tap m :Trong khi xay dng cac mo hnh m, co nhng trng hp ngi ta thay can

thiet phai nh ngha cac cac toan t khac thay the cho cac toan t c banAND, OR, NOT cua Zadeh. Cac toan t nay c goi la cac toan t bu.

Ten goi Giao HpZadeh min(A[x],B[y]) max(A[x],B[y])Mean A[x]+B[y]) /2 (2*min(A[x],B[y])++4*max(A[x],B[y])) /6Mean2 Mean

2

mean2

Mean1/2 Mean1/2 mean1/2Product (A[x]*B[y]) A[x]+B[y]) (A[x]*B[y])

Bounded Sum max(0,A[x]+B[y]-1) min(1, A[x]+B[y])

Khi i vao xem xet cac he m phan sau ta se s dung 2 toan t bu laproduct andva bounded sumortrong cac phep lien he va tng quan m.1. Toan t product and:

gproduct and = A[x]*B[y]

A ~A


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Toan t product and khong thay oi cac ac tnh min/max cua toan t giao cban cua Zadeh. gproduct and(0,A[x]) = 0 gproduct and(1, A[x]) = A[x]Ngoai ra toan t product andco them 1 tnh chat la tng tac hoan toan nghala no thay oi vi moi cap gia tr (A[x],B[y]). Tnh chat nay can thiet khimo ta cac trang thai m bien oi theo thi gian.

2. Toan t bounded sum or:gbounded sum or = min(1, A[x]+B[y])

Khi s dung toan t bounded sum orca hai vung m tham gia eu ong gopvao ket qua cuoi cung cho du 1 trong chung co o phu thuoc nho hn (se b

bo qua khi s dung toan t hp c ban cua Zadeh).

1.4. Bo t m (fuzzy hedge).Hedgela bo t them vao trc ten cua mot tap m nham thay oi va bo sungtnh chat cua tap m o. Hedgethay oi hnh dang cua tap m, thay oi hamphu thuoc va do o tao ra mot tap m mi. Hedgekhoang, xap x, gan vicon dung e chuyen mot so thc thanh mot tap m c goi la so m.1.4.1. S dung cac Hedge :Ta co the s dung cung luc nhieu Hedgee them vao mot tap m.Th du:

chac chan khong rat caoc giai thch nh sau :

chac chan (khong (rat cao))

1.4.2. Xap x mot vung m :e xap x mot vung m (bao gom ca viec chuyen mot so thc thanh mot tapm) ta s dung cac Hedgekhoang, xap x, gan vi . Cac Hedge nay co tacdung hi m rong vung m.Th du : xet tap m tuoi TRUNG NIEN va tap m xap x cua no la tap mKHOANG TRUNG NIEN.

TRUNG NIEN KHOANG TRUNG NIEN


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1.4.3. Gii han mot vung m :Co 2 Hedgedung e gii han mot vung m la tren va diTh du:

1.4.4. Lam manh va lam giam tnh chat cua tap m :Hedgerat dung e tang o manh tnh chat cua tap m. ieu nay c thchien bang cach giam o phu thuoc cua moi gia tr trong mien lam viec ngoaitr cac gia tr co o phu thuoc la 0 hay 1.Th du : xet tap m CAO va RAT CAO

TRUNG NIEN TREN TRUNG NIEN

TRUNG NIENDI TRUNG NIEN

RAT CAOCAO


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Hedgehi dung e giam o manh tnh chat cua tap m. ieu nay c thchien bang cach tang o phu thuoc cua moi gia tr trong mien lam viec ngoaitr cac gia tr co o phu thuoc la 0 hay 1.Th du: xet tap m CAO va HI CAO

1.4.5. Lam tang hay giam tnh m cua tap m :Hedgechac chan dung e giam tnh m cua tap m. ieu nay c thc hienbang cach tang o phu thuoc cua cac gia tr co o phu thuoc ln hn 0.5 vagiam cua cac gia tr co o phu thuoc nho hn 0.5Th du: xet tap m CAO va CHAC CHAN CAO

HI CAO CAO

CHAC CHAN CAO CAO


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Hedgenhn chung dung e tang tnh m cua tap m. ieu nay c thc hienbang cach giam o phu thuoc cua cac gia tr co o phu thuoc ln hn 0.5 vatang o phu thuoc cua cac gia tr co o phu thuoc nho hn 0.5Th du: xet tap m CAO va NHN CHUNG CAO

1.5. Bien ngon ng.Cac bo ieu khien m thao tac tren cac bien ngon ng. Moi bien ngon ng laai dien cua mot khong gian m. Cau truc cua mot bien ngon ng nh sau :

Lvar {q1qn} {h1hn} fs

q : cac t ch tan suat nh thng, luon luon h : cac Hedge nh rat, hi a khao sat trong phan trc fs : tap m trung tam

Th du: cao, thap rat cao, hi thap thng cao, luon luon thap thng rat cao, luon luon hi thap

1.6. Menh e m.Mot bo ieu khien m bao gom mot chuoi cac menh e m. Mot menh ethiet lap mot moi quan he gia mien lam viec va mot khong gian m.Mot menh e n gian co dang :x la A

x : gia tr vo hng thuoc mien lam viec A : bien ngon ng

NHN CHUNG CAO CAO


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A (xA)Qua trnh ma t gia tr ro x=x1 tm ra o phu thuoc A(x1) c goi la quatrnh m hoa. Trong trng hp co nhieu bien ngon ng qua trnh m hoalatm ra mot vect bao gom nhieu o phu thuoc.

Th du : xet bien NHIET O gom cac tap m LANH,MAT,AM,NONG.

M hoabien nhiet o :

5.0

5.0

0

0

45

0

0

75.0

25.0

15 00 CC

(x)(x)(x)(x)

xno nga mma tla nh

Menh e m co ieu kien :Neu y la B th x la A x,y : gia tr vo hng thuoc mien lam viec A,B : bien ngon ng

Co the giai thch menh e nay nh sau :

x la phan t cua A tuy theo mc o y la phan t cua B1.7. X ly m.1.7.1. Cac phep tng quan :Xet mot menh e co ieu kien sau :Neu y la B th x la ACac phep tng quan qui nh vung m ket qua c tao ra nh the nao t giatr cua menh e ieu kien va bien ngon ng menh e ket qua.

1

0

0.25

0.75

0.5

150C 450C

MAT AM NONGLANH

x


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Cac phep tng quan la c s cho cac luat hp thanh c s dung trong boieu khien m.Co 2 phep tng quan la : tng quan toi thieu va tng quan tch.

1. Tng quan toi thieu :ay la phng phap tng quan thng c dung nhat, thc hien bang cachbo i phan co o phu thuoc ln hn gia tr cua menh e ieu kien tren mienm ac trng bi bien ngon ng menh e ket qua.Th du: xet menh e co ieu kien sau :Neu nhiet o THAP th cong suat lo LN

Phep tng quan toi thieu tao ra cac oan nam ngang tren mien m ket quadan en mat mat mot phan thong tin. Tuy nhien phep tng quan nay tngoi n gian va cho phep giai m de dang hn.

2. Tng quan tch :

Phng phap nay thng cho ket qua tot hn, c thc hien bang cach nhanham phu thuoc cua mien m ac trng bi bien ngon ng menh e ket quavi gia tr cua menh e ieu kien.Luc nay dang cua mien m c bao toan, thong tin khong b mat mat, tuy

nhien viec giai m kho khan hn.Th du: van xet menh e co ieu kien tren :Neu nhiet o THAP th cong suat lo LNe so sanh ket qua gia 2 phep tng quan.

Nhiet o Cong suat lo

THAP LN

Nhiet o Cong suat lo

THAP LN


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1.7.2. Cac luat hp thanh m :Trong mot bo ieu khien m, cac menh e c x ly song song e tao ramot khong gian ket qua cha thong tin t tat ca cac menh e. Cac luat hpthanh qui nh cach thc tng quan va tong hp cac khong gian m t s tacong qua lai gia cac menh e cua he.Tng ng vi 2 phep tng quan toi thieu va tng quan tch ta co cac luathp thanh nh sau : Tng quan toi thieu : luat hp thanh Max-Min, Sum-Min Tng quan tch : luat hp thanh Max-Prod, Sum-ProdHai luat hp thanh m thong dung la luat hp thanh Max-Min va luat hpthanh Sum-Min.

1. Luat hp thanh Max-Min :

Gia s he gom n menh e :

Neu y la B1th x la A1Neu y la B2th x la A2........................................Neu y la Bnth x la An

Cac mien m ket qua c thc hien bang phep tng quan toi thieu. Sau omien m bien ra c cap nhat bang cach hp cac mien m nay theo toan tOR c ban cua Zadeh.Th du: xet lo nhiet c ieu khien bi 2 luat sau :

Neu nhiet o THAP th cong suat lo LNNeu nhiet o TRUNG BNH th cong suat lo TRUNG BNHBien vao nhiet ogom 2 tap m : THAP va TRUNG BNH.Bien ra cong suat lo gom 2 tap m : TRUNG BNH va LN.Tien hanh m hoa bien vao nhiet ota thu c vect gom 2 phan t la 2 ophu thuoc cua nhiet o vat ly t vao 2 tap m tren.

(t)

(t)tBNHRUNG

THAP


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V du, m hoa gia tr nhiet o t1=200C ta co :

0.25

0.75C00 S dung phep tng quan toi thieu ta thu c 2 mien m ket qua nh sau :

Sau o mien m bien ra thu c bang cach hp 2 mien m nay theo toan tOR c ban cua Zadeh nh sau :

2. Luat hp thanh Sum-Min :

Cac mien m ket qua van c thc hien bang phep tng quan toi thieu.Tuy nhien mien m bien ra c cap nhat bang cach thc hien toan t bu

bounded sum orthay cho toan t OR c ban cua Zadeh.

0.75

0.25

THAP TRUNG

Nhiet % cong suat lo

TRUNG BNH LN

200C

% cong suat

TRUNG BNHLN

8/21/2019 i

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