MC LCMC LC1LI NI U3CHUYN 1 : M HNH HA NG C IN MT CHIU4I. M hnh ha ng c mt chiu41. M hnh l thuyt42. M phng trn Matlab Simulink6II. Cc phng php nhn dng m hnh thc nghim101.Phng php da trn p ng qu 102.Nhn dng m hnh da trn p ng tn s133. Phng php nhn dng bnh phng ti thiu.18III. S dng Ident Toolbox19CHUYN 2 : THIT K B IU KHIN TRN MIN TN S24I.Thit k b iu khin theo phng php ti u modul v ti u i xng241.L thuyt242.p dng vo i tng243.M phng26II. Thit k b iu khin theo m hnh ni (Internal Model Control)291. Cc bc thit k b iu khin292. M phng32III. Thit k b iu khin d bo Smith331. Cu trc iu khin332. p dng cho i tng343. M phng35IV. Thit k b iu khin PID chng bo ha tch phn361. L thuyt362. p dng vo i tng373. M phng38V. S dng cng c PID tunner401. L thuyt402. p dng vo i tng41VI. Phng php thit k loopshaping441. Tng quan442. Cc bc thc hin441. Tng quan v l thuyt482. p dng cho i tng51CHUYN 3 : TRIN KHAI B IU KHIN LN THC T60I . M hnh trin khai b iu khin trn nn vi iu khin60II . Thit b chp hnh (IC L298)61III . Cm bin61IV . Ci t ln vi iu khin65I.Thit k b iu khin m721. Cc bc thit k b iu khin m theo m hnh Mamdani.732. Cc bc thit k b iu khin m theo m hnh Sugeno.76II.Trin khai thc t83TI LIU THAM KHO91

LI NI U

Hin nay ng c mt chiu ng vai tr cc k quan trng trong cc lnh vc ca i sng . Chnh v vy vic iu khin ng c mt chiu lun l mt ti c nghin cu rt nhiu. Do khi c giao bi tp ln mn thit k h thng iu khin chng em chn ti dng ng c mt chiu kch thch vnh cu iu khin v tr qu nng. Trong thi gian 15 tun chng em tm hiu c cch nhn dng m hnh ng c, thit k b iu khin, trin khai b iu khin trn thc t. Chng em xin cm n Thc s Chu c Vit tn tnh hng dn v gip chng em hon thnh bi tp ln ny. D c gng ht sc nhng chc chn bn bo co ny vn cn nhiu sai st, chng em mong nhn c s gp v ph bnh ca thy. Chng em xin chn thnh cm n.

CHUYN 1 : M HNH HA NG C IN MT CHIU I. M hnh ha ng c mt chiu M hnh l thuyt

i tng : ng c mt chiu kch thch vnh cu : t thng = const u vo : in p phn ng. u ra : gc quay .

Hnh 1 : M hnh ng c mt chiu kch thch vnh cuTheo nh lut Kirchoff ta c :

U = R . I + L .+ E

E = k.. = k..Chuyn sang Laplace U = R . I + L.s.I + k..s.

= R . I +L.I.s + k..s.

= R . I +L.I.s +

G = = Trong : R l in tr cun dy phn ng E l sc in ng phn ng ng c Rf l in tr ph I l dng phn ng k l h s cu to ca my in M l momen ng c U l in p t vo phn ng ng c l tc gc ng c l t thng ng c T hm truyn t trn ta c s cu trc ca ng c in mt chiu nh sau : MUu

McIu

K -E

KHnh 2: S cu trc ca ng c in mt chiuVi T = L /R

M phng trn Matlab Simulink

Hnh 3 : M phng s ng c mt chiu trn SimulinkT s v hm truyn trn , ta chn tham s cho ng c nh sau :Cc tham s : - in tr phn ng : R = 250m- Momen qun tnh : J= 0,012Kgm2- in cm phn ng : L = 4mH- T thng danh nh : = 0,04 Vs - Hng s ng c : kM = 38,2Tn hiu in p c a vo iu khin ng c nm trong khong t 0 n Umax.V vy trong m phng vic u tin l chun ha tn hiu u vo t 0 n 1.Li dng c tnh ca khu qun tnh bc nht ta d dng a u vo constant chuyn v dng u vo t 0 n 1.Vic thc hin c th hin trn cu trc sau:

Hnh 4: M phng s cu trc ng c mt chiu trn simulink sau khi chun ha- th gc quay:

Hnh 5 : p ng gc quay

- th dng in

Hnh 6 : p ng dng in phn ng- th tc

Hnh 7 : p ng tc

- th momen

Hnh 8 : th momen

II. Cc phng php nhn dng m hnh thc nghim1. Phng php da trn p ng qu

Vi hng s thi gian chuyn i t tc gc w sang gc quay (T) mnh chn,by gi ch cn quan tm n cc tham s cn li hay chnh l tm tham s cho khu dao ng bc hai sau :.Vi u vo (in p phn ng) l tn hiu 1(t) th ta c c th hm qu h(t) ca tc w ca ng c.h qu iu chnhT0 T1 T2 T3 t hmax

hh(t)

Hnh 9 : th hm qu h(t) ca ng cVi th hm qu nh trn ta d dng a ra c cc h phng trnh sau:

=h

D=

T=

=2.T.D

=T2By gi c c cc tham s ca hm truyn i tng cn iu khin nhng cha th c c c th cc tham s ca ng c.V vy vic cn thit by gi l xc nh c mt trong ba tham s Ru,Lu,J ta c th m hnh ha c ng c.Nhn thy rng ta c th o c Ru mt cch d dng hn so vi hai tham s kia.V vy sau khi o c Ruth ta c th tnh ton ra c Lu,J da vo cc phng trnh trn.p dng cho i tng ca mnh ta c c p ng qu sau:

Hnh 10 : p ng qu ca i tng ng c mt chiu T th ta xc nh c cc thng s sau:h=hxl=0.655;hmax=1.07;T1=0.014;h=1.07-0.655=0.415;

T cc thng s trn d dng tnh c cc thng s D,T, nh sau:

D=

T=

G=So snh p ng u ra vi u vo 1(t) vi hai hm truyn thc t v c lng ta c th sau:

Hnh 11 : So snh p ng gc quay ca hm truyn thc t v c lngNhn xt : Tuy vn tn ti sai lch gia hai m hnh 0.2s u tin nhng sai lch cng khng ng k v sau c hai u bm vi gi tr xc lp nn c lng ny c coi l tt

2. Nhn dng m hnh da trn p ng tn s Nhn dng da trn s liu c tnh p ng tn s trc ht c th phc v cc phng php thit k iu khin trc tip trn min tn s, hoc phc v c lng gin tip m hnh lin tc t cc s liu thc nghim ch ng. c tnh p ng tn s ca qu trnh c xc nh ti nhng tn s quan tm, thng qua thc nghim trc tip vi tn hiu kch thch hnh sin hoc vi cc dng tn hiu ph hp khc. Kch thch trc tip tn hiu hnh sinS dng tn hiu kch thch dng hnh sin l mt trong nhng phng php c in nht ly c tnh tn s ca mt qu trnh. u vo ca mt qu trnh c thay i theo dng hnh sin vi bin v tn s . Sau khi p ng u ra t trng thi dao ng xc lp vi bin v tn s , h s khuch i v lch pha c ghi li. Qu trnh thc nghim c lp li vi cc tn s khc nhau trong di tn quan tm.Mt khc ta c th chuyn t c tnh tn s sang cc dng m hnh c tham s, v d sang m hnh hm truyn t. Trn c s cc s liu thc nghim, trc ht ta v phc th Bode hoc Nyquist. Vic phn tch cc ng th c tnh tn cho ta nhng thng tin rt quan trng v cu trc m hnh. th Bode cng l mt cng c cho php c lng mt cch trc quan h s khuch i tnh cng nh cc hng s thi gian ca m hnh. Tuy nhin t chnh xc cao, cc tham s m hnh cn c xc nh trn c s mt thut ton thch hp trn my tnh.S lng cc tn s c chn th nghim khng ng vai tr quyt nh ti cht lng m hnh nhn c, nhng di tn th nghim th li l yu t ht sc quan trng. Thng tin ban u v tn s cn chn mi ng vai tr quyt nh ti cht lng m hnh. Vi bi ton iu khin, ta ch quan tm ti di tn nm trong phm vi [0, -pi]Thut ton nhn dng da trn p ng tn s khng chp nhn thi gian tr trong m hnh, m ch cho ta kt qu l mt hm truyn t di dng phn thc thc-hu t.Cch th nht, ta c th nhn bit thi gian tr ring, sau sa li cc s liu c tnh pha thu c v tin hnh nhn dng m hnh khng tr nh thng thng. Trn th c tnh tn s ta khng d dng c lng thi gian tr, v vy cn s dng p ng qu . Thi gian tr khng nh hng ti c tnh bin , m ch lm chm pha thm mt lng l . Nh vy ti mi tn s thc nghim i ta ch cn sa li s liu gc pha thu c theo nh hng ca thi gian tr : 0(i) = delay(i) iCch hai l s dng m hnh bc cao hn nhn nh ban u ( 1 hoc 2 bc ) thnh phn tr ni tip c c hi c t ng xp x v mt hm truyn t thc hu t trong thut ton nhn dng. Bn cnh chnh xc cao, mt u im quan trng ca phng php kch thch ch ng bng tn hiu hnh sin l tnh bn vng vi nhiu. Cho d l nhiu qu trnh hay nhiu o,chng kh c th nh hng ln ti mt tn hiu c di tn bng 0 theo l thuyt. Ngay c khi tn hiu ra c b nh hng th vn lc nhiu hon ton n gin bi ta bit chc tn s no cn gi. Phng php ly c tnh tn s thc nghim cung cp cho ta mt cch tng i trc quan nhng thng tin ht sc quan trng v cu trc m hnh cng nh v ng hc ca qu trnh.Nhc im chnh ca phng php s dng trc tip tn hiu hnh sin ly c tnh p ng tn s l mt rt nhiu thi gian, c bit l nhng qu trnh cng nghip thng c hng s thi gian kh ln. Vic ly s liu cho mi cp vo ra c khi mt nhiu ngy. Hn na, v mt thit b chp hnh cng nh mt cng ngh sn xut khng phi qu trnh no cng cho php kch thch dao ng. Chnh v vy vic kch thch tn hiu hnh sin t khi c thc hin ly mt cch y c tnh p ng tn s ca mt qu trnh, m thng ch c p dng cho mt vi tn s quan trng.

p dng cho i tng ca mnh y th ta s dng cu trc sau:

Hnh 12 : M phng cu trc m hnh nhn dng da trn p ng tn s trn simulink

Khi Sine Wave y c bin l 10,tn s chy t 0,001 n 1.Cc thng s trn khi Parameter c chn nh di hnh sau:

Hnh 13 : Thit lp thng s cho khi sine wave v Parameter.

Chy m phng,m Scope xem p ng ng ra v tn hiu ng vo.Phng to trc Y tm bin ca p ng ng ra.T s dng cng thc Ac /Ar sau y s dng cng thc A=20.log( Ac /Ar) tm bin ca hm truyn gia u vo v u ra.Phng to trc X tm lch pha gia hai tn hiu t thi gian tr t bng cng thc sau:=t.w.180/.Sau khi m phng v tnh ton ta c bng sau:Tn s w(rad/s)Bin (dB)Gc pha(deg)

10-3.67-0.72

25-3.65-1.8

50-3.05-2.86

75-1.62-4.3

100-0.63-9.74

2503.5-125.94

500-17.84-168.62

750-22.64-171.82

1000-30.25-174.84

5000-56.67-176.36

10000-72.04-180

Bng 1 : Cc gi tr tn s, bin v gc pha ca i tngT cc thng s trn ta v th bode cho h thng:

Hnh 14 : th Bode m t u ra ca h thngT th nhn thy hm truyn ca u vo v u ra c bc khng nh hn hai.T y s dng hm invfreqs tm ra hm truyn c lng ca i tng.

Kch thch tn hiu dng xung.i vi h tuyn tnh th cc tn hiu vo ra c th c phn tch thnh cc tn s khc nhau. c tnh tn s c th thu c mt cch gin tip d trn php bin i Fourier ri rc . Theo l thuyt ta c :

Khi tn hiu vo c chn l dng xung v qu trnh c tnh n nh , cng thc trn mi c th s dng c. Trong trng hp tn hiu u ra chu nh hng r rt ca nhiu o , vic p dng trc tip php bin i Fourier dn n sai lch m hnh rt ln. Lc nhiu l mt bin php ci thin cht lng nhng cng li mang n nhng vn khc. y chnh l mt tri ca phng php s dung mt tn hiu bng rng nh tn hiu xung.

Phng php phn tch ph tn hiu Hai phng php trn u da vo tn hiu kch thch ch ng. Khi iu ny khng cho php, dy cc gi tr vo-ra bt buc phi ly hon ton t s liu vn hnh thc. Phn tch ph tn hiu l mt phng php quen thuc phc v nhn dng c tnh tn s .Mt h tuyn tnh tham s hng vi cc tn hiu vo/ra l u(t) v y(t), mt ph u(t) c quan h vi mt ph cho ca u(t) v y(t) theo cng thc Puy(= G(. Puu(Trong G( : c tnh tn s ca h ti tn s Puu( : mt ph ca u(t)Puy( : mt ph cho gia u(t) v y(t) c tnh tn s c th c c lng mt cch gin tip thng qua c lng cc hm mt ph :

Phng php ny c u im l tn hiu vo c th chn tng i t do, v d ta c th s dng tn hiu xung vung , xung tam gic, tn hiu gi ngu nhin,.. Ngoi ra ,thi gian tin hnh thc nghim c rt ngn kh nhiu bi theo l thuyt ch cn kch thch mt ln duy nht. Cui cng cc s liu c th ly t mt qu trnh ang vn hnh ch khng bt buc phi thng qua kch thch ch ng. Tuy nhin cht lng m hnh nhn c ph thuc rt nhiu vo dng tn hiu c s dng, chu k trch mu tn hiu cng nh thi gian quan st tn hiu.Phng php nhn dng bnh phng ti thiu. p dng cho cc qu trnh phc tp v yu cu cao v cht lng. Phng php da trn nguyn l bnh phng ti thiu. Thc cht l a v bi ton ti u vi hm mc tiu cn cc tiu ha l tng bnh phng sai lch gia s liu quan st thc t v gi tr tnh ton c lng. Nguyn l: gi s m hnh, gi tr quan st ph thuc tuyn tnh vo tham s m hnh ( khng cn bt buc l tuyn tnh).y(ti) = 1(ti)1 + 2(ti) 2 + + n(ti) n = T(ti) Trong : y(ti): gi tr quan st ti thi im ti.: vector tham s m hnh cn xc nh. = [1 2 n]Tj: hm bit trc( dy gi tr bin u vo hoc ra)T(ti) = [1(ti) 2(ti) n(ti)]Yu cu bi ton l xc nh tham s m hnh sao cho sai lch gia gi tr quan st thc v gi tr tnh ton theo m hnh l nh nht.V(,tN) = i) i))2 = i) i). )2Trong y(ti) l gi tr quan st thc ti thi im tii). l gi tr tnh ton theo m hnh c lng . t =[] = RN*n=[] RnSuy ra = . (1)Nghim ti u ca (1) l: = argmin [ ( - . )T . ( - . ) ]Chn N n ta c: = (T. )-1. T. Thc t gi tr o lun chu nh hng ca nhiu nn yu cu khi nhn dng tham s m hnh bng phng php bnh phng ti thiu l m hnh phi tha mn: Nhiu tc ng l nhiu n trng. Gi tr N phi ln. Tn hiu nhiu o khng tng quan vi vector hi quy( dy bin gi tr vo hoc ra).III. S dng Ident Toolbox Vic u tin cn lm l to s liu nhn dng.Vic ny c thc hin trn Matlab bng cc cu lnh sau:>>syms s;>>Gs=1.528/(4.8e-5*s^2+3e-3*s+2.335);>>Hs=1.528/(4.8e-5*s^3+3e-3*s^2+2.335*s);>>t=[0:0.01:0.2];Vic chn la khong t ny rt quan trng bi v n ph thuc vo c p ng qu ca i tng mnh cn c lng,nhn dng.>>Ht=ilaplace(Hs);>>y=subs(Ht,t);>>y=double(y);>>u=ones(1,21);>>y=y;>>u=u;>>save data u y;Sau khi c s liu by gi n vic nhn dng m hnh s dng ident tool>>identG ident ln Matlab s hin ln ca s sau:

Hnh 15: Ca s ident tool trn matlab

By gi ta s a d liu vo nhn dng bng cch nh sau:Sau khi chn Time domain data s xut hin ca s nh bn di.

Hnh 16 : Ca s xut hin sau khi Sau khi chn Time domain data ca s nh y ta in input l u, output l y,startime l 0,sampling interval l 0.01 v data name l data.Sau khi in cc thng tin xong v nhn Import th coi nh mnh a d liu vo thnh cng.Tip tc n phn nhn dng m hnh,ta chn nh di hnh:

Hnh 17 : Thit lp cho phn nhn dng m hnhSau khi chn nh trn th s xut hin ca s nhn dng sau v ta li chn nh hnh di:

Hnh 18 : Chn thng s cho ca s nhn dng Process ModelsNhn Estimate nhn dng m hnh s thu c b tham s K,Tw, Zeta nh sau:K=0.6544;Tw=0.00453;Zeta=0.142;Nh vy m hnh c lng thu c s c dng sau:

M=By gi vic cn thit l so snh gia hai p ng ca hai m hnh thc t v c lng>>G=tf([1.528],[4.8e-5 3e-3 2.335]);>>step(G);>>hold on;>>M=tf([0.6544],[2.056e-5 1.285e-3 1]);>>step(M);>>grid on;

Hnh 19 : th so snh gia hai p ng ca hai m hnh thc t v c lng

Nhn xt : Nhn th trn ta c th thy p ng ca hai m hnh l hon ton kht nhau,sai lch rt nh .Nh vy m hnh c lng trn hon ton ging vi m hnh thc t.

CHUYN 2 : THIT K B IU KHIN TRN MIN TN S

I. Thit k b iu khin theo phng php ti u modul v ti u i xng1. L thuytPhng php ti u modul ch s dng cho lp i tng c im cc nm bn tri trc o.

Phng php ti u i xng khc phc nhc im trn v tm b iu khin sao cho nn thng c thit k cho i tng c mt im cc nm trn gc ta .2. p dng vo i tng

Hnh 20 : Cu trc iu khin tng iu khin i tng ng c mt chiu-Thit k b iu khin vng trong(dng in):

Vi hm truyn t

+Theo phng php ti u modul ta a ra c b iu khin tch PI c dng: vi +Theo phng php ti u i xng ta a ra c b iu khin c dng :

vi Ti=Tu+4Tt, Td,-Thit k b iu khin vng ngoi (gc quay):

Xem nh vng iu khin dng in t gi tr t th hm truyn t :+V i tng ny l khng n nh nn khng th p dng phng php ti u modul

+Theo phng php ti u i xng ta a ra c b iu khin c dng: vi Ti=4.T1,, T1=3Tu ( m bo cho gi tr dng in t gi tr t trc khi iu khin gc quay).Cc tham s : - in tr phn ng : R = 250m- Momen qun tnh : J= 0,012Kgm2- in cm phn ng : L = 4mH- T thng danh nh : = 0,04 Vs - Hng s ng c : kM = 38,2-Hng s thi gian ca b chnh lu:Tt=10-3 sVi cc tham s trn ta d dng tnh c tham s ca cc b iu khin:B iu khin dng in:

Theo phng php ti u modul,b iu khin c dng:Ri=Theo phng php ti u i xng,b iu khin c dng:Ri=B iu khin gc quay:Sau khi chnh nh b iu khin ta a ra cc tham s sau:Ralpha=3. M phng Vi b iu khin dng in s dng phng php ti u modul th ca p ng gc quay

Hnh 21 : th p ng gc quay khi dng ti u modulNhn xt : p ng gc quay bm rt nhanh gi tr t vi khong thi gian xc lp T3%=0.3s.Nh vy b iu khin cho gc quay ny cho p ng ra rt tt.

th ca p ng dng in

Hnh 22: th p ng dng in khi dng ti u modulNhn xt : p ng ca dng in dao ng trong khong kh ln trong 0.2s u tin v nhanh chng bm vi gi tr t ngay sau .Hay vi thi gian xc lp l T3%=0.25 ny th b iu khin cho dng in ny kh tt. Vi b iu khin dng in s dng phng php ti u i xng

th ca p ng gc quay

Hnh 23 : th p ng gc quay khi dng ti u i xng Nhn xt: p ng gc quay dao ng trong 0.8s u tin vi qu iu chnh khng ng k v bm vi gi tr t ngay sau .Thi gian xc lp T3%=0.6s. th p ng dng in

Hnh 24 : th p ng dng in khi dng ti u i xngNhn xt : th ca dng in dao ng rt nhanh v trong khong kh ln t 1s u tin v sau lp tc bm gi tr t vi thi gian xc lp T3%=0.9s.Nh vy b iu khin dng in thit k theo phng php ti u modul s em li cht lng iu khin tt hn so vi thit k theo phng php ti u i xng

II. Thit k b iu khin theo m hnh ni (Internal Model Control)1. Cc bc thit k b iu khin M hnh ha i tng Thit k BK theo m hnh ni M phng p ng vo-ra sau khi c BKa. M hnh i tng cn iu khin Hm truyn gia in p gc phi:

Cc tham s ng c :

- in tr phn ng : R = 250m- Momen qun tnh : J= 0,012Kgm2- in cm phn ng : L = 4mH- T thng danh nh : = 0,04 Vs - Hng s ng c : kM = 38,2

b. Thit k b iu khin theo m hnh niCu trc iu khin IMCGIMC (s)Gp(s)p(s)-uu

-

Hnh 25 : Cu trc iu khin IMCBi ton thit k: Chn cu trc v tham s ca b iu khin IMC sao cho hm truyn h kn tin ti 1Ta c:

khi v ch khi :

Trong trng hp m hnh l tng: Ta thy rng, s khng kh thi khi c bc mu s ln hn bc ca t s hoc c cha khu tr. Bn cnh khi c im khng nm bn phi trc o th nu c kh thi, BK l tng s c im cc nm bn phi trc o v h iu khin s mt tnh n nh ni.Gii php: thit k thm b lc thng thp kh thi ha b iu khin IMC

Da trn cc phn tch trn, ta i ti cc bc xc nh b iu khin IMC nh sau: Phn tch m hnh c lng ca i tng v dng

Trong : cha thnh phn tr v cc im khng nm bn phi trc o (nu c), c h s khuch i tnh bng 1 Thit k b iu khin IMC theo cng thc:

Trong l b lc thng thp vi h s khuch i bng 1Cu trc ca b lc c dng:

Vi k l s nguyn dng, k c chn va ng bng bc tng i ca . a cu trc IMC v cu trc iu khin phn hi vi b iu khin c dng

P DNG VO BI TON VI I TNG Ta c: B iu khin IMC c dng:

Chn = 0.1;

1. M phngCu trc iu khin:

Hnh 26 : M phng cu trc iu khin IMC trn simulinkKt qu m phng vi i tng gc quay:

Hnh 27 : p ng gc quay khi s dng b iu khin IMCNhn xt : T th ta c nhn xt qu iu chnh=21%,thi gian xc lp T3% l 1.1s.Nh vy b iu khin theo m hnh ni ny cho cht lng iu khin tt nhng li kh trin khai ngoi thc t bi hm truyn ca n kh phc tp.III. Thit k b iu khin d bo Smith1. Cu trc iu khinPhng php thit k b iu khin d bo Smith thng dng cho cc i tng c thnh phn tr . tha k t b iu khin thit k cho i tng khng c tr nhng li khng th xp x thnh phn tr ny. Nguyn tc l : thit k b iu khin Gr(s) cho i tng : GR(s)S(s)

-

yi tng iu khin

Hnh 28 : Thit k b iu khin Gr(s) cho i tngGs(s) = . S(s)Th ta thit k b iu khin R(s) ring cho i tng S(s) khng c thnh phn tr. Hnh 29 : Thit k b iu khin R(s) cho thnh phn khng c trR(s)S(s)

-

y

Vic thit k R(s) theo phng php ti u i xng,ti u modul hay cn bng m hnh.T ta c b iu khin cho i tng Hnh 30 : Cu trc b iu khin theo nguyn l d bo SmithR(s)S(s)

-

y

S(s)--B iu khin GR(s)

Gr(s) = p dng cho i tng

Hnh 31 : Cu trc i tng ng c mt chiuVi i tng c hm truyn l: ta c th xp x n tr thnh i tng sau (coi nh b qua thnh phn Eu quay tr v).Nh vy nu s dng phng php ti u i xng xc nh R(s) th R(s) s c dng l ) do nguyn tc thit k l a h h v dng .V vy nn ta c cc tham s ca b iu khin R(s) =).Sau khi thm khi momen ti thay i theo gc quay u ra th ta chnh inh b R(s) c cc tham s sau:R(s)=)M phngCu trc iu khin:

Hnh 32 : M phng cu trc iu khin theo nguyn l d bo Smith trn SimulinkThay b iu khin bn trn vo cu trc iu khin ta c kt qu m phng sau:

Hnh 33 : kt qu m phng p ng gc quay khi dng b iu khin d bo SmithKt lun : T th ta nhn thy p ng khng n nh v bm gi tr t v vy b iu khin ny khng c gi tr.IV. Thit k b iu khin PID chng bo ha tch phn1. L thuyt Hin tng bo ha tch phn ( Reset Windup ) l hin tng u ra ca b iu chnh vn tip tc tng qu mc gii hn khi sai lch iu khin tr v khng.Hin tng ny c th xy ra khi b iu khin cha thnh phn tch phn v tn hiu iu khin b hn ch.Cc bin php khc phc hin tng ny:(1) Ct b thnh phn tch phn khi gi tr c iu khin t ti gi tr t ,loi tr hon ton hin tng windup. (2) Gim h s khuch i u ra ca b iu chnh nm trong gii hn cho php ,trnh vic xy ra hin tng windup. (3) Theo di gi tr thc ca tn hiu iu khin b gii hn v phn hi v b iu chnh gim thnh phn tch phn hn ch windup.

(4) t mt khu gii hn ti u ra ca b iu chnh PID m phng c tnh phi tuyn ca phn t chp hnh,s dng thut ton b nh trong phng php 3.

Hnh 34 : B iu khin PID chng bo ha tch phn c thit k theo phng php 4 trn

y cc tham s Kp,Ti,Td c c th tnh ton theo phng php ti u i xng hoc ti u modul khi cha c chng bo ha tch phn.Tt y c tnh bng vi n=2,3... p dng vo i tng y ta s dng cu trc iu khin tng:

Hnh 35 : M phng cu trc iu khin tng Cc tham s : - in tr phn ng : R = 250m- Momen qun tnh : J= 0,012Kgm2- in cm phn ng : L = 4mH- T thng danh nh : = 0,04 Vs - Hng s ng c : kM = 38,2-Hng s thi gian ca b chnh lu:Tt=10-3 sVi cc tham s trn ta d dng tnh c tham s ca cc b iu khin:B iu khin dng in:

Theo phng php ti u modul,b iu khin c dng:Ri=

Theo phng php ti u i xng,b iu :Ri=B iu khin gc quay:Ralpha=

M phngV ch c b iu khin dng in c thit k theo phng php ti u modul c dng PI nn ch s dng cu trc chng bo ha tch phn trn cho trng hp ny.Kt qu m phng cho gc quay:

Hnh 36 : Kt qu m phng gc quayT th trn ta c th thy p ng gc quay khng c qu iu chnh tuy nhi n th gian xc lp T3%=1,8 s,kh ln so vi b iu khin c thit k khng c khu bo hatch phn ny.p ng ca dng in

Hnh 37 : p ng dng inNhn xt: th ca dng in c hai khong dao ng rt nhanh nhng trong phm vi tng i nh v t sau 1.8 s th lp tc bm vi gi tr t.Cng nh i tng gc quay, p ng ca dng in qua b iu khin PI chng bo ha tch phn c thi gian xc lp kh ln so vi khng c khu chng bo ha.

V. S dng cng c PID tunner1. L thuytKhi c m hnh ca i tng trn Simulink,vic by gi l thit k b iu khin. y s s dng cng c PID tunner tm ra b iu khin cho i tng.u tin ta vo Simulink-Continuous chn khi PID Controller ri cho vo trc m hnh i tng thit lp cu trc iu khin.Sau y l Hnh 38 : Hnh nh bn trong khi PID ControllerSau khi chn cu trc iu khin ti khung Controller l P,PI,P,PID hoc c th thm cc iu kin khc nh gi tr u ra b iu khin b gii hn v s dng chng bo ha tch phn ti khung PID Advanced th ta nhn nt Tune cng c tm ra thng s ca b iu khin vi cu trc b iu khin c vit r ti khung Compensator formula.p dng vo i tng y s dng cu trc iu khin trc tip.

Hnh 39 : M phng trn Simulink cu trc iu khin trc tip i tng

Sau khi thc hin Tune th ta thu c b iu khin c dng: vi cc tham s P=0.128,I=0.011,D=-0.558,N=0.229.Kt qu m phng th ca p ng gc quay :

Hnh 40 : Kt qu m phng th ca p ng gc quay khi s dng cu trc iu khin trc tip

Vi b iu khin PD c dng: th sau khi Tune ta s thu c b iu khin c cc tham s sau:P=6.57;D=0;N=100.Kt qu m phng cho gc quay vi b tham s trn:

Hnh 41 : Kt qu m phng cho gc quay vi b tham s sau khi TuneNhn xt : Sau mt thi gian c hai b iu khin trn u bm gi tr t nhng vi b iu khin PID th thi gian xc lp qu ln T3%=50s cn vi b iu khin PD mc d thi gian xc lp cha y 1s nhng p ng ca n khng hon ton bm vi gi tr t ,tuy nhin vn trong khong chp nhn c. Nu cu trc iu khin l iu khin tng nh phng php ti u modul v i xng

Hnh 42 : Cu trc iu khin tng iu khin i tng ng c mt chiu

Sau khi Tune tm b iu khin dng in s thu c b iu khin c dng: vi P=0.135;I=23.466.

T y tip tc Tune tm b iu khin gc quay s thu c b iu khin c dng: Vi P=3.417;I=0.634;D=1.888;N=41.317 th s thu c kt qu m phng sau:

Hnh 43 : Kt qu m phng p ng gc quay khi s dng cu trc iu khin tngNhn xt:Mc d tin ti gi tr t rt nhanh nhng sau mt thi gian di mi hon ton bm gi tr t vi thi gian xc lp T3%=7.5s.Cht lng ca b iu khin ny khng tt.Nh vy so vi b iu khin c thit k bng phng php ti u modul v ti u i xng th cht lng iu khin ca b iu khin c thit k bng cng c ny km hn kh nhiu.

VI. Phng php thit k loopshaping1. Tng quan tng ca phng php thit k loopshaping l thit k b iu khin cho h thng vng kn da trn cc hm chc nng ca h h.Mt h thng h vng kn c th hin qua s khi sau:

Hnh 44 : S cu trc thit k b iu khin cho h thng vng knTrong :e - sai lch gia u ra y v gi tr t rn - nhiu od - nhiu ca qu trnhHm truyn h h: Xt hm nhy l hm lin h gia d v y:

V hm b nhy l hm lin h gia n v y:

V mong mun loi b c nhiu o v nhiu qu trnh, nn c hai v cng nh cng tt. Tuy nhin, , nhng do nhiu o tp trung tn s thp v nhiu qu trnh tp trung tn s cao, v vy gii php a ra: Gi nh tn s thp. Gi T nh tn s cao.Cc bc thc hinDng tng qut ca l:

thit k , ta s dng kin thc v cc khu hiu chnh pha: Hiu chnh sm pha Lead network:

Hiu chnh chm pha Lag network:

B iu khin y c thit k da vo tiu chun n nh Nyquist v bng thng ca h h.-Tiu chun n nh ca Nyquist:Nu hm truyn Gh(s) ca h h c m im cc khng nm bn tri trc o(nm trn trc o hoc nm bn phi trc o) th cn v h kn n nh l c th Nyquist ca h h ,k hiu bng Gh(N),bao im -1+0j ca mt phng phc ng m ln theo chiu ngc kim ng h.Hay gn gi hn vi i tng ca mnh ta c nh l sau:Nu h h n nh hoc ch c s=0 l im cc duy nht khng nm bn tri trc o th h kn s n nh khi v ch khi ng th c tnh tn bin pha Gh(jw),0w ca h h khng i qua v khng bao im -1+0j.Tip theo ta s i xem bng thng ca h h c nh hng g n cht lng ca h thng.-Bng thng l tn s m ti th bin (trong th Bode) ca h h t gi tr -3dB.Tn s ny cho thy tc ca h thng v t l nghch vi thi gian qu ca h thng.Nh vy bng thng cng ln th p ng ca h thng cng nhanh.Ta c hm truyn h kn l:

Suy ra: v vy nu p ng h h nhanh th p ng h kn cng s nhanh.Da vo qu o nghim s chng ta thy khi thm mt im cc c phn thc m vo hm truyn h h th QNS ca h kn c xu hng tin gn v pha trc o ,h thng s km n nh hn, d tr bin v d tr pha gim, vt l tng.Cn nu thm mt im khng c phn thc m vo hm truyn h h th QNS ca h kn c xu hng tin xa trc o do h thng s n nh hn , d tr bin v d tr pha tng, vt l gim.V vy b iu khin ca mnh s c t nht mt im khng. p ng u ra c th bm vi gi tr t nhanh th nn cn mt khu tch phn.V vy d thit k v trin khai ,cu trc b iu khin C s tr thnh:C(s)=.p dng cho i tng :G(s)=S dng cng c sisotool thc hin vic thm b iu khin vo qu o nghim s v bt u chnh nh sao cho p ng qu bm v n nh nhanh nht.Hoc ta c th s dng ca s Automated Tunning v chn thit k theo phng php Loop Shaping s ra c b iu khin C(s)=0.0037 vi p ng qu sau:

Hnh 45 : p ng u ra khi cha c MtBn trn l b iu khin cho i tng khi cha c Mt thay i theo thi gian.Lp b iu khin trn vo m hnh c Mt thay i th ta c p ng u ra sau:

Hnh 46 : p ng u ra khi c MtNhn xt: Thi gian qu ca p ng u ra l rt nh,b iu khin bm nhanh v khng c thnh phn qu.Thi gian xc lp T3% l 0.5s.V vy phi ni y l b iu khin rt tt v n gin, d trin khai. VII. Thit k b iu khin s dng phng php qu o nghim s1. Tng quan v l thuytNguyn tc thit k h thng dng phng php hiu chnh thng s hay cn gi l QNS l da vo phng trnh c tnh ca h thng sau khi hiu chnh:

Ta cn chn thng s ca b iu khin sao cho phng trnh trn c nghim ti v tr mong mun.Sau y l mt s dng ca b iu khin.1.1Hiu chnh sm pha(Khu Lead) thun li cho vic v QNS chng ta biu din hm truyn khu hiu chnh sm pha di dng sau :

(>1)Bi ton t ra l chn gi tr Kc, v T p ng ca h thng tha mn yu cu v cht lng qu ( vt l, thi gian xc lp, )Ta bit cht lng qu ca h thng hon ton xc nh bi v tr ca cp cc quyt nh. Do nguyn tc thit k khu hiu chnh sm pha dng phng php QNS l chn cc v zero ca khu hiu chnh sao cho QNS ca h thng sau khi hiu chnh phi i qua cp cc quyt nh mong mun. Sau bng cch chn h s khuch i KC thch hp ta s chn c cc ca h thng chnh l cp cc mong mun. Nguyn tc trn c c th ha thnh trnh t thit k sau:Trnh t thit k-Bc 1: Xc nh cp cc quyt nh t yu cu thit k v cht lng ca h thng trong qu trnh qu :

vt l v thi gian qu =>, => -Bc 2: Xc nh gc pha cn b cp cc quyt nh

nm trn QNS ca h thng sau khi hiu chnh bng cng thc:

trong pi v zi l cc cc ca h thng G(s) trc khi hiu chnh.Dng hnh hc ca cng thc trn l:

gc t cc cc ca G(s) n cc -gc t cc zero ca G(s) n cc -Bc 3: Xc nh v tr cc v zero ca khu hiu chnh V hai na ng thng bt k xut pht t cc quyt nh s* sao cho hai na ng thng ny to vi nhau mt gc bng *. Giao im ca hai na ng thng ny vi trc thc l v tr cc v zero ca khu hiu chnh.C hai cch v thng dng:- PP ng phn gic ( cc v zero ca khu hiu chnh gn nhau).- PP trit tiu nghim ( h bc ca h thng).-Bc 4: Tnh h s khuch i Kc bng cch p dng cng thc:

1.2.Hiu chnh tr pha(Khu Lag)Hm truyn khu hiu chnh tr pha cn thit k c dng:

(> H=tf(1,1);Sau y g sisotool vo khung lnh s xut hin ca s sau:

Hnh 47 : Ca s siso tool

Tip tc s Import hm G v H vo cu trc iu khin c th sau:

Hnh 48 : th sau khi Import Hm G v H

y ta s thit k da trn p ng qu nn ta phi cho ra th ca p ng qu thit k b iu khin mt cc trc quan.

Hnh 49 : Ca s hiu chnhSau khi ta hiu chnh xong s xut hin th p ng qu vi b iu khin C=1

Hnh 50 : p ng qu vi b iu khin C=1Nhn xt: vi b iu khin bng 1 th i tng iu khin n nhBy gi phi thit k b iu khin.Nhy chut phi vo th nghim s ca ca s sisodesign chn nh sau:

Hnh 51 : Thit lp ca s DesignSau y ta nhy chut phi v chn Design Requirements,chn New. y ta s thit lp yu cu ca p ng qu nh thi gian xc lp hay vt l nh t ra ban u.

Hnh 52 : Hnh nh sau khi thit lpYu cu by gi l thit k b iu khin C sao cho cc im cc nm trong vng cho php bng cch ko im khng v im cc ca b iu khin v theo di p ng qu .Hoc ta c th cho Matlab t ng tm kim b iu khin cho i tng trn ti ca s Automated Tuning nm trong sisotool.B iu khin tm c c dng:C=Vi th p ng qu u ra nh sau:

Hnh 53 : th p ng qu u raNhn xt:Kt qu u ra tha mn yu cu t ra ban u. Bn trn l cu trc iu khin gc quay trc tip sau y ta s tm b iu khin bng cu trc iu khin tng nh phng php ti u modul v ti u i xng.Tng t nh cu trc iu khin trc tip:Vi i tng dng in c dng: v tiu chun vt l =0%,thi gian xc lp T3%