THIET KE THIET BI DOC LOI XE OTO THEO C H U A N O B D II<br />
TRONG HE T H 6 N G CHAN DOAN OTO TlT XA<br />
<br />
Nguyin Vdn Tiim, Le Hdng Lan<br />
Bd mdn Dieu khiin hgc, Khoa Diin-Diin tir, Truang Dgi hgc GTVT<br />
<br />
Tdm tdt:<br />
Bdi bdo dua ra md hinh he thong chdn dodn d td tir xa vd tap trung vdo thilt kl mdt chi<br />
tilt mdt phdn cua thilt bj tren xe, dd la thilt bj dgc md loi theo chudn OBD II. Thii nghiem<br />
thiet bj vd ddnh gid ket qud d^t dugc.<br />
Tir khod: OBD II - On-Board-Diagnostic System<br />
Abstract:<br />
This paper proposes a remote vehicle diagnostics system model and focus on a detailed<br />
design of the device on a vehicle, that's error code reader OBD II standard. Test equipment<br />
and evaluate the results achieved.<br />
<br />
I. Gidl THI£U M 6 H I N H H ? T H 6 N G CHAN D O A N 6 T 6 Tir XA<br />
Hinh 1 Id he thdng chdn ..-^„^^.^<br />
dodn d td tir xa, bao gdm 3 he -^^'^"^<br />
chuyen gia: He chuyen gia I tren xe „„^*»,,<br />
cd chiic ndng chdn dodn nhanh, so "^"^<br />
bg tren cdc ca sd thdng tin tir OBD<br />
va sd lieu ky thudt xe; Neu cd dau<br />
hieu sy cd nghiem trgng se bdo ve<br />
tmng tdm. He chuyen gia II tai tmng<br />
tam cd chiic narig chdn dodn ciing Hinh L Hf thing chdn doan 6 to tir xa<br />
dya tren cdc ngudn thdng tin nhu he<br />
chuyen gia I vd nhung sau ban, ky hon ve nguyen nhdn, miic do sy co dua ra chdn dodn giiip<br />
ngudi qudn ly, gidm sat ra quyet djnh cudi ciing de bdo cho Idi xe, ciiu hd hodc tram sua chua.<br />
He chuyen gia III tai tram sua chira su dyng ngodi cdc ngudn thdng tin tren cdn them cdc<br />
thdng tin khdc tu cdc thiet bj do tai tram. Vi vay kit qud chdn dodn se chi'nh xdc vd toan dien<br />
hon.<br />
Thdng minh hoa qua trinh chan doan dya tren sir dung mdt sd cdng cy cua ITnh vyc<br />
tri tue nhdn tao, dd Id he chuyen gia, logic md vd mang no ron.<br />
He chuyen gia chdn dodn mdy cd tdc dyng: Cho phep thyc hien chdn dodn mdy khdng can sy<br />
CO mat cua chuyen gia; Thay the cho con ngudi cd tn thiic cao, tao dieu kien cho cdng viec<br />
chan dodn mang tfnh khdch quan, nhdt la khi chdn dodn he thdng phiic tap; Phdt huy uu diem<br />
cua mdy tfnh ve do Idn cdc thdng tin tri thiic ciing nhu tdc do xu ly so vdi con ngudi.<br />
Thiet bj dgc ma Idi Idy thdng tin ve ma Idi tren xe de cung cdp dii lieu ben canh tri thiic<br />
chuyen gia cho chan dodn d td. Muc 2 trinh chi tiet thiet ke chi tilt thilt bj dgc ma Idi.<br />
n. THIET KE THIET BI DQCMA LOI XE 6 T 6 TOYOTA CAMRY 2.0<br />
2.1. Cac giao thirc truyen thdng OBD 2<br />
Cd 10 giao thiic:<br />
+ SAEJI850PWM; +SAEJ1850VPW<br />
+ ISO 9141-2; + ISO 9141-4 KWP (5 baud init, lO, 4<br />
Kbaud);<br />
+ ISO 9141-4 KWP (fast init, 10, 4 Kbaud); + ISO 15765-4 CAN (11 bit ID, 500 Kbaud);<br />
+ ISO 15765-4 CAN (29 bit ID, 500 Kbaud); + ISO 15765-4 CAN (11 bit ID, 250 Kbaud);<br />
+ ISO 15765-4 CAN (29 bit ID, 250 Kbaud); + SAE J1939 (NEW CAN)<br />
<br />
<br />
<br />
691<br />
2.2. Cac chudn chung ciia OBD II<br />
Cau triic CLia phhn cirng OBD II la jack cai, 16 chan (2x8), chuan noi J1962. Vi trf<br />
Jack ndm d xung quanh khu vuc ghc ngudi lui, ben ghc phai hodc dudi vi trf tay lai [3-5J.<br />
Cac tin hieu s u dung trong giao dicn ghep noi chudn OBD II:<br />
Hien nay cd 5 giao thirc tfn hieu sir dyng trong giao dien ghep ndi chudn OBD II [1].<br />
+ SAE J1850 PWM (pulsc-widlh modulation -41.6 k-baud, chudn ciia cdng ty Ford Motor)<br />
+ SAE J1850 VPW (variable pulse with -10.4/41.6 k-baud, chudn ciia General Motor)<br />
+ ISO 9141-2 Id giao thirc cd tic do du lieu 10,4 k-baud, vd tuong tu nhu RS-232. ISO 9141-<br />
2<br />
+ ISO 14230 KWP2000 (Keyword Protocol 2000)<br />
+ ISO 15765 CAN (250 kbit/s hoac 500 kbit/s). Giao thirc CAN la mgt chudn phd biln ben<br />
canh cua cdng nghiep d td My va dugc sdn xudt theo chudn OBD II. Tir 2008, tdt cd cdc xe<br />
ban d My se yeu cau thyc hien CAN: pin 6: CAN high, pin 14: CAN low.<br />
2.3. Thiet ke bg giai ma OBD II<br />
Lya chgn chip chuyen dyng PIC24HJ64GP506; xir ly 16 bit, cd tdc do tfnh todn<br />
nhanh, chju dugc mdi tmdng rung xdc [6-7]. So do khoi ciia mach dien tren xe d td chuan<br />
OBD II nhu hinh 2.<br />
Tir cdc ECU cua mdy tfnh tren xe, theo BUS CAN din bg tmyln dir lieu ra Jack OBD<br />
II tren xe, nhu hinh 2.<br />
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Hinh 2. So* do khoi mach dien tren xe o to<br />
<br />
So dd chdn ciia chudn OBD II nhu hinh 3 Pin 2 Pin 7<br />
<br />
So do khdi ciia bd dgc ma Idi nhu hinh 4. 1 1<br />
Bao gdm cdc khdi: khdi ghep ndi ngudn nudi; naatDaoaa<br />
khdi ghep ndi vdi Jack chudn OBD II de gidi md aaaaaaaa<br />
loi vd tmyen md loi len mdy tfnh thdng qua khdi<br />
pimo Pin 10<br />
ghep noi chudn USB hodc chudn RS-232.<br />
Hinh 3. Jack tren xe theo chuan OBD II<br />
Trong dd: Khdi cym CPU<br />
PIC24HJ64GP506: Bd vi xu- ly 16 bit. Giao tiep vdi CPU cua xe qua chudn CAN (baudrate:<br />
500kbit/s). Xir ly thdng tin nhdn tir xe vd giri cdc thdng tin dd qua chudn RS-232; Khdi cum<br />
PL-2303: Bd chuyen ddi USB-UART. Tgo cong COM do tren mdy tinh de giao tiep vai chudn<br />
RS-232; Khdi cym SN65HVD1050: Bg truyen nhdn CAN. Truyen nhan tin hieu giira CPUvi<br />
Khdi ngudn nudi cho cdc IC: idy tnrc tiep tir xe hodc mdy dnh (USB) qua cdc IC dn dp 3.3V<br />
vd 5V. Khdi nap chuang trinh firmware.<br />
<br />
A K -r--~ : 1<br />
' Cohipu t e r j A J S B A W W ^<br />
<br />
/I N PIC24HJ64GP506^<br />
••-:v Progammer '^B<br />
f Cai-baitery 6r (JSB": ^1- I804AC cortralvd<br />
- 1 1 • tSOrtAC wnitv»»6<br />
<br />
<br />
byeofDTC2. 11 • m«nufac>wr«r wiHiBl«< k« PTOCD m<br />
11 • 8 A E ( M O T > « d l B m « » « e r 3 * n<br />
<br />
Chu y: chi dua toi da 16 loi ,vf dy: 00-1<br />
01*«<br />
<br />
<br />
ndi dung ciia cdc byte va ma Idi xem Osplay character 3 m used to Ueniify a tpcaic v«hiae<br />
area Withm any araa. ^ p b y c^aractara 4 and 5 alow up lo<br />
256 code definittona<br />
hinh 6.<br />
Hinh 6. Noi dung cac byte va giai ma loi<br />
DTCHigh (bytel) = 0x92;<br />
DTCLow(byte2) = 0x34; DTC se Id : B1234.<br />
<br />
$9 $2 $3 $4<br />
1 0 0 1 0 0 1 1 |o 0 |o 1 1 1 1 0 1 |o |o<br />
B 1<br />
<br />
Xe khdng cd Idi:<br />
2<br />
1^ 3 4<br />
<br />
<br />
<br />
0x02 0x41^ MIL BB<br />
Mdt kit ndi vdi xe: dung OxFE di phdn biet byte ndy do firmwere quy dinh<br />
0x02 0x41 OxFE GS<br />
Mdy tinh yeu cdu lay dir li^u true tiip tirxe Read Live Data:<br />
+ PC giri xudng Tool:<br />
0x01 0x02<br />
+ Tool giri trd Idi len PC: cd 2 dang trd Idi<br />
Kit ndi diing xe (Camry 2.4L 2009 nhdp khdu )<br />
OxOA 0x42 LDlSt LDIH LDIL LD2St LD2H LDIL LD3St LD3H LD3L<br />
LDlSt, LD2St, LD3St: do firmwere qui djnh<br />
LDIH : High bye of Engine RPM; LDIL: Low bye of Engine RPM.<br />
LD2H : High bye of Vehicle Speed; LD2L: Low bye of Vehicle Speed.<br />
LD3H : High bye of Time Since Engine Start; LD3L: Low bye of Time Since Engine Start.<br />
De ra dugc gia trj thyc te, ta cdn phdi nhdn data nhdn dugc vdi I he sd ty le dugc quy djnh:<br />
Engine RPM: he sd ty le: 0.25; Vehicle Speed : he sd ty le: 1.<br />
Thdi gian tir luc bdt ddu khdi ddng xe (gidy): Time Since Engine Start: he sd ty le: 1.<br />
Mdi thdng sd cdn 2 byte de xdc djnh gid trj<br />
Vfdy : gid trj trd vl tir tool: LD 1 Hi =0x12; LDlLow = 0x78.<br />
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694<br />
Engine RPM se hiln thi 0x1278 ^= scale(0.25) = 1182 rpm<br />
Mdt kit ndi vdi .\e<br />
0x02 0x42 0x02 CS<br />
- Mdy tinh yeu cdu lay dulieu VIN ciia xe (md xdc nhdn xe) Read Vehicle Information:<br />
+ May tfnh yeu cau Tool:<br />
0x01 0x03 CS<br />
+ Tool giri trd Idi len PC: cd 2 dang<br />
Ket noi dung xe (Camry 2.4L2009 nhdp khau,....)<br />
0x12 0x43 Datal Data2 ... Data 16 Data 17 CS<br />
Datal-Datal7: 17 ASCII characters of VIN<br />
Xe khdng ho trg dgc VIN qua ECU hodc khdng ket noi vdi xe<br />
0x02 0x43 Data 0x46<br />
Data = 0 : xe khong ho tig dgc VIN qua ECU; Data = 1: khong ket ndi vdi xe<br />
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III. KET QUA THU NGHIEM THIET B| DOC MA LOI OBD II<br />
Giao dien ket noi tren PC<br />
Giao dien tren may tfnh nhu hinh 7, bao gdm cdc chirc nang:<br />
Dgc ma loi: Read DTC; Kilm tra kit nli Tool Link; Sl lieu xe Live Data; Thong tin xe<br />
Vehicle Inf va thoat khoi chuang trinh Exit.<br />
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U^j.:i:.^mm9m^'-'<br />
I«^Lr* 1 Mil ijfl<br />
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r fle*dDTc 1 p:i4r<br />
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UveOtfs<br />
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