dieu khien dco dc dung pid
TRANSCRIPT
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LI CM N
Trc ht chng em xin cm n Khoa K Thut Cng ngh to iu kin chng em c th c xt vi thc t cng nh nh gi c nng lc v trnh ca bn thn mnh. Chng em xin gi li cm n chn thnh n Thy V TH NG tn tnh hng dn ch bo chng em trong sut qu trnh thc hin n. V chng em cng xin gi n cc Thy C, bn b, v ng nghip chn tnh gip v ng gp kin trong qu trnh thc hin n ny. Chng em xin chn thnh cm n! Bnh Dng, thng 05 nm 2012.
Sinh vin thc hin. L Duy Tn V Duy Khnh
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LI NHN XT CA GIO VIN............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ Bnh Dng, ngy thng nm 2012
K tn
V Th ng
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MC LCLI CM N ....................................................................................................................... 1 MC LC ............................................................................................................................ 3 LI NI U ...................................................................................................................... 4 PHN GII THIU ............................................................................................................. 5 Chng I. t vn ........................................................................................................ 5 1. Tnh hnh nghin cu ............................................................................................ 5 2. Cng vic thc t ca n ................................................................................. 5 3. S kho st, m t thc t ................................................................................ 6 PHN NI DUNG............................................................................................................... 7 CHNG 1. C S L THUYT CA TI.......................................................... 7 A. PHN CNG ....................................................................................................... 7 I. VI IU KHIN ............................................................................................... 7 Tng quan v vi iu khin AT89S52 ................................................................... 7 II. CC THIT B KHC TRONG MCH .................................................... 20 2.1. ng c bc: .......................................................................................... 20 2.2. Optical encoder: ........................................................................................ 22 2.3. IC L298: .................................................................................................... 23 2.4. IC to n p 7805( IC n p 5v) ............................................................... 24 B. PHN MM ....................................................................................................... 26 1. Phn mm m phng mch: Phn mm Proteus 7 Professional ...................... 26 2. Phn mm lp trnh: KeilC compiler ............................................................... 27 CHNG 2. THIT K TNG QUT PHN CNG ............................................... 28 I. H THNG IU KHIN ............................................................................... 28 1. S khi tng qut ........................................................................................ 28 2. S lc chc nng ca tng khi ..................................................................... 28 2.1. Khi ngun ............................................................................................... 28 2.2. Khi Reset ................................................................................................ 29 2.3. Khi iu khin: ....................................................................................... 29 2.4. Khi to xung dao ng: S dng thch anh 12MHz .............................. 30 2.5. Khi iu khin trung tm ........................................................................ 30 2.6. Khi hin th LCD .................................................................................... 30 2.7. Khi khuch i cng sut........................................................................ 31 2.8. Khi chp hnh: ng c DC ................................................................... 31 II. CHNG TRNH IU KHIN ...................................................................... 32 1. S gii thut ca chng trnh .................................................................... 32 2. Code lp trnh cho vi iu khin ...................................................................... 35 3. Nguyn l hot ng ca mch ........................................................................ 35 4. S mch in................................................................................................... 36 5. Board mch hon chnh.................................................................................... 37 PHN 3. KT LUN ........................................................................................................ 38 I. KT QU T C. ......................................................................................... 38 II. HN CH CA TI: ................................................................................... 38 III. HNG PHT TRIN CA TI: .............................................................. 38 TI LIU THAM KHO .................................................................................................. 39
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LI NI UCng cuc cng nghip ha hin i ha t nc ang din ra theo s tin b ca khoa hc k thut. Trc tnh hnh c kh nhiu yu cu cp bch v cng c nhng thch thc t ra cho gii tr thc . in t v c bit l vi x l l mt lnh vc mi m nc ta ang nghin cu v tng bc pht trin ng dng vo qu trnh sn xut gp phn nng cao nng sut lao ng . Do vy l sinh vin vi chuyn ngnh k thut in t cn phi nm vng kin thc v k nng t n gin n phc tp nh trong cc h thng iu khin ng m ca xe hi, my bay, robot,... Rn luyn k nng lp trnh trn cc h thng s dng vi iu khin trong cc h thng cng nghip v cc ng dng trong sinh hot v sn xut. Tuy nhin do thi gian v kin thc chng em cn hn ch nn khng trnh khi s thiu st, mong Thy C v cc bn thng cm. Em xin chn thnh cm n ! Bnh Dng, thng 05 nm 2012 Nhm sinh vin thc hin !!! L Duy Tn V Duy Khnh
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PHN GII THIUChng I. t vn 1. Tnh hnh nghin cu iu khin ng c DC l mt ng dng thuc dng c bn nht ca iu khin t ng v ng c DC mt c cu chp hnh (actuator) c dng nhiu nht trong cc h thng t ng nh robot, cc m hnh my bay, xe hi, cc c cu truyn ng yu cu tnh chnh xc trong cc my mc, iu khin c ng c DC l chng ta c th t xy dng c cho mnh rt nhiu h thng t ng. Vy cu hi t ra y l lm sao chng ta c th bit c tc ca ng c v lm th no iu chnh c n?. Chnh v nhng l do , nn nhm em quyt nh chn ti iu khin ng c DC servo pht huy thm kh nng ca mnh v gp phn nh vo cho i sng x hi. 2. Cng vic thc t ca n Vi mc ch nghin cu v ng dng vi iu khin vo thc t nn trong n s dng cc phn t c bn nh: o Vi iu khin h Atmel 8051 o ng c DC 12V c gn encorder c s vng quay. o Nt nhn iu khin. o Vi iu khin pht xung PWM iu chnh vn tc ng c. o LCD hin th d liu ( vn tc ca ng c). o Dng mch cu H khuch i cng sut iu khin ng c (v ng ra ca vi iu khin ch mc logic 5V khng cp cho ng c hot ng). Ngi s dng s iu chnh tc ca ng c thng qua nt nhn vo vi iu khin, vn tc ca ng c s c hin th ln LCD thng qua encorder.
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J101 1 2 12V J102 1 12V 2
U101 GND 1 VIN VOUT 3 C102 + 10uF VSS VDD VEE RS R/W E D101 LED VCC D0 D1 D2 D3 D4 D5 D6 D7 R101 330 VCC LCD501 LCD 16X2 BUTTON VDD (BL) VSS (BL) SW302 BTN2 BUTTON SW303 BTN3 BUTTON VCC RP201 MCU201 VCC C201 + 10uF BTN1 BTN2 BTN3 BTN4 BTN5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 T2/P1.0 T2X/P1.1 P1.2 P1.3 P1.4 (MOSI) P1.5 (MISO) P1.6 (SCK) P1.7 RST P3.0/RXD P3.1/TXD P3.2/INT0 P3.3/INT1 P3.4/T0 P3.5/T1 P3.6/WR P3.7/RD X2 X1 GND AT89S52 12MHz 33pF 8 VCC AD0/P0.0 AD1/P0.1 AD2/P0.2 AD3/P0.3 AD4/P0.4 AD5/P0.5 AD6/P0.6 AD7/P0.7 EA/VPP ALE/PROG PSEN A15/P2.7 A14/P2.6 A13/P2.5 A12/P2.4 A11/P2.3 A10/P2.2 A9/P2.1 A8/P2.0 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 SW305 BTN5 VCC RS E D4 D5 D6 D7 BUTTON VCC VCC U401 L298 L298_IN1 L298_IN2 5 7 10 12 6 11 1 15 IN1 IN2 IN3 IN4 ENA ENB SENSA SENSB ENCODER 1 2 3 ENCODER J402 OUT1 OUT2 OUT3 GND OUT4 2 3 13 14 MOTOR 2 1 J401 1 2 3 4 5 6 7 8 9 10k R501 10k BUTTON RS D4 D5 D6 D7 SW304 BTN4 E SW301 BTN1
C101 7805 + 10uF
2
7 8 9 10 11 12 13 14 VS 4 V12
SW201 RST
ENCODER
C202 33pF C203 Y201
VCC
Hnh 1. S nguyn l ca mch
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L298_IN1 L298_IN2
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15 16
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PHN NI DUNGCHNG 1. C S L THUYT CA TIA. PHN CNGI. VI IU KHINTng quan v vi iu khin AT89S52 Vi iu khin 89S52 l mt vi iu khin ca hng Atmel, dung CMOS c cng sut thp, hiu sut cao. Vi 8 KB Flash Memory 256 Byte RAM ni 4 Port xut nhp I/O 8 bit 2 con tr d liu, 3 b nh thi timer/counter 16 bit. 1 kin trc 6 vector ngt vi 2 mc, 1 b dao ng v 1 mch xung clock. Giao tip ni tip 64 KB vng nh m ngoi 64 KB vng nh d liu ngoi X l Boolean ( hot ng trn bit n) 210 v tr nh c th nh v bit. 4s cho hot ng nhn hoc chia. Thm vo , vi iu khin 89S52 cn c thit k vi logic tnh c th hot ng n tn s 0Hz v c h tr 2 ch tit kim nng lng c th la chn c bng phn mm. Ch khng ti (Idle mode) dng CPU trong khi cho php RAM, Timer/Counter, Port ni tip v h thng ngt tip tc hot ng. Ch tt ngun ( Power down mode) lu tr d liu trong RAM nhng ng bng b dao ng, dng hot ng cc chc nng khc ca Chip cho n khi ngt xy ra hoc phn cng c Reset.
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U319 XTAL1 P0.0/AD0 P0.1/AD1 P0.2/AD2 P0.3/AD3 P0.4/AD4 P0.5/AD5 P0.6/AD6 P0.7/AD7 P2.0/A8 P2.1/A9 P2.2/A10 P2.3/A11 P2.4/A12 P2.5/A13 P2.6/A14 P2.7/A15 P3.0/RXD P3.1/TXD P3.2/INT0 P3.3/INT1 P3.4/T0 P3.5/T1 P3.6/WR P3.7/RD 39 38 37 36 35 34 33 32 21 22 23 24 25 26 27 28 10 11 12 13 14 15 16 17
18
XTAL2
9
RST
29 30 31
PSEN ALE EA
1 2 3 4 5 6 7 8
P1.0/T2 P1.1/T2EX P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 AT89C52
Hnh 2. S chn IC 89S52
Hnh 3. Hnh dng thc t IC 89S52
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Hnh 4. S khi ca b vi iu khin AT 89S52
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Chc nng cc chn IC AT89S52: Chn 29 (PSEN Program Store Enable): l chn tn hiu ng ra c tc dng cho php c b nh chng trnh m rng v thng c ni n chn OE ca Eprom, cho php c cc byte m lnh. Chn 30 (ALE: Adress Latch Enable) l tn hiu iu khin xut ra, n cho php phn knh bus a ch v bus d liu ca port 0. Chn 31 (EA: Eternal Acess) c a xung thp cho php chon b nh m ngoi 32 chn cn li chia lm 4 cng vo ra: Vo ra tc l c th dng chn c mc logic. Port 0: t chn 32 n chn 39 tng ng l cc chn P0_0 n P0_7, c 2 chc nng: Trong thit k c nh khng dng b nh m rng, c chc nng nh ng I/O. i vi cc h thng ln c b nh m rng n va l bus a ch byte thp va l bus d liu truy cp b nh ngoi. Port 1: t chn 1 n chn 9 tng ng l cc chn P1_0 n P1_7 Port 2: t chn 21 n chn 28 tng ng l cc chn P2_0 n P2_7: l Port c tc dng kp nh cc ng I/O hoc l byte cao (A8 A15) ca bus a ch i vi cc thit b dng b nh m rng. Port 3: t chn 10 n chn 17 tng ng l cc chn P3_0 n P3_7P3.0 RxD : chn nhn d liu ni tip khi giao tip RS232(Cng COM). P3.1 _ TxD : phn truyn d liu ni tip khi giao tip RS232. P3.2 _ INTO : interrupt 0 , ngt ngoi 0. P3.3 _ INT1: interrupt 1, ngt ngoi 1. P3.4 _T0 : Timer0 , u vo timer0. P3.5_T1 : Timer1, u vo timer 1. P3.6_ WR: Write, iu khin ghi d liu. P3.7 _RD: Read , iu khin c d liu. Chn 18, 19 ni vi thch anh to thnh mch to dao ng cho VK. Tn s thch anh thng c dng trong cc ng dng l : 11.0592Mhz(giao tip vi cng com my tnh) v tn s ti a 24Mhz. Tn s cng ln VK x l cng nhanh. Chn 9 (RST Reset): Khi tn hiu ny a ln mc cao t nht 2 chu k my, cc thanh ghi bn trong c np nhng gi tr thch hp khi ng h thng. Khi cp in cho h thng th mch t ng reset.
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+5V 10UF
8,2K
Hnh 5. Mch Reset h thng
Trng thi tt c cc thanh ghi ca 8051 sau khi reset:Thanh ghi
m chng trnh Tch ly B PSW SP DPTR Port 0-3 IP IE Cc thanh ghi nh thi SCON SBUF PCON(HMOS) PCON(CMOS)
Ni dung 0000H 00H00H
00H 07H 0000H FFH XXX00000B 0XX00000B 00H 00H 00H 0XXXXXXB 0XXX0000B
Quan trng nht trong cc thanh ghi trn l thanh ghi m chng trnh, n c t li 0000H. Khi Reset tr li mc thp, vic thi hnh chng trnh lun bt u a ch u tin trong b nh chng trnh: a ch 0000H, ni dung ca RAM trn chip khng b thay i bi lnh Reset. Chn 18, 19(XTAL1,XTAL2): ni vi thch anh to thnh mch to dao ng cho VK. Tn s thch anh thng dng trong cc ng dng l : 11.0592Mhz(giao tip vi cng com my tnh) v 12Mhz Tn s ti a 24Mhz. Tn s cng ln VK x l cng nhanh.
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Hnh 6. Xung dao ng thch anh
Chn 40, 20 ( VCC, GND): cp ngun v ni t cho vi iu khin. 2.2. T chc b nh bn trong vi iu khin 89S52 RAM bn trong 89S52 c phn chia nh sau: Cc bank thanh ghi c a ch t 00H n 1FH RAM truy xut tng bit c a ch 20H n 2FH RAM a dng t 30H n 7FH Cc thanh ghi c chc nng c bit t 80H n FFH bao gm: Thanh ghi trng thi chng trnh ( PSW: Program Status Word) Thanh ghi B Thanh ghi con tr ngn xp (SP1, SP2: Stack Pointer). Thanh ghi con tr d liu (DPH, DPL). Cc thanh ghi Port xut nhp (P0, P1, P2, P3). Cc thanh ghi Timer/ Counter. Cc thanh ghi Port ni tip (SBUF, SCON) Cc thanh ghi ngt (IE, IP) Thanh ghi iu khin cng sut (PCON)
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Bng tm tt cc vng nh ca 8051
a ch Byte7F
a ch bit
a ch Byte
a ch bitB
FF F0 F7 F6 F5 F4 F F2 F1 F0 3 RAM a dng E0 E7 E6 E5 E4 E E2 E1 E0 3
ACC
D0 D7 D6 D5 D4 D3 D2 D1 D0 PSW 30 2F 2E 2D 2C 2B 2A 29 28 27 26 25 24 23 22 21 20 1F 18 17 10 0F 08 07 00 B8 7F 7E 77 76 6F 6E 67 66 5F 5E 57 56 4F 4E 47 46 3F 3E 37 36 2F 2E 27 26 1F 1E 17 16 0F 0E 07 06 Bank 3 Bank 2 Bank 1 Bank thanh ghi 0 (mc nh cho R0-R7) 7D 75 6D 65 5D 55 4D 45 3D 35 2D 25 1D 15 0D 05 7C 74 6C 64 5C 54 4C 44 3C 34 2C 24 1C 14 0C 04 7B 73 6B 63 5B 53 4B 43 3B 33 2B 23 1B 13 0B 03 7A 72 6A 62 5A 52 4A 42 3A 32 2A 22 1A 12 0A 02 79 71 69 61 59 51 49 41 39 31 29 21 19 11 09 01 78 70 68 60 58 50 48 40 38 30 28 20 18 10 08 00 BC BB BA B9 B8 IP
B0 B7 B6 B5 B4 B3 B2 B1 B0 P.3 A8 AF AC AB AA A9 A8 IE
A0 A7 A6 A5 A4 A3 A2 A1 A0 P2 99 khng c a ch ha bit 98 9F 9E 9D 9C 9B 9A 99 98 90 97 96 95 94 93 92 91 90 8D 8C 8B 8A 89 khng c a ch ha bit khng c a ch ha bit khng c a ch ha bit khng c a ch ha bit SBUF SCON P1 TH1 TH0 TL1 TL0 TMOD TCON PCON DPH DPL SP P0
88 8F 8E 8D 8C 8B 8A 89 88 87 khng c a ch ha bit 83 82 81 80 khng c a ch ha bit khng c a ch ha bit khng c a ch ha bit 87 86 85 84 83 82 81 80
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3. Hot ng nh thi 3.1. Gii thiu Cc b nh thi (Timer) c s dng rng ri trong cc ng dng o lng v iu khin. Ty thuc vo ng dng u vo ca b nh thi c th l ngun xung ly t xung nhp ca vi iu khin hoc ngun xung t bn ngoi a n. Vi iu khin h 8051 c ba b nh thi 16 bit trong hai b Timer 0 v Timer 1 c bn ch hot ng, cn Timer 2 c ba ch hot ng. 3.2. Cc thanh ghi ca b nh thi. 3.2.1. Cc thanh ghi ca Timer 0 v Timer 1. o Thanh ghi ch nh thi TMOD: Thanh ghi TMOD cha hai nhm 4 bit dng t ch lm vic cho Timer 0 v Timer 1 Bit 7 6 Name GATE C/T Timer 1 1 Description Khi GATE = 1, Timer ch lm vic khi INT = 1 Bit m s kin hay ghi gi C/T = 1: m s kin C/T = 0: Ghi gi u n 5 4 3 2 1 0 M1 M0 GATE C/T M1 M0 1 1 0 0 0 0 Bit chn Mode ca Timer 1 Bit chn Mode ca Timer 1 Bit chn cng ca Timer 0 Bit chn ch Timer/Counter ca Timer 0 Bit chn Mode ca Timer 0 Bit chn Mode ca Timer 0
o Thanh ghi iu khin Timer TCON: Thanh ghi TCON cha cc bit trng thi iu khin cho Timer 0 v Timer 1. Bit TCON.7 Symbol TF1 Bit Address 8FH Description C bo trn ca Timer1, c t bi phn cng khi c trn, c xa bi phn mm hoc bi phn cng khi b x l ch n chng trnh phc v ngt. Bit iu khin Timer 1 hot ng, c t/ xa bng phn mm iu khin cho Timer chy/dng
TCON.6
TR1
8EH
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TCON.5 TCON.4 TCON.3 TCON.2 TCON.1 TCON
TF0 TR0 IE1 IT1 IE0 IT0
8DH 8CH 8BH 8AH 89H 88H
C bo trn Timer 0 Bit iu khin Timer 0 hot ng C ngt do Timer 1. C ngt ngoi 1. C ngt do Timer 0 C ngt ngoi 0
3.2.2. Cc thanh ghi ca Timer 2. o Thanh ghi T2CON o Thanh ghi T2MOD: c a ch 0C9H, thanh ghi ny khng nh a ch bit. o Thanh ghi TH2 v TL2, RCAP2H v RCAP2L: Thanh ghi TH2 v TL2 cha gi tr m ca Timer 2, cn RCAP2H v RCAP2L cha gi tr cn np li ca Timer 2. 3.3. Ch ca b nh thi 3.3.1 Cc ch ca Timer 0 v Timer 1. - Mode 0 (mode Timer 13 bit): l ch nh thi 13 bit, ch ny tng thch vi cc b vi iu khin trc , trong cc ng dng hin nay, ch ny khng cn thch hp.
- Mode 1 (Mode Timer 16 bit): trong ch 1, b Timer dng c 2 thanh ghi TH v TL cha gi tr m, v vy ch ny cn c gi l ch nh thi 16 bit.
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- Mode 2(ch 8 bit t np li): Timer dng TL cha gi tr m v TH cha gi tr np li v vy ch ny c gi l ch t np li 8 bit. Cch iu khin ging ch 1.
- Mode 3(Ch tch Timer): Timer 0 c tch thnh 2 b Timer hot ng c lp, ch ny s cung cp cho vi iu khin thm mt Timer na.
3.3.2 Cc ch ca Timer 2: c 3 ch hot ng l ch thu nhn, t np li v cung cp tc baud cho cng ni tip. RCLK+TCLK TR2 0 0 0 1 1 X X X CP/#RL2 1 1 1 0 Ch 16 bit Auto reload: 16 bit t np li 16 bit capture: 16 bit thu nhn Baud rate Generator: cung cp tc baud (Off)
ch thu nhn (capture):
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- Ch cung cp tc Baud
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4. Hot ng truyn d liu ca Vi iu khin 89S52 4.1 Gii thiu. Truyn d liu ni tip ca MCS 51 c th hot ng nhiu kiu ring bit trong phm vi cho php ca tn s. D liu dng song song c chuyn thnh ni tip truyn i v nhn v dng ni tip c chuyn thnh song song. Chn TXD (P3.1) l ng xut d liu i v chn RXD (P3.1) l ng nhn d liu v. c trng ca truyn d liu ni tip l hot ng song cng ngha l c th thc hin truyn v nhn cng 1 lc. Hai thanh ghi chc nng c bit phc v cho truyn d liu l thanh ghi m SBUF v SCON. Thanh ghi m SBUF nm a ch 99H c 2 chc nng: nu vi iu khin gi d liu ln thanh ghe SBUF th d liu s c truyn i, nu h thng khc gi d liu n th s c lu vo thanh ghi m SBUF. 4.2 Cc thanh ghi cng ni tip C 2 thanh ghi chc nng c bit cho php phn mm truy xut n cng ni tip l SBUF v SCON - Thanh ghi SCON ( Serial Controller): Thanh ghi iu khin cng ni tip a ch 98H, l thanh ghi c nh a ch bit, cha cc bit trng thi v cc bit iu khin lin quan ti cng ni tip. Cc bit iu khin t ch hot ng cho cng ni tip, cc bit trng thi bo co kt thc vic pht hoc thu mt k t. - Thanh ghi SBUF ( Serial buffer): Thanh ghi ny c chc nng m cc k t khi chng c nhn v t cng ni tip hoc c truyn i t cng ni tip, vic truyn nhn qua cng ni tip thc cht l vic truy xut thanh ghi ny 4.3 Cc ch hot ng - Ch 0: ch m cng ni tip c dng nh mt hanh ghi dch 8 bit. D liu truyn nhn trn chn RXD v TXD. Tc baud c nh bng Fosc /12. - Ch 1: Cng ni tip hot ng nh b UART 8 bit c tc thay i. D liu truyn nhn trn chn RXD v TXD, ch ny cung cp cho vi iu khin mt cng c giao tip vi my tnh qua cng COM. - Ch 2: Cng ni tip hot ng nh b UART 9 bit, ch ny thng c dng khi cn chn thm bit kim tra chn l vo trong khung truyn gim bt li trn ng truyn. - Ch 3: L s kt hp ca ch 1 v ch 2. 4.4 Trao i d liu qua cng ni tip Bao gm cc thao tc chnh nh sau: Khi to cng ni tip. Kim tra c TI khi truyn v c RI khi nhn. Ghi c byte d liu SBUF. 5. Hot ng ngt v x l ngt: Trong thc t ngi ta mun tn dng kh nng ca CPU lm thm nhiu cng vic khc na, ch khi no c cn trao i d liu mi cn yu cu CPU tm dng cng vic hin ti phc v vic trao i d liu. V vy 1 h thng s dng ngt c th p ng nhanh cc yu cu trao i d liu trong khi vn c th lm c cc cng vic khc. T chc ngt AT89S52 bao gm:
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- Ngt ngoi n t chn #INT0. - Ngt ngoi n t chn #INT1. - Ngt do b Timer0. - Ngt do b Timer1. - Ngt do b Timer2. - Ngt do Port ni tip. Su ngun ngt ny c xa khi reset v c t ring bng phn mm bi cc bit trong thanh ghi cho php ngt IE v thanh ghi u tin ngt IP. Phng php iu ch rng xung (PWM) - Phng php iu ch PWM ( Pulse Width Modulation) l phng php iu chnh in p ra ti hay ni cch khc l phng php iu ch da trn s thay i rng ca chui xung vung dn n s thay i in p ng ra. 6.
- Chng ta s dng b Timer 16 bit ca vi iu khin to ra xung c t s rng nh mong mun. 7. Gii thut iu khin PID - PID l vit tt ca Propotional (t l), Integral (tch phn) v Derivative (o hm).
Kp = h s t l Ki = h s tch phn Kd = h s vi phn
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GVHD: Th.S V Th ng
- Bin e l thnh phn sai lch, l hiu gia tn hiu vo mong mun v tn hiu ra thc t. Tn hiu sai lch (e) s a ti b PID v b iu khin tnh ton c thnh phn tch phn ln vi phn ca (e).
- c tnh b iu khin PID: Thnh phn t l (Kp) c tc dng lm tng tc p ng ca h thng, v lm gim ch khng trit tiu sai s xc lp ca h Thnh phn tch phn (Ki) c tc dng trit tiu sai s xc lp nhng c th lm gim tc p ng ca h. Thnh phn vi phn (Kd) l tng n nh h thng, gim vt l v ci thin tc p ng ca h
II. CC THIT B KHC TRONG MCH2.1. ng c bc: - ng c bc l mt c cu chp hnh rt thng dng trong cc ng dng iu khin chnh xc. - ng c bc c chia lm nhiu loi nh ng c bin t tr, ng c n cc, ng c hai cc v ng c nhiu pha. o ng c bin t tr: c 3 cun dy, c ni mt u chung li vi nhau (C), khi s dng th u ni chung (C) c ni vo dng ngun v cc cun c kch theo th t.
Hnh 7. ng c bin t tr
o ng c bc n cc: Cu to c 5,6 hoc 8 dy ra, c qun theo s (hnh bn di), vi 1 u ni trung tm trn cc cun. Khi dng, cc u ni trung tm thng c ni vo cc dng ngun v hai u cn li ca mi mu ln lt ni t o chiu t trng bi cun .
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n mn hc 2o
GVHD: Th.S V Th ng
Hnh 8. ng c bc n cc
o ng c bc hai cc: Cc cun dy ca ng c hai cc ging nh ng c n cc nhng khng c u ni trung tm 2 cun, v vy n gin hn nhng mch iu khin o cc mi cp cc trong ng c th phc tp hn. Mch iu khin cho ng c ny i hi phi c mch iu khin cu H cho mi mu.
Hnh 9. ng c bc hai cc
o ng c nhiu pha: ng c ny khng c ph bin nh cc ng c trn, cc cun dy ca n c qun ni tip thnh cc vng kn.
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n mn hc 2
GVHD: Th.S V Th ng
Hnh 10. ng c bc nhiu pha
2.2. Optical encoder: o Encoder l thit b qun l s vng quay, qun l v tr gc ca mt a quay, a quay c th l bnh xe, trc ng c, o H thng Optical encoder bao gm mt ngun pht quang (thng l hng ngoi infrared), mt cm bin quang v mt a c chia rnh.
Hnh 11. Optical encoder Optical encoder
o C hai loi encoder: encoder tuyt i (absolute encoder) v encoder tng i (incremental encoder). Trong ti ny chng em tm hiu incremental encoder. - Encoder thng c 3 knh (3 ng ra): knh A, B v I (Index)
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n mn hc 2
GVHD: Th.S V Th ng
- Hnh trn cng trong hnh trn th hin s b tr ca 2 cm bin knh A v knh B lch pha nhau. Khi cm bin A bt u b che th cm bin B hon ton nhn c hng ngoi xuyn qua v ngc li. Hnh bn di l dng xung ng ra ca 2 knh. 2.3. IC L298: L IC bn dn tch hp mch cu H iu khin cng sut ng c, tt c mch kch, mch cu u c tch hp sn
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n mn hc 2+ in p cp ln n 46V
GVHD: Th.S V Th ng
+ Tng Dng DC chu ng ln n 4A + in p bo ha + Chc nng bo v qu nhit + in p logic0t 1.5V tr xung
Tn cng sut ng ra: IC L298 tch hp 2 tng cng sut (A, B). Tn cng sut chnh l mch cu v ng ra ca n c th li cc loi ti cm thng dng nhiu ch hot ng khc nhau (ty thuc vo s iu khin ng vo) . Dng in t chn ng ra chy qua ti n chn cm ng dng : in tr ngoi RSA, RSB cho php vic cm ng cng dng in ny.
Hnh 12. Mch cu H
Tn ng vo: Mi cu c iu khin bi 4 cng ng vo In1, In2, EnA, v In3, In4, EnB. Cc chn In c tc dng khi chn En mc cao, khi chn En mc thp, cc chn ng vo In trng thi cm. Tt c cc chn u tng thch vi chun TTL. 2.4. IC to n p 7805( IC n p 5v) Vi nhng mch in khng i hi n nh ca in p qu cao, s dng IC n p thng c ngi thit k s dng v mch in kh n gin. Cc loi n p thng c s dng l IC 78xx, vi xx l in p cn n p. V d 7805 n p 5V, 7812 n p 12V. Vic dng cc loi IC n p 78xx tng t nhau, di y l minh ha cho IC n p 7805:
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n mn hc 2
GVHD: Th.S V Th ng
Hnh 13. S IC 7805
S chn 7805: Chn s 1 l chn IN Chn s 2 l chn GND Chn s 3 l chn OUT. Ng ra OUT lun n nh 5V d in p t ngun cung cp thay i. Mch ny dng bo v nhng mch in ch hot ng in p 5V (cc loi IC thng hot ng in p ny). Nu ngun in c s c t ngt: in p tng cao th mch in vn hot ng n nh nh c IC 7805 vn gi c in p ng ra OUT 5V khng i.
IC n p 7805 : u vo > 7V u ra 5V 500mA. Mch n p: cn cho VK v nu ngun cho VK khng n nh th s treo VK, khng chy ng, hoc reset lin tc, thm ch l cht chp.
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n mn hc 2
GVHD: Th.S V Th ng
B. PHN MM1. Phn mm m phng mch: Phn mm Proteus 7 Professional - Proteus l mt phn mm m phng v thit k mch in. Phn mm bao gm 2 thnh phn l ISIS v AREA. - ISIS l phn m phng mch, n c th m phng c mch s v mch tng t, tuy nhin, im mnh nht l n tch hp rt nhiu th vin linh kin s, c bit l vi iu khin. Trong qu trnh thit k mch s, cn m phng phn mm ca vi iu khin nh PIC, AVR, 8051, th y l phn mm l tng nht. Bn cnh , n cn tch hp m phng mch tng t, m phng ngn ng m t phn cng Verilog, - AREA l phn thit k mch in, bn kh nh, chy dy kh thng minh, tuy nhin vic qun l, sp xp v tr khi c nhiu linh kin cha hiu qu lm.
Hnh 14. Mn hnh Protues 7 professional
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n mn hc 2
GVHD: Th.S V Th ng
2. Phn mm lp trnh: KeilC compiler
KeilC l trnh bin dch C do cng ty pht trin phn mm Keil c tr s ti c. N cung cp mt s cng c pht trin nh: IDE Integrated Development environment, Project Manager, Simulator, Debugger, C Cross Compiler, Cross Assembler,
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n mn hc 2
GVHD: Th.S V Th ng
CHNG 2. THIT K TNG QUT PHN CNGI. H THNG IU KHIN 1. S khi tng qut
Khi ngun Vi iu Khin AT89S52
DAC
Khi iu khin
To xung dao ng
iu khin ng c Encorder
Reset
Khi hin th
Hnh 15. S khi tng qut
2. S lc chc nng ca tng khi2.1. Khi ngun Khi ngun cho VK:V12
J101 1 2 12V J102 1 12V 2
U101 GND 1 VIN VOUT 3 C102 + 10uF D101 LED R101 330 VCC
C101 7805 + 10uF
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n mn hc 2
GVHD: Th.S V Th ng
Ngun nui ca vi iu khin l ngun DC 5V, sau khi qua bin p 12V, in p xoay chiu 220V s cn 12V v c a qua chnh lu thnh dng 1 chiu, sau khi qua IC n p 7805,in p ra cn 5V v c a vo vi iu khin. y l mch dng to ra ngun in p chun +5V. S dng IC7805. u vo l in p xoay chiu sau khi c bin i qua my bin th, a vo b Diod cu cho ra dng in mt chiu( lc ny in p nm trong khong t 7->10V). Sau khi i qua IC n p 7805 s to ra ngun in p chun +5V cung cp cho mch
2.2.
Khi Reset
Khi RESET c tc dng a vi iu khin v trng thi ban u. Khi nt Reset c n in p +5V t ngun c ni vo chn Reset ca vi iu khin c chy thng xung t lc ny in p ti chn vi iu khin thay i t ngt v 0, VK nhn bit c s thay i ny v khi ng li trng thi ban u cho h thng. 2.3. Khi iu khin: Gm 5 nt n, hot ng tng t nt Reset. Khi n nt th cc chn ca vi iu khin c ni vi chn mass a in p xung t lc ny in p ti cc chn ny bng 0 lm cho vi iu khin nhn bit c s thay i ny v thc hin lnh cn SW301 iu khin. BTN1BUTTON SW302 BTN2 BUTTON SW303 BTN3 BUTTON SW304 BTN4 BUTTON SW305 BTN5 BUTTON
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n mn hc 2
GVHD: Th.S V Th ng
2.4. Khi to xung dao ng: S dng thch anh 12MHz
C202 33pF C203 12MHz 33pF Y201
2.5. Khi iu khin trung tm Vi iu khin AT89S52 l phn t thu nhp x l thng tin v a ra cc tn hiu iu khin thit b.
VCC RP201 MCU201 VCC C201 + 10uF ENCODER BTN1 BTN2 BTN3 BTN4 BTN5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 T2/P1.0 T2X/P1.1 P1.2 P1.3 P1.4 (MOSI) P1.5 (MISO) P1.6 (SCK) P1.7 RST P3.0/RXD P3.1/TXD P3.2/INT0 P3.3/INT1 P3.4/T0 P3.5/T1 P3.6/WR P3.7/RD X2 X1 GND AT89S52 12MHz 33pF VCC AD0/P0.0 AD1/P0.1 AD2/P0.2 AD3/P0.3 AD4/P0.4 AD5/P0.5 AD6/P0.6 AD7/P0.7 EA/VPP ALE/PROG PSEN A15/P2.7 A14/P2.6 A13/P2.5 A12/P2.4 A11/P2.3 A10/P2.2 A9/P2.1 A8/P2.0 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 1 2 3 4 5 6 7 8 9 RS E D4 D5 D6 D7 10k
SW201 RST
R201 10k
L298_IN1 L298_IN2
C202 33pF C203 Y 201
2.6. Khi hin th LCDLCD501 LCD 16X2
7 8 9 10 11 12 13 14 D4 D5 D6 D7
VCC
RS
R501 10k
E
VCC
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1 2 3
4 5 6
VDD (BL) VSS (BL)
VSS VDD VEE
RS R/W E
D0 D1 D2 D3 D4 D5 D6 D7
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n mn hc 2
GVHD: Th.S V Th ng
Dng LCD 4 bit kch thc 16x2, c ni vi Port 0 ca vi iu khin. Nhim v ca khi ny l hin th tc ca ng c. Chn VSS ni ln Vcc, chn VDD ni xung mass, cn chn VEE c ni vi 1 bin tr tng gim sng cho LCD. 2.7. Khi khuch i cng sut S dng IC L298 tch hp mch cu H khuch i cng sut ng ra ca vi iu khin iu khin ng c. Chn Vcc ca IC ni ln Vcc t n p 5V ra, cn chn VS th ni ln ngun 12V. Chn IN1 v IN2 ni v Port 2 ca vi iu khin ly tn hiu v, ng c c ni vo chn OUT 1 v OUT 2 .VCC VCC U401 L298 L298_IN1 L298_IN2 5 7 10 12 6 11 1 15 IN1 IN2 IN3 IN4 ENA ENB SENSA SENSB ENCODER 1 2 3 ENCODER J402 OUT1 OUT2 OUT3 GND OUT4 2 3 13 14 MOTOR 2 1 J401
9
VCC
VCC
2.8. Khi chp hnh: ng c DC
S dng ng c DC 12V, c gn mt Encoder ng trc, c ba dy: mt dy +5v, mt dy 0v, v mt dy xung (60xung/ vng.)
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VS
4
V12
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n mn hc 2 II. CHNG TRNH IU KHIN1. S gii thut ca chng trnh a. Chng trnh chnh:
GVHD: Th.S V Th ng
Begin
PWM Init Timer/Counter Init Interrupt Init LCD Init
Welcome Indication
Check BTN 1?
No
Yes LCD clear Indication Init
While (1)
End
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n mn hc 2b. Chng trnh qut phmWhile(1)
GVHD: Th.S V Th ng
BTN 1
Yes
Start system update DIR 1 Motor run with des_Speed
No Yes BTN 2 No BTN 3 YesIncrease Duty Cycle Set Duty Cycle Update LCD Run/ Stop Motor Init Des_Speed(PID) LCD Indication
No BTN 4 YesDecrease Duty Cycle Set Duty Cycle Update LCD
No BTN 5 No Duty Cycle PID YesChange DIR 0 Convert the motor direction
T 200ms? No End
Yes
Calculate speed indication
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n mn hc 2c. Chng trnh ngt to PWMInterruptTimer 0(PWM)
GVHD: Th.S V Th ng
NoPWM=0
PWM= 0 Recharged Timer 0
Yes
PWM= 1 Recharged Timer 0
End
d. Chng trnh PWM_Set_DutyPWM_Set_Duty PWM_Set_Duty
TR0 = 0 TRO=0
No Duty=100 Duty=100
No
Duty=0 Duty = 0
Yes
Yes
PWM = 1 PWM=1
PWM = 0 PWM=0
PWM = 0 Calculate TON, TOFF Recharged Timer TR0=0
End End
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n mn hc 22. Code lp trnh cho vi iu khin
GVHD: Th.S V Th ng
- Phn ny nhm em s trnh by trong bui bo co. 3. Nguyn l hot ng ca mch - Phn iu khin gm cc nt nhn: Run/Stop, motor chy thun (1), motor chy ngc(0), tng tc, gim tc v nt reset. - Khi ng chng trnh, khi to PWM, khi to Timer/Counter, khi to chng trnh ngt, li cho s c hin th LCD, sau nhn nt u tin s vo chng trnh iu khin. - Mn hnh LCD hin th 2 dng: dng 1 l tc t (SP) v chiu quay hin ti ca motor (DIR), dng 2 l tc thc t (PV) c o v qua Encoder v RUN hoc STOP ty thuc vo trng thi motor. - Nhn nt BTN 1(u tin) khi ng gi tr des_Speed cho motor ng thi motor chy theo chiu thun. i chiu ta nhn nt nhn th 5 (BTN 5) - Ci t tc cho motor bng cch nhn nt tng hoc gim, mi ln nhn tc s c tng ln hoc gim theo mc m chng ta quy nh trong chng trnh. - Dng chng trnh to PWM thay i chu k xung thay i tc cho motor. - p dng gii thut PID n nh tc cho motor. Khi tc c ci t, th motor phi chy bm theo 1 tc nht nh . - Chng ta phi iu chnh Kp, Ki, Kd t c tnh n nh .
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n mn hc 24. S mch in
GVHD: Th.S V Th ng
Hnh 16. S mch in
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n mn hc 25. Board mch hon chnh
GVHD: Th.S V Th ng
Hnh 17. Board mch hon chnh
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n mn hc 2
GVHD: Th.S V Th ng
PHN 3. KT LUNI. KT QU T C.
M hnh tuy nh nhng gip em hiu su hn v chuyn ngnh t ng ha, gm tt c nhng phn: iu khin, chp hnh, tn hiu hi tip, Hiu v nm r c cu trc ca vi iu khin, lp trnh C cho vi iu khin, cc phng php iu khin tc ng c nh PWM, PID. Tm hiu v bit thm v cc loi ng c, cc IC driver cho ng c, cm bin, encoder,LCD Bit thm v phng php thit k v thi cng mch in bng Orcad. Thi cng v lp trnh c mch chy ng nh yu cu. II. HN CH CA TI: - Lp trnh C cn ri rc, khng c logic. - Cha ng dng ht chc nng ca 89S52 ( b capture c gi tr ). - Khng th nhp tc t bng phm m phi s dng nt nhn tng gim 1 gi tr c lp trnh. - Cha hiu tht r rng v PID nn cn hn ch trong lp trnh. III. HNG PHT TRIN CA TI: ng dng vi iu khin vo iu khin ng c bc, servo. ng dng encoder o tc ca motor, o chiu di ca cc cun giy qun, my qun li, t ng dng vo PLC iu khin trong cng nghip. ng dng gii thut PID iu khin cc thit b khc trong cng nghip nh: iu khin nhit , robot,
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n mn hc 2
GVHD: Th.S V Th ng
TI LIU THAM KHO1. Ti liu VI IU KHIN CU TRC-LP TRNH V NG DNG _ Kiu Xun Thc (Ch bin). Nh xut bn gio dc Vit Nam. 2. Gio trnh 89C51,89S52 trng i Hc SPKT TP HCM. 3. Ti liu hc AVR Internet (www.hocavr.com) 4. Website: www.codientu.biz, www.electronicctu.net 5. Ti liu lp trnh C cho 8051, hng dn s dng KeilC,
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