TRNG I HC BCH KHOA THNH PH H CH MINH Khoa in-in t Ngnh iu khin t ng

NG DNG L THUYT HIN I THIT K MODUL IU KHIN NG C DC---------

Sinh vin thc hin:

Bi Trung HiuM s: 40200776 Lp: DD02KSTN

Thnh ph H Ch Minh, 2005-12-24

Index DC Motor Control Module I. Khi qut-gii thiu ti: Kin thc c bn: II. Gii thiu thut ton iu khin v cc chng trnh. II.1. iu khin kinh in II.2. Mng neural II.3. Fuzzy control II.4. Genetic Algorithm(GA). II.5. Chng trnh iu khin vit bng ngn ng C trong uV3 Hnh II.1 M hnh iu khin h thng khi cha c khu chnh nh Hnh II.2 M hnh iu khin h thng c thm khu chnh nh III. Phn cng chun b v phn mm s dng. III.1. Mch phn cng Mch giao tip MCU P89LPC922 vi PC qua cng COM Hnh III.1 Hnh III.2 Mch pht trin ng dng MCU P89LPC922 Hnh III.3 Mch c Encoder s dng MCU P89LPC922 Hnh III.4 Mch ng lc (mch cng sut). IV. Gii quyt vn : IV.1. nh hng chng trnh: Hnh IV.1 nh hng chng trnh dng TOP-DOWN design IV.2. Phc tho gii thut IV.2.1. c Encoder: Hnh IV.2.1.1 Cu hnh cc ngun to dao ng ca P89LPC922 Hnh IV.2.1.2 Cu hnh ca Counter/Timer 0 v cch khai bo khi T0 chc nng Counter Hnh IV.2.1.3 Cu hnh ca WDT chc nng Timer Hnh IV.2.1.4 S gii thut cch c Encoder bng Counter v gi ln PC IV.2.2. iu xung Hnh IV.2.2.1 S khi iu xung tham kho Hnh IV.2.2.2 Mch nguyn l ca Driver LMD18200 dng ch iu bin xung Hnh IV.2.2.3 Timer 1 mode 6 vi chc nng PWM IV.2.3. Khu iu khin kinh in PID: IV.2.3.1 Khu PID ri rc: Hnh IV.2.3.1 Tm cc thng s cho PID nh Matlab Hnh IV.2.3.2 S gii thut kho st c tnh ng c Hnh IV.2.3.3 Biu din kt qu vi Ts=9ms Hnh IV.2.3.4 Xp x cc kt qu kho st bng mt hm truyn khng n v IV.2.3.2 Thit k khu iu khin m PID ri rc dng MATLAB(Tm b thng s Kp,Ki,Kd bng thut ton GA kt hp mng neural): Hnh IV.2.3.1 S m phng ng c DC xy dng trong Matlab Hnh IV.2.3.2 Chc nng ca MCU P89LPC922 m phng trong Matlab Hnh IV.2.3.3 Kha m xy dng lut iu khin Hnh IV.2.3.4 Khi PID ri rc xy dng trong Matlab Hnh IV.2.3.5 Qun th c chn nh li khuyn ca chuyn gia. Hnh IV.2.3.6 p ng ca h thng khi tn hiu th l 1000+500sin(0.02t) (v/p) trn m phng. Hnh IV.2.3.7 Hnh phng to sai s gia tn hiu c v tn hiu p ng (vng/pht) trn m phng. Hnh IV.2.3.8 p ng ca h thng khi tn hiu th l 20+10sin(0.5t) (xung/Ts) trn thc t vi chu k lnh l 10xung/lnh.

Trang i

DC Motor Control Module Hnh IV.2.3.9 S gii thut iu khin vng kn cha chnh hng ch dng khu PID kinh in Hnh IV.2.3.10 p ng vng kn khi ch c khu PID vi cc tc khc nhau khi khng gy nhiu ti. IV.2.3.3 M rng chin lc iu khin, tm cch ti u ha p ng qu ca h thng-nhn dng i tng v xy dng mt m hnh tham chiu chun cho ng c-Mng neural truyn thng: Hnh IV.2.3.1 S gii thut kho st c tnh ng c. Hnh IV.2.3.2 c tnh iu xung theo vn tc (xung/Ts). Hnh IV.2.3.3 p ng bc khi c khu hiu chnh kt hp. V. Cc vn m rng v hng gii quyt: VI. Kt lun: VII. D nh: VIII. Ti liu tham kho VIII.1. Gio trnh. VIII.2. Ti liu tham kho chnh: T kha tra cu ti liu s dng. IX. Cc phin bn cp nht.

Trang ii

(I) Khi qut Gii thiu s lc v ni dung ti I Khi qut: Vic p dng l thuyt iu khin kinh in v hin i vo nhng m hnh thc t lun gp kh khn v gii thut phn mm ln p ng phn cng ca thit b. Bng cch s dng vi iu khin P89LPC922 ca Philips lm nhn iu khin trung tm, Matlab l chng trnh x l trung gian, phn mch cng sut s dng Driver tch hp , hi vng ti em n mt cch nhn nhn mi v vn p dng l thuyt iu khin vo thc t. ti phn tch kh k lng cc vn nh thit k v chn b thng s ca khu iu khin kinh in PID bng thut ton GA, cch chn tn s iu xung, x l ngt trong ly mu, thi gian thc hin ca cc hm, gii hn phn cng p ng ca thit b, cch xy dng m hnh tham chiu chun cho i tng, khc phc nhng s c v nhiu ti hoc/v nhiu o ln i tng. Lm vic trn nhn iu khin P89LPC922 ca Philips nn ti phn tch cc s gii thut v chng trnh, cng nh thi gian thc thc thi trn c s tp lnh ca h MCU8051. Kin thc c bn: L thuyt iu khin kinh in,l thuyt iu khin hin i, in t c bn, in t cng sut, cu trc vi iu khin, gii thut v lp trnh ngn ng C.

Trang I.1

(II) Thut ton iu khin v cc chng trnh II. Thut ton iu khin v cc chng trnh: II.1: iu khin kinh in: S dng khu vi tch phn t l (PID) lm b iu khin h thng. II.2: Mng neural: nhn dng c tnh ng c DC. iu khin theo m hnh tham chiu. Chuyn gia cho li khuyn v vng kh nghim ca khu PID, hng dn thut ton GA tm qun th thch nghi. II.3: Fuzzy control: iu khin vng kn bng cng tc m: Nu 120% th tt ngun, khong gia s dng khu hiu chnh PID kinh in. II.4: Genetic Algorithm(GA): chn b thng s PID cho khu iu khin kinh in, la c th tri theo yu cu thit k vi mc chnh xc t ra ca ngi dng. II.5: Chng trnh iu khin vit bng ngn ng C trong uV3. II.6: Cc m hnh iu khin h thng:

Hnh II.1

M hnh iu khin h thng khi cha c khu t chnh nh

Hnh II.2

M hnh iu khin h thng c thm khu chnh nh

Trang II.1

(III) Phn cng v phn mm III. Phn cng chun b v phn mm s dng: III.1: Mch phn cng: III.1.1 Mch giao tip MCU P89LPC922 vi PC qua cng COM. III.1.2 Mch pht trin ng dng MCU P89LPC922. III.1.3 Mch c Encoder s dng MCU P89LPC922 III.1.4 Mch cng sut iu khin ng c. III.1.5 ng c DC c Encoder. III.1.6 B ngun: 12VDC, 5VDC III.2: Chng trnh phn mm: III.2.1 Keil For 8051(uV3tools c51+a51). III.2.2 Hyper terminal. III.2.3 Matlab version 7.0. III.2.4 Orcad version 9.2.

Hnh III.1.1.: Mch giao tip MCU P89LPC922 vi PC qua cng COM.

Trang III.1

DC Motor Control Module

Hnh III.1.2.: Mch pht trin ng dng MCU P89LPC922.

Hnh III.1.3.: Mch c Encoder s dng MCU P89LPC922

Trang III.2

(III) Phn cng v phn mm

Hnh III.1.4.:S phn cng mch cng sut

Trang III.3

(IV.I) Gii quyt vn -nh hng chng trnh IV. Gii quyt vn : IV.1. nh hng chng trnh: Mun iu khin ng c vng kn, c hi tip: (i) ti s dng encoder quang phn hi vn tc . Nhim v phi c c gi tr ny. D nh s pht trin cch c Encoder s dng ngt cnh mode x4 (ii) p t vo 2 u ng c thay i s lm vn tc ng c thay i nn tn hiu iu xung c tc ng trc tip n vn tc ng c. Nhim v phi c chng trnh iu bin xung. (iii)Mun ng c p ng ng vn tc mong mun, phi c mt khu iu khin, c th dng khu iu khin kinh in (PID) hoc(/v kt hp vi) iu khin hin i (xy dng m hnh tham chiu, hoc/v khu iu khin m) (iv) Gi tr vn tc v chiu quay ca ng c c ra lnh t bn phm v hin th trn mn hnh PC bng giao tip RS232. Cc gi tr ny c th c nhn t mt MCU master khc qua cc giao tip I2C, song song, ty nhu cu s dng ca ngi thit k. (v) Khu PID cn cc thng s iu khin vng kn, nhim v phi tm c b 3 thng s KP, KI, KD, s dng thut GA kt hp vi li khuyn ca chuyn gia.

Hnh IV.2 nh hng chng trnh dng TOP-DOWN design

Trang IV.1

DC Motor Control Module IV. Gii quyt vn : IV.1. nh hng chng trnh: IV.2. Phc tho cc gii thut: IV.2.1. c Encoder: Hnh IV.2.1.1 Cu hnh cc ngun to dao ng ca P89LPC922 Hnh IV.2.1.2 Cu hnh ca Counter/Timer 0 v cch khai bo khi T0 chc nng Counter Hnh IV.2.1.3 Cu hnh ca WDT chc nng Timer Hnh IV.2.1.4 S gii thut cch c Encoder bng Counter v gi ln PC Mun iu khin ng c bng vng kn, c hi tip, trong ti ny s dng encoder quang phn hi vn tc . V c bn, c c gi tr vn tc ny, ta c th: (i) Tnh s cnh xung trong thi gian Ts (sampling time) suy ra vn tc trung bnh ca ng c.(pulse/Ts) (ii) Tm thi gian xut hin 2 cnh xung lin tip ca encoder, t cng suy ra c vn tc trung bnh ca ng c. Phn tch: i. Nu s dng phng n 1, ta cn 1 timer nh thi gian ly mu, 1 counter m s xung. ii. Nu s dng phng n 2, ta cng cn 1 timer nh khong thi gian v 1 chn (c th l counter/ngt ngoi/1 chn In/Out bnh thng) iii. Nu s dng phng n 2, thi gian thc thi chim hu ht thi gian hot ng ca MCU nn s dng mt Device ring bit lm nhim v ny. iv. Nu s dng phng n 1 s b gii hn v mt p ng do encoder gy ra v. Nu s dng phng n 2, trong thut gii ca MCU MASTER, dng giao tip song song gim thiu thi gian ly mu, tt nhin cn giao thc bt tay m bo nhn ng d liu, chiu quay ca ng c cng c ENCODER READER CARD nhn v gi ln bit cao nht ca byte cao. La chn: Trong ti chn phng n 1. Cch thc gii quyt: i. S dng Watchdog Timer nh khong thi gian ngt(Ts). Khong thi gian ny c lp trnh c th thay i ty mc ch s dng. ii. S dng Timer 0 mode 1 lm counter m s xung cnh encoder. Khng tnh n trng hp Counter trn do vt qu 65535xung/Ts.

Trang IV.2

(IV.2.1)Phc tho gii thut c Encoder

S qua v phn cng ca P89LPC922 phc v chc nng m xung:

Hnh IV.2.1.1. Cu hnh cc ngun to dao ng ca P89LPC922 Mun iu khin ng c i. ti s dng ngun xung nhp l thch anh 11.0592MHz. (High freq) b DIVM=0, tc l CCLK= (thi gian PCLK= f osc f osc tnh bng giy ) ii. Cu hnh ca Counter/Timer 0 v cch khai bo khi T0 chc nng Counter/Timer 16bit:

Hnh IV.2.1.2. Cu hnh ca Counter/Timer 0 v cch khai bo khi T0 chc nng Counter

Trang IV.3

(IV.2.1)Phc tho gii thut c Encoder i. Cu hnh ca WDT chc nng Timer:

Hnh IV.2.1.3. Cu hnh ca WDT chc nng Timer Cu hnh ca WDT chc nng Timer Khai bo cu hnh:Cc thanh ghi chu tc ng: TMOD, TAMOD,WDFEED1&2, WDCON, IE,IP . y, ta dng chn T0 ch Input Only. S gii thut:

Hnh IV.2.1.4. S gii thut cch c Encoder bng Counter v gi ln PC Trang IV.4

(IV.2.1)Phc tho gii thut c Encoder Code: Khi to WD chc nng Timer v sinh ra ngt sau mi Ts cho Counter 1 cp nht gi tr gi ln PC v Reset Counter. Phn tch gi tr ln nht v nh nht c th sinh ngt t WDT. T cng thc: tclks = 25+ PRE (WDL +1) + 1 , vi PRE=07, WDL=0255 ta thy rng: Khi chn PLCK=11.0592M/2 th (Ts)min=6s, (Ts)max=189.6ms Khi chn WDCLK=400kHz th (Ts)min=82.5s, (Ts)max=2.62s o Trong bi ny, ta thng nht chn WDCLK, c cc cng thc sau: 25+ PRE (WDL + 1) + 1 400000Ts 1 tclks o Ts = 2 PRE (WDL + 1) = = 25 400000 400000 400Ts 1 2 PRE (WDL + 1) = (Ts : ms ) 25 Nu ta thc hin cc php nhn chia v so snh tm ra s c sai s b nht th tng i tn dung lng b nh, vy nn ta chuyn sang cch dng cu trc sau tnh TS.(C sai s tng i ln) o Ts=[1:20]msPRE=000 o Ts=(20:2000]msPRE=111 T nh hng nh th, ta vit chng trnh:if(time>20) { WDCON = 0xE5; WDL = 25*time/256-1; } //Thoi gian lay mau >=1ms va =1&time20)?( WDCON = 0xE5,WDL = 25*time/256-1):( WDCON = 0x05,WDL = (400*time-1)/32-1);

Trong cc php tnh, khng c s no vt qu tm ca s unsigned int nn kt qu chp nhn(trong sai s tnh c) Ghi ch: Source code c ti http://www.robotics.khvt.com/dcmotor/code/openloop.zip Phn tch s kh khn v mt p ng ca Counter: o Khi x l thi gian thc, ta mong mun sao cho vi iu khin x l nhanh cc kt qu tnh ton hu mong to c tn hiu iu khin thch hp nht vi tn hiu hin ti. o S p ng phn cng bao gi cng gy ra nhng kh khn, y ta khng th ly mu khong thi gian qu nh, khng phi ch v thi gian p ng ca thut ton x l, m cn v s phn gii ca sensor l c gii hn. V d, trong bi, nu s dng encoder c phn gii 100xung/vng, ta ly mu vi chu k 10ms. Vy, c th c c s sai lch ca 1 xung, ng c cn c vn tc ti thiu: 60 1xung :10ms 100 xung :1s = 60v / p min = ( v / p ) . (Vi S l phn STs gii ca Sensor) cng thc trn, ta thy c 2 cch gim min: Tng phn gii ca Encoder. Hoc/v tng thi gian ly mu. o Tuy nhin: min STs = 60 l mt ng thc, v trong ng thc , ta mun 2 thnh phn: min v Ts cng nh cng tt, vy ch cn cch tng S, cch ny khng phi bao

Trang IV.5

(IV.2.1)Phc tho gii thut c Encoder gi cng thc hin c v gi thnh/cng nh phn cng p ng cng phi c gii hn. o Hng khc phc: s dng Encoder c phn gii cao hn, ngh a ra l 1000xung/vng. Lc ny, gi s vn dng Ts=10ms, vy th tc t phn gii xung l: min = 6 ( v / p ) . Vi cch khc phc ny, ta phi phn tch ngng trn ca p ng:1 1v : 362 s , 11.0592 MHz = 165840 ( v / p ) , gii hn trn ny khng cn xt ti trong ti ny. 1xung : 4CCLK 1000 xung : 4000CCLK 1v : 4000

Phn tch kh khn khi ko ti: Khi ko ti, vn tc ca ng c s gim xung v dng qua ng c tng ln, lc ny, gi tr encoder gi v (nu vn gi thi gian ly mu nh trc) s gy rt nhiu kh khn (do phn gii gy ra) vi iu khin c th hiu c. >>>>Cch gii quyt vn : Ta s iu khin ng c bng cch sau: Khi gn vn tc>vn tc hin ti, ta m hm Vmax, t sai s khong gn 20%, chuyn sang PID. Khi gn vn tc>>General model Exp1: f1(x) = a*exp(b*x)Tm thng s ng tin cy: (t ) a Gi tr: = 1 + e at , (khng n v); th tm bng thng k xem kt qu c hi t hay

0

0

khng? Matlab cho ta m hnh ng c l: H ( s ) =

K 25 = . ( s + a ) ( s + 25)

Trang IV.12

(IV.2.3.1)Khu PID s

Hnh IV.2.3.3 Sau 10 mu th, ta thu c hnh:

Biu din kt qu vi Ts=9ms

Hnh IV.2.3.4

Xp x cc kt qu kho st bng mt hm truyn khng n v Trang IV.13

(IV.2.3.1)Khu PID s

Kt qu l chp nhn c! C 2 nguyn nhn gy sai lch chnh: thi gian ly mu v s p ng trong Ts ca encoder. Khi thi gian ly mu gim, s lch 1 xung cng gy ra sai s h thng tng i ln, khi thi gian ly mu tng, s mu ly trong thi gian qu qu t khng th hin c tnh ng c Thng s gn ng ca ng c m ta chn s l: a=25. K 25 = T : H ( s ) = ( s + a ) ( s + 25) Hnh v vi gi tr Vmax chnh l ngng p ng trn ca ng c, ta khng th qua c bn tri mt phng quy nh bi hm truyn H(s). Hm truyn H(s) xy dng trn khng dng mt n v no chun ha c! iu khin vn tc, ta c th nhn H(s) vi mt h s K no . V d nh: o Nu u vo H(s) l vn tc yu cu v u ra H(s) l p mong mun th ta c quan h: V s )=0.060 (V s ) . U=12VDC v=31.7(v/g) K=12/31.7=0.378 ( 2 o Tuy nhin, trong phm vi ti ny, ngi vit li c ch nh dng mt hm truyn khng n v. Bi vy, s chun ha cc tn hiu vo v ra!

Trang IV.14

DC Motor Control Module IV. Gii quyt vn : IV.1. nh hng chng trnh: IV.2. Phc tho gii thut IV.2.1. c Encoder: IV.2.2. iu xung IV.2.3. Khu iu khin kinh in PID: IV.2.3.1 Khu PID ri rc: IV.2.3.2 Thit k khu iu khin m PID ri rc dng MATLAB(Tm b thng s Kp,Ki,Kd bng thut ton GA kt hp neural): Trong matlab, ta xy dng li m hnh ng c v cc tnh nng ca MCU m phng:

Hnh IV.2.3.1 S m phng ng c DC xy dng trong Matlab Trong , khi chc nng ca MCU P89LPC922 l:

Hnh IV.2.3.2 Chc nng ca MCU P89LPC922 m phng trong Matlab Vi kha m l cng tc c xy dng theo quy lut:

Hnh IV.2.3.3

Kha m xy dng lut iu khin

Trang IV.15

(IV.2.3.2) Thut ton GA-Neural tm b thng s PID Khi PID ri rc c xy dng nh sau:

Hnh IV.2.3.4 Khi PID ri rc xy dng trong Matlab Cch tm b thng s PID bng thut ton GA: Trong thi i my tnh s hin nay, cch s dng vng lp hoc khi to nhiu mu th ngu nhin tm gi tr tt nht tha mn yu cu t ra thng c dng khi m cch gii bng l thuyt ton hc kinh in qu phc tp, hoc khng cho li gii tng minh. Thut ton GA (Genetic algorithm) khai sinh da trn thuyt tin ha ca Darwin, nh lut di truyn ca Mendel t c s rt ln trn my tnh s. Trong phm vi ng dng ca ti, vi cng c h tr Matlab, ta s kt hp mt mng Neural (np nhn ca v no hay tri thc) vi lut la chn c th trong qun th ch nh, bng cc php lai to ngu nhin v chn lc cc c th tm ra c th tri nht sng st sau php o thi ca hm pht ta xy dng! a) Np nhn v no: Ngun gc tri thc: C s ton hc xy dng da trn l thuyt a ra ca cc tc gi: Guillermo J. Silva, Aniruddha Datta, S. P. Bhattacharyya: Vng kh tn ca b thng s KP, KI, KD, trong khng gian s thc ( 3 ) y chnh l qun th c chn trong thut ton GA. Thut xp x: Xp x th 1:Vi hm truyn tm c, so snh vi dng hm truyn chun ca cc tc gi trn a ra, ta c th ly L=0.001s (tc 1/10 thi gian ly mu). Xp x th 2: ta gi nh ang lm trn m hnh lin tc ch khng phi ri rc. Kt qu vi hm truyn khng n v: T=0.04,L=0.001: qun th c chn

Hnh IV.2.3.5

Qun th c chn nh li khuyn ca chuyn gia

Trang IV.16

(IV.2.3.2) Thut ton GA-Neural tm b thng s PID b) Php chn lc v lai to: Tm c th thch nghi bng ti sinh chn lc ngu nhin: Trong qun th ch nh, cc c th tn ti l c lp v xc xut tn ti nh nhau khi cha c bin c o thi ca t nhin, khi xy ra bin ng v iu kin sinh tn, nhng c th thch nghi c s tip tc tn ti, cc c th khng thch nghi hoc s b o thi, hoc phi tin ha thnh dng khc, php chn lc u sa thi ton b nhng c th khng thch nghi. Ta gi li phn qun th thch nghi ban u hoc s chn trong qun th y mt vi c th tt nht lai ghp. Thut GA ti sinh: Ly ngu nhin mt lng ln c th(b thng s KP, KI, KD) trong qun th c chn, th thch nghi ca chng vi hm pht: min(ITAE(closeloop(PID.HS))) c th tt nht s c chn. Lai to c th tri tm c th mnh: T c th tm c bng hm pht trn, ta xy dng thm lut sinh tn: L(POT,steady_state_error,settling_time), c th sinh ra bng cch gi c nh KP, lp vng KI v KD, tm c th tt nht trong qun th lai mi. y c th l c th c chn nu tha yu cu t ra ca ta. Nu khng, phi cho KP thay i, hoc bt u li thut tan ti sinh tm c th tri mi! C th gp trng hp xu, trong qun th khng c c th no p ng ni vi lut sinh tn, lc , buc ta chp nhn phi thay i li lut tm c th thch nghi, nu khng nh th, ton b cu trc loi b dit vong! Bi ton v nghim! Thut GA lai to: Ly c th tn ti sau bin c ban u, cho php n sinh sn thnh nhng tp on c th mi, th thch nghi ca chng vi lut sinh tn: f(POT,state_error,settling_time), c th no p ng c cc yu cu t ra s tn ti, v tt c cc c th khc b b i, khng xt ti na, thut lai to kt thc. Ghi ch: Cc hm ITAE, POT, state_error, settling_time c trn http://www.khvt.com trong phn Matlab> p ng ca h thng vi b thng s: (2,1,0.0005)

Hnh IV.2.3.6 k lnh 1 giy

p ng ca h thng khi tn hiu th l 1000+500sin(0.02t) (v/p) chu

Trang IV.17

(IV.2.3.2) Thut ton GA-Neural tm b thng s PID Sai s l thuyt:

Hnh IV.2.3.7 Hnh phng to sai s gia tn hiu c v tn hiu p ng (vng/pht) vi chu k lnh l 1 giy. Theo l thuyt v m phng, kt qu tng i tt, by gi, ta thc hin vo gii thut iu khin cho MCU P89LPC922.

Hnh IV.2.3.8 p ng ca h thng thc khi tn hiu t l 20+10*sin(0.05*t) vi chu k lnh chn l 10xung/lnh.

Trang IV.18

(IV.2.3.2) Thut ton GA-Neural tm b thng s PID Nhn xt: Do sai s ca phn cng nn ta cha th phn tch gi tr p ng c tt hay khng? Ch c th ni gi tr xc lp ng vi tn hiu t v sai s xc lp bng sai s phn cng. Chng trnh gii thut c th vit nh sau:/************************************************************************ Chuc nang : Ham PID la khau tao tin hieu dieu khien de tao tin hieu dieu xung dua vao chan PWM. Dau vao : Khong co Dau ra : Khong co, gia tri dieu khien cap nhat trong ham Tac gia : Bui Trung Hieu, Webmaster: http://www.khvt.com Su dung : Duoc phep su dung mien phi voi moi muc dich. Khoi tao : 9h59PM ngay 10 thang 11 nam 2005 Lien he : Moi trao doi xin lien lac qua email: buitrunghieu@khvt.com Tai lieu tham khao cho khau PID so: -Sach "LT Dieu Khien tu dong" - NXB DHQG TPHCM Nguyen Thi Phuong Ha (Chu bien) -Huynh Thai Hoang -Co tai http://www.khvt.com/Documents/DKTD.html -The PID Control Algorithm: How it works, how to tune it, and how to use it- John A. Shaw Cac thong so Kp,Ki,Kd cho khau PID so duoc tim bang chuong trinh Matlab 7.0 (C) Mathworks /*************************************************************************/ void PID (void) { double temp; temp=(double)control_value/k1; //k1 la he so ho*.p thu*c temp+=(double)Know*(double)ek+(double)Klast*(double)ekp1+(double)Klast_last*(double)ekp2; temp=temp*k1; (temp>255)?(temp=255):(temp