Điều khiển mờ và giao thức CAN trong đồng bộ tốc độ động cơ DC

7/30/2019 iu khin m v giao thc CAN trong ng b tc ng c DC

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AI HOC QUOC GIA THANH PHO HO CH MINHTRNG AI HOC BACH KHOA

KHOA IEN IEN T

BO MON IEU KHIEN T ONG------------o0o------------

BKTP.HCM

GVHD : KS. LE NGOC NHSVTH : NGUYEN GIA MINH THAOLP : DD04KSTNMSSV : 40402363

TP. HO CH MINH , 1/ 2009


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BO GIAO DUC VA AO TAO CONG HOA XA HOI CHU NGHA VIET NAMTRNG AI HOC BACH KHOA oc Lap T Do Hanh PhucThanh pho Ho Ch Minh ===================================Khoa: IEN IEN TBo mon: IEU KHIEN T ONG

HO VA TEN:....................................................................................MSSV:.NGANH:........................................................................................LP:........

1. au e luan an:______________________________________________________________________

______________________________________________________________________2. Nhiem vu (yeu cau ve noi dung va so lieu ban au):__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. Ngay giao nhiem vu luan an:______________________________________________4. Ngay hoan thanh nhiem vu: ______________________________________________5. Ho ten ngi hng dan: Phan hng dan:

1) ___________________________________ _________________________2) ___________________________________ _________________________3) ___________________________________ _________________________

Noi dung va yeu cau LATN a c thong qua bo mon.Ngay_____ thang_____ nam________

CHU NHIEM BO MON NGI HNG DAN CHNH(Ky va ghi ro ho ten) (Ky va ghi ro ho ten)

PHAN DANH CHO KHOA BO MONNgi duyet (cham s bo): ______________________n v: ______________________________________Ngay bao ve: _________________________________iem tong ket:________________________________Ni lu tr luan an: ____________________________


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TRNG AI HOC BACH KHOA CONG HOA XA HOI CHU NGHA VIET NAMKHOA IEN-IEN T oc Lap T Do Hanh Phuc

-----------Ngay thang nam

1. Ho va ten SV: ___________________________________________________________MSSV: Nganh (chuyen nganh): ______________________________

2. e tai : _________________________________________________________________3. Ho ten ngi hng dan : __________________________________________________4. Tong quat ve bang thuyet minh : ____________________________________________

So trang _________ So chng _____________So bang so lieu _________ So hnh ve _____________So tai lieu tham khao _________ Phan mem tnh toan _____________Hien vat (san pham ) _________

5. Tong quat ve cac ban ve :- So bang ve: ban A1 ban A2 kho khac- So ban ve tay so ban ve tren may tnh

6. Nhng u iem chnh cua LVTN :________________________________________________________________________________________________________________________________________________

________________________________________________________________________________________________________________________________________________7. Nhng thieu sot chnh cua LVTN:

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

8. e ngh: c bao ve Bo sung them e bao ve Khong c bao ve9. 3 cau hoi SV phai tra li trc Hoi ong :

a) ______________________________________________________________________

______________________________________________________________________b) ____________________________________________________________________________________________________________________________________________

c) ____________________________________________________________________________________________________________________________________________

10. anh gia chung ( bang ch :gioi, kha, TB) : iem __________ / 10Ky ten (ghi ro ho ten )


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TRNG AI HOC BACH KHOA CONG HOA XA HOI CHU NGHA VIET NAMKHOA IEN-IEN T oc Lap T Do Hanh Phuc

-----------Ngay thang nam

1. Ho va ten SV: ___________________________________________________________MSSV: Nganh(chuyen nganh) : ______________________________

2. e tai : _________________________________________________________________3. Ho ten ngi phan bien :___________________________________________________4. Tong quat ve bang thuyet minh : ____________________________________________

So trang _________ So chng _____________So bang so lieu _________ So hnh ve _____________So tai lieu tham khao _________ Phan mem tnh toan _____________Hien vat (san pham ) _________

5. Tong quat ve cac ban ve :- So bang ve: ban A1 ban A2 kho khac- So ban ve tay so ban ve tren may tnh

6. Nhng u iem chnh cua LVTN :________________________________________________________________________________________________________________________________________________

________________________________________________________________________________________________________________________________________________7. Nhng thieu sot chnh cua LVTN:

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

8. e ngh: c bao ve Bo sung them e bao ve Khong c bao ve9. 3 cau hoi SV phai tra li trc Hoi ong :

a) ______________________________________________________________________

______________________________________________________________________b) ____________________________________________________________________________________________________________________________________________

c) ____________________________________________________________________________________________________________________________________________

10. anh gia chung ( bang ch :gioi, kha, TB) : iem __________ / 10Ky ten (ghi ro ho ten )


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Trc het xin cam n ba me , gia nh a la nguon ong vien rat ln va la cho da vngchac nhat cua con trong suot qua trnh hoc tap.

Knh gi en thay LE NGOC NH li cam n chan thanh va sau sac, cam n thay a

tan tnh hng dan, ch day em t cac o an mon hoc cho en khi hoan thanh luan van tot

nghiep.

Em xin cam n tat ca quy thay co cua trng ai hoc Bach Khoa TP.HCM noi chung,

quy thay co cua khoa ien-ien t va bo mon ieu Khien T ong noi rieng a tan tnhgiang day , trang b cho em nhng kien thc bo ch trong khoang thi gian hoc ai hoc.

Toi xin cam n tat ca ban be a ong vien, gop y, giup toi rat nhieu trong qua trnh

hoc tap va thc hien luan van .

Toi xin cam n tat ca.

Thanh pho Ho Ch Minh ,thang 1 nam 2009

Nguyen Gia Minh Thao


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iii

Nhiem vu cua e tai la s dung giai thuat ieu khien ket hp vi vi ieu khien e on

nh va ong bo toc o he ong c ien mot chieu ( ong c DC ).

e tai c thc hien nh sau: S dung giai thuat ieu khien PI-M ket hp vi vi ieu

khien 16-bit MC9S12DP512 e on nh va ong bo toc o he ong c DC . Mo hnh phan cng

bao gom 3 mo-un mach : mo-un 0 ong vai tro lam trung tam ieu khien-giam sat toan he

thong , mo-un 1 ieu khien ong c 1, mo-un 2 ieu khien ong c 2 .

Vi ieu khien tren mo-un 1 se nhan toc o at t ngi dung ,s dung giai thuat ieukhien PI-M e ieu rong xung (PWM: Pulse Width Modulation) ieu khien ong c 1 chay

ung theo toc o at , ong thi truyen gia tr toc o cua ong c 1 cho vi ieu khien tren mo-

un 2 qua Port A cua 2 vi ieu khien. Vi ieu khien tren mo-un 2 se lay gia tr toc o cua

ong c 1 t Port A e lam toc o at , va s dung giai thuat ieu khien PI-M e ieu rong

xung ( PWM ) ieu khien ong c 2 chay ung theo toc o cua ong c 1.

Ca 3 mo-un eu c ket noi vi nhau trong mang CAN ( Controller Area Network) e

hai mo-un 1 va 2 co the truyen nhanh d lieu ve mo-un 0 (co vai tro la trung tam ieu

khien-giam sat) cho ngi dung co the giam sat .Them vao o , ket hp vi may vi tnh at tai

mo-un 0, ngi dung co the ieu khien toan bo hoat ong cua he thong.

Ket qua at c thoa man kha tot yeu cau e ra: ieu khien on nh c toc o ong

c DC , ong bo c toc o cua 2 ong c DC . Thay oi toc o kha linh hoat . Xay dng

thanh cong mang CAN dung e ket noi cac mo-un trong he thong , cho phep ieu khien vagiam sat toan he thong t may vi tnh hay t mo-un ieu khien trung tam.


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iv

Trang ba iNhiem vu luan vanLi cam n iiTom tat iiiMuc luc iv

1.1 at van e.......................................................................................................................1

1.2 Cac phng phap a c s dung e ong bo toc o ong c va ng dung thc te......21.3 Nhiem vu cua luan van ...................................................................................................5

1.4 Thc hien ........................................................................................................................5

1.5 S lc ve mo hnh he thong...........................................................................................71.5.1 S o khoi cua mo hnh he thong .............................................................................71.5.2 Mo ta hoat ong cua mo hnh he thong....................................................................7

2.1 Ly thuyet ieu khien M..................................................................................................92.1.1 Gii thieu ve Logic M ...........................................................................................92.1.2 Mot so khai niem c ban ........................................................................................112.1.3 Menh e hp thanh m, luat hp thanh m............................................................142.1.4 Bo ieu khien m ...................................................................................................17

2.2 Ly thuyet ieu khien PID...............................................................................................202.2.1 Khau hieu chnh ty le P ..........................................................................................202.2.2 Khau hieu chnh vi phan ty le PD...........................................................................202.2.3 Khau hieu chnh tch phan ty le PI .........................................................................212.2.4 Khau hieu chnh vi tch phan ty le PID...................................................................21

2.2.5 Thiet ke bo ieu khien PID ....................................................................................22

3.1. Gii thieu ( CAN: Controller Area Network ) ...............................................................24

3.2. Giao thc CAN ( CAN Protocol ) .................................................................................263.2.1 Noi dung giao thc..................................................................................................26


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3.2.2 Mo hnh CAN trong OSI .........................................................................................273.2.3 Lp vat ly ...............................................................................................................293.2.4 Cau truc bc ien ...................................................................................................323.2.5 Cau truc bit trong giao thc CAN ..........................................................................35

3.2.6 Truy cap va giai quyet tranh chap tren ng truyen.............................................373.2.7 S ong bo xung clock............................................................................................38

4.1 ac tnh c tnh cua ong c ien mot chieu ( ong c DC ) ........................................40

4.2 S lc ve cac phng phap ieu khien toc o ong c DC..........................................444.2.1 ieu khien t thong................................................................................................454.2.2 ieu khien ien ap phan ng .................................................................................464.2.3 ieu khien hon hp ien ap phan ng va t thong kch t.....................................47

4.3 Phng phap ieu rong xung (PWM: Pulse Width Modulation)....................................48

4.4 Gii thieu ve Encoder c s dung trong luan van ......................................................50

5.1 Gii thieu chung ve ho vi ieu khien HCS12................................................................535.1.1 Cac thanh phan c ban cua bo x ly........................................................................555.1.2 Cac che o hoat ong..............................................................................................56

5.2 Vi ieu khien c s dung trong Luan van - MC9S12DP512.......................................58

5.2.1 Cac Port xuat nhap a dung....................................................................................605.2.2 Khoi chc nang thi gian ( Timer ).........................................................................635.2.3 Bo ieu rong xung ( PWM )....................................................................................675.2.4 Giao tiep noi tiep bat ong bo ( SCI ) ....................................................................705.2.5 Khoi chc nang Key-WakeUp................................................................................725.2.6 Khoi Mo-un chc nang CAN ( Controller Area Network ) ..................................73

6.1 Cau truc phan cng cua cac mo-un trong mo hnh ......................................................79

6.2 Cac khoi mach chc nang tren mo-un ieu khien ong c va mo-un trung tam. .....806.2.1 Khoi mach vi ieu khien trung tam........................................................................816.2.2 Khoi mach giao tiep may vi tnh qua cong noi tiep................................................826.2.3 Khoi giao tiep CAN................................................................................................846.2.4 Khoi giao tiep song song gia 2 mo-un ieu khien 2 ong c ..............................856.2.5 Khoi ban phm ieu khien ong c ( 4 phm) ........................................................856.2.6 Khoi ban phm chon cac che o hoat ong cho mo hnh ........................................86


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6.2.7 Khoi mach nguon 5 Vdc cho he thong ieu khien..................................................876.2.8 Khoi thi gian thc .................................................................................................876.2.9 Khoi hien th LCD ..................................................................................................916.2.10 Khoi mach ong lc ieu khien ong c ...............................................................92

6.2 Khoi nguon 24/12/5 Vdc cung cap cho mach ong lc va ong c ...............................94

6.3 S o mach BDM-Pod :Mach dung e Nap ,Debug cho ho HCS12...............................95....

7.1 Thiet ke bo ieu khien PI-M , on nh toc o ong c DC .......................................977.1.1 S lc s o khoi va he phng trnh toan............................................................977.1.2 Thiet ke bo ieu khien PI-M ................................................................................98

7.1.3 Cach tnh toc o cua ong c DC c s dung trong luan van ...........................1027.2 Cach thc ieu khien t may vi tnh ( PC ) ...............................................................103

7.3 Lu o giai thuat cho vi ieu khien tren cac mo-un................................................1107.3.1 Lu o giai thuat oan chng trnh MAIN........................................................1127.3.2 Trnh t chi tiet trong cac chng trnh con va 5 chng trnh phuc vu Ngat.......116

8.1 Mot so hnh anh ve hoat ong cua he thong ................................................................1238.1.1 Tai giao dien tren may tnh mo-un ieu khien ong c 1................................. 123

8.1.2 Hnh anh tai giao dien tren may tnh va mo-un trung tam ieu khien ..1258.2 Cac ket qua a at c..............................................................................................127

8.3 Mot so iem han che...................................................................................................128

8.4 Hng khac phuc cac iem han che va phat trien e tai ............................................1288.4.1 Hng khac phuc cac iem han che......................................................................1288.4.2 Hng phat trien e tai..........................................................................................129


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Chng 1: Tong quan ve e tai GVHD: KS. Le Ngoc nh

SVTH: Nguyen Gia Minh Thao 1

- Cung vi cong cuoc cong nghiep hoa-hien ai hoa cua at nc , lnh vc t ong hoa co

nhng bc phat trien vt bac va tr thanh yeu to quan trong khong the thieu cua nen

cong nghiep hien ai. Khi noi en t ong hoa la noi en s thay the dan dan en hoan

toan cac hoat ong chan tay bang may moc trong cac day chuyen san xuat.

- Trong nen cong nghiep hien ai va phat trien , cac day chuyen san xuat hoat ong chu

yeu da tren cac may moc , di s ieu khien va giam sat cua con ngi. Khi co cang

nhieu may moc va nhieu cong oan s dung may moc th s phoi hp an khp hay con goi

la s ong bo gia cac cong oan la ieu can phai quan tam. ieu nay cang c chu

trong trong cac lnh vc can co o chnh xac toc o cua cac ong c cao nh: nganh cong

nghiep vai , giay , det , .

- Xet mot v du n gian ve ng dung cua s ong bo , nh mo hnh bang chuyen sau:

Hnh 1.1: Mo hnh bang chuyen co 2 truc quay


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+ Trong mo hnh bang chuyen nay ta co 2 ong c: ong c 1 dung e keo truc xa va

ong c 2 dung keo truc cuon .

+ Yeu cau ieu khien la: ong c 1 va ong c 2 luon phai hoat ong on nh cung mot

toc o at trc , ngay ca khi bang tai van chuyen cac hang hoa co khoi lng khac

nhau. Khi ong c 1 thay oi toc o th ong c 2 cung phai thay oi toc o theo-phu

hp vi s thay oi cua ong c 1 , e bang tai khong qua un hay qua cang.

- Qua cac dan chng tren , ta nhan thay van e c at ra ay la: S an khp , ong bo

o t au ma co? S dung phng phap nao e co the on nh c toc o cac ong c va

ieu khien chung hoat ong ong bo toc o vi nhau ? Ngoai ra, khi he thong co nhieu daychuyen xa nhau, lam sao e ieu khien ong bo va giam sat tat ca hoat ong cua cac

day chuyen o? .

- ong bo toc o ong c ien xoay chieu (ong c AC ) hay ong c ien mot chieu (ong

c DC ) eu c s dung rong rai trong nhieu lnh vc . Pham vi cua Luan van la giai

quyet bai toan ong bo toc o ong c DC .

Hnh 1.2: S o ong bo toc o ong c AC s dung bien tan

ong c AC 1 Encoder

Bo ty le AnalogBien tan 2ong c AC 2

Bien tan 1


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- Bien tan 1 co nhiem vu ieu khien ong c 1 chay ung toc o a at. Encoder se phanhoi toc o that cua ong c 1 va a vao bo t le analog . Sau o bien tan 2 se ieu

khien ong c 2 chay theo ung toc o ma ong c 1 ang chay.

- u iem : c dung cho cac ong c AC co cong suat ln va ieu khien toc o rat tot.- Nhc iem: can s dung nhieu bien tan ma gia thanh cua mot bo bien tan la kha cao .

Hnh 1.3 : ieu khien toc o ong c DC dung phng phap chnh lu ieu khien pha

- Cac bo ieu khien 1 va 2: s dung phng phap chnh lu ieu khien pha e ieu khien

on nh toc o ong c DC co hoi tiep , vi phan hoi vong trong la dong ien va phan

hoi vong ngoai la van toc.

- Bo ieu khien 1 se ieu khien ong c 1 chay ung theo toc o at . Toc o that cua

ong c 1 se c truyen en cho bo ieu khien 2 e ieu khien ong c 2 chay ungtheo toc o nay.

- u iem: He thong ieu khien nhieu vong nen ieu khien on nh toc o ong c tot.

- Nhc iem: Cach thiet ke bo ieu khien dung phng phap chnh lu ieu khien pha th

phc tap , yeu cau co nhieu kien thc va kinh nghiem trong lnh vc ien t cong suat.

Bo ieu khien 1 ong c DC 1

Phan hoi: Vong trong-dong ien ; vong ngoai-toc o

Bo cap nhat toc o ong c 1( Encoder hay Tacho generator )

Bo ieu khien 2ong c DC 2

Phan hoi: Vong trong-dong ien ; vong ngoai-toc o


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+ Trong day chuyen san xuat banh kem:

Hnh 1.4: ng dung cua ong bo toc o ong c - day chuyen san xuat banh kem

+ Trong he thong nhuom vai:

Hnh 1.5: ng dung cua ong bo toc o ong c he thong nhuom vai

+ Trong may xeo giay:

Hnh 1.6: ng dung cua ong bo toc o ong c trong may xeo giay


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- Tm hieu ong c ien mot chieu ( ong c DC ) va cac phng phap ieu khien toc o

ong c DC.

- S dung cac giai thuat ieu khien ( kinh ien , hien ai ,thong minh ) va ket hp vi vi

ieu khien nham thiet ke bo ieu khien toc o ong c DC , thoa man cac yeu cau : ap

ng qua o , sai so xac lap , am bao hoat ong tot nhieu mc van toc va on nh ngay

ca khi tai thay oi.

- Thiet ke va thi cong cac mach ieu khien va mo hnh co t nhat 2 ong c e tng trnghe thong nhieu ong c.

- Viet chng trnh ieu khien vi 2 muc ch chnh : Th nhatla on nh toc o cua mot

ong c DC , sau o la ieu khien ong bo toc o cua tat ca cac ong c trong he thong

ngha la: Khi ong c 1 thay oi toc o th ong c 2 , ong c 3 phai thay oi toc o

va luon bam theo ong c 1.

- ong thi phai ieu khien va giam sat c hoat ong cua tat ca cac ong c t machieu khien va t may vi tnh.

Luan van c lay ten la:

- ong c DC c s dung trong luan van la ong c DC 24V-20W , c gan ong trucencoder quang loai tng oi ( 100 xung/vong ) . Mo hnh cua luan van gom 2 ong c.

ieu khien toc o bang phng phap ieu rong xung ( PWM: Pulse Width Modulation).


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- Nghien cu ly thuyet ieu khien PID , Logic M va a thiet ke bo ieu khien PI-M (vi luat hp thanh m 5x5 cho tng tham so: PK DK a ) e ieu khien on nh toc o

ong c DC . ay la bo ieu khien tch hp gia bo ieu khien PI kinh ien va Logic M

, tong hp c cac u iem cua ieu khien kinh ien va ieu khien thong minh.

- Vi ieu khien c s dung trong luan van la MC9S12DP512 , thuoc ho vi ieu khienHCS12 cua hang Motorola ( HCS12 la ho ieu khien 16-bit c phat trien t cac ho vi

ieu khien 68HC11 / 68HC12 ) . ay la vi ieu khien kha manh, toc o nhanh, hoat

ong on nh , tch hp nhieu mo-un chc nang phu hp vi cac yeu cau cua e tai.

- a tm hieu va thiet ke mot mang truyen thong e ieu khien va giam sat tat ca cac hoatong 2 ong c trong mo hnh cua luan van ( khi m rong co the la nhieu ong c ) .

Giao thc truyen thong c chon la giao thc CAN ( Controller Area Network ) v cac

ac iem sau:

+ Co tnh on nh , toc o truyen kha cao ( 1 Mbit/s tren khoang cach 40m) , truyen

c d lieu ln , ap ng thi gian thc , , phu hp vi yeu cau ieu khien va giam

sat he thongcua e tai - ac biet khi m rong ra he thong co nhieu ong c .

+ Vi ieu khien MC9S12DP512 co ho tr giao thc CAN va IC lai ( Transceiver ) cho

mang CAN nh : MCP2551 cua hang MicroChip co gia re , rat de kiem tren th trng.

- Thiet ke va thi cong 3 mo-un mach , gom: 2 mo-un trc tiep ieu khien 2 ong c (

, ), mot mo-un co vai tro la trung tam ieukhien-giam sat he thong (

) .Bao gom cac khoi mach: mach nguon 24/12/5 VDC cung cap cho ong c vakhoi mach ong lc , mach vi ieu khien (s dung nguon 5 VDC rieng) va cac khoi mach

giao tiep : RS232 , CAN , ong ho thi gian thc , LCD dung e hien th , phm nhan.

- Thiet ke giao dien ieu khien va giam sat tren may vi tnh, s dung ngon ng Visual

Basic 6 . T o ngi s dung co the thiet lap cac thong so e ieu khien va giam sat he


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thong ngay tren may tnh at tai mo-un ieu khien ong c so 1 ( con goi la ong c

chu trong mo hnh ) hay tai trung tam ieu khien cua toan he thong.

- Mo hnh he thong hoat ong kha tot , ap ng ay u cac yeu cau cua luan van e ra va

con c m rong them mot so chc nang khac.

Hnh 1.7: Mo hnh cua he thong trong luan van

- Moi mo-un ( 1 va 2) se ieu khien on nh toc o mot ong c DC tng ng:

+ Cam bien Incremental encoder dung e phan hoi toc o ong c ve cho vi ieu khien


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+ Vi ieu khien vi thuat toan ieu khien PI-M se tao ra tn hieu ieu khien cho mach

ong lc ieu khien ong c chay theo ung toc o at bang phng phap ieu rong

xung PWM .

- Hai vi ieu khien MC9S12DP512 tren 2 mo-un ieu khien so 1 va so 2 c ket noi vi

nhau qua 2 port giao tiep song song ( Port A, H ) nham trao oi nhanh thong tin ve toc o:

+ Vi ieu khien tren Mo-un 1 ieu khien toc o ong c 1 theo toc o at trc, va gi

toc o that cua ong c 1 ra Port A ( Chu ky gi la 20ms va ch gi khi gia tr toc o that

cua ong c 1 co thay oi) , va oc gia tr toc o that cua ong c 2 t Port H e hien th

len LCD va may vi tnh.+ Vi ieu khien tren mo-un 2 se oc gia tr toc o t Port A , ieu khien ong c 2 chay

theo ung toc o nay( luc o toc o ong c 2 se bam theo va phu thuoc vao ong c 1 )

, va gi toc o that cua ong c 2 ra Port H (Chu ky oc gi cung la 20ms )

- Ca ba mo-un gom: 2 mo-un ieu khien va mo-un giam sat (mo-un 0) c ket noi vi

nhau qua mang CAN :

+ Tat ca d lieu cua 2 mo-un ieu khien nh : toc o cac ong c , che o hoat ong

eu c gi en mo-un giam sat ( hay la mo-un trung tam) , t o c gi len may

tnh c at tai mo-un nay (chuan RS232C ) e: Hien th, ve o th kiem chng,.

+ T mo-un 0 hay may tnh at tai trung tam , ta co the ieu khien va giam sat c tat

ca cac ong c trong mang vi cac che o ieu khien a nh trc.

-Ngoai ra , con co mot so chc nang c m rong nh:

+ T trung tam, ta co the ieu khien ca 2 ong c chay cung toc o , chay va dng lai cung

luc ma khong phu thuoc vao nhau. Va cung co the ieu khien rieng le tng ong c.

+ Co 2 che o ieu khien : che o ieu khien bang tay ( Manual ) va che o ieu khien T

ong (Auto). Trong che o t ong, he thong t hoat ong theo thi gian cai at t trc


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Chng 2: Ly thuyet ieu khien M, ieu khien PID GVHD: KS. Le Ngoc nh


( Fuzzy Logic )

Khai niem ve logic m c giao s L.A Zadeh cong bo lan au tien tai My vao nam

1965, tai trng ai hoc Berkeley, bang California, My. T o, ly thuyet m a co nhieu phat

trien va c ng dung rong rai trong lnh vc ieu khien-t ong hoa.

- Nam 1970 , tai trng ai hoc Mary Queen , thanh pho Lodon nc Anh , EbrahimMamdani a s dung logic m e ieu khien mot may hi nc ma ong khong the ieu khien

bang ky thuat co ien.

- Tai Nhat , logic m c ng dung vao nha may x ly nc cua hang Fuji Electronic vao

nam 1983, he thong xe ien ngam cua Hitachi vao nam 1987. Tuy Logic m ra i My , ng

dung au tien Anh , nhng lai phat trien va ng dung nhieu nhat Nhat.

- u iem cua ieu khien m so vi cac phng phap ieu khien kinh ien la co the tong

hp c bo ieu khien ma khong can biet trc ac tnh cua oi tng mot cach chnh xac.

ieu nay thc s rat hu dung cho cac oi tng phc tap ma ta cha biet ro ham truyen.

- ieu khien m ch can x ly nhng thong tin khong chnh xac hay khong ay u, nhng

thong tin ma s chnh xac cua no ch nhan thay c gia cac quan he cua chung vi nhau va

cung ch co the mo ta bang ngon ng nhng van co the a ra nhng quyet nh chnh xac.

ieu khien m hay con goi la ieu khien thong minh, mo phong tren phng thc x ly

thong tin va ieu khien cua con ngi, khi au cho s ng dung cua tr tue nhan tao tronglnh vc ieu khien.

- Xet mot v du ve logic M:

Co mot ngi ang lai thuyen cano tren song, khi o ngi lai thuyen cano c xem nh la

thiet b ieu khien va chiec thuyen cano la oi tng ieu khien. Nhiem vu cua ngi lai


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thuyen cano la ieu khien thuyen cano ti ben an toan . Muon tm hieu phng thc thc hien

nhiem vu o cua ngi lai thuyen cano th phai xem xet ngi o phai x ly nhng thong tin

g va x ly chung nh the nao.

+ ai lng ieu khien th nhatla hng di chuyen cua mui thuyen, phu thuoc vao dong

song pha trc cua thuyen . Ngi lai thuyen co nhiem vu ieu khien chiec thuyen i ung

phan song quy nh, tc la phai luon gi cho thuyen nam trong phan ben phai cua dong song (

gan ve pha b ben phai cua dong song hn , nhng tranh khong qua gan b e thuyen khoi b

mac can ), tr trng hp phai vt chiec thuyen khac. e lam cong viec nay , ngi lai

thuyen khong can phai biet mot cach chnh xac rang chiec thuyen cua mnh hien ang cach b

song ben phai bao nhieu bao nhieu met , ma ch can nhn vao dong nc trc mat : ngi oco the suy ra c rang chiec thuyen hien ang cach b song ben phai nhieu hay t, co con

nam pha ben phai cua dong song khong va t o a ra quyet nh phai anh tay lai sang

phai manh hay nhe.

+ ai lng ieu khien th hai la toc o cua thuyen cano. Vi nguyen tac: e cam thay

chuyen i c thoai mai va tiet kiem xang, ngi lai thuyen co nhiem vu gi nguyen toc o

cua thuyen, tranh khong giam toc hoac tang toc khi khong can thiet . Gia tr ve toc o thuyen

ma ngi lai xe phai gi cung phu thuoc nhieu vao nhieu yeu to nh: Thi tiet ma hay nang,

canh quan, mat o thuyen tren song, va cung con phu thuoc them la ngi lai thuyen co

quen oan song o hay khong? Tuy nhien quy luat ieu khien nay cung khong phai co nh.

trc mat co mot chiec thuyen khac , co kch c ln , i cham hn va choang v tr

dong song pha trc. Vay th thay cho nhiem vu gi nguyen toc o, ngi lai thuyen phai tam

thi thc hien mot nhiem vu khac: la giam toc o thuyen va t ieu khien thuyen theo mot

toc o mi, phu hp vi s phan ng cua chiec thuyen pha trc cho ti khi ngi lai thuyenieu khien thuyen cua mnh vt qua c chiec thuyen kia.

+ Ngoai 2 ai lng ieu khien tren, ngi lai thuyen cung phai quan tam en cac trang

thai cua thuyen nh: ong c cua thuyen hoat ong co qua nong khong , he thong chan quat


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nc ( chan vt ) con am bao khong , thuyen co b vao nc do b thung khong e co the

kp thi sa cha ,tranh b am thuyen, hay gay tai nan tren song.

+ oi tng ieu khien la chiec thuyen cung co nhng tham so thay oi can phai c thu

thap va giam sat thng xuyen cho cong viec ra cac quyet nh ve ai lng ieu khien. S

thay oi cac tham so o, ngi lai thuyen co the nhan biet c trc tiep qua cac en bao hieu

trong thuyen, song cung co the gian tiep qua phan ng cua thuyen vi cac ai lng ieu

khien.

+ Ngi lai thuyen a thc hien tot chc nang cua mot bo ieu khien: T thu thap thong

tin, thc hien thuat toan ieu khien cho en khi a ra tn hieu ieu khien kp thi ma khong

can biet mot cach chnh xac ve v tr, toc o, tnh trang. cua thuyen. Hoan toan ngc lai vikhai niem ieu khien chnh xac, ngi lai thuyen cung ch can a ra nhng ai lng ieu

khien theo nguyen tac x ly m nh:

- Neu thuyen hng nhe ve pha gia dong song va co xu hng qua pha ben trai dong

song th anh tay lai nhe sang phai. Con neu thuyen hng ot ngot ra pha gia dong

song va co the i lan sau qua pha ben trai dong song th anh manh tay lai sang phai.

- Neu thuyen hng nhe ve pha b song ben phai th anh tay lai nhe sang trai. Con neu

thuyen hng ot ngot ra pha b song ben phai va co the b mac can do qua gan b th

anh manh tay lai sang trai.

- Neu thuyen chay cung chieu vi dong nc chay, mat o thuyen tren song t, tam nhn

khong b han che: toc o cua thuyen co the cao hn bnh thng mot chut .

- Neu dong song co mat o thuyen ong , tam nhn b han che: toc o cua thuyen co the

thap hn bnh thng mot chut.

Mot cach tong quat , he thong m la tap hp cac qui tac di dang : ( Neu

Th ) e mo phong hanh vi cua con ngi va tch hp vao cau truc cua ieu khien cua he

thong.


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- Ky thuat thiet ke mot he thong m mang rat nhieu tnh chat chu quan, tuy thuoc rat nhieu

vao kinh nghiem va kien thc cua ngi thiet ke. Ngay nay , tuy ky thuat M a co nhieu phat

trien vt bac ,nhng van cha co mot cach thc chuan va hieu qua cho viec thiet ke he thong

m. Viec thiet ke van da tren ky thuat rat c ban la: Th Sai Sa , mat nhieu thi gian

cho viec chnh sa e at c mot ket qua co the chap nhan c.

- Tap m F xac nh tren tap kinh ien X la mot tap ma moi phan t cua no la mot cap cac

gia tr ( ))(, xxFm trong o Xx va

Fm la anh xa [ ]1,0: XFm .

+ Anh xa Fm c goi la ham lien thuoccua tap m F.

+ Tap kinh ien X c goi la tap nen cua tap m F.

-- Cho mot tap hp A, anh xa A: RA c nh ngha nh sau:

= Ax

AxA ,0

,1m , c goi la ham thuoc cua A.

- Mot tap luon co 1)( =xXm vi moi x c goi la khong gian nen (tap nen)

- Vay vi khai niem nh tren th ham thuoc Am cua tap A co tap nen X se c hieu la anh

xa }{ 1,0: XAm .

Hnh 2.1: Ham lien thuoc


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- o cao cua tap m F (nh ngha tren tap nen X) la gia tr: Xxxh F = ),(supm - : Mien xac nh cua tap m F (nh ngha tren c s X) c ky hieu bi S

la tap con cua M thoa man: { }0)(| >= xXxT Fm ; M: tap ro c s

- Mien tin cay cua tap m F (nh ngha tren c s X) c ky hieu bi T latap con cua M thoa man: { }1)(| == xXxT Fm

Bien ngon ng la phan t chu ao trong cac he thong s dung logic m. ay , cac thanh

phan ngon ng cua cung mot ng canh ket hp vi nhau.

- Moi gia tr ngon ng cua bien c xac nh bang mot tap m nh ngha tren tap nen latap cac so thc ch gia tr vat ly cua bien.

Khi o nhiet o cua mot phong , ta co cac khai niem nh: nhiet o rat lanh, hi lanh,

trung bnh, hi nong va rat nong .Theo kinh nghiem ta co the chon di C015 la rat lanh,

C020 la hi lanh, C025 la trung bnh, C030 la hi nong, tren C035 la rat nong.

+ Vay vi mot nhiet o ta co mot anh xa nh sau:

=

ratnong

hoinong

vua

hoilanh

ratlanh

t

m

m

m

m

m

m

+ Anh xa nh tren con goi la qua trnh M hoa cua gia tr ro nhiet o t.

Hnh 2.2: V du ve logic m trong ng dung o nhiet o


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- Giao cua hai tap hp: { })(),(min)().( xxxx BABABA mmmmm == (2.1)

- Hp cua hai tap hp: { })(),(max)().()()( xxxxxx BABABABA mmmmmmm =-+= (2.2)

- Bu cua mot tap hp: )(1)( xx AAC mm -= (2.3)

- Menh e hp thanh tng ng vi mot luat ieu khien thng co dang:< menh e ieu kien > < menh e ket luan >

-o phu thuoc cua ket luan khong c ln hn o phu thuoc cua ieu kien. (Nguyen

tac nay thng c s dung e mo ta menh e hp thanh m trong ieu khien)

- Neu he thong co nhieu au vao va nhieu au ra th menh e tong quat co dang nh sau:

N = n i and M = m i and R = ri and K = ki and

- Xet menh e hp thanh BA , ta co gia tr cua menh ehp thanh m la mot tap m Bnh ngha tren nen Y (khong gian nen cua B) va

co ham lien thuoc la: { })(,min)(' yy BAB mmm =

- Xet menh e hp thanh BA , ta co gia tr cua menh e hp thanh m la m la mot tap mB

nh ngha tren nen Y (khong gian nen cua B) va co ham lien thuoc la: )()(' yy BAB mmm =

Khai niem

+ Neu mot luat hp thanh ch co mot menh e hp thanh th goi la luat hp thanh n.


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+ Neu mot luat hp thanh co nhieu hn mot menh e hp thanh th goi la luat hp thanh

kep. Phan ln cac he m trong thc te co mo hnh la luat hp thanh kep.

Cac luat hp thanh m c ban:

+ Luat hp thanh MAX - MIN

+ Luat hp thanh MAX - PROD

+ Luat hp thanh SUM MIN

+ Luat hp thanh MAX PROD

Cac ham lien thuoc c xac nh theo quy tac hp thanh MIN va phep hp c thc

hien theo quy luat MAX.

Cac ham lien thuoc c xac nh theo quy tac hp thanh PROD va phep hp c thc

hien theo quy luat MAX.

- Cac ham lien thuoc c xac nh theo quy tac hp thanh MIN va phep hp c

thc hien theo quy luat Lukasiewicz.

- Phep hp Lukasiewicz: { })()(,1min)( xxx BABA mmm += (2.4)

Cac ham lien thuoc c xac nh theo quy tac hp thanh PROD va phep hp c thc

hien theo quy luat Lukasiewicz.

Giai m la qua trnh xac nh ro au ra t ham phu thuoc cua tap m.

Co nhieu phng phap c dung trong bc nay :


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+ Nguyen ly cc ai : hay con goi la phng phap o

cao, ch dung cho loai tap m ra co nh nhon, c

bieu dien qua bieu thc

m(z*) m(z), "z Z

Trong trng hp co nhieu nh nhon hay gia tr cc ai khong phai la mot iem duy

nhat th ngi ta s dung :

+ Trung bnh cac cc ai(MoM):

2

21*

zzz+=

+ Cc ai au tien (LoM): z* = z1

+ Cc ai cuoi cung (RoM): z* = z2

+ Phng phap trong tam ( CoG Center of Gravity

hay CoA Center of Area) : thng dung trong cac

ng dung, c bieu dien qua bieu thc

=dzz

zdzzz

)(

).(*

m

m

+ Phng phap trung bnh theo trong so (CoM Center of Maximum) : la mot bien dang cua

phng phap trong tam khi thay dau tch phan bang dau sigma, c dung nham n gian hoa

s tnh toan, phu hp vi cac ieu khien nho.

Cac tap m ra co dang singleton :

= )().(

* z

zzz

m

m

Cac tap m ra khong co dang nh, nhng oi xng :

=

)(

).(*

z

zzz

m

m


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+ Phng phap trong tam dien tch ln nhat: tnh theo phng phap trong tam nhng ap dung

trong trng hp co t nhat vung tren tap nen ra, tnh tren vung co dien tch ln nhat.

Co rat nhieu phng phap giai m , trong thc te thng ch dung: Phng phap trongtam, trung bnh theo trong so hay trung bnh cac cc ai. Phng phap trong tam hay phng

phap trung bnh theo trong so cho ket qua mang tnh chat thoa hiep cac tap m ra, thng dung

trong cac ng dung ieu khien. Trong khi phng phap trung bnh cac cc ai cho ket qua

mang tnh dung hoa cac tap m ra, thng dung trong cac ng dung nhan dang va phan loai.

Hnh 2.3: Cau truc cua mot bo ieu khien m

Mot bo ieu khien M gom 3 khau c ban :

+ Khau m hoa

+ Thc hien luat hp thanh m

+ Giai mV du : Bo ieu khien m MISO ( nhieu au vao- mot au ra ) , vi vector au vao la:


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Hnh 2.4: V du ve bo ieu khien m MISO

Hnh 2.5: Nguyen ly ieu khien m

Cac nguyen ly thiet ke he thong ieu khien m :

+ Giao dien au vao gom cac khau: M hoa , cac khau hieu chnh nh ty le ,tch phan , vi

phan

+ Thiet b hp thanh: S trien khai luat hp thanh m.

+ Giao dien au ra gom: Khau giai m va cac khau trc tiep vi oi tng

- Bc 1: nh ngha tat ca cac bien ngon ng vao/ra

- Bc 2: Xac nh cac tap m cho tng bien ngon ng vao/ra ( m hoa )


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+ Mien gia tr vat ly cua cac bien ngon ng

+ So lng tap m

+ Xac nh ham phu thuoc

+ Ri rac hoa tap m

- Bc 3: Xay dng luat hp thanh

- Bc 4: Chon thiet b hp thanh

- Bc 5: Giai m va toi u hoa.

Mot so nhc iem cua ieu khien M:

- Tuy ieu khien m co nhieu phat trien ,nhng cho en bay gi van cha co cac nguyen tac

chuan mc cho viec thiet ke cung nh cha co the khao sat tnh on nh, tnh ben vng, chat

lng, qua trnh qua o cung nh qua trnh anh hng cua nhieu cho cac bo ieu khien m

va nguyen ly toi u cho cac bo ieu khien nay ve phng dien ly thuyet. iem yeu cua ly

thuyet m la nhng van e ve o phi tuyen cua he, nhng ket luan tong quat cho cac he thong

phi tuyen hau nh kho at c.

- Nham khac phuc nhc iem o , co mot hng giai quyet bai toan thiet ke he thong ieu

khien t ong rat hieu qua la: Ket hp gia cac phng phap ieu khien kinh ien ( ieu

khien P, PI, PD, PID ; ieu khien bien trang thai) vi logic m ,nham tan dung u iem cua ca

hai phng phap ( kinh ien va m ). o la nguyen nhan ra i cac bo ieu khien tch hp

nh:

+ PID M

+ PID M Thch Nghi


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Cac khau hieu chnh P , PD , PI , PID va cach thiet ke bo ieu khien PID

- Ham truyen: G C (s) = pK (2.5)

- He so t le cang ln sai so xac lap cang nho.- Trong a so cac trng hp he so t le cang ln o vot lo cang cao, he thong cang kem

on nh.

- Ham truyen: G C (s) = sKK Dp + = )1( sTK Dp + (2.6)

- La trng hp rieng cua khau hieu chnh sm pha, trong o o lech pha cc ai gia

tn hieu ra va tn hieu vao la: , tng ng vi tan so

Hnh 2.6: Khau hieu chnh vi phan ty le PD

- Khau hieu chnh PD lam nhanh ap ng cua he thong, nhng cung lam cho he thong

rat nhay vi nhieu tan so cao . : Thi hang vi phan cang ln ap ng cang nhanh


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- Ham truyen: GC (s) =s

KK Ip + = )

11(

sTK

i

p+ (2.7)

- Khau hieu chnh PI la mot trng hp rieng cua khau hieu chnh tre pha, trong o o

lech pha cc tieu gia tn hieu ra va tn hieu vao la tng ng vi tan so

- Khau hieu chnh PI lam tang bac vo sai cua he thong, tuy nhien cung lam cho he

thong co vot lo, thi gian qua o tang len

Hnh 2.7: Khau hieu chnh tch phan ty le PI

- Thi hang tch phan cang nho o vot lo cang cao

- Co the noi trong lnh vc ieu khien , bo ieu khien PID c xem nh mot giai phap anang cho cac ng dung ieu khien Analog cung nh Digital . Theo mot nghien cu cho

thay: Hn 90% cac bo ieu khien c s dung la bo ieu khien PID . Bo ieu khienPID neu c thiet ke tot co kha nang ieu khien he thong vi chat lng qua o tot (

ap ng nhanh , o vot lo thap ) va triet tieu sai so xac lap.

Ham truyen: G C (s) = sKs

KK D

Ip ++ = )

11( sT

sTK D

i

p ++ (2.8)


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- Khau hieu chnh PID: Lam nhanh ap ng qua o , tang bac vo sai cua he thong.

Hnh 2.8: Khau hieu chnh vi tch phan ty le PID

- Trng hp 1: Xac nh thong so bo ieu khien PID da vao ap ng nac co dang ch S

cua he h ( s dung phng phap Ziegler Nichols )

Hnh 2.9: Thiet ke bo ieu khien PID bang phng phap Ziegler Nichols

+ Ham truyen: GC (s) = sKs

KK D

I

p++ = )11( sT

sTK D

i

p++

+ Bang 2.1: Chon thong so cho bo ieu khien PID theo Ziegler Nichols


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- Trng hp 2: Xac nh thong so bo ieu khien PID da vao ap ng cua he

kn bien gii on nh

- Tang dan gia tr he so khuyech ai K cua he kn en gia tr gii han ghK ( Ngha la gia tr

ln nhat e he thong van con on nh , neu tang them na th he thong se mat on nh) .

Luc o ap ng ra cua he kn trang thai xac lap la dao ong on nh vi chu ky ghT

Hnh 2.10:He thong bien gii co nh

+ Bang 2.2: Chon thong so cho bo ieu khien PID da vao ap ng he thong bien gii

on nh


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Chng 3: Ly thuyet giao thc CAN GVHD: KS. Le Ngoc nh


- CAN ( Controller Area Network : Mang ieu khien khu vc ) la giao thc giao tiep noi tiep

co khung truyen d lieu ln vi o on nh, bao mat va ac biet chong nhieu cc ky tot.

- CAN c phat trien au tien bi nha cung cap phu tung xe oto cua c: Robert Bosch vao

gia nhng nam 80. Nham thoa man yeu cau ngay cang nhieu cua khach hang trong van e antoan va tien nghi, va e tuan theo yeu cau viec giam bt o nhiem va tieu thu nang lng.

Nganh cong nghiep oto a phat trien rat nhieu he thong ien t nh :he thong chong trt

banh xe, bo ieu khien ong c, ieu hoa nhiet o, bo ong ca v.vVi muc ch chnh la

lam cho nhng he thong cua xe o to tr nen an toan, on nh va tiet kiem nhien lieu ; ong

thi phai giam thieu viec i day chang cht, n gian hoa he thong, tiet kiem chi ph san xuat,

th CAN a c phat trien.

- Ngay nay, CAN a c chuan hoa thanh tieu chuan ISO11898 ; va t nam 1991 , CAN co

chuan phat trien cuoi cung la Version 2.0 ( gom : Version 2.0A va Version 2.0B). Hau nh

moi nha san xuat chip ln nh: Intel, NEC, siemens, Motorola, Maxim IC, Fairchild,

Microchip, Philips, Texas Instrument, Mitsubishi, Hitachi, STmicro... eu co san xuat ra chip

CAN, hoac co tch hp CAN vao thanh ngoai vi ( peripheral) cua vi ieu khien. Do o viec

thc hien chuan CAN tr nen cc ky n gian , rut gan thi gian thiet ke va chi ph thc hien

re.

- iem noi troi nhat chuan CAN la tnh on nh va an toan ( Reliability and Safety). Nh

c che truy cap-chong xung ot ng truyen kha thong minh : ( Carrier Sense


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Multiple Access / Collision Detecsion) va c che phat hien , x ly loi cc manh, nen tat ca

Loi hau nh c phat hien. Theo thong ke, xac suat e mot khung truyen cua CAN b loi

ma khong c phat hien la:

Hnh 3.1: Thong ke ve s phat hien loi khung truyen CANGia s c 0.7s th moi trng tac ong len ng truyen CAN lam loi 1 bit, Toc o

truyen la 500 kbits/s ; Hoat ong 8h/ngay va 365ngay/ nam.

Th trong vong 1000 nam, trung bnh se co mot khung truyen b loi ma khong phat hien.

- Mang CAN thuoc loai he thong da vao bc ien (message base system), khac vi he thong

da vao a ch( address base system)::

+ Nhng he thong da vao a ch th moi node c gan cho mot a ch co nh,nen khi

co them hay bt i 1 hay mot nhom node trong he thong nay th bat buoc phai thiet ke

lai qui trnh giam sat mang , dan en ton nhieu thi gian va chi ph.

+ Nhng he thong da vao bc ien se co tnh m hn v: Moi loai bc ien (message) se

c gan mot so can cc . Khi them, bt mot node hay thay mot nhom node bang mot

node phc tap hn cung khong lam anh hng en ca he thong. Co the co vai node cung

nhan bc ien va cung thc hien mot cong viec ( task ), hay thc hien nhng cong viec

khac nhau, cung co the la khong lam g ca.. Do o he thong ieu khien phan bo da

tren mang CAN co tnh m va linh hoat, de dang thay oi ma khong can phai thiet ke lai

toan bo he thong.


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- Ngoai ra , CAN thng c dung e truyen d lieu ln ( trong khung truyen : co the cha

t 0 en 8 bytes d lieu ), co toc o truyen tng oi cao ( 1 Mbs khoang cach 40m) , on

nh, ap ng thi gian thc va trong cac moi trng khac nhau .

- Cac chuan Field bus: DeviceNet, CANopen, J1939 thng dung trong cong nghiep chnh

la chuan CAN m rong. ( Lp vat ly va Lp lien ket d lieu cua cac chuan nay la CAN ).

o la cung la tat ca cac ly do tai sao CAN c s dung rong rai trong nhieu nganhcong nghiep khac ngoai oto nh : cac may nong nghiep, tau ngam, dung cu y khoa, day

chuyen san xuat t ong ..v.v.. va tr thanh giao thc giao tiep rat pho bien.

- Mang CAN c tao thanh bi mot nhom cac node. Moi node co the giao tiep vi bat ky

node khac trong mang. Viec giao tiep c thc hien bang viec truyen i va nhan cac bc

ien - goi la message. Moi loai bc ien trong mang CAN c gan cho mot so can cc ID

(identifier ) tuy theo mc o u tien cua bc ien o. Bc ien co so can cc cang nho th

cang co mc u tien cang cao.

- Phng thc giao tiep cua bus CAN la s phat tan thong tin ( broadcast ): Moi iem ket noi

vao mang thu nhan khung truyen t node phat. Sau o, noi node se quyet nh viec x ly bc

ien : co tra li hay khong, co phan hoi hay khong Cach thc nay giong nh s phat thong

tin ve ng i cua mot tram phat thanh: khi nhan c thong tin ve ng i, ngi lai xe co

the thay oi lo trnh cua anh ta, dng xe hay thay oi tai xe hoac chang lam g ca

- Moi node co the nhan nhieu loai bc ien khac nhau, va ngc lai: mot bc ien co the

c nhan bi nhieu node va cong viec c thc hien mot cach ong bo trong he thong phan

bo.


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- So can cc cua bc ien phu thuoc vao mc o u tien cua bc ien. ieu nay cho phep

phan tch thi gian ap ng cua tng bc ien ay la Y ngha quan trong trong viec thiet ke

he thong nhung thi gian thc. Trc khi co mang CAN, la chon duy nhat cho mang giao tiep

trong he thong thi gian thc la mang cham chap.

- Cong nghe day cap truyen cua mang CAN n gian : S truyen d lieu thc hien nh cap

day truyen tn hieu vi sai, co ngha la chung ta o s khac nhau gia 2 ng ( CAN_H va

CAN_L). ng day truyen thng c ket thuc bang ien tr 120 Ohm (thap nhat la 108

ohm va toi a la 132 ohm) .

Hnh 3.2: Mo hnh v du cho he thong s dung mang CAN

- CAN trong mo hnh OSI : bao gom phan tren lp vat ly ( Physical layer ) va lp lien ket d

lieu ( Data link layer )

- Tieu chuan ISO11898 nh ngha Lp vat ly va Lp lien ket d lieu nh sau:

+ Lp vat ly nh ngha cach bieu dien/thu nhan bit 0- bit 1, cach nh thi va ong bo hoa.


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+ Lp lien ket d lieu c chia lam 2 lp nho la Logical link control ( LLC) va Medium

Access Control (MAC) , co chc nang :

-nh ngha khung truyen ( frame ) va nhng nguyen tac phan x (arbitration ) e tranhtrng hp ca hai node trong mang cung truyen ong thi.

-Ngoai ra, con co them nhieu c che khac e: kiem tra, x ly loi . C che kiem tra,x ly loi chia lam 5 loai loi: Bit error, Stuff error, CRC error, Form error, ACK error.

Hnh 3.3: Giao thc CAN trong mo hnh 7 lp OSI


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Phng phapma hoa None-return-to-zero:Moi bit trong mang CAN c ma hoa bang phng phap None-return-to-zero (NRZ

method). Trong suot qua trnh cua mot bit, mc ien ap cua day c gi nguyen, co

ngha trong suot qua trnh mot bit c tao, gia tr cua no gi khong oi.

Hnh 3.4: Phng phap ma hoa None-return-to-zero

Ky thuat Bit stuffing: Mot trong nhng u iem cua cach ma hoa NRZ la mc cua bitc gi trong suot qua trnh cua no. ieu nay tao ra van e ve o on nh neu mot

lng ln bit giong nhau noi tiep. Ky thuat Bit Stuffing ap at t ong mot bit co gia tr

ngc lai khi no phat hien 5 bit lien tiep trong khi truyen.

Hnh 3.5: Ky thuat Bit stuffing

Bit Timing : Ta nh ngha thi gian n v nho nhat, la Time Quantum. Thi gian c bannay la mot phan so cua thi gian dao ong cua bus. Mot bit khoang 8 en 25 quantum.

Hnh 3.6: S o lien quan gia thi gian bit va Time Quantum


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o dai cua mot ng truyen (bus)o dai cua mot ng truyen phu thuoc vao nhng thong so sau: - o tre lan truyen tren

ng day vat ly cua ng truyen

- S khac nhau cua thi gian Time Quantum (nh ngha tren), v s khac nhau cua xungclock tai cac node.

+ Bien o tn hieu thay oi theo ien tr cua cap va tong tr vao cua cac node

+ Can chu y rang bat c mo-un nao ket noi vao mot bus CAN phai c ho tr vi toc

o toi thieu la 20kbit/s. e s dung bus dai hn 1 km, phai can mot he thong ket noi

trung gian nhrepeaterhoac bridge.

Trang thai troi va lan- lp vat ly, Bus CAN nh ngha hai trang thai la troi ( dominant ) va lan

(reccessive), tng ng vi hai trang thai la 0 va 1. Trang thai troi chiem u the so vi

trang thai lan .Bus ch trang thai lan khi khong co node nao phat i trang thai troi.

ieu nay tao ra kha nang giai quyet chanh chap khi nhieu hn mot Node cung muon chiem

quyen s dung ng truyen.

Hnh 3.7: Hai trang thai troi va lan trong giao thc CAN


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- Toc o truyen d lieu tren CAN-bus ty le nghch vi chieu dai cua Bus (ng truyen)

Hnh 3.8: Moi lien quan gia toc o truyen va chieu dai cua ng truyen

- Bi tnh chat vat ly cua bus, can thiet phai phan biet 2 dang truyen:

+ Truyen CAN toc o thap ( low speed )

+ Truyen CAN toc o cao ( high speed )Bang 3.1: Thong so cua CAN toc o thap va CAN toc o cao

Hnh 3.9: S o ien ap cua CAN toc o thap


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Hnh 3.10: S o ien ap cua CAN toc o cao

- V tnh chat vi sai tren ng truyen tn hieu cua bus CAN, s mien tr tac ong ien

t c bao am v 2 day cua bus eu b tac ong nh nhau cung mot luc bi tn hieu

nhieu. La ly do cho viec s dung 2 ien tr 120 Ohm 2 au cua day dan ng truyen.

Hnh 3.11: S khang nhieu cua CAN-Bus vi anh hng cua ien t

Chuan CAN nh ngha bon loai khung truyen ( Frame):- Khung d lieu ( DATA FRAME ) : dung khi node muon truyen d lieu ti cac node

khac.

- Khung yeu cau ( REMOTE FRAME ) : dung e yeu cau truyen d lieu.

- Khung loi ( ERROR FRAME )

- Khung qua tai ( OVERLOAD FRAME ) : Khung loi va Khung qua tai c dung trong

viec phat hien va x ly loi.

: Co hai dang : Khung chuan (standard frame) va khung m rong


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( extended frame)

Hnh 3.12: Khung d lieu

- Hai loai khung nay ch khac nhau vung phan x (Arbitration Field ):

Hnh 3.13: S khac nhau gia 2 loai khung d lieu

ac iem chung cua 2 loai khung d lieu:+ Bat au bang 1 bit khi au khung truyen ( SOF : Start of frame ) luon trang thai troi

+ Tiep theo la phan vao vung phan x : 11-bit ID vi khung chuan , 29-bit ID vi khung

m rong .

+ 1 bit yeu cau truyen ( RTR: Remote Transmit Request ) e phan biet khung yeu cau va

khung d lieu: Neu la mc troi ngha la khung d lieu, neu la mc lan ngha lakhungyeu cau.

+ 1 bit can cc m rong ( IDE: Identifier Extension) e phan biet gia khung chuan ( khi

la mc troi ) va Khung m rong (khi la mc lan ) .

+ 1 bit r0 luon trang thai troi .


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+ Vung ieu khien : gom 3 bit ieu khien chieu dai ( Data Length Control ) cho biet so

lng byte d lieu cua khung truyen.

+ Tiep en la vung d lieu: Co t 0 en 8 bytes d lieu .

+ Vung kiem tra: 15 bit CRC va 1 bit CRC delimiter , 1 bit Acknoledge , 1 bit delimiter.

+ Cuoi cung la: 7 bits ket thuc chuoi ( End of frame ) luon trang thai lan va khoang

cach toi thieu gia hai khung truyen ( IFS: inter-frame space).

: Dung e yeu cau truyen khung d lieu ti mot node khac. Gan giongkhung d lieu nhng co DLC = 0 ( Data Length Control ) va khong co vung d lieu

Hnh 3.14: Khung yeu cau

: c phat ra khi node phat hien loi

Hnh 3.15: Khung loi

- c gi t bat k tram nao trong mang khi phat hien loi tren ng truyen

- Khung loi bao gom 2 phan: C loi ( Error flag) va phan cach loi ( Error demiliter )

- Loi phan biet thanh loi chu ong va loi b ong : Tng ng vi 2 dang c loi: dang c

loi chu ong gom 6 bit troi lien tiep , c loi b ong gom 6 bit lan lien tiep


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- 1 tram loi chu ong khi phat hien loi se bao hieu bang c loi chu ong. C loi chu

ong lam vi pham luat nhoi bit nen cac tram khac se phat hien loi va gi chong c loi.

: Dung khi b tran bo em

Hnh 3.16: Khung qua tai

1. Khung qua tai gom c qua tai ( overload flag ) va phan cach qua tai (overload delimiter )2. C qua tai bao gom 6 bit troi lien tuc ( tng t nh c loi chu ong )

- Phan cach qua tai la 8 bit lan lien tuc

( Nominal Bit Time )Moi node tren bus phai ieu chnh nhp cung vi Nominal Bit Time e co the phat va

nhan chnh xac d lieu tren bus.

Hnh 3.17: Thi gian bit

- Thi gian bit c tnh theo cong thc:

Thi gian bit = 1 / Toc o truyen Bus


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+ : gia s toc o truyen Bus la 1Mhz th: thi gian bit = 1/ 1Mhz = 1 us

Moi bit trong CAN gom 4 oan (segment) khong chong lap:+ oan ong bo hoa( Synchronization Segment) : Nhiem vu ong bo hoa cac node tren bus

+ oan lan truyen ( Propation Segment ): Nhiem vu bu thi gian truyen tn hieu

trong toan mang

+ oan pha 1 ( Phase 1 Segment )

+ oan pha 2 (Phase 2 Segment)

- Ca oan pha 1 va oan pha 2 eu co hiem vu la bu sai so pha canh , va chieu dai cua

2 oan nay thay oi dai ngan v hien tng ong bo lai ( resynchronisation)

Thi gian lng t ( Time Quantum ) va o dai cua 4 segment :- Thi gian lng t : la mot n v thi gian tao thanh t chu k dao ong noi cua moi

node. Thi gian lng t gom rat nhieu xung clock cua bo dao ong. Chu k xung clock

c goi la thi gian lng t nho nhat (Minimum Time Quantum). Neu gia tr bo chia (

prescale) la m th:

Thi gian lng t = m * Thi gian lng t nho nhat

( m co gia tr t 1 en 32 )

Hnh 3.18: Thi gian lng t

o So Thi gian lng t trong moi Thi gian bit thay oi t 8 en 25


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o S la chon so lng Thi gian lng t cho moi oan (segment ) phu thuoc vao tan socua bo dao ong. Mot so lng ln Thi gian lng t cho oan se tang tnh chnh xac

cua s ong bo cua cac node trong ng truyen.

Hnh 3.19: So lng Thi gian lng t cho moi oan

- CAN s dung phng phap truy cap ( Carrier Sense Multiple Access with

Collision Detection), ieu khien phan kenh theo tng bit , co cac ac iem chnh sau:

+ Moi node tren mang phai luon kiem tra tren ng truyen ,e phat hien thi gian ng

truyen ranh e co the truyen i 1 bc ien ( message )

+ Khi ng truyen ranh , tat ca cac node eu co c hoi nh nhau e truyen i mot bc ien

+ Moi bc ien c bat au bang 1 bit khi iem va ma can cc (so ID ), nen khi co 2

node cung truyen bc ien len ng truyen , viec phan x ung o tren ng truyen da

vao tng bit cua ma can cc . Moi bo thu phat phai so sanh mc tn hieu cua bit gi i so vi

bit nhan ve, neu co s khac biet th phai ngng phat.Bc ien nay c phat khi ng truyen

ranh tr lai

+ Thc te la bit 0 (mc troi ) lan at bit 1 (mc lan ) nen bc ien co the can cc cangnho th o u tien cang cao.


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Hnh 3.20: Phng thc giai quyet tranh chap tren ng truyen

Trong trng hp nay , khi so sanh tng bit cua ma can cc ( ID )cua 3 node phatcung luc ,th node 3 co o u tien cao hn ( do co gia tr ma can cc nho nhat) nen

c quyen phat bc ien len ng truyen ,con cac node con lai vao trang thai ch .

CAN co 2 chuan : Version 2.0 A va Version 2.0B

+ Chuan Version 2.0A : Ma can cc ( ID ) cua moi bc ien , la mot t gom 11 bit xac nh

mc u tien. Phan u tien nay nam au moi bc ien. Mc u tien c xac nh bi 7

bit , mc: 0000000 la co o u tien cao nhat.

+ Chuan Version 2.0B : Ma can cc cua moi bc ien , la mot t gom 29 bit xac nh mc

u tien.

Moi nut phai tao mot thi gian danh ngha Thi gian bit ( Bit Time ) e co the nhan va phat

d lieu xuong bus vi s ong bo cac node khac. Thc te, neu Thi gian bit cua moi nut

khong c ong bo vi nhau, gia tr oc t bus tai thi iem lay mau co the khong la gia tr

ung vi thi iem mong muon. o tre nay co the lam anh hng trong node nhan khungtruyen, khi ma co t thi gian tnh toan CRC va gi 1 bit troi trong ACK Slot e xac nhan

rang khung truyen a ung.


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Hnh 3.21: S ong bo xung clock trong CAN

( Synchronization Jump Width ) : SJW ieu chnh mot bit clock i t 1 en 4 Thigian lng t (c khi tao trc trong thanh ghi va khong oi trong qua trnh hoat

ong) e thc hien viec ong bo vi bc ien truyen.

( Phase Error ) : Loi pha c phat hien khi s thay oi 1 bit troi thanh lanhay 1 bit lan thanhtroi khong xay ra ben trong oan ong bo( Synchronization

Segment ) .

- ( Hard Synchronization ): ch xay ra khi chuyen canh bit au tien t lan

thanh troi ( logic 1 thanh 0) khi bus ranh, bao hieu khi au khung truyen ( SOF).

ong bo cng lam cho bo em Thi gian bit khi ong lai, gay nen mot chuyen canh

trong oan ong bo ( Sync_Seg) . Tai thi iem nay, moi node nhan se ong bo vi

node phat. ong bo cng ch xay ra mot lan trong suot mot bc ien. Va ong bo lai co

the khong xay ra trong cung mot bit ( SOF ) khi ma ong bo cng ang xay ra.

- ( Resynchronization ): c thc hien e bao toan s ong bo a thc hien

bi ong bo cng. Thieu ong bo lai, node nhan khong the co c s ong bo v s lech

pha cua cac bo dao ong tai moi node.


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Chng 4: ong c DC va cac phng phap ieu khien toc o GVHD: KS. Le Ngoc nh


- Co 4 loai ong c DC thong dung, bao gom : ong c DC kch t oc lap, kch t song

song, kch t noi tiep, kch t tong hp.

+ ong c DC kch t oc lap: dong phan ng va dong kch t co the ieu khien oc lap

vi nhau.

+ ong c DC kch t song song: phan ng va cuon kch t c au vi nguon cung cap.

V vay, vi loai ong c nay, dong phan ng hoac dong kch t ch co the ieu khien oc lap

bang cach thay oi ien tr phu trong mach phan ng hoac mach kch t. Tuy nhien, ay la

cach ieu khien co hieu suat thap.

+ ong c DC kch t noi tiep: dong phan ng cung la dong kch t, va do o, t thong

ong c la mot ham cua dong phan ng.+ ong c DC kch t hon hp: Bao gom ca kch t noi tiep va kch t song song . Yeu

cau can au noi sao cho sc t ong cua cuon noi tiep cung chieu vi sc t ong cua cuon

song song.


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Hnh 4.1: Cac loai ong c ien mot chieu (ong c DC)

- Mach tng ng che o tnh cua ong c mot chieu c trnh bay hnh 3.2, ientr Rbieu th ien tr phan ng. oi vi ong c mot chieu kch t oc lap hoac song

song, ien tr nay la ien tr phan ng. oi vi ong c kch t noi tiep hoac ong c

kch t hon hp, R la tong ien tr cua cuon phan ngva cuon kch t noi tiep.

Hnh 4.2: Mach tng ng che o tnh cua ong c DC

He Phng trnh c ban cua ong c mot chieu la:

E = KnF (4.1)

U = E+ RI (4.2)M = KFI (4.3)

Trong o:

R: ien tr phan ng (W)


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I: Dong phan ng (A)

U: ien ap phan ng (V)

w : Toc o ong c (rad/s)

F: T thong tren moi cc (Wb)

M : moment do ong c sinh ra (Nm)

K : hang so, phu thuoc cau truc ong c

T cong thc (4.1) - (4.3), ta co:

I

KR

KVF-F=w (4.4)

Hoac: ( ) MKR

KV

2

F-F=w (4.5)

- Lu y: Cac cong thc t (4.1) en (4.5) co the ap dung cho tat ca cac loai ong c motchieu a ke tren.

- Vi ong c mot chieu kch t oc lap, neu ien ap kch t c duy tr khong oi, co

the gia thiet rang t thong ong c khong oi khi moment ong c thay oi. Khi o ta co:

KF = constant (4.6)

- Nh vay theo (4.5), ac tnh c cua ong c mot chieu kch t oc lap la mot ng

thang, nh ve tren hnh 4.3. Toc o khong tai cua ong c xac nh bi ien ap cung cap U va

t thong kch t KF. Toc o ong c suy giam khi moment tai tangva o on nh toc o phu

thuoc vao ien tr phan ng R.Vi moment ln, t thong co the suy giam en mc o doc

ac tnh c tr nen dng dan en hoat ong khong on nh. V vay, cuon bu thng hay c

s dung e lam giam hieu ng kh t cua phan ng phan ng. Vi ong c cong suat trung

bnh, o sut toc khi tai nh mc so vi khi khong tai khoang 50%.

- Vi ong c mot chieu kch t noi tiep, t thong F la mot ham cua dong phan ng. Neu

gia thiet ong c hoat ong trong vung tuyen tnh cua ac tnh t hoa, co the xem la t thong

ty le bac nhat vi dong phan ng, ngha la :


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F = Kkt I (4.7)

Thay (4.7) vao (4.1), (4.4) va (4.5), ta c :

M = KKktI2 (4.8)

kt

kt KKR

IKKV-=w (4.9)

kt

kt KKR

M1

KKV-=w (4.10)

Lu y la R luc nay la tong cua ien tr mach phan ng va ien tr cuon kch t.

- ac tnh c ong c mot chieu kch t noi tiep c ve tren hnh 3.3. Co the thay rang toc

o ong c suy giam nhieu theo moment tai. Tuy nhien trong thc te, cac ong c tieu chuan

thng c thiet ke lam viec tai cac canh cho ( knee-point ) cua ac tnh t hoa khi mang tai

nh mc. Vi tai tren nh mc, mach t ong c bao hoa, khi o t thong F khong thay oi

nhieu theo dong tai Idan en ac tnh c tiem can vi ng thang.

- ong c mot chieu kch t noi tiepthch hp cho cac ng dung oi hoi moment khi ong

cao va co the qua tai nang. Vi moment tai tang, t thong ong c cung tang theo. Nh vay

vi cung mot lng gia tangcua moment nh nhau, dong phan ng I cua ong c mot chieu

(a)

(b)(c)

Hnh 4.3 ac tnh c cac loai ong c DC

M(%Mm)100

100

w(%wm)

- ong c DC kch t oc lap- ong c DC kch t noi tiep- ong c DC kch t hon hp


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kch t noi tiep se tang t hn so vi ong c kch t oc lap. Do o, trong ieu kien qua tai

nang, s qua tai cua nguon cung cap va s qua nhiet cua ong c cung t hn so vi ong c

kch t oc lap.

- Theo cong thc (4.10) , toc o ong c kch t noi tiep ty le nghch vi can bac hai cua

moment. V vay toc ong c khi khong tai co the tang len rat cao, ch b han che bi t d cua

ong c va co the gap hang chuc lan toc o nh mc. ieu nay la khong cho phep vi may

ienthng ch cho phep hoat ong gap 2 lan toc o nh mc. Do o, ong c kch t noi

tiep khong c dung vi cac ng dung trong o moment tai co the nho en mc lam toc o

ong c vt qua mc gii han cho phep.

- ac tnh cua ong c mot chieu kch t hon hpco dang nh bieu dien tren hnh 3.3. Toc

o khong tai cua ong c phu thuoc vao dong kch t qua cuon song song, trong khi o doc ac

tnh c phu thuoc vao s phoi hp gia cuon song song va cuon noi tiep. ong c kch t hon

hp c s dung trong nhng ng dung can co ac tnh c tng t ong c kch t noi tiep

ong thi can han che toc o khong tai mot gia tr gii han thch hp. Cung can lu y cac

ac tnh c e cap tren hnh 4.3la ac tnh c t nhien cua ong c, ngha la cac ac tnh nay

nhan c khi ong c hoat ong vi ien ap cung cap va t thong nh mc, va khong co

ien tr phu nao trong mach phan ng hoac kch t.

T cong thc (4.5) bieu dien quan he gia toc omoment ong c, co the thay rang toc

o ong c co the c ieu khien bang cac phng phap sau:+ ieu khien t thong

+ ieu khien ien ap phan ng

+ ieu khien hon hp ien ap phan ng va t thong

+ ieu khien ien tr phan ng


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- ieu khien t thong c s dung khi can tang toc o lam viec cua ong c cao hn toc

o nh mc. Co the thay ieu o qua cong thc (4.5): ( ) MKR

K

U 2F-F=w

- ac tnh tnh cua ong c kch t oc lap va kch t noi tiep khi ieu khien t thong c

bieu dien lan lt tren hnh 4.4 (a) va (b)bang cac ng net t. Lu y la o cng ac tnh c

giam nhanh khi giam t thong.

- Toc o cao cua ong c at c khi giam t thong b han che bi:

+ S khong on nh cua ong c gay ra bi anh hng cua phan ng phan ng+ Gii han ve mat c kh cua ong c: cac ong c thong thng cho phep toc o at en

1,5 - 2 lan toc o nh mc. Mot so ong c che tao ac biet cho phep toc o cao nhat at

ti 6 lan nh mc.

- oi vi ong c DC kch t oc lapva song song, cong suat cc ai cho phep cua ongc gan nh khong oi vi moi toc o khi ieu khien t thong (xem hnh 4.5). Co the

thay ieu nay neu gia thiet la dong cc ai cho phep, Icua ong c khong thay oi khi

ieu chnh t thong va ien ap cung cap cho phan ng, U la nh mc, khong oi. Khio , ta co: E= U - RI = const

P = EI= const ( v I = const )

Vay cong suat ong c khong thay oikhi ieu chnh toc o bang phng phap thay oi t

thong . Do o moment cc ai cho phep cua ong c se bien thien t le nghch vi toc o ,v

M = wP

Trong thc te, gia thiet dong phan ng cc ai cho phep I khong thay oi khi giam t

thong ch la gan ung. Tac ong cua phan ng phan ng cang ln khi t thong cang giam, do

o, dong phan ng cc ai cho phep can giam xuong e khong sinh ra tia la ien qua mc

tren co gop. ieu nay dan en viec gia tr thc te cua I se giam xuong khi toc o tang cao.


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- Vi ong c DC kch t oc lap, viec ieu khien kch t c thc hien bang cach thay

oi ien ap kch t vi bo chnh lu co ieu khien hoac bo chopper, tuy theo nguon cung cap

c s dung la AC hoac DC. Vi ong c cong suat nho, cung co the noi tiep bien tr vao

mach kch t e ieu khien t thong.

- Vi ong c DC kch t noi tiep, viec ieu khien t thong c thc hien bang cach thay

oi ien tr song song vi cuon kch t. Mot so ong c kch t noi tiep co cuon kch t nhieu

au ra, va do o co the thay oi t thong bang cach thay oi so vong day cuon kch t

- Vi ong c mot chieu kch t oc lap, neu ien ap kch t c duy tr khong oi, hoac

ong c kch t dung nam cham vnh cu co the gia thiet rang t thong ong c khong oikhi momen ong c thay oi.

Khi o: KF = const

- Vay e thay oi toc o ong c ta thay oi ien ap phan ng. Bang cach thay oi ienap phan ng, ong c co the lam viec tai bat k toc o, moment nao.

- Tnh chat quan trong cua phng phap nay la o cng ac tnh c khong thay oi khitoc o ong c c ieu chnh. ieu nay khien he co kha nang ap ng vi tai co

moment hang so v dong phan ng cc ai cho phep Imax- tng ng vi no la moment

tai cc ai cho phep cua ong c khong oi vi moi toc o.

- ien ap phan ng ong c co the c ieu khien bang cach s dung:+ May phat DC (He May phat- ong c)+ Bo chnh lu co ieu khien ( bien oi AC DC )

+ Bo Chopper (Bo bien oi xung ap) : DC DC .


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Hnh 4.4: ieu khien bang thay oi ien ap phan ng , t thong.

- Phng phap nay c s dung khi can thiet ieu chnh toc o ong c trong mot dai rong

tren va di toc o nh mc. Toc o di toc o nh mc c ieu khien bang cach thay

oi ien ap phan ng trong khi gi kch t gia tr nh mc. Toc o tren nh mc c ieu

khien bang cach thay oi ien ap kch t.

Hnh 4.5: Moment va cong suat ra khi ieu khien hon hp: ien ap phan ng va t thong


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- Hnh 4.6 bieu dien ac tnh c cua ong c DC kch t oc lap va noi tiep khi ieu khien

toc o bang cach them ien tr phu vao phan ng.

- Khuyet iem chnh cua phng phap nay la co hieu suat cua he thong rat kem va o cng

ac tnh c thap, nhat la khi hoat ong toc o thap. Do o, phng phap nay hien nay t c

s dung e ieu khien toc o ong c, tr cac trng hp:

+ Khi ong ong c

+ Thay oi toc o ong c trong mot thi gian ngan trong che o ngan han hoac che o

ngan han lap lai.

Hnh 4.6 :ac tnh ong c DC khi them ien tr phu vao phan ng

Phng phap ieu rong xung ( PWM: Pulse Width Modulation) la phng phap thay oi

ien ap phan ng cua ong c DC bang cach thay oi thi gian ong ngat cong tac nguon.

ay la phng phap s dung rat pho bien v nhng u iem cua no nh :

+ Mach thiet ke kha n gian

+ Toc o ong c thay oi em va nh mong muon

+ Ton hao cong suat nho

Xet mach ien nh hnh ve :


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Hnh 4.7 Mach nguyen ly ieu rong xung

Bang cach thay oi thi gian ong ngat cong tac S, ta co the thu c ien ap trung bnh

at tren ong c thay oi theo y muon, khoang thay oi t 0 V en U. Dang ap ra nh sau :

Hnh 4.8: Dang ap ra sau khi ieu che

Tr trung bnh ien ap tren tai tnh theo cong thc :

gUT

tUU ont == (4.11)

Vi T = ton + toff la chu ky khong oi cua xung kch S.

T cong thc (4.11) ta thay 0Ut U , va Ut phu thuoc t sog, vay co the ieu chnh

ien ap tren tai theo y muon bang cach thay oi t sog.

o Trong ieu khien ong c DC bang phng phap PWM vi tan so cua xung ieu khiencao ,ngi ta co the s dung cac vi ieu khien e tao xung (tan so t 5 Khz en 20 Khz)

e ieu khien cac khoi mach ong lc ( trong cac khoi mach ong lc ,thng dung

IGBT hay MosFet lam khoa ong ngat ).


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- Trong thc te co nhieu loai encoder khac nhau nh: Encoder tiep xuc , Encoder t trng,

Encoder quang ( gom : Encoder quang tng oi, Encoder quang tuyet oi ) . Moi loai lai co

mot nguyen ly hoat ong khac nhau, trong luan van nay , toi ch s dung loai Encoder quang

tng oi( incremental encoder ) nen ch trnh bay ky ve loai encoder nay

- Loai incremental encoder dung trong Luan van c gan ong truc vi ong c DC 24V-

20W , va co o phan giai la 100 xung/vong.

- Mo hnh th 1- Incremental encoder ve c ban la mot a tron quay quanh mot truc c uc lo nh hnhtren. Tren vanh a se khac cac khe h eu nhau . V du: Encoder co 100 , 200 , 500 hay

1000 vach khe h tren vanh a

Hnh 4.13 : Encoder quang loai tng oi-mo hnh 1

- 2 ben mat cua cai vanh a, se co mot bo thu phat quang. Trong qua trnh encoderquay quanh truc, neu gap lo rong th anh sang chieu qua c, neu gap manh chan th

tia sang khong chieu qua c. Do o tn hieu nhan c t encoder quang la mot

chuoi xung. Moi encoder c che tao vi so khe h tren vanh a , se cho biet san so

xung khi quay het mot vong. Do o ta co the dung vi ieu khien em so xung o trong

mot n v thi gian va tnh ra toc o ong c.( co encoder c gan ong truc ) , khi


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o encoder nao co so khe h ( lo ) tren vanh a cang nhieu se cho o chnh xac cang

ln.

Hnh 4.14: Cach thc hoat ong cua encoder quang loai tng oi

- Encoder ma toi s dung trong Luan van,hoan toan giong vi mo hnh tren. Tuy nhien, mo

hnh tren co nhc iem ln la : ta khong the xac nh c ong c ang quay trai hay quay

phai, v co quay theo chieu nao i na th ch co mot dang xung a ra. Ngoai ra thi iem bat

au hoat ong cua ong c, ta cung khong the nao biet c.

- Mo hnh th 2 ( Cai tien t mo hnh 1 , nham khac phuc cac nhc iem )

Hnh 4.15: Mo hnh 2 cua encoder quang loai tng oi


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- Trong mo hnh nay, ngi ta uc tat ca la 2 vong lo . Vong ngoai cung giong nh mo hnh1 ( thng c goi la vong A ) , vong gia pha so vi vong ngoai la 90 o (goi la vong B).

Khi o, dang xung ra t 2 vong tren nh sau :

Hnh 4.16: S o xung ra cua encoder quang tng oi mo hnh 2

- Hai xung a ra t 2 vong lech nhau 90 o, neu vong ngoai ( chuoi xung A ) nhanh pha hnvong trong ( chuoi xung B ) th chac chan ong c quay t trai sang phai va ngc lai.

- Mot lo vong trong cung dung e phat hien iem bat au cua ong c. Co the viet chngtrnh cho vi ieu khien nhan biet : neu co mot xung phat ra t vong trong cung nay, tc la

ong c a quay ung mot vong. Tn hieu cua chuoi xung do 1 lo nay tao ra thng goi la

xung Z.

- Vi nhng ac tnh tren, encoder loai nay ( mo hnh 2) c dung rat pho bien trong viecxac nh v tr goc cua ong c..

- Tuy nhien: Van e quan trong trong viec tm mua nhng loai ong c co gan encoder nhthe nay e lam o an hay Luan Van oi vi sinh vien la kha kho , va cap mat quang 2

ben encoder e tao xung thng b h va khong co o thay the.


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Chng 5: Ho vi ieu khien HCS12 va MC9S12DP512 GVHD: KS. Le Ngoc nh


Ho vi ieu khien 68HC12 c hang Motorola cho ra i vao nam 1996 da tren ho vi

ieu khien 68HC11. Nam 2001 , hang Motorola tiep tuc phat trien ho vi ieu khien 68HC12

len thanh ho vi ieu khien mi ,o la HCS12 vi : toc o x ly nhanh hn , dung lng bo

nh c m rong va tch hp them nhieu chc nang chuyen dung . Nam 2004 , bo phan

thiet ke-san xuat linh kien ban dan cua hang Motorola tach ra thanh mot cong ty oc lap ,lay ten la FreeScale Semiconductor va tr thanh nha san xuat cho tat ca cac ho vi ieu

khien cua Motorola.

Hnh 5.1: S o phat trien cua vi ieu khien hang Motorola-FreeScale

Ho vi ieu khien HCS12 co cac ac iem chnh nh sau :

La ho vi ieu khien 16-bit co toc o x ly nhanh, tan so xung nhp bus noi co the len en32 Mhz ; va co tch hp Vong-khoa-pha , thng hay goi la bo PLL ( Phase-Lock-Loop)

Che tao theo cong nhe HCMOS nen co o on nh va o ben cao .


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c nang cap t ho vi ieu khien 68HC11/68HC12 va khong co s thay oi nao ve tochc cac thanh ghi x ly so vi 68HC11/68HC12 nen cac oan chng trnh viet bang hp

ng s dung cho 68HC11/68HC12 eu co the s dung lai c vi HCS12 .

Cac loai bo nh ben trong gom co: RAM , EEPROM , Flash . Dung lng bo nh ln,acbiet la bo nh Flash va co kha nang m rong bo nh ngoai.

Tch hp nhieu chc nang thi gian nh: Bat gi ngo vao , so sanh ngo ra, bo em xung vas kien cong, bo ieu rong xung PWM, ngat thi gian thc, Watchdog

Co cac mo-un truyen thong noi tiep nh : Giao tiep bat ong bo (SCI ), giao tiep ong bo( SPI ) , IIC.

Tch hp che o Debug chay nen ,ch can s dung 1 day tn hieu duy nhat (goi tat la BDM) Co cac che o hoat ong e tiet kiem nang lng Co 1 en 2 bo chuyen oi tn hieu tng t sang tn hieu so,o phan giai 10-bit, co 8 en

16 kenh ( channel )

Ho tr tap lenh logic M khi viet chng trnh bang hp ng. Nhieu Port xuat nhap a dung : Port A, Port B , Port K, Port J, Port H, Port M, Port S Ngoai ra, tuy theo ng dung ,moi dong chuyen dung trong ho HCS12 se tch hp them cac

mo-un chc nang chuyen dung nh: USB, CAN , BDLC , Ethernet , ieu khien LCD ,

ieu khien Motor:

+ Dong HCS12A : Danh cho nhng ng dung thong thng

+ Dong HCS12B hay C : Co tch hp them 1 bo giao tiep CAN , nhng lai khong co giao tiep

IIC , gia thap

+ Dong HCS12D : Tch hp ay u cac chc nang thong dung ,va co them giao tiep CAN ,

BDLC . Co nhieu chan Xuat/Nhap va chc nang ve thi gian ve thi gian nhat.+ Dong HCS12NE : Tch hp bo bien oi tn hieu so sang tn hieu tng t ben trong ( DAC)

va co them giao tiep Ethernet

+ Dong HCS12H : Tch hp mo-un ieu khien LCD , ieu khien cau H theo phng phap

PWM vi dong cao, phu hp cho ieu khien ong c. Co giao tiep CAN


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+ Dong HCS12L : Tch hp mo-un ieu khien LCD c ln (LCD 4x60) , giao tiep USB , tch

hp them khoi chc nang DMA

+ Dong HCS12UF: Giao tiep USB , co mo-un giao tiep vi cac loai the nh ngoai .Tch hp

chuan giao tiep ATA ,phu hp cho cac ng dung ve giai tr.

: Cac thanh ghi x ly cua HCS12 hoan toan giong vi cac thanh ghi x ly

cua ho vi ieu khien 68HC11/68HC12.

Hnh 5.2: Cac thanh ghi x ly cua ho vi ieu khien HCS12

Thanh ghi tch luy A: La thanh ghi tch luy 8 bit ,tat ca cac phep toan cua ALU eu co thethc hien tren d lieu trong thanh ghi nay. Mot so thao tac ac biet ch co the thc hien tren

thanh ghi nay, no c s dung vi ten la A hay AccA

Thanh ghi tch luy B: La thanh ghi tch luy 8 bit ,chc nang giong thanh ghi A. Nhng comot so thao tac ac biet ch co the thc hien tren thanh ghi A, ma khong the thc hien tren

thanh ghi B. No c s dung vi ten la B hay AccB.


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Thanh ghi tch luy D (A:B): Thanh ghi tch luy 16 bit ,la s ket hp cua thanh ghi A va B ,khong phai la thanh ghi rieng biet . c s dung vi ten D hay AccD.

Thanh ghi con tro X: La thanh ghi a ch 16-bit , s dung trong che o nh a ch so. Nocung co the s dung nh thanh ghi d lieu 16-bit, c s dung vi ten la X hay IX.

Thanh ghi con tro Y: Chc nang giong nh thanh ghi X , c s dungvi ten la Y hay IY. Thanh ghi ngan xep con tro SP (Stack Pointer) : La thanh ghi 16-bit, cha a ch cua onh kha dung tiep theo trong ngan xep .c s dung vi ten la SP.

Thanh ghi Bo em chng trnh PC (Program Counter): La thanh ghi 16-bit, cha a chcua lenh ke tiep. c s dung vi ten la PC.

Thanh ghi ieu kien CCR (Condition Code Register) : La thanh ghi 8-bit trang thai vaieu khien. c s dung vi ten la CCR.

Co 8 che o hoat ong chnh

c ieu khien bi trang thai cua 3 chan: MODA , MODB va MODC (BKGD)

Hnh 5.3: Cac che o hoat ong cua ho vi ieu khien HCS12


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Che o debug chay nen- BDM :+ La che o ac biet , cho phep phan cng ben ngoai ( thng goi la BDM- Pod ) truy cap

vao ben trong chip HCS12 thong qua chan BKGD . T o ngi dung co the nap chng trnh

vao vi ieu khien hay debug chng trnh ngay ca khi vi ieu khien ang hoat ong.

+ Trong ca 8 che o hoat ong chnh c neu tren ,th che o debug chay nen nay eu co

the s dung c.

( a) : Ket noi gia vi ieu khien vi PC qua mach BDM-Pod

+ Chuan jack cam cap cho che o debug-chay nen:

(b) Cap noi chuan (c) Cap noi chuan m rong

Hnh 5.4: Che o debug chay nen ( BDM: Background Debug Mode)

Ngoai ra, ho vi ieu khien HCS12 co 3 che o hoat ong tiet kiem nang lng:+ Che o NGH ( Stop mode)

+ Che o GIA-NGH ( Pseudo Stop mode )

+ Che o CH ( Wait mode)


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Trong luan van nay ,toi s dung vi ieu khien co ten la MC9S12DP512 , thuoc dong D cua ho

HCS12 la dong c phat trien cho cac ng dung trong lnh vc thuoc cong nghe oto va

trong cong nghiep.

Co ay u cac chc nang c ban chung cua ho vi ieu khien 16-bit HCS12 ( a c trnhbay chng 2 phan I : Gii thieu chung ho vi ieu khien HCS12)

c ong goi theo kieu chan LQFP co 112 chan , tam nhiet o la: -40 -:-150 o C Tan so xung nhp bus noi toi a la 32 Mhz , co tch hp bo PLL Bo nh: 14 KB bo nh RAM ; 4 KB bo nh EEPROM ; 512 KB bo nh FLASH 2 bo giao tiep noi tiep bat ong bo ( SCI), 3 bo giao tiep noi tiep ong bo ( SPI ),1 bo

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