Tap chi Tin hgc va Dieu khien hgc. T.26, S.3 (2010). 267-277
XAC DINH V! TRI CAC GIA DO HANG
Sir DUNG CHO XE TLT DONG BOC XEP TRONG KHO CANG
PHAM DUG LONG
Khoa Cong nghe thong tin, Dai hoc Thdi Nguyen
Abstract. Nowadays, the research on developing visional autonomous forklifts for engagement and move pallets in the store is interested in research on the world. The speed of computing location and orientation of pallet on the serial computer is slow, because amount of work in image processing is huge. This paper addresses early results of using parallel processing cellular neural network in determining the position and orientation of pallet to improve the image processing speed.
Tom tat. Nghien ciiu che tao cac xe nang hang tu ddng (autonomous forklift) quan sat bang camera de di chuyen hang hoa trong kho bai, cing la mot linh vuc dang dugc quan tam tren the gidi. Van de xac dinh vi tri va hudng ciia gia dd hang (pallet) cdn cham do tdc do ciia cac chuang trinh xu ly inh dimg miy tfnh xir ly tuan tu khdng cao. Trong bai bao nay chiing tdi dua ra mot sd ket qui nghien cuu ban dau ve xac dinh vi trf va hudng ciia gia dd hang tir inh theo cdng nghe mang CNN tang tdc do xu ly ciia he thdng.
1. D A T V A N D E
Cic thiing, kien hang trong kho cing dugc d i t tren cac gii dd (pallet). Cic gii dd nay d i dugc tieu chuan hoi. Hien nay cd nhieu loai gii dd hang ciia nhfeu nude cdng nghiep tren the gidi. Theo tieu chuan ISO 6780 cd 6 loai pallet su dung d Bac My, Uc, Chau A, Nam My, chau Au ... Hien nay thdng dung nhat la loai theo tieu chuan chiu Au (EU) cdn gpi l i CEN pallet.
Hinh 1. Gia dd h i n g (pallet) va xe nang ha van chuyen hang (forklift)
Khi t h u c hien xep rd hang trong kho cing ngudi dieu khien xe n i n g - v i n chuyen lii xe den nai dat g i i dd, diing hai cing ciia xe mdc v i o g i i dd sau dd lii xe den nai can thiet va ha kien hang xudng. Viec tao ra c i c xe t u dpng (thuc chat l i cic robot) thay the con ngudi hoan t o i n q u i trinh tren l i cdng viec t u ddng hda vdi miic do cao viec xep dd hang trong cac kho cing, lam g i i m thdi gian xep dd, t i n g he sd su dung cic kho cing v i giim nhan cdng van hanh true tiep.
268 PHAM D U C LONG
Da cd mdt sd nghien ciru ve xe nang hang t u ddng dugc thuc hien bdi Nygrds [2] va Nilsson [3], J. Pages, X. Armangue, J. Salvi, J. Freixenet va J. Mart [7] tim vi trf 3D ciia cic pallet dua tren cac die diem mau sac va hinh ding hinh hgc ciia pallet, Giovanni Garibctto, Stefano Masciangelo, Marco Ilic, Paolo Bassino [10] Michael Seehnger, John-David Yoder [11] da sir dung hai camera quang hpc chp viec xac dinh hudng va vi tri ciia pallet, cdn Daniel Decking, Oliver Wulf, Bernardo Wagner [13] trong cic nghien cuu ciia minh lai su- dung hai laser sanner cho viec thu tfn hieu de xir ly. Sungmin Byun va Minhwran Kim [12]
Jacob Roll [4] siir dung mdt camera dimg phuang phip back-project va md hinh pinhole [9]
de thuc hien hai nhiem vu tren. Ngoai ra cdn cd the ke them mdt sd nghien cmi khac nhu ciia Khadraoui, Motyl, Martinet, Gallice va Chaumette [5], ciia Corke va Good [6], nhung dugc ap dung vdi tay robot cdng nghiep. ^Phuang phip truyen thdng de nhan tim cac ddi tugng di chuyen la sir dung bd lgc Kalman (cho cic he thdng bien doi tuyen tfnh) hoac Kalman md rdng (vdi he bien doi phi tuyen). Tuy nhien viec thuc hien bd Igc nay cd khd khin l i md hinh hoi cic trang thai va viec do de xay dung phuang trinh cho bd lgc va qui trinh tfnh toin ciing nhieu. De tang tfnh thuc te thudng ngudi ta cd xu hudng siir dung cic phuang phap khdng qui phirc tap. Vdi viec thu va xii ly inh md hinh camera pinhole thudng dugc sir dung [4], [9] (hinh 2).
mgt phang anh
Hinh 2. Md hinh camera pinhole
Trong md hinh niy O la diem cira chan sing ciia dng kfnh dugc chgn lam gdc toa dp.
True X3 la true quang hgc (hoac true chfnh). Mat phang inh each mat phang Xi, X2 mdt khoing f la tieu cu. True X3 giao vdi mat phang inh tai R. R la gdc toa do tren mat phang inh. Mdt diem P trong khdng gian 3D dugc chieu len mat phang inh, cat mat phang nay
- y .
>
Q f
YI
0 X ,
P
Xa
Hinh 3. Sa dd quan he giira cac kfch thudc thuc va kich thudc tren inh ciia diem P tai Q. Nd cd cic toa do (yi, y2) trong he toa do mat phang inh. Nhu vay mdt diem trong
XAC DINH VI TRI CAC GlA DO HANG 269 khdng gian 3D da d u g c anh xa t h a n h mdt i n h 2D. Cac toa do (yi, y2) phu thudc vao cic
toa dp (xi, X2, X3) n h u hinh 3. Theo hinh ve xem xet quan he giira Xi, X3 chiing t a cd
- y i Xl Xl
— ^yi = -f— (1)
2:3 003
tu xem xet quan he X l , , X2
/ cd
- y 2 X2 rX2 ,r,^
r — ^y2 = - / — (2) / X3 X3
Trong t h u c te c i c i n h ciia camera dugc d i o lai de ngudi sir dung t h u i n tien b a n va dau trir trong cic cdng t h u c (1) va (2) t r d thanh duang. Chiing t a cd the viet tong q u i t t h a n h
'0--('0 ' (3)
y2 J X3 \ X2 J
Nhu vay mudn tim khoing each tir camera den v i t t h u c tren i n h cd the dimg cdng thuc (3) khi dd biet f v i cic kich t h u d c t h u c xi hoac X2 ciia i n h . Tuy nhien khi sir dung camera tren xe t u ddng (hinh 7) thi cdn can p h i i cd cic phep bien doi he toa do nira.
Cdc cong viic cdn thuc hien khi sii dung xu ly dnh trong du dn xe tu dpng xep ro gid do
* Xdc dinh mat truoc cua pallet: Bien doi Hough (Hough Transformation - HT) dugc p h i t minh 1962 bdi P.V.C.Hough, da ddng mdt vai trd quan trpng trong xu ly i n h bang m i y tinh.
Ve nguyen tac nd cd the tim mdt hinh d i n g bat ky trong i n h , neu nhu d i cho thdng sd dien t i ciia hinh dang can tim. Dang dan giin nhat la tim dudng thang. Ket hgp cic d i e diem ddi xiing d mat trude ciia pallet va sir dung bien ddi Hough la phuang phap ma cic du i n nghien cuu ve pallet trude d i y v i hien nay thudng su dung; tuy nhien gii t h i n h tfnh toin tuang ddi Idn.
* Dinh huong: Xac dinh gdc lech gifra cing xe (fork) vdi gii dd(pallet) nhu trong hinh 7. Tir inh ciia gia dd theo toa do hai chieu cd the tfnh ra gdc lech tren inh. Sau dd bien doi cic he toa d d Xic dinh dugc gdc lech xe vdi gii dd. Thdng sd nay dugc dimg de dieu chinh xe tiep can gii dd. Mdt phuang p h i p gan day dugc gidi thieu [12] l i su dung phuang p h i p chieu sau (back-projection) de dinh hudng xe va gii dd. Viec tfnh t o i n ra hudng lech thudng phii qua nhieu budc tfnh t o i n , bien doi he toa phiic tap. ^ •
* Xdc dinh vi tri cua gid do: Sir dung cic cdng thirc ca b i n (3) de tim ra khoing cieh thuc giira camera v i gii dd; ket hgp vdi cic phep bien doi he toa dp tim ra khoing cieh giira xe-gii dd hoac cing xe-gii dd.
2. S i y D U N G C A M E R A C N N N H A N D A N G P A L L E T A. M a n g noron t e b a o C N N
CNN (Cellular Neural Network) [1, 8, 16] l i mpt m i n g cic bd xii ly song song cd kfch thudc ming ve mat ly thuyet l i khdng gidi ban, x u ly ddng thdi cic tfn hieu dau vao ciia mdi bp xu ly bang mdt lenh duy nhat vdi thdi gian thuc hien chi vii phan trieu giiy (vai micro giiy). Lenh ciia CNN l i bd tham sd A, B, z; cdn dugc gpi l i bp m i u (template). Trong dd A, B l i cic ma tran trpng sd lien ket giiia bd xu ly (tebio-cell) trung t i m v i cac bd xir ly ling gieng vdi nd, z l i mdt ddng ngudng. Vdi cic t i c vu xu ly thdng thudng A va B la cic ma tran 3x3. C i c he sd ciia A,B vk gii tri z la cic sd thuc hoac tham chi la sd phirc [15,
m
PHAM D U C LONG17]. CNN CO the la loai mdt ldp dan hoac la CNN nhieu ldp. Chieu ciia mdi ldp cd the la ID, 2D hoac 3D. Ngudi ta cd the su dung mdt md hinh CNN vdi mdt bd miu hoac phdi hgp nhieu bp mau lien tiep de cd dugc ket qui xir ly theo yeu cau. Cic bd miu thuc hien cac tic vu ca ban dugc dua vao thu vien mau [14]; thu vien nay hien da cd khoing 160 bd miu ca bin. Cic bd man nay hien nay van dugc cic nha nghien cuu tiep tuc tim ra va bo xung vao thu vien. Cic md hinh CNN trude day pho bien dugc thuc hien tren phan cung CMOS, cdn ngay nay cd the thuc hien tren FPGA vdi gii thanh ngay cang re.
B . C a m e r a C N N Bi-I va Eye-RIS
Bi-I (dugc gidi thieu 2003) va Eye-RIS (dugc gidi thieu 2008) li cic thiet bi to hgp gdm cic ming sensor CCD ghep true tiep vao dau vao ciia ming CNN. Trong cic thiet bi niy [14]
ngoai cac ming CNN xu ly song song cdn cd cic bp DSP. Dieu nay giiip cho viec thu va xu ly tin hieu tren cic thiet bi nay thuan tien, mem deo ban do cd the xay dung cic thuat toin lai phdi hgp xii ly song song va ndi tiep va van dat dugc hieu q u i tdc dp xir ly thdi gian thuc. Eye-RIS cd cau tao tuang tu Bi-I la mdt miy tfnh van nang tuang tu logic CNN UM ket hgp camera vdi ming 25.384 bcD xu ly onchip cd the xu ly inh nhi phan, inh miic xim va anh mau vdi kfch thudc (3.5x4.5x8.0 cm), trgng lugng (118g), cdng suat tieu thu cue nho (2.7W)! cd the ndi day la mot con mat cdng nghiep cd the lirng dung cho nhieu nhiem vu xir ly inh thdi gian thuc.
C. Phan tich tong the
Mdt chiee xe bdc hang de bdc xep cic hang hda thdng dung thudng cd cic kfch thudc nhat dinh de dn dinh ve ca hpc. Nd cd trgng tam khdng thay doi nhieu khi cd hing ciing nhu khi khdng cd hing. Cac kfch thudc ciia xe li: chieu daixchieu rdngxchieu cao - LxeXWxe'xHxe
Ratadk»d
Hinh 4- Cac xe bdc hang cd cic kich thudc dim bio on dinh khi bdc hang
Ta thay rang viec dieu chinh forklift tiep can dugc cac gii de hang (hinh 5) chi cdn tic dung d ngoii khoing cieh k xL^e (I-xe la chieu dii xe, k la mdt sd thuc Idn ban 1). Neu xe tu ddng vugt qui khoing cieh nay thi khdng the dieu chinh kip niia. Neu dang d gan pallet qui nd phii liii lai mdi tiep can dugc. Dieu nay dan den khi xu ly inh de nhan dang cic pallet nay thi su cung cap cic thdng tin 3D phii tir ngoai khoing each tdi thieu dd; neu khdng phii liii xe lai.
Cac he tga dp (hinh 7): XYZcamera la he tga dp camera. XYZfork la he tpa dp ciia cang xe mdc vao gii dd. XYZbody he tpa dp ciia thin xe. XYZworld he tpa dp khdng gian chung.
Gia sir gia dd hang nam tren mat dat. Do trucY ciia XYZfork va XYZbody song song nen gdc (p de dieu chinh xe va cang li nhu nhau. Cic true ciia camera pentil XYZcamera cd the thay ddi so vdi cic true XYZ tuang ung ciia 3 he tpa dp kia.
XAC DINH VI TRI GAG GIA D O HANG 271
/~
» ' •
» - : .. ' » 1
Quy dao tiep can Hinh 5. Quy dao xe t u ddng tiep can pallet
C i c thdng sd diing de dieu chinh xe t u ddng trong q u i trinh tiep can gia dd hang la -|- Vi trf ciia xe t u ddng den gii dd h i n g (X v i Y ciia forklift).
-|- Gdc lech giiia hudng chuyen dong hien thdi ciia xe v i true ciia gia dd hang </?.
Ta ciing can x i c dinh d i u l i mat trude ciia gii d a hang nira de dua dugc xe t u ddng tiep can diing hudng ciia nd m i khdng hiic vao sudn ciia gii dd. C i c gii dd hang phii tim la cd hang (hoac khdng cd hang) d tren nd; nhung chii yen la trudng hgp cd hing. Khi xir ly bang m i y tfnh PC ngudi ta thudng sir dung bien doi Hough cho nhiem vu n i y v i viec tfnh t o i n rat phirc tap. Ket hgp mdt sd bien p h i p hd trg tren mat trude ciia pallet (son trang hoac d i n tam p h i n quang) va su dungcic camera CNN UM kieu Bi-I hoac Eye-RIS thi cdng viec se trd nen dan giin ban rat nhieu.
Hinh 6. Be mat t r u d e ciia pallet cd hinh dang ddi xung
xrz.
'worldHinh 7. C i c he toa dp va ba thdng sd can thiet x i c dinh vi trf giiia xe t u ddng va pallet Trong thirc te, mat s i n ciia nha kho hoac cing thudng cd man s i m (xam hoac nau), cic pallet thudng khdng san phii va qua sir dung cd man xam de lin vdi man san. Chimg ta
272 PHAM DUG LONG
thay rang mdt.pallet san mau trang tren nen san xim thi de dugc nhin ra bang xu ly inh.
Tuy nhien chiing ta chi can san trang (hoac din tam phan quang) 3 tam dd ciia cic mat trude, mat sau va san trang 2 ben sudn ciia pallet de nhan ra cic hinh 10a, 10c de dang han.
Giai phip nay hoan toan thuc te do dien tfch san nhu vay se khdng lam tang them nhieu gii thanh che tao pallet.
0\
(a) (b) (c) (d)
Hinh 8. Mdt pallet mang hang
Khi pallet khdng mang hang nd cd hinh dang nhu 8a. Nd tuang quan vdi hinh lOd. Trong trudng hgp khdi hang thap nhu 8b thi ciing gan gidng vdi khi khdng mang hang. Vdi cic trudng hgp nay ta de dang tim ra hudng (Orientation). Tuy nhien trong thuc te da sd cic trudng hgp se cd hinh nhu 8c hoac 8d; tiic la inh ma camera thu dugc khdng phin inh dung hudng ciia nd nira. Loai trir trudng hgp gdc ip = Q thi chieu cao ciia khdi hang khdng inh hudng vi inh ciia nd trimg vio inh ciia gii dd (10b). De thu dugc cac hinh 10a, 10c tir cic inh thu dugc chiing ta can xic dinh diu la mat trude (sau) ciia pallet. Die trung ciia mat trude la tfnh ddi xiing ciia nd (tat nhien inh ciia no thu dugc ciing ddi xirng) nhu hinh 6b.
Nhu da ndi d tren neu chiing ta sir dung cac tam phin chieu hoac san trang 3 tam dd be mat trude ciia pallet thi trude het nhin ra 3 mien inh nay sau dd cd the ap dung tim hudng bang ham CNN. Vdi bien phip nay khi chieu cao khdi hang tren gii dd Idn (8c hoac 8d) van cd the tach ra mat trude va mat sudn ciia gia dd (nhu 10a khi xe tiep can gii dd tir phia phai - hoac 10c neu tiep can tir phia trii).
Trong cac nghien cuu budc dau niy chiing tdi thuc hien gidi han cdng viec tim ra mot gii dd hang trong mdi trudng chua cd lin cac do vat hoac cic pallet khic, tiep can chfnh xic de mdc cang ciia xe vao mat trude ciia nd.
D. Xac dinh hiroTig va vi trf ciia gia do" h a n g t r e n C N N U M Nhgn xet
Camera (pan-til) dugc gan tren xe tu ddng thu inh nhu hinh 7. Vdi mdt dng kinh xic dinh, dp phan giii ciia anh xac dinh thi dp Idn ciia ddi tugng (gii dd) trong inh (tfnh bang sd pixel) phu thudc vi trf tuang ddi forklift va pallet: Khi khoang cieh cdn xa thi anh ciia gii dd be, xe tu dpng mang camera den gan thi inh ciia gii dd Idn. Do hinh dang ciia pallet la hinh chir nhit nen khi thu inh tir camera tren xe tu ddng dat d mdt do cao so vdi san nha kho thi mat trude (sau) va sudn ciia gii dd se cd hinh dang nhu d hinh 10 a,b,c. Tir day se de dang tim ta dau la mat trude (hoac sau) ciia pallet m i khdng phii la sudn ciia nd. Tai mdt thdi diem tuc thdi dii inh ciia ddi tugng nhd hay to (xa hay gan) thi hudng ciia nd so vdi xe tu ddng cd gan camera (tuc la gii tri gdc (/?) van khdng thay doi. Thdng sd nay la Orientation (hinh 9) dugc xic dinh rat nhanh diing CNN.
Neu ta cd mot t i p cic bing LUT chua cac con sd thdng ke md t i quan he khoAng each
= f(Orientation, sd pixel) thi sau khi matching thdng sd Orientation xong rdi bang cieh
XAC DINH VI TRI CAC GIA D O HANG 273 tra b i n g chiing t a se tim ra ngay khoing cieh (hoac X, Y). Tuy nhien budc nay khdng chfnh xac (tfnh thd); nhung cic ket q u i cd dugc mot cieh nhanh chdng nay dugc sir dung trong budc 4 (thuat t o i n hinh 14) se l i m giim tong thdi gian tfnh t o i n . Khi xe t u dpng di chuyen so vdi ddi tugng (gii dd) de tiep can dan vao mat trude thdng sd Orientation tat nhien ciing thay ddi. So s i n h dien tfch ddi tugng thu dugc vdi b i n g LUT de suy ra khoing each tir xe den pallet. O cac khoing cieh xa va gdc tiep can khdng chfnh giira thi sai sd se Idn. Tuy nhien thuat t o i n thuc hien p h u a n g p h i p ciia chiing tdi nham muc dich trude het dieu chinh xe di chuyen tiep can chfnh giira mat trude (sau) ciia pallet (budc kiem tra 8 ciia thuat toin) nen dieu n i y se khdng bi i n h hudng nhieu trong toan bd qua trinh xe tiep can pallet.
Centroid I
" 1 "
\ Orientation
i
Major Axis"
Minor Axis |
Hinh 9. True elip i o ciia ddi t u g n g i n h kfch t h u d c 20 x 20
E. T h u a t t o a n x a c d i n h vi t r i v a htfoTig ciia g i a do* h a n g
* Xdc dinh huong cua farklift voi pallet
Nhd thdng sd Orientation chuang trinh ciia chiing t a se suy ra gdc tiep can ciia forkHft vdi pallet.
(a)
(d)
(c)
(f)
Hinh 10. Cac k h i nang vi trf ciia g i i dd so vdi xe t u ddng (lech t r i i so vdi xe, ddi dien vdi xe, lech p h i i so vdi xe).
O cic vi tri khic nhau hinh i n h ciia ddi t u g n g can nhan dang mac dii cd kfch thudc, hinh ding khic nhau nhung thdng sd Orientation khdng bi thay doi chi phu thudc true tiep vao inh,
274 PHAM DUC LONG
* Xdc dinh khoang each tic forklift den pallet
Khi auto-forklift di chuyen den gan pallet hudng cac anh trong hinh 10 ciing thay doi.
Bang cieh tra cac bing lap sin quan he khoAng each = f(Orientation, sd pixel) chiing ta se suy ra dugc khoang each thuc.
* Xdc dinh chieu cao tic sdn den cdc Id ciia pallet
Gii dinh pallet dat tren san nen khoang cieh nay ludn bang hang sd xic dinh trude.
Thuat toin thuc hien phuang phip xic dinh hudng va vi tri gia dd hang vdi xe tu dpng dua tren y tudng ti'nh tain thd bang tra bing de nhanh chdng tiep can xe diing hudng vdi gia dd sau do giii vung hudng va tiep can dan den gii dd. Khi con mpt khoing each nhat dinh se tinh toan lai chfnh xac.
1 1 1
1
• J
1 1 1 1
0 0 0
0 0 0
0 0 0
A =
B
Hinh 11. Mau SMKILLER
B =
Hinh 12. Man HOLLOW
OS 0,5 0 5
0,5
">
0.5 0,5 0 5 0,5
A-
1.)
1
1]
1 1 1
"
1
N
13 0 O
(1
1
(1
()
1) 1)
Hinh 13. Mau PATCHMAK Gidi thich cac biro'c thuat toan (Hinh 14):
0 0 0
0
T
0 0 0 0
z = 3.25
4 .>
Buoc 1. Thu inh (loai nhieu, xoi ddi tugng nhd) su dung mau SMKILLER (hinh 11). Buoc 2. Tir inh pallet mang hang tich lay cac phan inh mat trude va sudn ciia paHet nhu hinh 10a,b,c. Sau dd chuyen thanh cac ddi tugng die (nhu hinh 10,e,f). Sir dung man HOLLOW (hinh 12) hoac PATCHMAK (hinh 13).
Buoc 3. Tinh Orientation, xem xe tiep can pallet tir phia nao (tir phfa trii hay phia phii).
Buoc 4. Tra bing LUT de suy ra X, Y. Budc nay tinh sa bd khoing cieh de biet xe cd phii liii lai khdng hay tiep can ludn theo quy dao nhu hinh 5.
Buoc 5. Gui cic thdng tin (p, X, Y den he dieu khien di chuyen xe.
Buoc 6. Tinh gdc lech sau khi da dieu chinh hudng.
Buoc 7. Neu thay gdc lech khdng giim di thi cd nghia la tfnh sai (hoac dieu khien sai). Se liii lai de tfnh lai (budc 11).
Buoc 8. Kiem tra xem d i diing hudng chfnh dien chua?
Buoc 9. Trude khi cieh gii dd 2 m bat dau tfnh chfnh xic theo cdng thuc (3) va cic cdng thirc chuyen he toa do xem den khoing cieh cd the mdc cang xe vao pallet chua?
XAC DINH VI TRI CAC GIA DO HANG 275
1 Thu anh (J^oai nhieu, xoa doi tuong nho) 2 Chuyen anh thirc
T
thanh cac doi tuong dac
3 Tinh Orientation cp„
4, Hoc luong khoang each
X
5 Gm thong tin cho he dieu khien xe
12 Doi xedieu chinh cho diing huong Pallet
16, Tinh Orientation q)i,i |
Hinh 14- Thuat t o i n x i c dinh hudng va vi trf g i i d a hang vdi xe t u ddng
Nhdn xet
Budc 6 (thuc hien nhu budc 3) v i budc 7 (dudng dirt net) khi thuc hien tren m i y tfnh tuan t u rat phiic t a p va dp chfnh x i c khdng cao; nhung khi chiing ta sir dung he CNN UM thi viec x i c dinh thdng sd Orientation rat chfnh x i c va dan giin. Do vay trong thuat toin chiing ta cd the bd qua khdng su dung hai budc 6 va 7.
3. T H t r C N G H I E M
Thuc nghiem n h i n ra dp lech cila pallet (gdc if) thuc hien vdi mpt md hinh pallet chiu An thu nh6 cd kfch thudc theo ty le 1:2 (paHet thuc cd kfch thudc 1200x800x144, pallet md hinh cd kfch thudc 600x400x72). Camera Bi-I diing yen va md hinh pallet diing yen.
Khoing cieh giiia camera va md hinh Idn nhat 2 m. Camera d i t d dp cao cd dinh 0,5 m (do md hinh thu nh6). Dieu kien dii i n h sang. Tdc dp bat i n h lOOOfps. Ong kfnh camera Bi-i V2 loai 1:1.4 50 mm va 1:1.4 25 mm. Thuat t o i n dugc ma h o i tren PC bang Code Compose 3.1 ciia hang Texas Instrument.
Chu y: Sd lieu d cic b i n g I va 2 d khoing cieh 2 m la sd lieu t h u nghiem de kiem tra k h i ning phin biet khoing cieh va sd pixel; khdng lien quan gi den budc 9 trong thuat toin.
Ket q u i :
* Nhin dang gdc lech ip vdi dp chfnh x i c cao (sai lech giua gdc lech thuc va chuang trinh nh6 Hon 2°). Ket q u i on dinh.
* Xac dinh vi tri giira camera v i md hinh pallet: Sai sd 3 cm d cac hudng sudn va chfnh dien. Ket q u i dn djnh.
276 PHAM DUC LONG
Bang 1. Quan he giiia sd pixel, dien tich ddi tugng va khoang each vdi dng kfnh 1:1.4 50mm
T T 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
So pixel (X) 70 70 70 70 70 70 70 70 70 70 70 70
'P 0°
0°
0°
0°
0°
0°
45"
45"
45"
45"
45"
45"
Jien tich dnh doi tiromg 2380
2808 3307 4110 5055 6824 2360 2832 3398 4011 5213 6818
Khoing each m 2.00 1.80 1.60 1.40 1.20 1.00 2.00 1.80 1.60 1.40 1.20 1.00
Bdng 2. Quan he giiia sd pixel, dien tich ddi tugng v i khoing cieh vdi dng kfnh 1:1.4 25mm.
T T 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
So pixel (X) 38 38 38 38 38 38 38 38 38 38 38 38
f 0°
0"
0"
0"
0°
0"
45"
45"
45°
45"
45"
45"
Dien tich dnh doi tirong 684
760 882 1012 1300 1624 660 726 835 960 1209 1524
Khodng each m 2.00 1.80 1.60 1.40 1.20 1.00 2.00 1.80 1.60 1.40 1.20 1.00
Nhdn xet
Be thuc hien dugc phuang phip can cd sin cic bing sd lieu nhu cic Bing 1,2, cd the han che sd lugng bing luu trii bang cieh chi luu trir cac vi trf die biet: Thuc chat gdc (p chi gom trong khoing tir 0" den 90" (cic vi trf Idn han 90", nhd ban 0" ...) chi la cdng them 1 sd hang sd. Tir nhin xet nay chiing ta se chi luu trir cic dii lieu tuang irng vdi cic gdc cieh nhau 10° mdt. Dieu nay ciing la thi'ch hgp vi viec tra bing chi la udc lugng va tinh toan thd.
Khi den khoang cieh gan gia dd van can tfnh toan chfnh xac theo cic cdng thuc toin hpc.
4. KET LUAN
Viec nhin dang, xic dinh vi tri ciia mdt xe tu ddng vdi mdt ddi tugng ma nd can tiep can cd nhieu phuang phip. Trong bai viet nay chiing tdi da sir dung mdt phuang phip dua
XAC DINH VI TRI CAC GIA D O HANG 2 7 7
t r e n c i c t i n h t o i n song song ciia m i n g C N N . P h u a n g p h a p n a y cho p h e p t a n g t h e m t d c d p v a d p chfnh x i c t i e p c a n ciia x e t u d d n g v a ddi t u g n g .
T A I L I E U T H A M K H A O
Leon O. Chua a n d L. Yang, Cellular neural networks: Theory, IEEE Trans. Circuits Syst. 3 5 (10) (1988) 1257-1272.
Nygrds, "J. On Robot Feedback from Range Sensors, Reliable Control by Active Reduction of Uncertainty and Ambiguities, Dissertation Robotics/Autonomous Mechanical Systems". De- partment of Mechanical Engineering, Linkping University, 1998.
Nilsson, B., "On Robot Control using Range Sensors with Special Reference to Active Un- certainty Reduction, Dissertation, Robotics/Autonomous Mechanical Systems", Department of Mechanical Engineering, Linkping University, 1997.
Jacob Roll, "A System for Visual-Based Automated Storage Robots", Master's Thesis, 3-1999.
D. Khadraoui, G. Motyl, P. Martinet, J. Gallice, F . Chaumette, Visual servoing in robotics scheme using a camera/laser-stripe sensor, IEEE Transactions on Robotics and Automation 1 2 (5) (Oct. 1996) 743-50.
P. I. Corke, M. C.Good, Controller design for high-performance visual servoing, IEEE Trans- actions on Robotics and Automation 1 2 (5) (Oct. 1996) 671-683.
Leon O. Chua and Tamas Roska, Cellular Neural Network and visual Computing Fundations and Applications, Cambridge University Press., 2003.
Richard Hartley and Andrew Zisserman, Multiple View Geometry in Computer Vision, Cam- bridge, 2003.
Giovanni Garibotto, StefanO Masciangelo, Marco Ilic, Paolo Bassino, ROBOLIFT: a Vision Guided Autonomous Fork-Lift for Pallet Handling, IEEE, (1996) 656-663.
Michael Seelinger, John-David Yoder, Automatic Pallet Engagment by a Vision Guided Forklift, Internatinal Conference on Robotics and Automation. Baccelona, Spain, April 2005 (4068- 4073).
Sungmin Byun and Minhwan Kim, Real-Time Positioning and Orienting of Pallets Based on Monocular Vision, 2008 20^^ IEEE International Conference on Tools with Artificial In- telligence, IEEE, 2008 (505-508).
Daniel Lecking, Oliver Wulf, Bernardo Wagner, Variable Pallet Pick-Up for Automatic Guided Vehicles in Industrial Environments, IEEE, 2006 (1169-1174).
AnaLogic Computers Ltd., Bi-i Programming Guide, H-1111, Budapest Hungary, 2004.
P h a m Due Long, P h a m Thuong Cat, Image R a m p Edge Enhancing and Denoising by Complex Nonlinear Diffusion Using Cellular Neural Network, Proceeding of ASGG2009 Hong Kong, IEEE, Hong Kong, 2009 (1509-1514).
P h a m Dire Long, P h a m T h u g n g Cat, Cdng nghe mang noron te bao CNN va ling dung. Tap chi Tin hoc vd Dieu khien hgc 2 2 (1) (2006) 37-44.
Pham Due Long, P h a m T h u g n g Cat, Cap T h a n h Timg, Xay dung md hinh mang noron te bao CNN giii p h u a n g trinh khuech t a n phuc tuyen tinh irng dung trong xii ly i n h . Tgp chi Khoa hoc vd Cong nghe, Dai hoc Thai Nguyen, (49) (2009) 51-56.
Nhdn bdi ngdy 25 - 10-2010
