KHOA HOC CONG NGHE
T H I E T K E V A IVIO PHOIMG B O D I E U KHIEIM iVllJ IMHIET D O BUOIXiii D I E U H O A K H O I V G K H I D U A TREIM iVlATLAB
Nguyin Viet Ngu^-^, Wang Hong-hua\ Le Thi Minh Tam^
TOM TAT
Viec tao ra moi trudng khong khi cd nhiet do can thiet la rat quan trong trong san xuat nong nghiep va trong cuoc song cua xa hoi. He thong dieu chinh nhiet do trong cac thiet bi nay thudng sir dung cac thuat toan dieu khien logic kinh dien dan den trong nhieu truong bop khong dap iing dugc cbi tieu chat lugng phu hgp vdi doi tugng d cac quy mo khac nhau, De khic phuc cac nhugc diem cua he thdng dieu khien kinh dien, ly thuyet dieu khien nang cao ra ddi va bit dau dugc ung dung, trong do dieu khien md la mot phuong phap dieu khien ndi bat bdi tinh linh boat va da thu dugc nhung ket qua kha quan trong nghien cuu, ling dung ly thuyet tap md, logic mo va suy luan md. Tren ca sd MATLAB 7.01, bai viet nay tien hanh thiet ke bg dieu khien md va thong qua ham sd S thuc hien tdi uu boa qua trinh dieu khien. Dong thdi tien hanh nghien cuu bang mo phdng bg dieu khien md dieu khien nhiet do budng dieu hda khong khi la he thdng dugc su dung trong cac Id ap trung gia cam, 16 say hoa qua, nong san sau thu hoach ....
Tukhoa: Dieu khien md, ham sdS, lidATIAB, ly thuyet tap md, logic md, suy luan md, budng dieu hda khdng khi LMUOAU
Dieu khien md II dya tren cle quy tac ngdn ngd vl phuong phip kiem solt cua suy luan md, Ip dung ngdn ngir dien dat cua con ngudi, tuong ddi true quan va dd hieu. Nd phu hgp vdi tinh phi tuyen tinh, quin tinh ldn, ddi tugng ed trd ldn vl ddi tugng khd xay dyng md hinh toln hgc, khi dd se thu duge hieu qua dieu khien tuong ddi tdt''".
Tuy nhien, trong q u i trinh thief ke bg didu khien rad van tdn tai r l t nhieu yeu td sau day: vi du nhu xlc dinh do phu thugc, clu true quy luat dieu khien, v.v..., lira cho he thdng dieu khien yeu clu phli dieu chinh thu di thif lai nhieu lan mdi cd the dat duge tinh ben viing v l kha nang thich ung cao.
Do dd, viec su dung mIy tinh sin cd bg dieu khien rad de tien h i n h nghien eiru, khIo s i t md phdng d n g td ra d p thiet v l quan trgng.
Xult phlt tfr yeu clu ky thuat cao ung dung trong d c he thdng ty ddng hda cdng nghiep, tie gil di sau nghien ciin v l umg dung dieu khien md de dieu khien budng dieu hda khdng khi. Day II ddi tugng dien hinh trong sinh hoat ddi sdng, trong he thdng sin xult vl dac biet trong nglnh ndng nghiep nhu: Id Ip tning gia d m . Id say hoa qui, say ndng sin sau thu hoach, v.v...
Hoc vien He thdng Dien lyc & Ty ddng hda, Dai hpc Ha Hai, Nam Kinh, Trung Qudc
^ Khoa Dien - Dien tu, Dai hoc Su pham Ky thuat Hung Yen, Viet Nam
I. NU DUnE VA PHUONG PHAP NGHBU CliU
1. Md hinh dgng hgc budng dieu hda khdng khi Dieu hda khdng khi II lly khdng khi sau khi da trii qua xu ly nhlt dinh dira vio trong budng theo ragt phuong thuc n h l t dinh, llm cho nhiet dp vl do Im, tdc do luu ddng v l do sach dugc dieu khien trong mdt phara vi n h l t dinh. Sy bien ddi thdng sd mdi trudng cd anh hudng den khdng khi trong budng, chu yeu xly ra bdi hai khia canh sau:
- Thu nhat II do nguyen nhan khich quan: chIng ban do birc xa mat frdi, sy bien hda khi hau ben ngoli.
- Thu hai II do nguyen nhan chii quan: chang han do ngudi v l e l c thief hi trong budng tao ra nhiet dd, do am v l e l e chat cd hai khic.
Khi thdng sd khdng khi trong budng da lech khdi gil fri quy dinh thi yeu cau phli cd phuong p h i p vl bien p h i p dieu hda khdng khi thich hgp d^
llm cho nd trd lai g i l tri quy dinh cua yeu cau.
Theo dinh luat bao toan nang lugng, cd nghia la nang lugng dua vio budng trong don vi thdi gian se giam di theo don vi thdi gian do trong budng tda ra nang lugng tuong ung bang suit bien ddi cua lugng tich trir nang lugng trong budng. Budng dieu hda co kich thude la 11 m x 5 m x 3,5 ra. Phuong trinh toln hgc cua md hinh budng dieu hda khdng khi II:
dt R
(1)
KHOA HOC CONG NGHE Trong dd: O he sd dung luong nhiet cua khdng khi
frong budng (kJ/"C); L- lupng gid dua vao budng (mVs);p -mat do gid dua vao budng (kg/m^;c-nhiet dung rieng cua khdng khi (kI/("C.kg)); t, - nhiet do ddng khi dua vio budng ("C); t„- nhiet do frong budng ("C); t^- nhiet dp mdi trudng ben ngoai budng ("C); q„- lurmg nhiet tda ra frong budng (kw); R- nhiet frd tdng cua ket cau bao ve C'C/kw).
Gil dinh t, = 25°C, t^, = (32+4xsin(7rxt/4))°C.
Thdng qua tinh toan vl tra cuu cle tai lieu diam khIo cd lien quan, da xlc dinh dupe elc thdng sd dua gid vio budng dieu hda khdng khi II: C = 82,5 kJ/"C ; R = 0,326
"C/kw, p = 1,2 kg/ra^; c = 1,01 kI/(kg°C).
Can cu vao cdng thuc phuang trinh toln hgc cua rad hinh budng dieu hda khdng khi (1) chung ta xay dyng dugc rad hinh md phdng cua budng dieu hda khdng khi dugc bieu didn tren hinh 1 vdi diu vao II luu lugng ddng khdng khi cdn diu ra II nhiet do trong budng dieu hda.
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Hmh 1 Md hinh md phdng budng dieu hda nhiet do 2. Thiet ke bg dieu khien md cho budng dieu hda nhiet do
De thief ke vl khIo sit q u i trinh didu khien nhiet do trong budng didu hda nhiet do ta su dung ngdn ngu MATLAB. Day II ngdn ngu dugc xay dung tren co sd tinh toln raa tran d c du lieu khoa hgc cd the dung de khao sit rad hinh rad phdng d c he thdng ed ddng thli k h i c nhau vdi r l t nhieu cdng dung ldn raanh, dd d i n g sir dung, dugc tdng hgp trong radi trudng Windows. Nd II ragt loai cdng cu lap trinh don giln, r l t hieu q u i de nghien cun khoa hgc, thief ke cdng trinh v l cung d p duge cho rat nhieu d c linh vyc khoa hgc'^'. Ddng thdi MATLAB, II mdt he thdng md cho e l c nglnh khoa hoc k h i c nhau, dira ra cle hop cdng cu k h i c nhau. Do dd, pham vi ung dung cua nd rat md rdng. Hien nay, da
dua ra duge cac bdm cdng cu lien quan den cac nglnh hgc thief ke he thdng didu khien, nhan dang he thdng, didu khien md de xu ly tin hieu vd cung phong phu. Trong bai bao nly ung dung SIMULINK cua MATLAB de xay dyng bd dieu khien md va khIo sit he thdng dieu khien nhiet do frong budng didu hda nhiet do cd md hinh neu tren day. Viec xay dyng bd dieu khien md duge thyc hien qua d c budc sau:
Xac dinh d c bien ngdn ngu, xay dyng h i m sd do phu thudc v l xay dung cle quy luat rad.
a. Xic dinh cic bien ngon ngu
SIMULINK II mdt phuang p h i p dung de thiet ke rad hinh he thdng, rad phdng ddng thli vl phan tich radi trudng tieh hgp. Ngudi su dung cd the fan dung nhidu tinh nang cua nd de d§ d i n g thief ke he thdng cho cac md hinh va rad phdng'^'. Dudi radi trudng SIMULINK, d frong thyc don cua nd, raodule Fuzzy Logic Controller dugc chgn frong Fuzzy Logic Toolbox, khda pid vio de xay dyng bd dieu khien rad.
Trong Fis Editor, bira vio Edit/Add input de tang thera diu vao ngdn ngu. O ngay niia phln dudi trong khung ralu trang ben phli dat ten d c bien theo trinh ty: input 1 II "E" (sai lech nhiet do); input 2 II "Ec" (dao hira sai lech nhiet do); output II "U".
a phln dudi ben trii "vl"; "hoac"; "quan he keo theo", phuang phip lya chgn thich hgp gill md vl phep toln hgp fhlnh eua quy luat md da dugc phan biet lya chgn nhu sau: "Min-nhd nhlt", "Max-ldn nhlt",
"Sentroid-phuong p h i p trgng tam dien tich".
b. Xiy dung him so do phu thugc
Trong Fis Editor, vio thyc dan Edit/Membership Function se cho ra giao dien Membership Function Editor. Niia phln tren cua bd phan dung de the hien hinh ve ciia h i m sd do phu thudc, nua phln dudi dung de thief lap tham sd cua h i m sd do phu thudc.
De thyc hien dat dugc tieu chuan hda eua bd dieu khien md, phuong an xir ly de xuat su dung Mamdani. Dua vio d c bien v l dinh mien'eiia bien II khoing thdi gian bien ddi lien hic [4, +4], the hien trong hinh 2. Phan hda Fis Editor fhlnh 9 sd nguyen cd tap hgp II (-4, -3, -2, -1, 0, 1, 2, 3, 4) vl ddng thdi cung chia nd fhlnh 5 d p (NB, NS, ZO, PS, PB).
Mdi mdt d p tuong ung vdi mdt tap con cua Fuzzy, 9 nguyen td trong khoang [4, +4] tuang ung vdi mdi d p do phu thugc.
KHOA HOC CONG NGHE
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Hinh 2 Bd chinh ly he thdng suy luan md c. Xay dung quy luat ma
Thdng qua bd chinh ly kho quy luat rad quyet dinh quy luat dieu khien md cd hinh thiic "If.. .Then".
Trong trudng hgp nly cd tdng cgng 25 quy lu|t dieu khien, mdi mdt gil tri trong cac quy luat mac dinh II 1, phep suy luan II phep hop fhlnh Max-Min, phuong phip gill md dugc chgn II phuang phip trgng tam dien tich. Su dung bg quan sit mat cong de thief ke mdi quan he tuong ung giira diu vio vl diu ra cua bg dieu khien md. Tir dd, tien hinh sua ddi vl tdi uu hda, nhu trong hinh 3.
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Hinh 3 Bg quan sit mat cong
3. Cai thien hieu qua dieu khi^n mdr cho budng di^u hda khong khi
Ky thuat dieu khien Idgic md da phlt trien qua gin 30 nam, da vl dang dugc ung dung trong rlt nhieu cic llnh vyc vl thu dugc nhieu thinh cdng ldn.
Nhung khdng it ngudi cho ring ky thuat dieu khien logic rad chi dung thich hgp vdi nhfmg trudng hgp didu khien don giln. Trong trudng hgp dieu khien ddi hdi do chinh xle cao thi hieu qui ciia ky thuat dieu khien rad II khdng ly tudng, vin dya vio ky
thuat dieu khien kinh dien hoac II ky thuat dieu khien rad ket hgp vdi ky thuat didu khien kinh dien.
Him sd do phu thugc vl quy luat dieu khien ddi vdi didu khien md midn bien deu khdng cd yeu clu qui cao. Bdi vi, khi thief ke bd dieu khien md nhu the nly se khdng yeu clu dya vio qui muc tri thuc cua d c chuyen gia va kinh nghiem thao tic ky thuat.
Thdng qua sy can thiep vao cua ham S den bd dieu khien md truyen thdng da cd sy cli thien.
Him S II d c hIra cd the kich hoat trong sa do SIMULINK nhd sii dung khdi S-Function. HIra S cd dang: MATLAB Scripts, tuc II ra-File; File chay viet bing ngdn ngir C, cdn duge ggi II C raex-Files, hoac File chay viet bang ngdn ngir bac cao C++, Frtran hay Ada, cung duge ggi II C mex-Files.
Viec lap trinh tren MATLAB ve nguyen tic dh hgc hon, vi sd lugng elc thu tuc (chuong frinh con) d n ggi II it. Tuy nhien, thuat toln cua him S cIng phirc tap ta lai d n g nen sii dung mgt ngdn ngir bac cao (vi du C) de lap trinh. CIc him S dang mex-File do ngudi su dung dich sin tfr trudc fhlnh dang File ehay vl cd the ggi khi cin. Ngugc lai, him S dang m- File se budc SIMULINK quet vl phan tich timg ddng radi khi ggi nen khi cham.
Dieu quan trgng II khi lap trinh him S II: Tuan thu nghiem ngat d c "dieu kien khung", giup cho SIMULINK cd the ddi thoai mdt cich chuan xlc vdi him S trong qui trinh md phdng. Ngoli ra, ngudi lap trinh holn toln ty do vdi sy sing tao cua minh. Nhd khi nang lap trinh him S, ta cd the md rdng thu vien chuan cd sin cua SIMULINK thera d c hIra bit ky.
Gidng nhu mgi khdi chuan cua SIMULINK, him S cung phan chia d c fin hieu thinh vector bien vio u, vector bien trang thli x vl vector bien ra y. Trong hIra S, d c bien trang thli lien tuc vl giln doan dugc xu ly tich biet, nghia II SIMULINK se ggi cic chuong trinh con khic nhau de tinh x^ vl yiy^-y. De hd trg ngudi sir dung khi viet chuong trinh tao him S, MATLAB da chuan hi sin d c Files ralu sfuntmpl.m vl sfuntmpl_basie.c / sfuntrapl_doc.c, cat tai hai thu muc $MATLABPATH / toolbox / siraulink / blocks vl $MATLABPATH / siraulink / src. CIc File mau dd da chua rat dly du d c "dieu kien khung' ml ta cin tuan thii.
Mdi ndi cua him S vdi SIMULINK II dya vio viec holn fhlnh Module him S-Function (chinh II bo dieu khien cua md hinh md phdng). Hinh 4 the hien
KHOA HOC CONG NGHE
giao dien thief lap tham sd cua module him S- Function. Bao gdm fen tap dn cua ham S va cac tham sd chuyen tdi SIMULINK. Day la thu fy cac fhdng sd, sd vl tham sd hang diu tien cua ham S deu phli cung bien thien.
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Hinh 4 Thiet lap tham sd S-Function III. KFT QUA Md PHONG VA P H A N TJCH
Bll viet sir dung SIMULINK, dieu khien md thdng thudng cho budng dieu hda khdng khi vl dya vio him S de dieu khien md mien bien. Ket qui rad phdng cudi cung dugc the hien tren hinh 7 vl hinh 8.
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Hinh 6 36 di^u khi^n mdr S-Function
Thdng qua md phdng SIMULINK ddi vdi nhiet do cd the fhly dieu khien md thdng thudng vin tdn tai dao dgng. Su dung phuong phip dieu khien md S Function cd hieu qui thu dugc cli thien ro ring.
Hinh 7 Ket qui rad phdng bg dieu khien md thdng thudng
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IV. KET LUAN
Dung MATLAB de tien hinh khIo sit he thdng dieu khien md cho budng dieu hda khdng khi II qui trinh thief ke don giln, khdng ddi hdi tien hinh tinh toln thu cdng nhieu, ml lai dd ding thay ddi linh boat clu true he thdng dieu khien, tdi uu hda hieu qui cua dieu khien rad.
Sir dung phuong phip thay ddi raien bien cd hieu qui giira bdt dugc sai lech tinh cda dieu khien md.
Viec sii dung chirc nang cOa hIra S de thyc hien dieu khien rad raien bien, cd the dya vio dd sai lech d tren dudng dieu chinh, dieu khien raien bien mdt d c h thuan tien vl nhanh chdng.
Ket qui md phdng cho fhly: Tic dgng cua nhidu gin nhu triet tieu holn toln, khdng d n cle bg khii nhilu, he thdng lira viec dn dinh, thdi gian tic ddng nhanh, d c chi tieu chit lugng dira bio, rat phu hgp vdi qui trinh gia nhiet trong Id ap trung. Id sly ndng san sau thu hoach.
T A I UEU THAM KHAO
1. H. X. Li (1997). A comparrative design and tuning for conventional fuzzy control. IEEE Trans.
Syst. Man. cybem. B. vol.27, pp. 884-889, Oct.
2. H. X. Li and H. B Gatland (1997). fuzzy variable fracture control. IEEE Trans. Syst. Man.
cybem. B. vol.27, pp. 306-312, Apr.
3. H. Ying (1993). A nonlinear fuzzy controller with hear rales is the sum of a global two- dimensional multilevel relay and a local nonlinear PI controller. Automafica, vol. 29, no. 2. pp. 499-505.
4. Mifuhiko Arki (1998). Two-degree-of-fredom PID controller classical technology Revisited. Japan- USA-Vietnara Workshop 1998, pp.9-15.
5. Zhang Weiguo, Yang Xiangzhong (1999). Ly luan dieu khien rad v l ung dung [M]. NXB Dai hgc Cdng nghiep Tay Bic, Tay An, Trang Qudc.
6. Wen Xin, Zhou Lou, Li Dongjiang, Bel Chao (2001). Phan tich hdra cdng cy logic rad MATLAB v l ung dung [M]. NXB Khoa hgc, Ble Kinh, Trang Qudc.
7. Shanghai Zhi Leng Xuehui, Zhi Leng Yu Kongqi Tiaojie Jishu [M] (1992). NXB Phd bien Khoa hgc, Thugng HIi, Trang Qudc.
8. Wang Zhenglin, Wang Shengkai, Chen Guoshun (2005). MATLAB/Siraulink v l md phdng
[M] he thdng dieu khien. NXB Cdng nghiep Dien hi, Ble Kinh, Trang Qudc.
9. Yao Jun, Ma Songhui Bianzhe (2002). Md hinh md phdng Siraulink v l Md phdng [Mj. NXB Dai hgc Khoa hgc Dien hi, Tay An, Trang Qudc.
10. Le B l Dung (1996). Thidt ke bg didu khien hr chinh PID. Tuyen tap cac b i o d o khoa hgc tai Hoi nghi toln qudc lln thir III ve ty ddng hoa.
11. Nguydn Thuang Ngd (1996). Chinh dinh fhdng sd tdi uu cua bd dieu chinh khi ddi tugng chua xlc dinh. Tuyen tap cle bio d o khoa hgc tai Hdi nghi toln qudc lln thii II ve ty ddng hoi.
12. Nguydn Van H o i (2001). Ca sd ly thuyet dieu khien ty dgng. NXB Khoa hgc v l Ky thuat.
13. Phan Xuln Minh & Doan Phude (1999). Ly thuyet dieu khien rad. NXB Khoa hgc vl Ky thuat
DESIGN AND SIMULATION OF FUZZY CONTROLLER FOR AIR CONDTTIONERS BASED ON MATLAB Nguyen Viet Ngu.Wang Hong" Hua, Le Thi Minh Tam Summary
Creating suitable air temperature is very important needs in agricultural production and the life of society.
Controls the temperature in these devices often use classical logic control algorithms. In many cases, these algorithms do not meet quality criteria in accordance with the objects in different scales. To overcome the disadvantages of classical control systems, advanced control theory is established and start to apply in which fuzzy control is a outstanding control method with flexibility and has archived many results, the applications of fuzzy set theory, fuzzy logic and fuzzy inference. Based on MATLAB 7.01, this study conducts a fuzzy controller design and implementation of the S function to optimize a process control.
Simultaneously, the research by simulation of fuzzy controllers to control temperature of air conditioning systems used in the poultry incubation oven, oven dried fruits, agricultural products after harvest ...were conducted.
Keyword: Fuzzy control, S function, MATLAB, fuzzy set theory, fuzzy logic, fuzzy inferring, chamber air conditioners.
Ngudi phln bien: TS. NguySn Van Hda
