ba o ca o tie u lua n

B GIAO THNG VN TIHC VIN HNG KHNG VIT NAMKHOA IN T VIN THNG HNG KHNG

TIU LUN TT NGHIP

TIU LUN : Thit k robot t ng d ng

Gio vin hng dn: Ths. Nguyn Trng HiSinh vin thc hin: Trn Thanh TnM s sinh vin: 1051020017Lp: DV2-K4

Thnh ph H Ch Minh-2014B GIAO THNG VN TIHC VIN HNG KHNG VIT NAMKHOA IN T VIN THNG HNG KHNG

TIU LUN : Thit k robot t ng d ng

Gio vin hng dn:Sinh vin thc hin:Th.s NGUYN TRNG HI TRN THANH TNM s SV: 1051020081Lp: DV2-K4

Thnh ph H Ch Minh- 2014

2

LI CM NEm xin gi li cm n chn thnh nht n Qu Thy C gio Hc Vin Hng Khng Vit Nam, Qu Thy C gio khoa in t Vin Thng Hng Khng dy d truyn t nhng kin thc qu bu cho em em p dng vo bi tiu lun tt nghip ny, c bit em xin cm n thy Nguyn Trng Hi tn tnh hng dn em thc hin trong sut thi gian hon thnh bi tiu lun tt nghip.Bi tiu lun tt nghip ny s khng trnh khi nhng thiu st vi vn kin thc hn hp v thi gian lm tiu lun tt nghip c hn nn em rt mong nhn c nhng kin ng gp ca Qu Thy C. s l hnh trang qu gi gip em hon thin kin thc ca mnh sau ny. Sinh vin thc hin TRN THANH TN

LI CAM OANTi cam oan rng bi tiu lun tt nghip ny l do chnh ti thc hin, da vo s hng dn ca thy Nguyn Trng Hi, c ti liu thu thp cc d liu cn thit v kt qu phn tch trong bi l trung thc, khng sao chp t bt c ti nghin cu khoa hc no.

Ngy 02 thng 06 nm 2014 Sinh vin thc hin TRN THANH TN

NHN XT CA GIO VIN HNG DN

Tp H Ch Minh, ngy.thng.nm 2014Gio vin hng dn(K v ghi r h tn)NHN XT CA GIO VIN PHN BIN

Tp H Ch Minh, ngy.thng.nm 2014Gio vin phn bin(K v ghi r h tn)

MC LCCHNG 1 : GII THIU TIU LUN91.Khi qut chung v robot v l do chn ti :92.Gii thiu tiu lun :93.Mc tiu ca tiu lun :9CHNG 2 : TNG V PHNG N CH TO ROBOT10CHNG 3 : GII THIU VI IU KHIN PIC 16F877A123.1S CHN VI IU KHIN PIC16F877A123.1Cc cng xut nhp ca PIC16F877A22CHNG 4 : CC THNH PHN CU TO ROBOT264.1. PWM_ IU CH RNG XUNG264.2. CM BIN TRONG ROBOT304.2.1Cm bin d ng :304.2.2B tr cm bin d ng324.3Mch cu H L298D:33CHNG 5 : S MCH V NGUYN L HOT NG CA ROBOT365.1 S nguyn l ca robot d ng v layout ca robot365.2S v nguyn l hot ng ca mch cm bin395.3S v nguyn l hot ng ca mch iu khin ng c.405.4Lu thut ton :41SN PHM T C42KT LUN43

LI M UCng vi s pht trin ca x hi loi ngi, cc ngnh khoa hc - k thut khng ngng i n nhng thnh cng mi. Nhiu cng trnh khoa hc, nhng pht minh ca cc nh khoa hc i vo cuc sng, phc v li ch ca con ngi. Vi s pht trin mnh m ca cc ngnh cng nghip, my mc dn thay th cho sc lao ng ca con ngi. c bit nhng thp nin gn y vi s xut hin v pht trin nhanh chng ca cng ngh robot, nhng dy chuyn t ng ch yu thc hin bng h thng cnh tay robot linh hot. Robot c ng dng rng ri trong cc ngnh cng nghip, thay th cho cc hot ng ca con ngi trong cc mi trng c hi, nguy him nh thm him. Robot khng nhng c s dng nhm mc ch tng nng sut lao ng m dn i vo i sng sinh hot ca chng ta. Ban u t con robot lau sn, nhng ch ch trng nh, mc ch ca chng ta l to ra nhng con robot ngy cng tr nn thn thin hn na vi con ngi. Sau mt thi gian tp trung nghin cu, tm ti, hc hi, c bit di s ch bo, hng dn nhit tnh ca thy: Nguyn Trng Hi gip , to iu kin cho em hon thnh n mn hc ny.Em xin chn thnh cm n thy gio: Nguyn Trng Hi gip em hon thnh tiu lun tt nghip ny!

33

CHNG 1 : GII THIU TIU LUN1. Khi qut chung v robot v l do chn ti :Ngy nay vi s pht trin mnh m ca khoa hc v cng ngh th robot tr thnh trong mt trong nhng ng quan trng trong cuc sng . Robot dn thay th con ngi lm nhng cng vic n gin n nhng cng vic cn chnh xc cao . Tm quang trng ca robot i vi cuc sng ca loi ngi v kh nng chinh phc thin nhin dn ti s pht trin vt bc ca ngnh cng ngh ny.Chnh bi nhng ng dng rng ri v s pht trin ng thi tip cn vi nhng kin thc ban u v robot nn em chn ti l : Thit k v ch to robot d ng t ng s dng led cm bin thu pht hng ngoi .2. Gii thiu tiu lun : ti t ra l robot d ng t ng dng cm bin thu pht hng ngoi. Kt qu t c ca em l mt robot t ng c kh nng di chuyn theo mt ng nh sn da trn vi iu khin PIC 16f877A, v c tnh ca vi iu khin ny em s trnh by phn sau. ti thit k ch yu gip cho sinh vin lm quen vi vic s dng vi iu khin , k nng lp trnh, phng php thu thp d liu t cc cm bin sensor, iu khin ng c, hin th trng thi hot ng ca h thng v cc mch ph tr khc . 3. Mc tiu ca tiu lun :Thit k v ch to hon thin robot d ng : Thit k ch to phn c kh. Thit k ch to mch iu khin robot. Lp trnh iu khin robot

CHNG 2 : TNG V PHNG N CH TO ROBOT2.1 Phng n v mng c kh : ph hp vi yu cu ca tiu lun m hnh ca e nh sau : M hnh robot xe 3 bnh chuyn ng v b li bng 2 bnh sau , d ng bng cm bin quang .1.2 2.2 Phng n lp trnh iu khin robot :Vi iu khin PIC Vi iu khin PIC ca microchip l mt s la chn rt tt cho cc i robocon do nhng tnh nng vt tri ca n so vi cc loi vi iu khin khc nh b nh flash ln v c nhiu modul nh : PWM, ADC,Timer, ngt.. c bit vi s h tr ca trnh dch nh CCS C v bng vic vit bng ngn ng C ngi lp trnh s rt mm ro trong vic khai trin thut ton . Hin nay trn th trng c kh nhiu dng vi iu khin PIC.VD: pic16f877, pic16f84, pic16f828, PIC18F4x31..v.v.vnh gi cc dng PIC - Dng PIC nhiu chn nht l dng PIC18Fxxxx, c nhng s chn ln n 80 chn.1. Dng PIC t chn nht l dng PIC10Fxxx, ch c 6 chn1. Dng PIC ph bin nht l dng PIC16F877A ( mnh v tnh nng,40 chn, b nh cho hu ht cc ng dng thng thng).1. Dng PIC h tr giao tip USB l dng PIC18F2550 v PIC18F45501. Dng PIC iu khin ng c mnh nht l dng PIC18F4x31

Kt Lun:Qua phn tch cc loi dng vi iu khin, chng em la chn vi iu khin loi PIC16F877A chuyn dng iu khin ng c vi cc u im ni bt so vi cc loi vi iu khin khc .CHNG 3 : GII THIU VI IU KHIN PIC 16F877A3.1 S CHN VI IU KHIN PIC16F877A

Hnh 3.1: S chn v hnh dng ca Pc 16F877A

1. Chc nng cc chn :ChnTnChc nng

1/VPP- : Hot ng Reset mc thp- VPP : ng vo p lp trnh

2RA0/AN0- RA0 : xut/nhp s- AN0 : ng vo tng t

3RA1/AN1- RA1 : xut/nhp s- AN1 : ng vo tng t

4RA2/AN2/VREF-/CVREF- RA2 : xut/nhp s- AN2 : ng vo tng t - VREF -: ng vo in p chun (thp) ca b A/D

5RA3/AN3/VREF+- RA3 : xut/nhp s- AN3 : ng vo tng t - VREF+ : ng vo in p chun (cao) ca b A/D

6RA4/TOCKI/C1OUT- RA4 : xut/nhp s - TOCKI : ng vo xung clock bn ngoi cho timer0- C1 OUT : Ng ra b so snh 1

7RA5/AN4/ /C2OUT- RA5 : xut/nhp s- AN4 : ng vo tng t 4- SS : ng vo chn la SPI ph- C2 OUT : ng ra b so snh 2

8RE0//AN5- RE0 : xut nhp s- RD : iu khin vic c port nhnh song song- AN5 : ng vo tng t

9RE1/ /AN6- RE1 : xut/nhp s- WR : iu khin vic ghi port nhnh song song- AN6 : ng vo tng t

10RE2/ /AN7- RE2 : xut/nhp s- CS : Chip la chn s iu khin port nhnh song song- AN7 : ng vo tng t

11VDDChn ngun ca PIC.

12VSSChn ni t

13OSC1/CLKINg vo dao ng thch anh hoc xung clock bn ngoi.- OSC1 : ng vo dao ng thch anh hoc xung clock bn ngoi. Ng vo Schmit trigger khi c cu to ch RC ; mt cch khc ca CMOS.- CLKI : ng vo ngun xung bn ngoi. Lun c kt hp vi chc nng OSC1.

14OSC2/CLKONg vo dao ng thch anh hoc xung clock- OSC2 : Ng ra dao ng thch anh. Kt ni n thch anh hoc b cng hng.- CLKO : ch RC, ng ra ca OSC2, bng tn s ca OSC1 v ch ra tc ca chu k lnh.

15RC0/T1 OCO/T1CKI- RC0 : xut/nhp s- T1OCO : ng vo b dao ng Timer 1- T1CKI : ng vo xung clock bn ngoi Timer 1

16RC1/T1OSI/CCP2- RC1 : xut/nhp s- T1OSI : ng vo b dao ng Timer 1- CCP2 : ng vo Capture 2, ng ra compare 2, ng ra PWM2

17RC2/CCP1- RC2 : xut/nhp s- CCP1 : ng vo Capture 1, ng ra compare 1, ng ra PWM1

18RC3/SCK/SCL- RC3 : xut/nhp s- SCK : ng vo xung clock ni tip ng b/ng ra ca ch SPI- SCL : ng vo xung clock ni tip ng b/ ng ra ca ch I2C

19RD0/PSP0- RD0 : xut/nhp s- PSP0 : d liu port nhnh song song



22RD3/PSP3- RD3: xut/nhp s- PSP3 : d liu port nhnh song song

23RC4/SDI/SDA- RC4 : xut/nhp s - SDI : d liu vo SPI- SDA : xut/nhp d liu vo I2C

24RC5/SDO- RC5 : xut/nhp s- SDO : d liu ra SPI

25RC6/TX/CK- RC6 : xut/nhp s- TX : truyn bt ng b USART - CK : xung ng b USART

26RC7/RX/DT- RC7 : xut/nhp s- RX : nhn bt ng USART- DT : d liu ng b USART

27RD4/PSP- RD4: xut/nhp s- PSP4 : d liu port nhnh song song




31VSSChn ni t

32VDDChn ngun ca PIC.

33RB0/INT- RB0 : xut/nhp s- INT : ngt ngoi

34RB1xut/nhp s

35RB2xut/nhp s

36RB3- RB3 : xut/nhp s- Chn cho php lp trnh in p thp ICPS

37RB4- xut/nhp s- Ngt PortB

38RB5- xut/nhp s- Ngt PortB

39RB6/PGC- RB6 : xut/nhp s- PGC : mch vi sai v xung clock lp trnh ICSP- Ngt PortB

40RB7/PGD- RB7 : xut/nhp s- PGD : mch vi sai v d liu lp trnh ICSP- Ngt PortB

3.2 MT VI THNG S V VI IU KHIN PIC16F877Ay l vi iu khin thuc h PIC16Fxxx vi tp lnh gm 35 lnh c di 14 bit.Mi lnh u c thc thi trong mt chu k xung clock. Tc hot ng ti a cho php l 20 MHz vi mt chu k lnh l 200ns. B nh chng trnh 8Kx14 bit, b nh d liu 368x8 byte RAM v b nh d liu EEPROM vi dung lng 256x8 byte. S PORT I/O l 5 vi 33pin I/O.Cc c tnh ngoi vi bao gmcc khi chc nng sau:Timer0: b m 8 bit vi b chia tn s 8 bit.Timer1: b m 16 bit vi b chia tn s, c th thc hin chc nng m da vo xung clock ngoi vi ngay khi vi iu khin hot ng ch sleep.Timer2: b m 8 bit vi b chia tn s, b postcaler.Hai b Capture/so snh/iu ch rng xung. Cc chun giao tip ni tip SSP (Synchronous Serial Port), SPI v I2C.Chun giao tip ni tip USART vi 9 bit a ch.Cng giao tip song song PSP (Parallel Slave Port) vi cc chn iu khin RD, WR,CS bn ngoi.Cc c tnh Analog:8 knh chuyn i ADC 10 bit.Hai b so snh.Bn cnh l mt vi c tnh khc ca vi iu khin nh:B nh flash vi kh nng ghi xa c 100.000 ln.B nh EEPROM vi kh nng ghi xa c 1.000.000 ln.D liu b nh EEPROM c th lu tr trn 40 nm.Kh nng t np chng trnh vi s iu khin ca phn mm.Np c chng trnh ngay trn mch in ICSP (In Circuit Serial Programming) thng qua 2 chn.Watchdog Timer vi b dao ng trong. Chc nng bo mt m chng trnh.Ch Sleep :C th hot ng vi nhiu dng Oscillator khc nhau.

3.3 S KHI VI IU KHIN PIC16F877A

Hnh 3.3: Cu trc bn trong ca Pic 16F877A

Nh ni trn , vi iu khin PIC c kin trc Harvard, trong CPU truy cp chng trnh v d liu c trn hai bus ring bit, nn lm tng ng k bng thng so vi kin trc Von Neumann trong CPU truy cp chng trnh v d liu trn cng mt bus.Vic tch ring b nh chng trnh v b nh d liu cho php s bit ca t lnh c th khc vi s bit ca d liu. PIC 16F877A, t lnh di 14 bit , t d liu 8 bit.PIC 16F877A cha mt b ALU 8 bit v thanh ghi lm vic WR (working register). ALU l n v tnh ton s hc v logic, n thc hin cc php tnh s v i s Boole trn thanh ghi lm vic WR v cc thanh ghi d liu. ALU c th thc hin cc php cng, tr, dch bit v cc php ton logic.Cn ch l khng c c hiu no cho bit trng thi stack, do ta khng bit c khi no stack trn. Bn cnh tp lnh ca vi iu khin dng PIC cng khng c lnh POP hay PUSH, cc thao tc vi b nh stack s hon ton c iu khin bi CPU

3.1 Cc cng xut nhp ca PIC16F877A

Hnh 3.4a S chn PIC16F877ACng xut nhp (I/O port) chnh l phng tin m vi iu khin dng tng tc vi th gii bn ngoi. S tng tc ny rt a dng v thng qua qu trnh tng tc , chc nng ca vi iu khin cth hin mt cch r rng. Mt cng xut nhp ca vi iu khin bao gm nhiu chn (I/O pin), ty theocch b tr v chc nng ca vi iu khin m s lng cng xut nhp v s lng chn trong micng c th khc nhau. Bn cnh , do vi iu khin c tch hp sn bn trong cc c tnh giao tip ngoi vi nn bn cnh chc nng l cng xut nhp thng thng, mt s chnxut nhp cn c thm cc chc nng khc th hin s tc ng ca cc c tnh ngoi vinu trn i vi th gii bn ngoi. Chc nng ca tng chn xut nhp trong mi cng honton c th c xc lp v iu khin c thng qua cc thanh ghi SFR lin quan n chn xut nhp . Vi iu khin PIC16F877A c 5 cng xut nhp, bao gm PORTA, PORTB, PORTC, PORTD v PORTE. Cu trc v chc nng catng cng xut nhp s c cp c th trong phn sau.

1. PORTA PORTA (RPA) bao gm 6 I/O pin. y l cc chn hai chiu (bidirectional pin), ngha l c th xut v nhp c. Chc nng I/O ny c iu khin bi thanh ghi TRISA (a ch 85h). Mun xc lp chc nng ca mt chn trong PORTA l input, ta set bit iu khin tng ng vi chn trong thanh ghi TRISA v ngc li, mun xc lp chc nng ca mt chn trong PORTA l output, ta clear bit iu khin tng ng vi chn trong thanh ghi TRISA. Thao tc ny hon ton tng t i vi cc PORT v cc thanh ghi iu khin tng ng TRIS (i vi PORTA l TRISA, i vi PORTB l TRISB, i vi PORTC l TRISC, i vi PORTD l TRISD vi vi PORTE l TRISE). Bn cnh PORTA cn l ng ra ca b ADC, b so snh, ng vo analog ng vo xung clock ca Timer0 v ng vo ca b giao tip MSSP (Master Synchronous Serial Port). Cc thanh ghi SFR lin quan n PORTA bao gm: 1. PORTA (a ch 05h) : cha gi tr cc pin trong PORTA. 1. TRISA (a ch 85h) : iu khin xut nhp.1. CMCON (a ch 9Ch) : thanh ghi iu khin b so snh.1. CVRCON (a ch 9Dh) : thanh ghi iu khin b so snh in p. 1. ADCON1 (a ch 9Fh) : thanh ghi iu khin b ADC.

1. PORTB PORTB (RPB) gm 8 pin I/O. Thanh ghi iu khin xut nhp tng ng l TRISB. Bn cnh mt s chn ca PORTB cn c s dng trong qu trnh np chng trnh cho vi iu khin vi cc ch np khc nhau. PORTB cn lin quan n ngt ngoi vi v b Timer0. PORTB cn c tch hp chc nng in tr ko ln c iu khin bi chng trnh. Cc thanh ghi SFR lin quan n PORTB bao gm: 1. PORTB (a ch 06h,106h): cha gi tr cc pin trong PORTB.1. TRISB (a ch 86h,186h): iu khin xut nhp.1. OPTION_REG (a ch 81h,181h) : iu khin ngt ngoi vi v b Timer0.

1. PORTC PORTC (RPC) gm 8 pin I/O. Thanh ghi iu khin xut nhp tng ng l TRISC. Bn cnh PORTC cn cha cc chn chc nng ca b so snh, b Timer1, b PWM v cc chun giao tip ni tip I2C, SPI, SSP, USART. Cc thanh ghi iu khin lin quan n PORTC: 1. PORTC (a ch 07h) : cha gi tr cc pin trong PORTC.1. TRISC (a ch 87h): iu khin xut nhp.

1. PORTD PORTD (RPD) gm 8 chn I/O, thanh ghi iu khin xut nhp tng ng l TRISD. PORTD cn l cng xut d liu ca chun giao tip PSP (Parallel Slave Port). Cc thanh ghi lin quan n PORTD bao gm: 1. Thanh ghi PORTD : cha gi tr cc pin trong PORTD.1. Thanh ghi TRISD : iu khin xut nhp.

1. PORTE PORTE (RPE) gm 3 chn I/O. Thanh ghi iu khin xut nhp tng ng l TRISE. Cc chn ca PORTE c ng vo analog. Bn cnh PORTE cn l cc chn iu khin ca chun giao tip PSP. Cc thanh ghi lin quan n PORTE bao gm: 1. PORTE : cha gi tr cc chn trong PORTE.1. TRISE : iu khin xut nhp v xclp cc thng s cho chun giao tip PSP. 1. ADCON1 : thanh ghi iu khin khi ADC.

CHNG 4 : CC THNH PHN CU TO ROBOT4.1 . PWM_ IU CH RNG XUNG Khi hot ng ch PWM (Pulse Width Modulation _ khi iu ch rngxung), tn hiu sau khi iu ch s c a ra cc pin ca khi CCP (cn n nh cc pin ny l output). Cc bc ci t b PWM:Bc 1. iu khin cc pin ca CCP l output bng cch clear cc bit tng ng trong thanh ghi TRISCBc 2. Thit lp thi gian ca 1 chu k ca xung iu ch cho PWM (period) bng cch a gi tr thch hp vo thanh ghi PR2.Bc 3. Thit lp rng xung cn iu ch (duty cycle) bng cch a gi tr vo thanh ghi CCPRxL v cc bit CCP1CON..Bc 4. Thit lp gi tr b chia tn s prescaler ca Timer2 v cho php Timer2 hot ng bng cch a gi tr thch hp vo thanh ghi T2CON.Bc 5. Cho php CCP hot ng ch PWMHnh 4.1: S ca b PWMTrong gi tr 1 chu k (period) ca xung iu ch c tnh bng cng thc:PWM period = [(PR2)+1]*4*TOSC*(gi tr b chia tn s ca TMR2).B chia tn s prescaler ca Timer2 ch c th nhn cc gi tr 1,4 hoc 16 (xem li Timer2 bit thm chi tit). Khi gi tr thanh ghi PR2 bng vi gi tr thanh ghi TMR2 th qu trnh sau xy ra:Thanh ghi TMR2 t ng c xa. Pin ca khi CCP c set.Gi tr thanh ghi CCPR1L (cha gi tr n nh rng xung iu ch duty cycle) c a vo thanh ghi CCPRxH. rng ca xung iu ch (duty cycle) c tnh theo cng thc:PWM duty cycle = (CCPRxL:CCPxCON)*TOSC*(gi tr b chia tn s TMR2)Nh vy 2 bit CCPxCON s cha 2 bit LSB. Thanh ghi CCPRxL cha byte cao ca gi tr quyt nh rng xung. Thanh ghi CCPRxH ng vai tr l buffer cho khi PWM. Khi gi tr trong thanh ghi CCPRxH bng vi gi tr trong thanh ghi TMR2 v hai bit CCPxCON bng vi gi tr 2 bit ca b chia tn s prescaler, pin ca khi CCP li c a v mc thp, nh vy ta c c hnh nh ca xung iu ch ti ng ra ca khi PWM nh hnh 4.12Mt s im cn ch khi s dng khi PWM:Timer2 c hai b chia tn s prescaler v postscaler. Tuy nhin b postscaler khngc s dng trong qu trnh iu ch rng xung ca khi PWM.Nu thi gian duty cycle di hn thi gian chu k xung period th xung ng ra tip tcc gi mc cao sau khi gi tr PR2 bng vi gi tr TMR2.Ch :*Cc thanh ghi lin quan:Thanh ghi PIR2: a ch 0DhTMR2 (a ch 11h): cha gi tr m ca Timer2.T2CON (a ch 12h): xc lp cc thng s cho Timer2Cc thanh ghi trn chi tit xem bng ph lc trang 96* Thanh ghi iu khin b PWMThanh ghi CCP1CON v thanh ghi CCP2CON: a ch 17h (CCP1CON) va 1Dh (CCP2CON)

--CCPXXCCPXYCCPXMP3CCPXMP2CCPXMP1CCPXMP0

7 0

Bit 7,6 Khng c tc dng v mc nh mang gi tr 0.Bit 5,4 CCPxX:CCPxY: PWM least Significant bits (cc bit ny khng c tc dng ch Capture v Compare). ch PWM, y l 2 bit MSB cha gi tr tnh rng xung (duty cycle) ca khi PWM (8 bit cn li c cha trong thanh ghi CCPRxL).Bit 3-0 CCPxM3:CCPxM0 CCPx Mode Select bitCc bit dng xc lp cc ch hot ng ca khi CCPx0000 khng cho php CCPx (hoc dng reset CCPx)0100 CCPx hot ng ch Capture, "hin tng" c thit lp l mi cnh xung ti pin dng cho khi CCPx.0101 CCPx hot ng ch Capture, "hin tng" c thit lp l mi cnh ln ti pin dng cho khi CCPx.0110 CCPx hot ng ch Capture, "hin tng" c thit lp l mi cnh ln th 4 ti pin dng cho khi CCPx.0111 CCPx hot ng ch Capture, "hin tng" c thit lp l mi cnh ln th 16 ti pin dng cho khi CCPx.1000 CCPx hot ng ch Compare, ng ra c a ln mc cao v bit CCPxIF c set khi cc gi tr cn so snh bng nhau.1001 CCPx hot ng ch Compare, ng ra c xung mc thp v bit CCPxIF c set khi cc gi tr cn so snh bng nhau.1010 CCPx hot ng ch Compare, khi cc gi tr cn so snh bng nhau, ngt xy ra, bit CCPxIF c set v trng thi pin output khng b nh hng.1011 CCPx hot ng ch Compare, khi cc gi tr cn so snh bng nhau, xung trigger c bit (Trigger Special Event) s c to ra, khi c ngt CCPxIF c set, cc pin output khng thay i trng thi, CCp1 reset Timer1, CCP2 reset Timer1 v khi ng khi ADC. 11xx CCPx hot ng ch PWM.

4.2 . CM BIN TRONG ROBOT4.2.1 Cm bin d ng : Mch cm binMch cm bin ng vai tr nh mt ca robot gip cho robot c kh nng nhn bit c mi trng xung quanh, gip cho robot i ng ng v xc nh c v tr trong khng gian ca mnh trn sn, t thc hin cng vic mt cch chnh xc.Ta c th s dng cc loi thu pht hng ngoi hoc s dng quang tr thc hin vic d ng bng cc vch trng trn sn, ta s ln lt i kho st tng loi cm bin mt. Mch cm bin dng thu pht hng ngoi

Hnh dng, cu to LED Thu, Pht

Mch cm bin hng ngoi pht thngTrong cp thu pht hng ngoi (IR) ny: mt linh kin pht hng ngoi (IR emitter (IRE)) v mt linh kin nhn (IR receiver (IRS)) to thnh 1 cp cm bin sensor. Led thu l loi phn quang, ngha l ch nhn c nh sng hng ngoi ca Led pht khi nh sng c phn x bi mt vt chn sng. Linh kin pht s to tia hng ngoi v sau khi phn x s truyn ti linh kin nhn.

Nguyn l thu pht ca thu pht hng ngoiDng in i qua linh kin thu s t l vi cng nng lng ca tia hng ngoi m n nhn c.

S ph thuc ca dng in vo cng tia hng ngoi

S nguyn l ca cp thu pht hng ngoiTrong mch thu pht th led pht v led nhn c ni mch theo s hnh di y, trong :

Chn TX l chn cp mass, nu cp thng mass vo chn ny th ta s c mch thu pht hng ngoi pht thng, cn nu chn TX c cp bi b dao ng vi tn s th ta c mch pht hng ngoi iu bin.im IRSO l im phn p ca R9, VR1 v led nhn hng ngoi (IRS1), dng s i qua linh kin pht v n s pht ra tia hng ngoi. Nu c 1 vt phn x mu trng th nng lng hng ngoi s phn hi li, IRS1 nhn c nh sng hng ngoi do Led pht pht ra, khi in tr ca Led thu s gim v to mt dng cao hn i qua IRS1, do in p trn IRS0 s h xung. Nu vt phn x c mu en, hoc mu sm hn th ngc li, do in p trn IRS0 s nng ln. IRSO l im phn p kch m Transistor.4.2.2 B tr cm bin d ngTrn robot, v nguyn tc b tr cng nhiu cm bin d ng th kh nng bm ng cng tt. Tuy nhin, trn thc t ta thng s dng 6, hoc 8 cm bin, ty vo ti, cht lng ng c m ta b tr cm bin. Thng c hai phng php b tr cm bin. S dng 6 cm bin xp thnh hng ngangCch ny thch hp vi loi ng c c kh nng hm tt (loi ng c c hp gim tc), khi quay thng s dng quay bng 1 bnh (1 bnh dng cn 1 bnh tin).

Hnh 19: B tr 6 cm bin theo hng ngang

4.3 Mch cu H L298D:L298D l mt chip toch1 hp 2 mch trong gi 15 chn. L298D c in p danh ngha cao (ln hn 50V) v dng in danh ngha ln hn 2A nn rt thch hp cho cc ng dng cng sut nh nh cc ng c DC loi va v nh.

Hnh 20: S chn ca IC L298D (phi)IC L298D (tri)

C 2 mch cu H trn mi chip L298D nn c th iu khin 2 i tng ring vi 1 chip ny. Mi mch cu H bao gm 1 ng ngun Vs (tht ra l ng chung cho 2 mch cu), mt chn current sensing (cm bin dng) phn cui ca mch cu H, chn ny khng c ni t m b trng cho ngi dng ni 1 in tr nh gi l sensing resistor.Bng cacch1 o in p ri trn in tr ny chng ta c th tnh c dng qua in tr, cng l dng qua ng c, mc ch ca vic ny l xc nh dng qu ti. Nu vic o lng l khng cn thit th ta c th ni chn ny vi GND. ng c s c ni vi 2 chn OUT1, OUT2 hoc OUT3, OUT4.Chn EN (ENA v ENB) cho php mch cu hot ng, khi chn ny c ko ln mc cao.L298D khng ch c dng o chiu ng c m cn iu khin vn tc ng c bng PWM.Trong thc t, cng sut thc ma L298D c th ti nh hn gi tr danh ngha ca n (U =50V, I =2A). tng dng ti ca chp ln gp i, chng ta c th ni hai mch cu H song song vi nhau (cc chn c chc nng nh nhau ca 2 mch cu c ni chung).

Hnh 21: S nguyn l ca IC L298D

CHNG 5 : S MCH V NGUYN L HOT NG CA ROBOT5.1 S nguyn l ca robot d ng v layout ca robot

S nguyn l ca robot d ng Nguyn l hot ng: * Nguyn l hot ng:Chp Vi iu Khin nhn tn hiu t mch cm bin ngoi,mch cm bin gm 8 cm bin a tn hiu qua 8 b so snh s dng b khch i thut ton IC LM324 mc theo kiu so snh in p gia 2 cc + v - qua Triger Smith IC 7414 tc dng sa xung, to tn hiu xung chun a vo Vi iu Khin. Cc Port B c s dng nhn tn hiu vo cm bin ( t chn RB0 n RB5 ) Cc bin tr tinh chnh 103 t vo cc + tc dng t 1 in p ln cc + so snh vi in p cc - do cm bin a v a ra tn hiu 0 hoc 1 vo Vi iu Khin x l.

Vi iu Khin nhn cc tn hiu vo x l v a ra cc thut ton iu khin ng c pht ng a vo port C ri a qua IC L298 iu khin tc ng c .

5.2 S v nguyn l hot ng ca mch cm bin

S mch cm bin Nguyn l hot ng ca mch cm bin : Nguyn l hot ng:Mch cm bin s dng 6 cm bin ta s dng LED pht v LED thu . LED thu mc theo kiu phn p da vo phn x ca LED pht quang s nh ra mc in p t ln cc - ca b so snh khch i thut ton.5.3 S v nguyn l hot ng ca mch iu khin ng c.

S mch iu khin ng c . Nguyn l hot ng mch iu khin ng c : Nguyn l hot ng: Trong mch ta s dng 2 b PWM iu khin cho 2 ng c ng c 1 ( Bnh tri ), ng c 2 ( Bnh phi.)5.4 Lu thut ton :

Begin

ENDPWM 1 = PWM 2Xe i thngTng PWM 1Gim PWM 2Tng PWM 2GIm PWM 1Xe lch phiKhi to PWMKhi to I/OXe lch tri

S

SS

SSN PHM T C

KT LUN

0. Thun li v kh khn0. Thun liKhi thc hin n chng em c nhng thun li sau:1. c s hng dn nhit tnh ca cc thy gio Nguyn Trng Hi1. S hc hi, trao i kinh nghim c cc bn gip .0. Kh khn1. Trong ti, chng em s dng mt loi chip mi m khng phi l loi chip m chng em c hc ti trng nn vn cn i cht kh khn trong vic tm kim thng tin, ti liu.1. Kin thc chuyn ngnh cha c su.1. Hng pht trin tiDo kin thc cn hn ch, thi gian thc hin ti c hn nn chng em ch dng li vic iu khin ng c vng h, cha c phn hi vng kn, cha hin th c tc ng c. Cng trn nguyn tc tng t, mch ny c th iu khin c tc ng c mt cch chnh xc bng cch dng timer ca b iu khin m s vng quay ca ca ng c, suy ra tc ng c(c hin th trn LED 7SEG hoc trn mn hnh LCD).

TI LIU THAM KHO4. Robot cng nghip TS . Phm ng Phc4. K thut mch in t _ Phm Minh H Nh xut bn Khoa hc k thut.4. in t cng sut Nguyn Bnh Nh xut bn Khoa hc k thut.4. http://www.dientuvietnam.net4. http://picvietnam.com4. http://bkit4u.com

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