c kiem tra khuyet tat cac chi tiet, san pham trong cdng nghiep

Gidi thieu _{eong nghi}

iJng dung cdng nghe chup anh cat icfp CT cho vi|c kiem tra khuyet tat cac chi tiet, san pham trong cdng nghiep

TS. N G U Y I N OlTC MINH - Phd Vi$n tru'dng Vl?n Miy vi Dyng cg cdng nghidp (IMI) THS. N G U Y I N C H I Cl/dl^G - PGD Trung tam Chuyen giao cdng ngh^ - Vi?n IMI

TOM

TAT

Bdi bdo tdng k^t cdc n^i dung chinh dd thi/c hi^n cua dig tdi KHCN cdp B^ do Vi^n IMI chu tri vd dd bdo v$ thdnh cdng. Dd tdi c6 tdn Ung di^ng cdng ngh$ chup anh c^t Idp CT cho vide kidm tra khuydt t$t cdc chi tidt, sdn phdm trong cdng nghidp" vdi md sd:

178.09.RD/HD-KHCN. Trpng tdm cua bdi bdo Id phdn tich, Idm rd cdc vdn dd trong qua trinh thidt kd, chd t^o vd tich hgip hd thdng thidt bi nhdm kidm tra khuydt tdt cdc chi ti^t, sdn phdm trong cdng nghidp theo hUdng Ung di^ng cdng nghd chup dnh c^t ldp CT.

1. HE THONG KIEM TRA KHUYET TAT CAC DOI

T U Q N G T R O N G

CONG NGHIEP THEO

P H U O N G PHAP

CHUP ANH PHONlS XA RT, l/NG DUNG KY

THUAT

CHUP ANH

CAT

LOP CT

Ngay nay vdi sU phat trie'n vUdt bac ciia nganh khoa hpc may h'nh va cdng nghe phan mem da tao cd sd cho viec xay dUng cac he thdng kiem tra khuyet tat eac ddi tUdng trong cac day chuyen san xuat trong cdng nghiep theo phUPng phap chup anh phdng xa RT (Radio Graphic Test), utig dung ky thuat chup anh cat Idp CT (Computed Tomography). Cac he thdng vdi cau hinh nay cho phep dUa ra nhieu bde anh phdng xa ciia vat kiem theo nhieu Idp vdi cac goc chieu khac nhau thay vi chf la mpt bdc anh phdng xa ciia vat kiem, do dd nang cao rat nhieu kha nSng cung nhUdp chinh xac ciia he thdng kiem tra.

Trong cac he thdng kiem tra theo phUPng phap RT ma cd utig dung ky thuat chup anh cSt Idp CT thi he thdng xd ly CT Scanner ddng vai trd chfnh trong viec quyet djnh tinh chinh xac ciia he thdng. Day la he thdng phdc tap bao gdm t d cac thiet bj phan ciitig: bd phat tia X, c^c detectors, bd truyen ddng, he thdng thu nhan anh, phan mem phan tich va xd ly anh, phan mem nhan danh dau nhan dang hinh anh, phan mem tai tao anh CT...

Trong khudn khd bai bio nay se phan tich mdt sd ndi dung thUc hien chinh cung nhU cac ket qua da dat dUdc ciia nhdm nghien cdu cho viec img dung cdng nghe chup anh c3t Idp CT cho kiem tra khuyet tat cac chi tiet, san pham trong cdng nghiep.

2. HE THONG KIEM TRA KHUYET T A T CAC CHI TIET, SAN

P H A M

TRONG CONG NGHIEP

LTNG D U N G

CONG NGHE CHgP ANH CAT LdP CT CUA VIEN I M I *

2.1. Sd do va nguyen ly lam vi^c cUa he thong:

Td cac yeu cau ky thuat ciia he thdng, nhdm nghien culi da du^ ra sd dd cau true va nguyen ly lam viec ciia he thdng

USIGClOio

Hinhl: Sd do nguyen ly ciia tii thdng

(hinhl):

-t- Cac thanh phan chfnh ciia he thdng:

- Bd phat tia X: bao gdm nguon phat, dng phat tia, bang mach va bd dieu khien ngudn phat tia X.

Collimator: la tam ch3n vdi tac dung lam manh tia X theo dung hinh quat, tap trung nSng IUdng vao dung day detectors hinh chd L.

Bd ga ddi tUdng kiem tra: de ga ddi tUdng kiem tra va chuye'n ddng theo yeu cau. Odi tudng se dUdc tinh tien theo budc (min la 0,5cm) trong khoang kiem tra, tai moi bUdc (Idp cSt), khi diitig lai de tien hanh chup cat Idp thi doi tUdng se dUdc xoay lien tuc vdi gdc 360° quanh true tjnh tien.

Detectors: day detectors dddc bd tri theo hinh chu" L, bao gdm 8 Detector Head Board (OH), moi board gdm 128 channel, vdi dp rdng moi detector la 0.8mm. Tat ca cac DH nay dUdc noi ndi tiep tdi board thu thap/xd ly tin hieu - Signal Procesing Board (SP) ciia XOAS.

- XOAS (X-Ray Data Aquisition System): la he tiidng thu thap dd lieu X-Ray dUdc sd dung rdng rai cho cac utig dung X-Ray linescan. XOAS giao tiep vdi PC qua giao dien USB2.

PC: Bao gom phan mem thu thap dd lieu, tai tao anh CT va phan mem dieu khien he thdng.

50| KHOA HQC & C Q N G N G H | • (S6 9 - 03/2012)

Gidi thieu cang riiii

-I- Nguyen ly boat ddng:

- BUdc 1: Odi tUdng kiem tra dUdc ga vao bp ga tai vj trf ga tdc la ben ngoai khoang chup.

- BUdc 2: Chuyen ddng bd ga vao vj trf de sin sang cho qua trinh chup.

- BUdc 3: Bd ga tinh tien ddi tUdng kiem tra vao vj trf de thUc hien chup cat Idp ddi tddng.

- BUdc 4: Tai vj tri moi Idp cat, tfn hieu dieu khien 'X-Ray ON' dUdc dUa ra - Bd phat tia X bSt dau boat ddng; Bd ga ddi tUdng tien hanh xoay lien tuc ddi tddng mdt gdc 360°.

Tai moi gdc chieu (gia trj ciia gdc chieu d la dUde thiet lap tren phan mem) tien hanh thu thap anh bdc xa ciia hddng chieu thupe Idp cat dd ciia ddi tddng. NhU vay tai moi Idp cat se thu dUdc nhieu anh bdc xa ciia Idp dd. Cac anh bdc xa nay dUdc truyen sang PC de phan mem tien hanh xd ly, tai tao anh CT.

Khi ddi tupng da dUdc xoay bet gdc 360° va qua trinh thu thap cac anh bdc xa cua Idp cSt hien tai ket thiic, tfn hieu dieu khien 'X-Ray OFF dddc du^ ra; Bp phat tia X dupe dimg boat dpng.

- BUdc 5: Bd ga tinh tien them 01 bddc (dp dai ciia 01 budc nay cd the dddc dieu chinh, ngam djnh la 0,5 cm), toan bp qua trinh dddc I3p lai nhu bUde 4.

- BUdc 6: Khi het chieu dai kiem tra(chieu dai ddi tUdng), thoat kh6i qua trinh chup cat Idp.

BUdc 7: Toan bd cac anh cac Idp cat (20) eiia ddi tupng dupc hien thj tren man hinh.

- BUdc 8: Bd ga dUa ddi tUOng kiem ra vj tri d bUde 1.

Chu k/ lam viec ket thuc.

2.2. Thiet keky thuat cUa he thong:

2.2.1. Phan k&:cau cdkhf, bg nguon phat, dieu khien tia X:

Thiet ke, xay ddng tren cP sd phat trien t d may soi hanh ly Dynavision 400A ciia hang Control Screening. May

vcc vcc •.TC

RIGHT LIMIT

< M 5 — I

CO cac th6ng sd chinh nhU sau:

- Chuye'n ddi tdpng soi bang bang tai.

- Khoang chieu: rpng 64 cm; cao 38 cm.

- Ngudn phat tia X: maximum 90 kv, van hanh d 85 kv.

cudng dp cho 01 lan kiem 0.1 mR.

- Hinh dang tia: fan beam.

- Bd trf detectors: hinh L.

2.2.2. Bg ga ddi tu'dng kiem tra:

Bp ga ddi tUPng, chi tiet kiem tra da dUpc thiet ke, che tao tai Vien IMI, dap dng eac yeu cau cP ban sau:

-I- Chuye'n dpng tjnh tien ddi tUpng theo phUPng dpc budng chieu (vu6ng g6c vdi chiim tia).

+ C6 cP cau xoay ddi tdpng kiem tra 3600 quanh true ehuyen dpng dpc.

+ Toan bp bp ga ddi tUPng kiem tra dUpe dieu khien tU dpng qua may tinh, cae th6ng sd trang thai dUPe tra ve may tfnh. Vf du nhU: vj tri theo phUdng tinh tien ciia moi Idp cat va gdc xoay ciia ddi tUpng khi thUe hien chup anh bdc xa ciia mpt phep chieu.

Bp ga ddi tUPng kiem tra bao gdm cae thanh phan ehii yeu nbd:

- 02 dpng cP ba pha + hop sd de thUe hien cac chuyen dpng tjnh tien va chuye'n dpng xoay.

- 02 Limit switch de gidi han chuyen ddng.

- 01 Encoder gan vao true ddng cP xoay de lay th6ng sd gdc xoay hien thdi ciia ddi tUpng.

- 01 til dien dieu khien vdi hai che dp "tay" va "tU dpng".

- Dieu khien tU dpng qua may tinh PC dUa tren 01 card da chdc nang PCI-1711 Advantech.

Phan mem dieu khien tren PC.

* Dieu khien ngudn phat tia X va bp ga ddi tUpng kiem tra qua may tinh PC:

Viec dieu khien tU dpng bp ga ddi tUPng kiem tra va ngudn phat tia X may Dynavision 400A dupe dieu khien bang phan mem tren may tfnh PC, thdng qua card PCI- 1711. De thUc hien dUpc viec nay, nhom nghien cud da thiet ke, che tao mach dieu khien, ghep ndi vdi card PCI-1711, dap utig cac yeu cau dieu khien ciia he thdng (hinh 2). Trong dd cac dja chi vao/ra nhU sau:

+ DOO - dieu khien chieu tien ddng cd tjnh tien.

-I- 002 - dieu khien chieu liii ddng cd tinh tien.

+ 004 dieu khien ddng cP xoay.

-I- 006 dieu khien ON/OFF ngudn phat tia X.

I 1 + 008 dieu khien hddng chay rSia.^"-^ bSng tai.

^ ^ 1 U + 010 - dieu khien ON/OFF chay bang tai.

* Module phan mem dieu khien bd ga ddi tUdng kiem tra: dddc xay dutig tren cd sd sd dung thiet bj card da nSng PCI-1711va cdng cu phat trien

« CX>M

.(COM

HinhZ: Sd dd mach ghep ndi vdi card Pa-1711

(S6 9-03/2012) -* KHOA HQC & CQNG N G H | |51

Gi(}i thieu i cang nghe

•Wnir CninmainlJ" lo Card KT 17II Sun OiiiyCri (tftnji "Lfli" dfli fUt^nn ->

"XVnicC.tmman.lJrinCardl'CI 1711 SPT (Timfn iliwiji "Liii' ilrti Immp

4

Ghi Iv inh a u liiVp cli

"Write Commind 1" to Card 1111711 Start Chuy6i Atmg 'TiCn" dOI tuong

^

•Rr3.l|>..n;'fn>nir«nim 1711 Oet Limit Lcfl valur

•WnlcdiiTiTiiindll iu( »rdll I I ' l l Sliip (Tjuydn dOnjJ li'n' ilrti llfinii!

n

l l l f N I H l K f I yuA MIA IUN(r lrtP( Al

"WnteOmmandirtoCardPa 1711 Slop Clw\-(!n dOn| "Tifti" dfii luonj

Kf ! THUC

V.nic0.rr.rr,in>]* i<> Lartl PU 1711 Sar O J V ^ (long "Xoay" 66) oipng

••Read pon3"

From card p a n 11 Get Encoder value

Read Xny DaU Prom cart XDAS

'WnieCoromaDd3rioCut)Pa 1711 Stop Qiuy& d<)og "Xoay" ddi tui?ng

ncyd >

Re«l Xray Dau from Duk lliMc hito til tao If] anh ciu tung

ldp tH dO l i ^ cua cic gdc chi6i diduygfaidf'j

OWnieXny DautoDivk (do liCu d6i v4i (ung gdc xoay ciia ddi tugng)

HinhS: Chu trinh dieu khi^n chung toin bg h$ thdng kli'm tra khuyit t$t sin phim bing tia X, ung dyng cdng nghi chdP dt ldp CT

SDK ciia hang Advantech-Taiwan.

2.2.3. He thong thu nh$n du'll$u X-ray:

Nhdm nghien cdu da li/a chpn h? thdng XDAS (X-Ray Data Acquisition System) ciia hang Electron Tubes Limited - UK lam cd sd de xSy di/ng h? thdng thu th§p dd li?u X- Ray.

Cac thdng sd ky thu|t ciia h? thdng XOAS:

Thdi gian tich phSn: t d 10 s den 100 s - Dimensions:

DH (101 X 110 mm); SP (101 x 122 mm)

Ty le signal / noise: > 10000:1 - Non - linearity: <0.1 % Toe dp qu6t: max 20 kHz - Oetetor pitch: 0.8 mm ho$c 1.6 mm

Dual energy option Interface: RS 485, max 9600 Baud

- Detector type: Scintillator type - Power suply: + 5V and +12V

- Data: 16 bit

* Module phan mem thu thap du" lieu X-Ray: dddc xSy dung tren cd sd sd dung thiet bj XOAS-USB va eong cu phat

trie'n SDK ciia hang Electron Tubes Limited.

2.2.4. Cac module phan mem khac:

+ Module phan mem xd ly dd lieu, tai tao anh CT:

Do qu^ trinh thu thap, x d ly dd lieu X-Ray va tai tao ^nh CT la khau quan trpng, cdt yeu nhat ddi vdi h^ thdng CT Scanner nen nhdm nghien cdu da tap trung nghien cdu, tim hieu cac thuat toin t i i tao anh CT dang dddc sd dung tren the gidi, d$c biet quan tam tdi kha nSng ap dung cho bcii toin kiem tra khuyet tat cac chi tiet, san pham trong cdng nghiep. Ket qua, nhdm nghien cdu da xay dytig dUdc thuat toan tai tao anh CT cho bai toan kiem tra khuyet tat tren cd sd "thuat toan chieu Ipc ngUdc"

-I- Module phan mem dieu khien chu trinh chung ciia he thdng:

Qua q u i trinh nghien cdu, thiet ke, che tao va xay dytig cac module ciia he thdng (phan cirtig v i phan mem), nhdm nghien cdu da dUa ra dUdc chu trinh dieu khien ehung ciia toan he thong.

Day la cP sd de xay dutig dUdc phan dieu khien ddng bp c i he thdng. Chu trinh nay dUdc the hien d hinh 3.

3. QUA TRINH TICH HpP, THlT NGHIEM VA DANH GIA KET QUA HOAT DONG CUA HE THONG

Sau khi da tich hpp hoan chinh toan bp he thdng, nhdm nghien cud da tien hanh chay thif nghiem va tien hanh danh gia mdt sd chdc nang cd ban ciia he thdng nhU:

+ Op chinh xic trong boat ddng ciia bp tiiiyen ddng de g i ddi tUdng, chi tiet kiem tra.

+ Chdc n3ng thu nhan dd lieu X-Ray va kha ning the hien sy" hap thy ning lutfng tia X (khac nhau ddi vdi cac lo^i vat lieu khie nhau hoic vcii dp day mdng khie nhau cua ddi tudng).

+ Chut ning chup va tai cau true anh cSt ldp CT.

* Oinh g i i chung v§ cac ket qua thd nghiem;

Cic k§t q u i ciia q u i trinh thd nghiem cho thay, toan bo h^ thdng ve cd ban la da d i p utig dutJc yeu cau d i t ra ciia bai t o i n , t u t la "chyp c5t ddi tu^ng kiem b3 theo nhieu ldp de cd dUdc hinh anh ciia tutig l i t cSt, phuc vu viec danh g i i khuy§t t$t cua ddi tUdng".

4. K i t L U A N

Bai b i o da tdng ket l^i cic npi dung chinh trong qua b-inh t h y t hign de tai 178.09.RD/KH-CN. Trong do, ti^ong t i m l i phan tich, lam r5 q u i trinh thiet k§, xay dutig h§

thdng kiem tra khuyet tat vdi doi ti/dng la cac chi tiet, san pham trong cdng nghiep theo phddng phip utig dung eong nghf chyp cSt Idp CT. Vdi cac ket qua da dat dude trong q u i trinh d i d nghiem, khSng djnh, nhdm nghien ciiU da giai quyet tiianh cdng cac van de cua bai toan dat ra. Day la cd sd de cd thg tien hanh thuttng mai hda san pham va xa hdn la phit tri^n nhdm sin pham cung loai, tren cd sd utig dung cdng ngh| chyp cSt ldp CT, su* dung tia X . *

S2| KHOA HQC & C Q N G N G H | • (S6 9 - 03/2012)