%? chi Khoa hgc Trudng Dgi hgc Cdn Tho Phdn A: Khoa hgc Tif nhien. Cdng nghi vd Mdi trudng: 33 (2014): 83-91
Tap chi Khoa hoc TriTdng Dai hoc Can Thd website: sj.ctu.edu.vn
GIAI THU^T DINH VIVI TRI TRONG KHONG GIAN 3-D CHO THE RFID D I T A VAO ClTOTNG DO TIN HIEU (RSS)
Vu Due Lung', Phan Dinh Duy' vi Pham Qudc Cucmg'
' Trudng Dgi hgc Cdng nghi Thdng tin, Dgi hgc Qudc gia Thdnh phd Hd Chi Minh Thdng tin chung:
Ngdy nhgn: 22/04/2014 Ngdy chdp nhgn: 28/08/2014 Title:
A new 3D localization algorithm for RFID Tags based on Received Signal Sti-ength
Tirkhda:
RFID, thugt todn dinh vi, the RFID, dg mgnh tin hiiu, cudng dg tin hiiu Keywords:
RFID, Localization Algorithm, RFID Tags, Signal Sti-ength, RSS
ABSTRACT
In recent years, RFID technologies have been developed enormously and attracted special attention in the development of efficient and applicable algorithms, e.g., the method of locating Spot On, the positioning techniques of Landmarks, Virtual Landmarks. There are; however, various issues relating with environments which have a large number of obstacles as well as a huge density of Tags in a particular unit area.
This research paper presents a method to locate tags with high accuracy in three-dimensional space when eight antennas are located at the corners in the monitored areas. The position of each lag is obtained based on the aggregate Received Signal Strength (RSS) value and the elimination of errors occurred in the communication process between the Tags and the reading range of the Readers.
The simulation results show that the system can operate with relatively good accuracy in specific space which has a vast density of obstacles such as libraries, warehouses, etc. In addition, the application of the localization algorithm can ensure practicality, easy installation, economy, the possibility of rapid expansion as well as the proper optimization of management system for various types of environment.
Nhitng ndm gdn ddy. cdng nghi RFID dd_ phdt triin vugt bdc vd thu hut su quan tdm ddc biet trong viec xdy dung mgt^idi thudt djnh vi phii hap de ung dung thuc ti hieu qud [4]. Trong do, cd the ki den phucmgphdp xdc dfnh vi tri Spot On, ky thudt dinh vi Landmarc vd Virtural Landmarc. Hien bdi todn ndy con nhiiu vdn di cdn nghien cuu gidi quyet trong mdi trudng xudt hiin nhiiu vdt cdn cSng nhu mat do phdn bo so luong Tags cue ldn trong mdt dan vi dien tich nhdt dinh.
Bdi bdo gidi thiiu vi thiit ki mgt phuang phdp djnh vi tags vdi dg chinh xdc cao trong khdng gian 3D khi bd tri 8 anten a cdc gdc trong khu v^rc qmn ly.
Vi tri cua Tags dugc tinh todn dtfa vdo viic tong hap gid tri ciia cudng dg tin hieu trd vi (RSS) [8] ddng thdi loai bd di cdc sai sd xdy ra trong qud trmh giao tiip giiia Tags vd tdm dgc cua Readers.
Kit qud md phdng cho thdy he thing boat dgng co do chinh xdc tuang ddi tdt trong khdng gian cd mat do vdt dung nhieu nhu thu viin, kho chua hdn^ hda.
Ngodi ra, viic ung dung gidi thugt ddm bdo tinh thiet thuc, de ddng lap dgt thiit bi vdi hieu qud kinh ti cao, co khd ndng md rgng nhanh chdng, cUng nhu tiiy tirng logi mdi tnrdng khdc nhau di liiy biin tii tru hoa hi thdng qudn ly mdt cdch phit hgp.
Tgp chi Khoa hgc Trudng Dgi hgc CSn Tha 1 GlOfI THIEU
Vice nghien cftu cac giii thuit dinh vi ddi tupng trong mdi trudng RFID di dupe nghien cftu nhidu trdn till gidi. Tuy thudc vio cdng nghf vi cie ftng dung cy thd mi cic giai thuit nay tap trung vio df ehinh xic, tilt kifm nang lupng, kieh thudrc, hay nhftng rar^ budc vd mat phin cung. Tidu bieu cd ba hudng phit trien nhu sau:
Cae kl thuit xdc dinh khoing each tiiudng su dung ^ i tri cudng do tin hieu tra ve cua tin hieu (Received signal sti-ength - RSS) [8], thdi gian tra vl (Time of Anival - TOA) [2], chenh Ifch thdi gian tri vd (Time Difference of Arrival - TDOA) [5]. Cac phuang phdp do khoang eich thudng chiu dnh hudng cfta sy che khuit v i sy Ifch hudng.
Chung thudng ddi hdi eae ky thuit chuyen bift dl ddng bp hda hoic dk tinh goc ciia ddi tupng cin dupe dinh vi.
Phuong phap phan tich ngogi cdnh (Scenes Analysis) [2] ed dp chinh xac cao ban so vdi cac phuong phdp ke tren, my nhien chi phi thiet lap hf thong qud cao do sft dung sd lupng ldn cac thidt bi vd tdc dp xft 1^ chim vi cdn nhieu diem mdc (nodes) dk xdc dinh vi trf cua ddi tupng.
Mpt phuang phdp khac la phuang phdp lin can, diy li mft phuong phap ca bin va de thyc hifn.
Tuy nhien, dp chinh xdc 1^ tuy thudc vao kich thudc cic d djnh vj [1].
Phuang phap Spot On [7] sft dung cdc phep do RSS de udc tinh khodng cdch gifta tdi diidu ba readers vi mft thd ddi tupng, tft do sd ftng dung phdp do 3 canh tam gidc (trilateration) [2] U'nh ra cic khodng each nay. Ky thuit Kalman filtering sft dyng cic tiii tham ehidu va dua tren mpt bin dd xdc suat Idi phep ^do cho khu^vuc dd tim cua cic readers. Vdi'cic^ dgng udc tmh khoing each, Bechtler va Yenigun cung da trinh bay mpt phuang phap dya vao mdt bp reader phit va hai readers nhin: hf thong SAW-ID, U'nh todn khoar^ each nhd sft dyng ki thudt TDOA [3]. Tilp do, cic phep
Phdn A: Khoa hgc Tv nhiin. Cong nghi vd Mdi Irudng: 33 (2014): 83-91 dinh vi duac tiiuc hifn bing cich ftng dying phuang phip trilateration. Mpt phuong phap khic khi ndi tidng l i Landmarc [3]. Phuong phip phan tich ngogi cinh nay sft dung cdc the tham chieu cd vi tri da ro dupe cd dinh dk lam cdc mdc kilm soit, cic readers se cd nhilu mftc ngudn khic nhau. Cic Readers khic nhau vl phgm vi dpc se sft dyng phep do RSS cho tit c i cic the tham chilu vi thd ddi tupng. Nhibig the tham ehidu gin nhat sS dupe chpn va vi tri cua chftng sd dupe liy gii tri trung binh de udc lupng vi tri cfta the ddi tupng[6].
Bii bio niy trinh biy mpt phuong phap gidi thuat dinh vi mdi: bang cich bd tri S Anten dd thu nhan tin hifu RSS cfta tags tri ve rdi tft dd tinh khoing eich giua tag vdi cac thiet hi, dong thdi kit hpp vdi viec so sinh cic gii tri nhgn dupe dk suy ra vi tri chinh xic cua tag. Ky thu§t niy dya tren thdng tin ca ban gifta giao tiep Anten vi tag do dd dd ddng xay dyng va md rdng hf thdng, chi phi xiy dyng he thong hpp li cung vdi dp chinh xac chip nhan dupe.
2 PHAN TICH, THIET KE G U I THU.^T DINH VI
a. Gidi thiiu vi Received Signal Strength Indicator (RSSI)
RSSl id gia tri do mftc ning lupng ciia song Radio ma Anten nhin dupe tft Tag hoi dip trong qui trinh giao tiep Reader - Tag [8].
Trong qui trinh giao tilp gifta Reader va Tag, Reader sd cap ngudn nang lupng cho hf thdng phit song, tfty theo mftc dp cap ngudn mi song phdt ra cd mftc nang luai^ khic nhau, rdi thdng qua Anten cung cip ndng lupng cho cic tag. Sau khi nhdn dupe tm hifu ndy cic thd tag sd su dyng ngu6n nang lupng do de phin hdi lgi cho Reader. Tft dd, thdng qua vifc do ludng cudng dp mgnh yeu cfta tin hifu phan hdi de so sdnh vdi mftc ning lupng ban dau, gia tri khoing each gifta Anten vi tag ed the dupe tinh toan va xic dinh mpt cich chinh xic.
c u p GobetnMa
(^e^
Hiah 1: So- dd giao tilp giiia Reader va Tag 84
Kl bieu R^
H VJ dj
Chd thi'ch Anten j The Tag cin dinh vi
Gia tri cudng do tin hieu cua Tag H ma Anten j nhan dupe
Khodng cdch tuang ddi gifta Tag H vi Anten j
Tgp chi Khoa hgc Trudng Dgi hgc CSn Tho Phdn A: Khoa hgc Tu nhien. Cdng nghi vd Mdi iruang: 33 (2014): 83-91 b- Thiet lap hi thdng Bang 1: C i c chu thich cho cac bien dupe su Pli ,. . . . . . , . , . ... . dung trong thuat toan
E^e thyc hien viec dinh vi tpa dp trong mpt • - - —=
Kh^ng gian cd kich thudc Id: Chilu ddi a; Chidu rong b; Chilu cao e ta se bd tri 8 Readers tai cae goc. Gid djnh rang vifc giao tiep lien lac giua mdt Reader bit ky va mpt tag trong khoing khdng gian gii dinh la cd thd va ti-d vl mdt gii tri cudng df tin hifu tui/ theo khodng cich tuong doi cua Reader va Tag. Ddng thdi gii sft ring ldp dia chi MAC cfta RFID da dupe nhftng c i hai ca ehl phat hien v i
chdng dyng dd (collision detection and singulation) ^^ '"^'^^ ^^^ ^ ^ S ^^^^ ^°^ ^^ ^!- vi cic readers nay cd mdt thuat toan dieu khiln Budc 1:
ngudn.
Xic dinh khoang each tuong ddi giira Anten j va Tag H dya vio gii tri cudng dp tin hifu RSS.
Tren thyc td gia tri cudng dp tin hifu md Reader nhgn dupe cdn phy thudc vdo ylu td ngogi cdnh VI thd dd chinh xdc cin thyc nghifm theo tftng mdi trudng khic nhau de bilt co kSt qui chinh xac nhit; trong mdi trudng ma ta thyc nghiem 1 RSS~10em—+15cm. Cudi cung budc nay ta se thu dupe cdc gid tri tuong d6\ di
Hinh 2: Stf dh bh tri cic Readers trong khdng gian
c Ca sd ciia gidi thugt dinh vi
Thugt toan dinh vj dupe xiy dung dya tren 2 van dk chinh:
Diu tidn dya vio hf thdng 8 Anten dk thu thap gia tri RSS eua Tag ma ta cdn dinh vj vi tri ket hpp vdi viec so sinh vdi mftc dp cip ngudn ban diu cua Reader cho eic Anten dl tft dd ti'nh toan suy ra khodng cdch tuang doi gifta Anten vi Tag. Luu y ring gia trj RSS tid ve se cd thay ddi nhit dinh phu thupc vao each chinh mftc ngudn phat eua reader- cung ddng thdi tang phgm vi dpc cua Anten.
Phin thft hai ta se sft dung gii tri khoing each cua mpt tag cin dinh vi doi vdi 8 Anten ma ta vfta tinh toan dupe dd tinh todn, so sanh ddi chieu de xic dinh vj tri cfta Tag trong khdng gian qua do cung ddng tiidi lpc cdc tin hieu nhieu giup ting dp chinh xic cua tiiugt todn.
d. Thugt todn djnh v/
Lift ke cae chft thich vi thugt toin dinh vj 3D cbo mdt tag duoc md ti nhu trong Bing 1.
Hinh 3: Vj tri va gii tri cudng dp tin hifu Vi ciia tag H vdi cac readers
Ta sft dyng phuang thfte tpa dp hda cac vi tri dit Anten va Tag H:
Rl(0,0,0)|R5(0,0,c) R2(a,0,0) j R6(a,0,c) R3(a,b,0) I R7(a,b,c) R4(0,b,0) I R8(0,b,c) Va tpa dp tag H(x,y,z)
Budc3:
Tft cdc gid tri dl,d2,d3,d4,d5,d6,d7,d8 cftng cdc tpa dp vi tri dit cdc Anten vi tag H ta suy ra he
Tgp chi Khgg hgc Tntgng Dgi hgc Can Thg Phan A: Khga hgc Tif nhien. Cgngngh4 va M6i Iruang: 33 (2014): 83-91 phirong trinh khoang each tir Tag H toi cac digm
dat Anten [8] :
O f - « > * + ( 3 ' - « « + ?'=1^3'
Giai he phuong trinh tren ta se co dugc cac gia tri x,y,z ciia H:
Za
t t , ' t a ' - t i t ' 2a
Gia tri y:
•*.'
•*.' d . ' d , '
¥u?- 2b 2&
1- 0=- 26
- < 4 ' - < * , ' - 4 ' -^'
ll.2* =
<J.'
•i.=
i^^
d,' + » ' •
2 P + 0= -
2c 2 P
-<J,=
-*.'
- d . '
- < « . "
Trong didu kifn 1;^ tudng, kit qui ta thu dupe sd li nhu nhau, tftc li:
y = yi.=s = s = 3i
Tuy nhien trong dieu kifn thudng ludn ludn cd nhftng sai s6 trong tinh toin, die bift la trong kj thu^t RFID v6n rit hay chiu inh hudng tft mdi trudng giam sat, vi thi thyc tl cic gii tri Xj.Yj va Z] se ludn cd sy chSnh Ifch gii tri vdi nhau. Vi vgy, dk xdc dinh vi tri ehinh xic eua Tag H(x,y,z) ta eo:
X = (Xi + X2 + X3 + X4)/4 Y = ( y i + y 2 + y3 + y4)/4 Z = (Zl + Z2 + Z3 + Z4)/4
Ddn diy ta hoin toin dinh vi dupe vi tri eua tags H trong khdng gian 3D. Tuy nhidn, trong fliyc tl ta ludn gip rat nhidu vin dk inh hudng tin vifc giao tilp gifta tag va Anten tft do cung tryc tilp dnh hudng tdi gid trj RSS tri vl mi Reader nhgn dupe.
Ddi vdi eic tic nhin giy dnh hudng tuong ddi ta cd the thyc hifn budc 5 tiep theo sau diy de giad quylt, tuy nhien d6i vdi cdc tic nhin giy dnh hudng mgnh, lim sai Ifch tryc tilp din gidi thu|lt djnh vi thi ta phii cd mft phuang phdp phft hpp de lpc nhieu.
e Vdn di nhiiu vd lgc nhiiu (Budc 5) Vi cdc loi CO the xuat hifn trong qui trinh Anten dpc sai gid tri RSS, t h ^ chi li khdng dpc dupe gid tri RSS sd giy anh hudng tdi dd chinh xic cfta gidi thugt do no tao ra sy sai Ifch rat ldn vd ^ tri titih toan gifta cic diem tags, so vdi gii tri cua cic didm tags.th|lt sy.
Nhin xet thiy ring cic dilm t a ^ sai Ifnh ndm rii ric trong khdng gian v i khdng hi tip trung nhu cic gii trj tags dung vi the ta cd the tim noi mgt dd cao nhat cua cdc dilm bing cdch nhu sau:
Chpn trong s6 cic dilm nam trong phgm vi r cua cfta dilm dinh trudc, vdi */ la dgi lupng dung dl xdt dilu kifn thda man cdc diem ndm trong hay nim ngodi pham vi r :
VT, = ffji ¥t^ € VT,B,j = 1%
Tgp chi Khoa hgc Trudng Dgi hgc CSn Tho Phdn A: Khoa hgc Tif nhien. Cdng nghi vd Moi Irudng: 33 (2014): 83-91 K = \VT I
Trong tit c i cic t|p hpp didm FTf chpn ra "mtse ' ' '•mo*'
*^'K(a: Ii tip hop dilm ldn nhit /^.SSf "^S^ ^'^Sf \
^ , Trong do Xe, ye, Ze li cdc tpa dp udc tinh cfta the - Tinh ra sd dilm thda min ydu ciu, cd mftc y^ x, yi z, la tpa do cua dilm Vi.
dp tgp trung cao nhit
Tr^#
Hinh 4: Sai Ifch giu^ tag tinh toin vdi tag thit do sai gia tri RSS. Gia tri gan diing c6 mau hong; c gia tri sai Ifnh Idn cd mau xanh la
3 THU" NGHIEM VA ©ANH GIA KET QUA M. Thiet lap mo phdng
D I md phdng he thdng, bdi bdo nay dftng Matiab. Quy djnh ring mdi I don vi tuang ftng vdi 1 cm dan vj chilu dii d ngodi thyc tl.
: ^ - Cic Anten se nim d 8 gdc trong khdi^ gian ma
^ ta mudn md phdng thyc nghifm. Cie thdng tin can nhip vd khdng gian mi ta mu6n md phdng gdm:
- Chieu cao - Chidu dii Chidu rpng
- Tpa dp X, y, z cua t ^ cin dupe dinh vi hoic ID cua 1 tag di dupe quy dinh vj tri tfty cbi dp lya chpn
b. Giao diin md phong:
Giao difn chuang trinh md phdng dupe thiet kl nhu sau [10]:
Room Information Length ; 100 ' Width L " ™ Height ' ' 100
C Cai )
Hinh 5: Giao dien chuong trinh md phdng
Tap chi Khoa hgc Trudng Dgi hgc Cdn Tha Phan A: Khoa lioc Tu nhien. Cdng nghi vd Mdi Irudng: 33 (2014): 83-91 ' Bdn trai la khdi^ gian md phdng dien tich Id
100 x 100 x 100. Ta sd thi hifn Anteii, didm ein dinh vi, tpa dp udc tfnh thda man eic didu kifn sau:
Anten se dupe bd tri 8 gdc cua khdng gian ma ta mudn md phdng v i dupe bidu dien bing hinh luc giic ldn bao quanh.
Tpa dp thyc eua dilm dgt tag li hinh sao cd miu xanh.
Tpa dp ude tinh dupe cung li hinh sao nhung cd miu do.
- Cdc tpa dp diem tinh toin se la binh *. Sau khi lpc nhieu tin hifu, nhung tpa dp diem gin dung sS ed mau h6ng, cdn nhung tpa do bi logi se cd mau xanh Id.
Ngudi dung cin nhgp cdc thdng tin sau : Thdng tin Room's Information, Search Information, Location gii lip cin djnh vi
Chpn 1 trong 3 che dp sau:
M: Che dp Normal Noise tinh toan trong dieu kifn thudng. Ngucri dung se nhgp tpa dp x, y, z cua diem cin dinh vi vdo. Hf thdng se md phdng gid dinh gia tri RSS rdi tinh todn de thdng bdo ket qud cfta tpa dp ude tinh.
Hinh 6: Mo phong, tinh toin khi cb^y mode M H: Che df Heavy Noise se thft dp chinh xdc ciia giii thu^t trong trudng hop hf thdng dupe d|t vio mdi trudng ed df nhidu cao. Ngudi dftng sd nh^p tpa dp x,y,z cfta diem cin dinh vj vdo. Hf thong se ty dpng gid dinh mftc dp giy nhidu d trgng thai cao, sau do tinh toan dd dua ra kit qui cua tpa dp udc ti'nh.
Hinh 7: Mo phdng, tinh toan khi chay mode H A: Chl df Auto, ngudi diing sS nhap gid trj tdn ID cd sin, sau do nhin nftt Call de tinh todn kit
Hinh 8: Md phdng, tinh toan khi chay mode A Dya vio kit qui md phdng ta tiiiy ring dp ehinh xdc cfta giai thuit li tuong ddi tot (dp Ifch cdc diem mau xanh v i miu hdng). Vdi sai s6 ndm trong khodng tft 20 - 70 cm d mdi trudng khdng gian 3D la hoan toin chip nhin dupe. Thdm chi trong nliftng ftudng hpp md phdng, rapt vii Anten dpc sai gii trj hay mat tin hifu, df chi'nh xdc cfta giii thudt cung khdng bj inh hudng nhilu.
c Md td hi thdng thit nghiim thiic ti Md hinh ftng dung 8 anten bai bio tiln hinh thft nghifm dftng ho trp quin ly sich vi tim kilm vi tii sich trong thu vifn v i dupe bd trf nhu Hinh 9. D I thyc hidn vifc chia chu ky cap nhit thu vifn, ta chia thu vien thinh nhimg khu vyc nhd hon, moi khu vye gdm 2 kf don: kd trdi vd kf phii. Gifta khoing khdng gian 2 kf bd tri 4 hf tii6ng anten dl thyc hien dpc va dinh vj vj tri sach trong khu vycdd.
^9P chi Khoa hgc TrudngDgi hgc Cdn Tho PhSn A: Khoa hgc Ttr nhiin. Cong nghi vd Mdi trudng: 33 (2014) • 83-91
Hinh 9: Md hinh b6 tri anten trong 1 khu vuc phan chia nhd thu vien kf do.
Mdi hf thdng anten gdm eo khdi Reciever {Rx) vd Anten RFID, kh6i Rx chiu trach nhifm nhgn tui hifu va dinh thdi hoat ddng cua anten RFID. Mdy chft diSu khien dieu khien cdc hf thdng nay bSng tin bifu wireless thdng qua khoi Tranmister (Jx).
Hogt dpng cua hf thdng dupe chia lam 2 gim dogn ehinh:
Giai doan 1: Hf thdng difiu khien cae anten RFID hudng vl kf ben phai d tftng khu vyc, tiln hanh dpc thdng tin sach va djnh vj vi tri sach d cic
Kit thuc gi£u dogn 1 hf thong tien hanh dilu khiln cdc anten RFID quay hudng vl cac ke ben trdi.
Giai dogn 2: Hf thing dilu khiln cic anten RFID hudng vl ke cdn lai cua tftng khu vyc, sau dd tiln hanh cip nhat thdng tin sach cung nhu vi tri sich d eae kf con lai.
Kdt thuc giai doan 2 he thong trd vl vj tri ban diu, chd din chu ky cap nhgt thu vifn ke tilp.
Hinh 11: Giai doan 2 cac anten hudng ve kf trai
Tgp chi Khoa hgc Trudng Dgi hgc Cdn Tho Pban A. Khoa hgc T{r nhiin. Cdng nghi vd Mdi trudng: 33 (2014): 83-91 d. Thir nghiim thuc te
Giii phip dinh vi mdi niy di dupe ung dung trong he thdng quin ly va tim kiem sich trong thu vifn, dupe bd tri trong mdi budng phong Lab cua
Khoa KJr Thuat Miy Tinb, Truong Dai hpc Cdng nghd Thdng tin. Cac the RFID dupe sft dyng ti logi thy ddng (UHF Passive), tin sd hogt dpng : 860~960MHz, chuin : EPC CLASS 1 GEN2/ ISO 18000-6C.
Hinh 12: He thong quan Iy sach thu vifn Vdi vifc sft dyng Reader FX9500 hd trp 8
anten RFID vd cd khi nang dpc cd hai loai the thy dfng vi tich eye, gii thinh hf thong chi khoang 2000USD so vdi 8000USD nlu dung 8 Reader RFID ddc l^p [I I]. Bai bdo Uiu nghiem he thdng
vdi trgn 200 ddu sach dupe gdn tag RFID vi cho ket qua tim Idem sdch cung nhu cdc thdng tin kem theo la rdt khd quan va chinh xdc (ket qud tim kifim trd ve nhu Hinh 13)
• T£rJ T A C G U tiffi H O R K J N S
" CATCGORY CNTT
^ ?
EPC 3 0 3 < » } « : 4 1 K ; « C O O O O O K 8 7
\>
PUSUSHER r j E W M O n Z O N S; Sach ^ n tim nim cr ke 1 hang 2 o thCf 1
&"•' * = ^ S " ' ! ^ ^ ^ :
Hinh 13: Ket qua tim kidm sach cua hf thdng e Ddnh gid kit qud
Ket qui thyc te khi vin hinh he thdng demo cho thiy hf thing quin ly sich dap ftng khd tot trong didu kien cd khodng 500 - 700 cudn sach
tren tdng so 4 kf sich don (kf gifta cd 2 kf don dit canh nhau) trong khdng gian cd difn tich 2m x 3m.
Ddng thdi chuong trinh quin ly v i tim kilm sich trong thu vifn bao gdm hoan chinh cic chftc ning ca bdn nhu: vifc xdc dinh thing ke nhftng cuon
7<¥> chi Khoa hgc Trudng Dgi hgc Cdn Tho Phdn A: Khoa hgc Tif nhiin, Cdng nghi vd Moi Irudng: 33 (2014): 83-91 sach da bj dit sai vi tri, hay cac thdng tin vd cudn
sich can tim,... cung cho kdt qui tit ban so vdi cac he thdng dinh vj hien nay. Kit qui trong Bing 2 cd duoc sau khi tdng hpp ddnh gid phuang phap dinh
Bang 2: So sinh kit qui ciia phmmg phap de xoat vdi mpt so phinmg phip thdng dung khic vi de xuit dya trdn ci 2 qui trinh md phdng cung nhu hf thdng trong thyc td va so sinh vdi cac giii thuit khae hifn ed trdn the gidi [5].
Land-marc SPOT ON SAW tags Our New Method Distance estimation RSS RSS
Dimension 2D 2D Reader's deployment Ceiling (or Floor) Ceiling(or Floor) Price Normal Low Accuracy l-2m ~3m
TOA RSS 2D 3D Ceiling(or Floor) Ceiling and Floor High Low 0.2m 0.2-Inr Vifc sft dyng he thing ndu tirdn khdng chi giup
gia ting hifu qui xft l^ ehinh xac trong vifc xic djnh vi tri sich cin tim mi cdn giftp giim ding ke chi phi xdy dyng hf thdng so vdi vifc su dung nhung bf Anten - Readers rieng le.
4 KET LUAN
Vdi vifc chi sft dung mdt hf thdng gdm 1 Reader RFID cd khd nang hd trp tdi da 8 Anten ket hpp vdi phucmg phdp giii thuat dinh vj ndy ddm bao tinh thilt tiiuc cung nhu dl ding trong xiy dyng va bo tri hf thdng, cd klii ning md rdng vi phit triln nhanh chdng. Ky thudt nay khdng chi cung cap mpt gidi phip djnh vj tuong ddi chinh xic trong mdi trudng 3D phftc tap, ddng thdi cdn tilt kifm ehi phi khi xiy dyng hf tiiong, mang lai hifu qud kinh tl cao, phu hpp vdi vifc xdy dyng cdc ftng dyng qudn ly trong thu vifn, kho chfta.
Hf thing thft nghifm qudn ly va dinh vi sdch trong thu vifn di cho thiy khd nang quin ly dupe vj trf tai nguydn sdch tren kf vi tft do cd the md rdng hd trp nhin vidn quin thu nhieu vifc khac nhu phin loai, sip xip, kilm ke til lifu.
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Nghidn eftu niy nhgn dupe sy hd trp eua Dgi hpc Quic gia Thanh phi Hd Chi Minh (VNU- HCM) trong dl tai ma sd B2012-26-02.
TAI Ll£U THAM KHAO 1. Mathieu Bouet, G. Pujolle Computer
Communications - "Range ft-ee 3D localization of RFID tags based on opologlcal constraints "-Computer Communications Volume 32, Issues 13-14, 17 August 2009, Pages 1485-1494.
2. Mathieu Bouet- Universit'e Pierre et Marie Curie, Aldri L. dos Santos- Federal UniversiQ' of Paran'a, "RFID Tags:
Positioning Principles and Localization
Techniques"- Wireless Days, 2008. WD '08.
IstlFiP.
3. Lionel M. Ni and Yunhao Liu, Yiu Cho Lau and Abhishek P. Patii, ''landmarc: indoor location sensing using active RFID" - Wheless Networks 10, 701-710, Kluwer Academic Publishers, 2004.
4. Paul Wilson, Daniel Prashanth, Hamid Aghajan, "Utilizing RFID Signaling Scheme for Localization of Stationary Objects and
Speed Estimation of Mobile Objects", l^
IEEE International Conference on RFID, 26-28 March 2007.
5. Mathieu Bouet and Guy Pujolle, "A Range- Free 3-D Localization Method for RFID Tags Based on Virtual Landmarks" - pages 1-5. IEEE 19* Intemational Symposium on Personal, Indoor and Mobile Radio Communications, 2008. PIMRC 2008.
6. C. Wang, H. Wu, and N.-F. Tzeng, "RFID- based 3-D positioning schemes" - INFOCOM 2007. 26th IEEE Intemational Conference on Computer Communications.
7. Jeffrey Hightower and Gaetano Borriello :f
"SpotON: An Indoor 3D Location Sensing Technology Based on RF Signal Strength" - UW CSE Technical Report #2000-02-02 February 18, 2000.
8. Christian Nftfiez Alvarez and Crisdan Crespo Cintas, "Accuracy evaluation of probabilistic location methods in UWB- RFID systems " -Aalborg University - pages 30-32, Master Thesis 10* Semester, Group Number 1097,2010.
9. Radio Frequency Identification (RFID) home page,
http ://www.aimglobaI .org/teehnologies/rfid/
10. Matiab, http://www.mathworks.com/
11. http://www.atiasrfidstore.com/RFID_reader_s/
29.hun
