DO an TOT NGHIEP DAI HOC Mang Cam Bien Khong Day

HC VIN CNG NGH BU CHNH VIN THNG ----------------* *----------------

NTT NGHIP I HC ti

CC NG DNG CA CNG NGH CM BIN KHNG DY V NH GI BNG M PHNG

Ngi thc hin: Lp: Ngi hng dn:

ngc Anh D2001VT TS. inh Vn Dng

H Ni 2005

HC VIN CNG NGH BCVT KHOA VIN THNG I ----------o0o----------

CNG HO X HI CH NGHA VIT NAM c lp - T do - Hnh phc ----------o0o----------

TI N TT NGHIP I HCH v tn: ngc Anh Lp: Nghnh: D2001VT in t - Vin thng Kho hc: 2001 - 2006 Tn ti: Cc ng dng ca cng ngh cm bin khng dy v nh gi bng m phng. Ni dung n: - Gii thiu tng quan v mng cm bin khng dy.-

Cc ng dng ca Cng ngh mng cm bin khng dy.

M hnh v phn mm m phng ng dng mng cm bin khng dy. nh gi mt s tham s Cht lng dch v QoS ca mng cm bin khng dy. Ngy giao ti: Ngy np n: 25/07/2005. 25/10/2005

Ngy

thng

nm 2005

Gio vin hng dn

TS. INH VN DNG

NHN XT CA NGI HNG DN:

im:

(Bng ch:

).

Ngy

thng

nm 2005

NHN XT CA NGI PHN BIN:

im:

(Bng ch:

).

Ngy

thng

nm 2005

MC LCMC LC...................................................................................................................................I THUT NG VIT TT........................................................................................................III LI NI U............................................................................................................................1 CHNG 1................................................................................................................................3 TNG QUAN V MNG CM BIN KHNG DY............................................................3 1.1 Gii thiu v mng cm bin khng dy..........................................................................3 1.2 M t h thng tng qut..................................................................................................3 1.3 Cc nhn t nh hng n mng cm bin khng dy....................................................5 1.3.1 Tiu th ngun mc thp...........................................................................................5 1.3.2 Chi ph thp................................................................................................................6 1.3.3 Mc kh dng.......................................................................................................6 1.3.4 Kiu mng..................................................................................................................6 1.3.5 Bo mt......................................................................................................................7 1.3.6 Thng lng d liu...................................................................................................9 1.3.7 Tr bn tin..................................................................................................................9 1.3.8 Tnh di ng.............................................................................................................10 1.4 c im ca mng cm bin khng dy.......................................................................10 1.4.1 Kch thc vt l nh...............................................................................................10 1.4.2 Hot ng ng thi vi tp trung cao...............................................................10 1.4.3 Kh nng lin kt vt l v phn cp iu khin hn ch........................................10 1.4.4 Tnh a dng trong thit k v s dng....................................................................11 1.4.5 Hot ng tin cy.....................................................................................................11 1.5 Kin trc v giao thc mng cm bin khng dy..........................................................11 1.5.1 Lp ng dng...........................................................................................................13 1.5.2 Lp giao vn............................................................................................................13 1.5.3 Lp mng.................................................................................................................14 1.5.4 Lp lin kt s liu...................................................................................................14 1.5.5 Lp vt l.................................................................................................................15 1.6 Cc h tr truyn thng cho mng cm bin khng dy.................................................16 1.6.1 H iu hnh TinyOS...............................................................................................16 1.6.2 H thng Cm bin mng tch hp khng dy WINS ............................................26 CHNG 2 .............................................................................................................................37 CC NG DNG CA MNG CM BIN KHNG DY................................................37 2.1 Cc ng dng ca cng ngh mng cm bin khng dy...............................................37 2.1.1 Gim st v iu khin cng nghip........................................................................37 2.1.2 T ng ho gia nh v in dn dng...................................................................40 2.1.3 Cm bin trong qun s...........................................................................................42 2.1.4 Cm bin trong y t v gim st sc kho...............................................................43 2.1.5 Cm bin mi trng v nng nghip thng minh..................................................44 2.2 Mt ng dng gim st mi trng sng - o Great Duck Island................................46 2.2.1 Cc yu cu cho gim st mi trng sng trn o GDI.......................................47 2.2.2 Cc k hoch thi hnh..............................................................................................51 CHNG 3 .............................................................................................................................57 M HNH HO V PHN MM M PHNG MNG CM BIN KHNG DY.........57 3.1 M hnh ho m phng...................................................................................................57 3.1.1 M hnh SWAN theo di mc nhim mi trng...........................................57 3.1.2 M hnh ca trng i hc Los Angeles California .............................................64 3.2 Thit k phn mm m phng mng cm bin khng dy.............................................70

I

3.2.1 Phn mm NS-2.......................................................................................................70 3.2.2 C s pht trin m phng mng cm bin trn nn NS-2......................................73 3.2.3 Cc b sung vo NS-2..............................................................................................74 3.2.4 Cc chnh sa trong NS-2........................................................................................76 3.3 M t m lp trnh m phng..........................................................................................78 3.3.1 Thit lp knh hin tng v knh d liu ..............................................................78 3.3.2 Thit lp mt giao thc MAC cho knh Phenomenon.............................................79 3.3.3 Thit lp cc node Phenomenon..............................................................................79 3.3.4 Thit lp tc v kiu xung ca Phenomenon......................................................79 3.3.5 nh hnh node cm bin.........................................................................................80 3.3.6 Thit lp cc node non-sensor (im thu thp d liu, Gateway)............................81 3.3.7 Gn kt cc tc nhn cm bin.................................................................................81 3.3.8 Gn kt mt tc nhn UDP v ng dng cm bin cho mi node ..........................81 3.3.9 Khi ng ng dng cm bin.................................................................................81 4.1 M t kch bn m phng...............................................................................................82 4.2 Thc hin m phng ......................................................................................................82 4.2.1 Vit m v chy m phng......................................................................................82 4.2.2 Tnh ton kt qu......................................................................................................84 4.2.3 Tnh t l mt gi udp ti lp giao ..........................................................................85 4.2.4 Tnh tr gi (s).....................................................................................................87 4.2.5 Tnh tc gi udp trung bnh (kbps).....................................................................88 4.3 nh gi kt qu t c sau m phng.......................................................................90 KT LUN...............................................................................................................................92

II

THUT NG VIT TTAODV CSMA DAM DSDV DSR GLONASS GPS HVAC MAC NS-2 PDA RF RFM RKE SMP SQDDP SWAN TADAP TDMA TORA UART VHDL WINS WLAN WPAN Ad hoc On - Demand Distance - Vector Routing Carrier Sense Multiple Access Distributed Aggregate Management Destination-Sequenced Distance-Vector Dynamic Source Routing Global Navigation Satellite System Global Positioning System Heating, Ventilation, and Air Conditioning Medium Access Control Network Simulator - 2 Personal Digital Assistant Radio Frequency RF Monolithic Remote Keyless Entry Sensor Management Protocol Sensor Query and Data Dissemination Protocol Simulator for Wireless Adhoc Networks Task Assignment and Data Advertisement Protocol Time Division Multiple Access Temporally Ordered Routing Algorithm Universal Asynchronous Receiver Transmitter VHSIC Hardware Description Language Wireless Integrated Network Sensors Wireless Local Area Network Wireless Personal Area Network Chui ch hng theo yu cu Ad hoc a truy nhp cm bin sng mang Giao thc qun l khi kt hp phn tn Chui ch hng vi ch tun t Giao thc nh tuyn ngun ng H thng v tinh iu hng ton cu H thng nh v ton cu Hi m, thng gi v cc iu kin khng kh iu khin truy nhp mi trng B m phng mng phin bn 2 Tr t s c nhn Tn s v tuyn Thnh phn nguyn khi tn s v tuyn ng nhp ch mc khng kho t xa Giao thc qun l cm bin Giao thc truy vn cm bin v ph bin s liu M hnh m phng cc mng Ad hoc khng dy Giao thc phn nhim v v qung co s liu a truy nhp phn chia theo thi gian Thut ton tm ng tun t theo thi gian B thu pht khng ng b chung Ngn ng m t phn cng Mch tch hp mt cao Cm bin mng tch hp v tuyn Mng ni ht v tuyn Mng vng c nhn v tuyn

III

n tt nghip i hc

Li ni u

LI NI UTrong qu trnh pht trin ca con ngi, nhng cuc cc mng v cng ngh ng mt vai tr rt quan trng, chng lm thay i tng ngy tng gi cuc sng ca con ngi, theo hng hin i hn. i i vi qu trnh pht trin ca con ngi, nhng thay i do chnh tc ng ca con ngi trong t nhin, trong mi trng sng cng ang din ra, tc ng tr li chng ta, nh nhim mi trng, kh hu thay i, v.v... Dn s cng tng, nhu cu cng tng theo, cc dch v, cc tin ch t cng c hnh thnh v pht trin theo. c bit l p dng cc cng ngh ca cc ngnh in t, cng ngh thng tin v vin thng vo trong thc tin cuc sng con ngi. Cng ngh cm bin khng dy c tch hp t cc k thut in t, tin hc v vin thng tin tin vo trong mc ch nghin cu, gii tr, sn xut, kinh doanh, v.v..., phm vi ny ngy cng c m rng, to ra cc ng dng p ng cho cc nhu cu trn cc lnh vc khc nhau. Hin nay, cng ngh cm bin khng dy cha c p dng mt cc rng ri nc ta, do nhng iu kin v k thut, kinh t, nhu cu s dng. Song n vn ha hn l mt ch n tiu biu cho cc nh nghin cu, cho nhng mc ch pht trin y tim nng. p dng cng ngh ny vo thc t trong tng lai, c khng t cc nh khoa hc tp trung nghin cu, nm bt nhng thay i trong cng ngh ny. c s nh hng v ch dn ca Tin s inh Vn Dng, phng Nghin cu Pht trin Dch v mi v T ng ha, Vin Khoa hc K thut Bu in, em chn ti n: Cc ng dng ca cng ngh cm bin khng dy v nh gi bng m phng. Vi mc ch tm hiu v mng cm bin khng dy, da trn cng ngh mng di ng tm thi, trin khai nhanh khng cn mt c s h tng trong lnh vc cm bin thu nhn d liu. Trong n cn thc hin mt m phng cho mng cm bin khng dy vi mc ch tm hiu phng php m hnh ho, m phng mng v phn tch nh gi kt qu t mt chng trnh m phng. Ni dung ca n c th hin qua 4 chng: Chng 1: Tng quan v mng cm bin khng dy. Chng 2: Cc ng dng ca mng cm bin khng dy. Chng 3: M hnh ho v phn mm m phng mng cm bin khng dy. Chng 4: nh gi cht lng dch v QoS ca mng cm bin khng dy.

n tt nghip i hc

Li ni u

Do kin thc v kh nng ca em cn hn ch, nn n tt nghip ny khng trnh khi cc sai st. Mong c s gp ca cc thy, cc c v cc bn ni dung n c hon thin hn. Em xin chn thnh cm n Tin s inh Vn Dng, phng Nghin cu Pht trin Dch v mi v T ng ha, Vin Khoa hc K thut Bu in, hng dn em v chuyn mn, phng php lm vic em c th xy dng v hon thnh ni dung n theo ng k hoch. Em cng xin gi li cm n chn thnh n cc thy, cc c, cc bn trong Khoa Vin thng I, Hc vin Cng ngh Bu chnh Vin thng gip , to iu kin cho em hon thnh n ny.

Ngy 25 thng 10 nm 2005 Sinh vin thc hin

ngc Anh

n tt nghip i hc

Chng 1. Tng quan v mng cm bin khng dy

CHNG 1 TNG QUAN V MNG CM BIN KHNG DY 1.1 Gii thiu v mng cm bin khng dyMng cm bin khng dy (Wireless Sensor Network) bao gm mt tp hp cc thit b cm bin s dng cc lin kt khng dy (v tuyn, hng ngoi hoc quang hc) phi hp thc hin cc nhim v cm bin phn tn v i tng mc tiu. Mng ny c th lin kt trc tip vi node qun l ca gim st vin hay gin tip thng qua mt im thu (Sink) v mi trng mng cng cng nh Internet hay v tinh. Cc node cm bin khng dy c th c trin khai cho cc mc ch chuyn dng nh gim st v an ninh; kim tra mi trng; to ra khng gian thng minh; kho st, chnh xc ha trong nng nghip; y t;... Li th ch yu ca chng l kh nng trin khai hu nh trong bt k loi hnh a l no k c cc mi trng nguy him khng th s dng mng cm bin c dy truyn thng c. Vic kt hp cc b cm bin thnh mng li ngy nay to ra nhiu kh nng mi cho con ngi. Cc b vi cm bin vi b x l gn trong v cc thit b v tuyn hon ton c th gn trong mt kch thc rt nh. Chng c th hot ng trong mt mi trng dy c vi kh nng x l tc cao. Do , vi mng cm bin khng dy ngy nay, ngi ta c th khm ph nhiu hin tng rt kh thy trc y. Ngy nay, cc mng cm bin khng dy c ng dng trong nhiu lnh vc nh cc cu trc chng li a chn, nghin cu vi sinh vt bin, gim st vic chuyn ch cc cht gy nhim, kim tra h sinh thi v mi trng sinh vt phc tp, v.v...

1.2 M t h thng tng qutCc node cm bin c trin khai trong mt trng cm bin (sensor field) c minh ha trn hnh 1.1. Mi node cm bin c pht tn trong mng c kh nng thu thp thng s liu, nh tuyn s liu v b thu nhn (Sink) chuyn ti ngi dng (User) v nh tuyn cc bn tin mang theo lnh hay yu cu t node Sink n cc node cm bin. S liu c nh tuyn v pha b thu nhn (Sink) theo cu trc a lin kt khng c c s h tng nn tng (Multihop Infrastructureless Architecture), tc l khng c cc trm thu pht gc hay cc ngc Anh - D2001VT

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trung tm iu khin, nh trong hnh 1.1. B thu nhn c th lin lc trc tip vi trm iu hnh (Task Manager Node) ca ngi dng hoc gin tip thng qua Internet hay v tinh (Satellite).

Hnh 1.1: M hnh trin khai cc node cm bin khng dy Mt node cm bin c to ln t bn thnh phn c bn l: b cm bin, b x l, b thu pht khng dy v ngun. Tu theo ng dng c th, node cm bin cn c th c cc thnh phn b xung nh h thng tm v tr, b sinh nng lng v thit b di ng. Cc thnh phn trong mt node cm bin c minh ha trn hnh 1.2. B cm bin thng thng gm hai n v thnh phn l thit b cm bin (Sensor) v b chuyn i tng t/s (ADC). Cc tn hiu tng t c c t cc cm bin trn c s cm bin cc hin tng c chuyn sang tn hiu s bng b chuyn i ADC, ri mi c a ti b x l. B x l, thng kt hp vi mt b nh nh, phn tch thng tin cm bin v qun l cc th tc cng tc vi cc node khc phi hp thc hin nhim v. B thu pht m bo thng tin gia node cm bin v mng bng kt ni khng dy, c th l v tuyn, hng ngoi hoc bng tn hiu quang. Mt thnh phn quan trng ca node cm bin l b ngun. B ngun, c th l pin hoc acquy, cung cp nng lng cho node cm bin v khng thay th c nn ngun nng lng ca node thng l gii hn. B ngun c th c h tr bi cc thit b sinh nng lng, v d nh cc tm pin mt tri nh. Hu ht cc cng ngh nh tuyn trong mng cm bin v cc nhim v cm bin yu cu phi c s nhn bit v v tr vi chnh xc cao. Do , cc node cm bin thng phi c h thng tm v tr. Cc thit b di ng i khi cng

ngc Anh - D2001VT

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n tt nghip i hc


cn thit di chuyn cc node cm bin theo yu cu m bo cc nhim v c phn cng.H thng tm v tr B cm bin B x l Thit b x l Sensor ADC Thit b nh B thu pht Thit b di ng

B ngun

B sinh nng lng

Hnh 1.2: Cc thnh phn ca node cm bin

1.3 Cc nhn t nh hng n mng cm bin khng dy1.3.1 Tiu th ngun mc thp Cc ng dng mng cm bin khng dy in hnh yu cu cc thnh phn vi ngun tiu th trung bnh, thc cht thp hn hin ti c cung cp trong cc b xung ca cc mng khng dy hin ti ging nh Bluetooth. V d cc thit b cho cc kiu cm bin cng nghip v y t, cc nhn thng minh, cc huy hiu, c cp ngun t cc ngun pin nh, thi gian tiu th mt vi thng n mt vi nm. Cc ng dng bao gm gim st v iu khin thit b cng nghip yu cu thi gian sng ca ngun pin di duy tr s tn ti a v vo thit b c gim st khng c tha thun. Cc ng dng khc, ging nh gim st mi trng cc vng rng, c th yu cu mt s lng ln cc thit b nn khng th thay i ngun thng xuyn. Hn na, cc ng dng no khng th tn dng mt ngun cho tt c; cc node mng trong cc ng dng ny phi nhn ngun nng lng nh qu trnh khai thc v lc nng lng t mi trng. Mt v d ca kiu ny l cm bin p sut lp xe, mong mun nhn c nng lng t cc ngun nng lng c hoc nhit hin din trong cc lp t thay v mt ngun c th yu cu c thay th trc khi lp chy. b xung cho mc tiu th ngun trung bnh, cc ngun nng lng chnh vi kh nng ngun nng lng trung bnh thng c cc kh nng ngun nng lng nh gii hn; thc t ny c quan tm trong thit k h thng.

ngc Anh - D2001VT

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n tt nghip i hc


1.3.2 Chi ph thp V mng cm bin bao gm mt s lng ln cc node cm bin nn chi ph sn xut mt node rt quan trng nh hng n gi thnh ton mng. Nu chi ph ca mng cao hn so vi vic pht trin cc cm bin truyn thng th mng cm bin l khng chp nhn c. Nh vy, gi thnh mt node cm bin cn phi gi mc thp. Hin nay, chi ph sn xut ca mt node cm bin phi thp hn 1Dollar th mng mi c th thc hin c. Cc node cm bin ngoi cc thnh phn chnh l b cm bin chuyn dng, h thng thu pht v tuyn, b x l, ngun nui, cn phi trang b thm cc thit b khc c kh nng tm v tr, di ng, to nng lng, v.v... tu theo ng dng c th. Do , chi ph sn xut tr thnh mt thch thc khi mt khi lng cc chc nng c gii hn trong gi thnh thp hn 1 Dollar. 1.3.3 Mc kh dng Nhiu ng dng c xut ca mng cm bin khng dy, ging nh cc th hnh l khng dy v cc h thng nh v container tu hng, yu cu mng c mc kh dng cao. Hn na, tng sn lng, mc tip th, mua bn, v hiu qu phn tn ca sn phm m c th c cc thit b mng cm bin khng dy c nhng trong chng, v trnh qu trnh hnh thnh nhng thay i trong vng khc nhau phi c gim st ring l thng qua (c th l ring r) dy truyn phn tn, do mong mun cung cp cc thit b m c kh nng vn hnh trn khp th gii. D vy, theo l thuyt, kh nng ny c th c s dng bi vic tn dng cc b thu nhn GPS (Global Positioning System) hoc GLONASS (Global Navigation Satellite System) trong mi node mng v iu chnh node cch thc hot ng theo v tr ca n, chi ph thm mt b thu nhn th hai, cng thm tnh mm do thc thi b xung c yu cu nhn cc yu cu khp th gii khc nhau, v phng din kinh t phng php ny l khng tn ti. Bi vy, mong mun tn dng mt bng thng n - c t trong cc yu cu iu lut cu chnh ph t quc gia n quc gia - tng cc i ton b th trng tiu th cho cc mng cm bin khng dy. 1.3.4 Kiu mng Mt mng star thng thng tn dng mt thit b master n v mt hoc nhiu hn thit b slave c th tho mn nhiu ng dng. Bi v cng sut truyn dn ca cc thit b mng b gii hn bi cc iu lut chnh ph v cc cng ty cung cp ngun nui battery-life, tuy nhin, thit kt mng ny s hn ch phm ngc Anh - D2001VT

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n tt nghip i hc


vi vt l mt mng c th phc v n phm vi ca mt thit b n (master). Khi phm vi b xung c yu cu, cc kiu mng h tr nh tuyn multi-hop (v d cc kiu mesh hoc cluster) phi c tn dng; b nh b xung v chi ph tnh ton cho cc bng hoc thut ton nh tuyn, trong qu trnh b xung overhead bo tr mng, phi c h tr khng cn chi ph tha hoc mc tiu th ngun. c xc nhn cho nhiu ng dng, cc mng cm bin c bc tng i ln (>256 node); mt thit b cng c th cao (v d trong cc ng dng th bo gi trong siu th). 1.3.5 Bo mt Bo mt trong mng cm bin khng dy c hai vn c gi tr quan trng bo mt thc t mng nh th no v bo mt mng nh th no c nhn bit do ngi s dng v (c bit) l ngi s dng tim nng. Vic nhn bit bo mt l vn quan trng bi v ngi s dng c mt mi lo t nhin l khi d liu ca h (hoc bt c th g c th) c truyn dn qua khng kh cho bt c ai nhn. Thng, mt ng dng tn dng mng cm bin khng dy thay th mt phin bn c dy m ngi s dng c th nhn thy t nhin cc dy dn hoc cc cp ti thng tin, v bit, chc chn hp l, rng khng c ai cng c th nhn c thng tin hoc xen thng tin sai lch vo chng n ni nhn. ng dng khng dy phi lm vic chim li tin cy m bo vi th trng rng ln c yu cu vi chi ph thp hn. Tuy nhin, bo mt hn na l qu trnh m ho ng bn tin. Thc t, trong nhiu ng dng, qu trnh m ho (qu trnh gi mt b mt hoc mt ring t bn tin) khng phi l mt mc ch bo mt quan trng ca cc mng cm bin khng dy. Thng, cc mc ch bo mt quan trng l m bo rng nhiu bn tin c nhn khng b sa i theo nhiu con con ng t ngi gi n vi ni dung . Tuy nhin, iu g quan trng hn, my nghe trm c trn ng khng th xen cc bn tin li hoc sa i vo mng cm bin khng dy, v d c th nguyn nhn do n bt v tt mt cch ngu nhin. Cc yu cu ny l mt kiu bo mt th hai, qu trnh xc nhn ng bn tin hoc kim tra tnh nguyn vn ca bn tin, m n c thc hin bi vic gn mt MIC (Message Integrity Code) ph thuc bn tin v ngi gi vo bn tin c truyn pht. (Trong cc trng bo mt, MIC thng c gii hn MAC (Message Authentication Code) nhng MIC c s dng trong vn bn ny trnh c s xo trn c

ngc Anh - D2001VT

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n tt nghip i hc


th vi lp MAC ca ngn xp giao thc OSI). Ngi thu mong mun v ngi gi chia s mt kho, n c s dng bi ngi gi to ra MIC ph hp vi ngi nhn ph chun tnh nguyn vn ca bn tin v nh dng ngi gi. trnh replay attacks, trong mt my nghe trm ghi nhn mt bn tin v truyn pht li n sau , mt b m hoc b nh thi bn tin c gp li trong trng tnh ton MIC. Trong cch ny, khng c hai bn tin xc thc thm ch cha cng d liu - c nhn dng. V bo mt, ngi thit k mng cm bin khng dy gp phi ba vn kh khn:-

Chiu di MIC, ph hp vi k hoch bo mt ti mi ni, phi c cn bng vi chiu di in hnh ca d liu c truyn pht, v mong mun cho cc bn tin c truyn pht ngn. D vy, mt MIC 16-byte (128 bit) thng c a ra nh mt thit yu cho hu ht cc h thng bo mt, n tr nn cng knh khi d liu bit n c truyn i (v d bt, tt). Ngi thit k c th cn bng cc yu cu bo mt ca nhiu ngi s dng vi cc yu cu ngun thp ca mng. Ch rng iu ny c th bao gm cc la chn chiu di MIC, ph hp vi cc qu trnh kt hp xc nhn bn tin, kim tra tnh ton vn, v m ho - v phi c thc hin t ng, ging nh mt phn ca mt mng t t chc. ti thiu ho chi ph cc thit b mng, cc tnh nng bo mt phi c kh nng b xung vi phn cng r, vi mt b xung ti thiu cc cng logic, RAM, v ROM. Thm na, cng sut tnh ton (v d tc ng h my vi tnh, s lng cc ht x l c sn, v.v) c sn trong hu ht cc thit b mng l rt gii hn. S kt hp ny ca s lng cng thp, cc yu cu b nh nh, v s lng lnh thc thi thp gii hn cc kiu cc thut ton bo mt m c th c s dng. Cui cng, vn kh khn nht gii quyt ph bin l qu trnh phn tn kho. Nhiu phng php c hiu lc, bao gm mt vi kiu ca mt m ho kho cng cng tn dng kho chuyn dng ti trn cc thit b v cc loi kho khc nhau ca qu trnh can thip ca ngi s dng trc tip. Tt c u c nhng u im v nhc im khi c s dng trong mt h thng nht nh; ngi thit k mng cm bin phi la chn mt m thch hp nht cho ng dng trong tm kim sot.

-

-

ngc Anh - D2001VT

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n tt nghip i hc


Cc mng cm bin c cc yu cu b xung, bao gm yu cu cho t l phn chia n cc mng rng ln, dung sai li, v yu cu vn hnh trong s a dng rng ln trong cc mi trng i nghch mt cch hp l. Mc d vic thit k mt mng nh vy nhn c cc yu cu c th coi nh l nn ch, ngi thit k ca mt mng cm bin khng dy khng cn cc cng c. Cc yu cu v ngun v chi ph cht ch hnh thnh cc yu cu khn bt buc trong cc phm vi khc. 1.3.6 Thng lng d liu Khi cp ngay u tin, cc mng cm bin khng dy c gii hn v cc yu cu thng lng d liu khi so snh vi Bluetooth (IEEE 802.15.1) v vi cc mng WPAN v WLAN khc.Vi cc mc ch thit k, tc d liu mong mun cc i, khi tnh ton trung bnh qua m chu k mt gi, c th thit lp l 512b/s (64 byte/s), d vy phc ha ny c phn tu tin. Tc d liu in hnh c mong i c ngha ng k di iu ny; c th 1 b/s hoc thp hn trong mt vi ng dng. Ch rng y l thng lng d liu, khng phi l tc d liu ban u khi truyn pht qua knh, c th cao hn ng k. Lng thng lng d liu c yu cu thp ny gi rng vi nhiu s lng overhead giao thc c ch (v d cc header, trng a ch,v.v), hiu qu truyn thng ca mng s rt thp c bit khi so snh ngc li vi mng gi cc gi TCP/IP c th di 1500 byte. Khng c vn g khi thit k c la chn, hiu qu s rt thp, v trong tnh th , c th c nhn thy mt cch r rng: ngi thit k giao thc c kh nng phc ho t mi quan tm hiu qu truyn thng, thng l mt tham s quyt nh trong thit k giao thc. 1.3.7 Tr bn tin Cc mng cm bin c cc yu cu QoS rt rng, bi v, ph bin, chng khng h tr truyn thng ng thi hoc ng b, v c cc gii hn thng lng d liu ngn cn qu trnh truyn pht video v voice thi gian thc, trong nhiu ng dng. Yu cu tr bn tin cho cc mng cm bin khng dy v vy rt thoi mi trong s so snh n vi cc mng WPAN khc; trong nhiu ng dng, mt tr v giy hoc vi pht c th chp nhn tng i.

ngc Anh - D2001VT

-9-

n tt nghip i hc


1.3.8 Tnh di ng Cc ng dng mng cm bin khng dy, ph bin, khng yu cu tnh ng. Bi v mng c gii phng t gnh nng ca qu trnh nhn dng cc ng nh tuyn truyn thng m, cc mng cm bin khng dy mang overhead lu lng iu khin t hn v c th tn dng cc phng php nh tuyn n gin hn so vi mng di ng Ad hoc.

1.4 c im ca mng cm bin khng dy1.4.1 Kch thc vt l nh Trong bt k hng pht trin cng ngh no, kch thc v cng sut tiu th lun chi phi kh nng x l, lu tr v tng tc ca cc thit b c s. Vic thit k cc phn cng cho mng cm bin phi ch trng n gim kch c v cng sut tiu th vi yu cu nht nh v kh nng hot ng. Vic s dng phn mm phi to ra cc hiu qu b li cc hn ch ca phn cng. 1.4.2 Hot ng ng thi vi tp trung cao Phng thc hot ng chnh ca cc thit b trong mng cm bin l cm bin v vn chuyn cc dng thng tin vi khi lng x l thp, gm cc hot ng nhn mt lnh, dng, phn tch v p ng li. V d, thng tin cm bin c th c thu nhn ng thi bi cc cm bin, c thao tc v truyn ln mng. Hoc d liu c th c node cm bin nhn t cc node cm bin khc v c hng ti nh tuyn a lin kt hay lin kt cu. V dung lng b nh trong nh nn vic m mt khi lng ln d liu gia dng vo v dng ra l khng kh thi. Hn na, mi dng li to ra mt s lng ln cc s kin mc thp xen vo hot ng x l mc cao. Mt s hot ng x l mc cao s ko di trn nhiu s kin thi gian thc. Do , cc node mng phi thc hin nhiu cng vic ng thi v cn phi c s tp trung x l cao . 1.4.3 Kh nng lin kt vt l v phn cp iu khin hn ch S lng cc b iu khin c lp, cc kh nng ca b iu khin, s tinh vi ca lin kt x l - lu tr - chuyn mch trong mng cm bin thp hn nhiu trong cc h thng thng thng. in hnh, b cm hay b truyn ng (actuator) cung cp mt giao din n gin trc tip ti mt b vi iu khin chip n. Ngc li, cc h thng thng thng, vi cc hot ng x l phn tn, ng thi kt hp vi mt lot cc thit b trn nhiu mc iu khin c ngc Anh - D2001VT

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n tt nghip i hc


lin h bi mt cu trc bus phc tp. Cc hn ch v kch thc v cng sut, kh nng nh hnh vt l trn vi mch b gii hn c chiu hng cn h tr qun l dng ng thi, tp trung nh b x l kt hp. 1.4.4 Tnh a dng trong thit k v s dng Cc thit b cm bin c ni mng c khuynh hng dnh ring cho ng dng c th, tc l mi loi phn cng ch h tr ring cho ng dng ca n. V c mt phm vi ng dng cm bin rt rng nn cng c th c rt nhiu kiu thit b vt l khc nhau. Vi mi thit b ring, iu quan trng l phi d dng tp hp cc thnh phn phn mm c c ng dng t cc thnh phn phn cng. Nh vy, cc loi thit b ny cn mt s iu chnh phn mm mt mc no c c hiu qu s dng phn cng cao. Mi trng pht trin chung l cn thit cho php cc ng dng ring c th xy dng trn mt tp cc thit b m khng cn giao din phc tp. Ngoi ra, cng c th chuyn i gia phm vi phn cng vi phn mm trong kh nng cng ngh. 1.4.5 Hot ng tin cy Cc thit b c s lng ln, c trin khai trong phm vi rng vi mt ng dng c th. Vic p dng cc k thut m ha sa li truyn thng nhm tng tin cy ca cc n v ring l b gii hn bi kch thc v cng sut. Vic tng tin cy ca cc thit b l l iu ct yu. Thm vo , chng ta c th tng tin cy ca ng dng bng kh nng chp nhn v khc phc c s hng hc ca thit b n l. Nh vy, h thng hot ng trn tng node n khng nhng mnh m m cn d dng pht trin cc ng dng phn tn tin cy.

1.5 Kin trc v giao thc mng cm bin khng dyNgn xp giao thc c s dng trong b thu nhn (node Sink) v tt c cc node cm bin c minh ha trong hnh 1.3. Ngn xp giao thc ny phi hp cc tnh ton v nh tuyn v nng lng, kt hp s liu vi cc giao thc mng, truyn tin vi hiu qu v nng lng thng qua mi trng khng dy v tng cng s hp tc gia cc node cm bin. Ngn xp giao thc bao gm lp ng dng (Application Layer), lp giao vn (Transport Layer), lp mng (Network Layer), lp lin kt s liu (Datalink Layer), lp vt l (Physical Layer), mt bng qun l nng lng (Power Management Plane), mt bng qun l di ng (Mobility Management Plane) v mt bng qun l nhim v (Task Management Plane). ngc Anh - D2001VT

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n tt nghip i hc


Hnh 1.3: Ngn xp giao thc mng cm bin khng dy Tu theo nhim v cm bin, cc kiu phn mm ng dng c th c xy dng v s dng trn lp ng dng. Lp giao vn gip duy tr dng s liu khi cc ng dng ca mng cm bin yu cu. Lp mng tp trung vo vic nh tuyn s liu c cung cp bi lp giao vn. Do mi trng c nhiu v cc node cm bin c th di ng c, giao thc MAC phi c tnh ton v nng lng v ti thiu ha va chm trong vic pht qung b vi cc node ln cn. Lp vt l s dng cc k thut iu ch, truyn v nhn cn thit n gin nhng mnh m. Thm vo , cc mt bng qun l nng lng, di ng v nhim v iu khin s phn phi nng lng, phi hp di chuyn v nhim v gia cc node cm bin. Cc mt bng ny gip cho cc node cm bin c th phi hp trong nhim v cm bin v gim c tng nng lng tiu th. Mt bng qun l nng lng qun l vic mt node cm bin s dng nng lng ca n nh th no. V d, node cm bin c th tt b phn nhn sau khi nhn mt bn tin t mt trong cc node ln cn. iu ny c th trnh c vic nhn bn tin ti hai ln. Ngoi ra, khi mc nng lng ca node cm bin thp, node cm bin s thng bo ti tt c cc node ln cn rng mc nng lng thp ca n thp nn n khng th tham gia vo vic nh tuyn cho cc bn tin. Nng lng cn li c d tr cho vic cm bin. Mt bng qun l di ng d tm v ghi li chuyn ng ca node cm bin, v th mt tuyn ng hng ti node user lun c duy tr v cc node cm bin c th theo di c cc node cm bin ln cn. Vi vic nhn bit c cc node cm bin ln cn, node cm bin c th cn bng gia nhim v v nng lng s dng. Mt ngc Anh - D2001VT

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n tt nghip i hc


bng qun l nhim v cn bng v sp xp nhim v cm bin cho mt vng c th. Khng phi tt c cc cm bin trong vng c yu cu thc nhim v cm nhn ti cng mt thi im. Kt qu l mt vi node cm bin thc hin nhim v nhiu hn cc node khc tu theo mc nng lng ca chng. Nhng mt qun l ny rt cn thit, nh vy, cc node cm bin c th lm vic cng vi nhau c hiu qu v mt nng lng, c th nh tuyn s liu trong mt mng cm bin di ng v chia s ti nguyn gia cc node cm bin. Nu khng, mi node cm bin s ch lm vic mt cch n l. Xut pht quan im xem xt trong ton mng cm bin, s hiu qu hn nu cc node cm bin c th hot ng hp tc vi nhau, nh th cng c th ko di tui th ca mng. 1.5.1 Lp ng dng Mc d nhiu lnh vc ng dng cho mng cm bin c vch r v c xut, cc giao thc lp ng dng cn tim tng cho mng cm bin vn cn l mt vng rng ln cha c khm ph. Trong phn ny, chng ta s kho st ba giao thc lp ng dng quan trng l giao thc qun l cm bin SMP (Sensor Management Protocol), giao thc phn nhim v v qung co s liu TADAP (Task Assignment and Data Advertisement Protocol), giao thc truy vn cm bin v ph bin s liu SQDDP (Sensor Query and Data Dissemination Protocol), rt cn thit cho mng cm bin trn c s nhng s c xut c lin quan ti nhng lp khc v cc lnh vc ng dng mng cm bin. Tt c cc giao thc lp ng dng ny u l nhng vn nghin cu c tnh m. 1.5.2 Lp giao vn Lp giao vn cung cp cc dch v t chc lin lc u cui t cc node cm bin c bo co cn chuyn ti node thu nhn (Sink) v node ngi s dng. Lp giao vn c bit cn thit khi h thng c k hoch truy nhp thng qua Internet hoc nhng mng bn ngoi khc. Giao thc TCP vi c ch ca s truyn dn cha ph hp vi c trng ca mi trng mng cm bin hin nay. Do , vic thit lp mt lin kt u cui t cc node cm bin trc tip n node qun l ca ngi s dng l khng hiu qu. Phng php phn tch TCP l cn thit mng cm bin tng tc vi cc mng khc v d nh Internet. Trong phng php ny, kt ni TCP c s dng lin lc gia node qun l ca ngi s dng v node thu nhn (Sink) v mt giao thc lp giao vn ph hp vi mi trng mng cm bin c s dng cho truyn thng gia node - 13 -

ngc Anh - D2001VT

n tt nghip i hc


thu nhn v cc node cm bin. Kt qu l truyn thng gia node ngi s dng v node thu nhn c th s dng giao UDP hoc TCP thng qua Internet hoc qua v tinh. Mt khc, vic truyn thng gia node thu nhn v cc node cm bin ch s dng hon ton cc giao thc kiu nh UDP, bi v cc node cm bin c b nh hn ch. Khng ging cc giao thc kiu nh TCP, cc phng php truyn thng u cui (end to end) trong mng cm bin khng a ch ton cc. Cc phng php ny da trn vic t tn thuc tnh c s ch ra im ch ca gi s liu. Cc nhn t nh tiu th nng lng, kh nng m rng v cc c trng nh nh tuyn tp trung s liu khin cho mng cm bin cn phi c nhng c ch khc trong lp giao vn. Yu cu ny nhn mnh s cn thit ca nhng loi giao thc mi lp giao vn. 1.5.3 Lp mng Cc node cm bin c phn b dy c trong mt trng gn hoc ngay bn trong cc hin tng mc tiu nh trong hnh 1.1. Giao thc nh tuyn khng dy a bc ph hp gia node cm bin v node Sink l cn thit. K thut nh tuyn trong mng Ad hoc thng thng khng ph hp nhng yu cu ca mng cm bin. Lp mng ca mng cm bin c thit k theo nhng nguyn tc sau : Hiu sut nng lng lun l yu t quan trng. Hu ht cc mng cm bin l s liu tp trung. Vic tp hp s liu ch c thc thi khi n khng cn tr hot ng hp tc ca cc node cm bin. Mt mng cm bin l tng phi nhn bit c vic nh a ch thuc tnh c s v v tr.

1.5.4 Lp lin kt s liu Lp lin kt s liu chu trch nhim ghp knh cho cc dng s liu v tch khung s liu, iu khin truy nhp mi trng v sa li. N m bo s tin cy cho kt ni im - im (Point to Point) v im - a im (Point to Multipoint) trong mng truyn thng. Hai phn di s trnh by v chin lc truy nhp mi trng truyn dn v iu khin sa li cho mng cm bin.

ngc Anh - D2001VT

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n tt nghip i hc


1.5.5 Lp vt l Lp vt l chu trch nhim la chn tn s, to tn s mang, tch sng, iu ch v m ho s liu. K hoch chn tn s c trnh by trong bng 1.2. Vic to tn s v tch sng thuc phm vi thit k phn cng v b thu pht nn s khng c xem xt y. Cc phn tip theo s ch trng v cc hiu ng pht sng, hiu sut nng lng v cc phng php iu ch trong mng cm bin. Hin nhin l truyn thng v tuyn vi khong cch xa l rt tn km xt c v nng lng v phc tp ca hot ng. Trong khi thit k lp vt l cho mng cm bin, vic ti thiu ho nng lng c coi l rt quan trng, ngoi ra cn cc vn v suy hao, pht tn, vt cn, phn x, nhiu, cc hiu ng fading a ng. Thng thng, cng sut u ra ti thiu chuyn mt tn hiu qua mt khong cch d t l vi dn , trong 2 n < 4. S m n gn 4 vi antenna tm thp v cc knh gn mt t in hnh trong mng cm bin. Nguyn nhn l do s trit tiu mt phn tn hiu bi tia phn x mt t. gii quyt vn ny, ngi thit k phi hiu r cc c tnh a dng c hu v khai thc chng mt cch trit . V d, truyn thng qua nhiu bc nhy trong mng cm bin c th vt qua mt cch hiu qu cc vt chn v cc hiu ng suy hao ng truyn nu mt node mng ln. Tng t, trong khi suy hao ng truyn v dung lng knh hn ch tin cy ca s liu th nh ta c th s dng li tn s theo khng gian.Di tn (kHz)6765 - 6795 12.553 - 13.567 26.957 - 27.283 40.66 - 40.70 433.05 - 434.79 902 - 928 2400 - 2500 5725 - 5875 24 - 24.25 61 - 61.5 122 - 123 244 - 246

Tn s trung tm (kHz)6780 14 27 40.68 433.92 915 2450 5800 24 61.25 122.5 245

Bng 1.1: Cc di tn dnh cho cc ng dng Cng nghip, khoa hc v y t ISM (Industrial, Scientific and Medical) ngc Anh - D2001VT

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n tt nghip i hc


Vic la chn phng thc iu ch tt l vn quyt nh i vi s tin cy trong truyn thng ca mng cm bin. Trong khi mt phng php iu ch c s M c th gim c th gim thi gian truyn dn bng vic gi nhiu bit trn mt k hiu th n li lm tng phc tp ca mch in v tng cng sut v tuyn. Vi iu kin cng sut khi kch vt tri th phng php iu ch c s hai c hiu qu v nng lng hn. V th, phng php iu ch c s M ch c li vi cc h thng c cng sut khi kch thp. Thit b bng tn cc rng UWB (Ultrawideband) hay v tuyn xung IR (Impulse Radio) tng c s dng cho h thng radar xung bng tn gc v cc h thng o khong cch, gn y c ch trong cc ng dng thng tin c bit l cc mng khng dy trong nh. UWB truyn dn vi bng tn gc nn khng cn cc tn s mang hoc trung tn. Thng thng, iu ch v tr xung c s dng. u im chnh ca UWB l kh nng mau phc hi vi i vi hin tng pht a ng. Vic s dng cng sut truyn thng thp v thit k mch n gin lm cho UWB rt thch hp vi cc mng cm bin.

1.6 Cc h tr truyn thng cho mng cm bin khng dy1.6.1 H iu hnh TinyOS H iu hnh TinyOS cung cp cc khi nim tru tng cc thit b vt l rt thun tin v nhng thc thi phi hp mc cao cc nhim v chung. Mc ch ny l thch thc c bit bi v s rng buc ng cnh ti nguyn v cc thit b ng dng ring bit cao. Mt ng dng TinyOS bao gm mt b lp lch (scheduler) v cc thnh phn (component). Mi mt thnh phn c m t bi giao din ca n v s thc thi bn trong ca n, trong mt kiu tng t nh cc ngn ng m t phn cng, ging nh VHDL (VHSIC(Mch tch hp mt rt cao) Hardware Description Language) v Verilog (mt cng c m phng s cc Cadence Design System). Mt giao din bao gm cc lnh ng b v cc s kin khng ng b. Mi thnh phn c giao din cao hn bn trn t tn cho cc lnh thc thi v cc s kin bo hiu, v mt giao din thp hn m n t tn cho cc lnh s dng v cc s kin iu khin. S thc thi ny c vit nn nh s dng khng gian tn giao din. Mt thnh phn cng c phn lu tr ni b, c cu trc thnh mt khung, v trng hp ni b, trong mt khun dng cc lung trng lng rt nh gi l cc tc v (task). Cc b iu khin lnh, s kin v tc v c khai bo r rng trong ngun ti nguyn. Cc vng ngc Anh - D2001VT

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n tt nghip i hc


trng tm ni mt lnh bn ngoi c gi, c bo hiu s kin, hoc c gi tc v, cng rt r rng trong cc on m tnh, ging nh l cc on tham kho ti phn lu tr khung. M t cc ng dng ring r ch ra rng lm th no cc giao din cng mc hnh thnh tng th kt cu ng dng. Mt s kin c th c pht tn ti nhiu thnh phn hoc nhiu thnh phn c th s dng cng mt lnh. V vy, d ng dng l cc module, b bin dch vn c thng tin tnh s dng trong qu trnh ti u ha cho qua ton ng dng (entire application), bao gm c h thng vn hnh. b xung, m hnh thc thi thi gian thc v m hnh lu tr mc dui c th c ti u ho cho cc nn tng c th. Mt lc ng dng in hnh c ch trong hnh 1.4, cha ng mt ngn xp v tuyn, mt ngn xp cng ni tip UART (Universal Asynchronous Receiver Transmitter), cc ngn xp cm bin, v node m mng mc cao hn, v nh tuyn chuyn dng h tr b thu d liu cm bin phn tn. ng dng nguyn khi ny chim dng khong 3Kb. M hnh trng hp TinyOS (TinyOS concurrency model) l mt m hnh phn cp lp lch hai mc, cc s kin n trc cc tc v, v cc tc v ny khng n trc cc tc v khc. Phn ln cch hot ng nm trong mt dng cc chuyn giao trng thi nonblocking. Trong vng mt tc v, cc lnh c th c gi ti, mt lnh c th gi cc lnh cp di, hoc n c th y cc tc v tip tc lm vic hp l song song vi cc li triu gi ca n. Theo quy c, tt c cc lnh tr v mt ch th trng thi sau d lnh c cng nhn hay khng, cung cp mt ci bt tay (handshake) y . Do tt c cc thnh phn u c gii hn lu tr, mt thnh phn c th cho php t tri cc lnh. Mt lnh c th khi to mt ton t, v d, nh truy cp n mt cm bin hoc gi mt thng bo, di chuyn ton t c ti ra ngoi ng thi vi cc kch hot khc, nh s dng song song phn cng hoc cc tc v. Cc s kin c khi to ti mc thp nht nh cc ngt phn cng. Cc s kin c th bo hiu cho cc s kin mc cao hn, gi cc lnh, hoc y ln cc tc v. Cc lnh khng th bo hiu cho cc s kin. D vy, mt s kin ring r c th truyn qua nhiu mc cc thnh phn, gy ra kch hot ph. Mi khi cng vic khng th hon tt trong mt khong thi gian nh c gii hn, thnh phn c th ghi li thng tin lin tc trong khung lm vic ca n v y ln mt tc v hon thnh cng vic. Theo quy c, cc thnh phn tru tng ho phn cng mc thp thc thi qu trnh ngt va cho php cc ngt hot ng trc khi bo hiu s kin. Cc s kin (hoc cc tc v c

ngc Anh - D2001VT

- 17 -

n tt nghip i hc


y ln trong vng cc s kin) thc hin cc hot ng split-phase c khi to bi cc lnh, bo hiu n thnh phn mc cao hn hot ng c hon thnh v c th thng qua d liu ca n.

Hnh 1.4: Mt biu thnh phn ng dng mng Bn tin kch hot (AM - Active Message) l mt kiu n gin, m rng cho truyn thng da trn bn tin (message-based) nh s dng cc cuc gi th tc. Mi thng ip cha ng tn mt iu khin c triu gi ti mt node ch theo hng n, v mt ti trng d liu. Chc nng iu khin handler phc v cho hai mc ch l ly bn tin t mng v kt hp d liu vo n my tnh hoc gi i mt p ng. Kiu truyn thng AM l kiu iu khin s kin v c thit k ring cho php mt ngn xp truyn thng rt nh x l trc tip cc gi ra khi mng, trong khi n h tr mt di rng cc ng dng. Khi to mt AM bao gm cc ch nh v cc i s d liu, nh tn iu khin handle, yu cu truyn dn, d tm y hng truyn i. Qu trnh nhn AM bao gm triu gi iu khin handle trn mt bn sao ca d liu truyn i. Lnh bn tin gi i nhn dng cc pha nhn theo yu cu, iu khin handle s x l bn tin gi hng n v b m bn tin u ra ngun trong khung ni ht. Mt bn ng k iu khin handle c gi li, v b nhn dng cho iu khin handle tn c ly ra. Bt tay (handshake) trng thi cho lnh ny minh ha khi nim tng qut cc thnh phn qun l gii hn cc ti nguyn ca chng.

ngc Anh - D2001VT

- 18 -

n tt nghip i hc


Thnh phn bn tin c th t chi yu cu gi i, v d, nu n ang bn truyn i hoc nhn mt bn tin v khng c cc ti nguyn m gi n hng i c yu cu. phn hi li s kin ny l cc ch nh ng dng. S kin bn tin n tng t vi cc s kin khc. Mt s khc bit chnh l thnh phn AM pht i s kin n thnh phn vi iu khin handle bn tin kt hp. Nhiu thnh phn c th ng k mt hoc nhiu iu khin handle bn tin. Ngoi ra, u vo b iu khin handle l mt tham kho n mt b m bn tin c cung cp bi thnh phn AM. Qun l lu tr b m l mt vn kh khn trong mt ngn xp truyn thng bi v l do sau phi c tho lun: ng gi d liu s dng vi thng tin header v trailer vn chuyn. Xc nh khi no vic lu tr d liu bn tin i c th c dng li, v Cung cp mt b m u vo cho mt bn tin n trc khi bn tin ny c kim tra, xc nh ni n n.

Lp AM Tiny cung cp cc gc nguyn thu n gin cho vic quyt nh n cc kin trn vi vic khng cn sao chp li v vic qun l lu tr rt n gin. B m c mt kiu nh ngha trong khung cung cp cc trng cho qu trnh tm lc c trng ca h thng, ging nh thng tin nh tuyn v pht hin li. Cc trng ny c s dng ging nh l cc gi chuyn xung ngn xp, ng hn l cc con tr hoc vic sao chp sau. Cc thnh phn ng dng ch cp n cc trng d liu hoc ton b m. Cc tham chiu n b m bn tin ch l cc con tr c mang qua cc bin gii thnh phn trong TinyOS. Trc khi lnh gi c gi, b m truyn dn c quan tm c mng s hu cha cho n khi thnh phn bn tin bo hiu rng s truyn dn c hon thnh. C cu cho quyn s hu theo di l c trng ng dng. Cc b iu khin handle bn tin nhn mt tham chiu n mt b s hu h thng, rt khc bit so vi khung ca n. Cch thc hot ng in hnh l x l thng tin trong bn tin v tr li cho b m. Tng qut, b m iu khin handle phi tr v mt tham chiu n mt b m trng. N c th gi li b m m n c cp bi h thng v tr li mt tham chiu cho mt b m khc, m l ca ring n. Mt trng hp c bit chung ca vin kch ny l mt b iu khin handle to nn mt thay i nh n mt bn tin i n v truyn pht li n. Chng ta c th ngn nga vic sao chp phn cn li ca bn ngc Anh - D2001VT

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n tt nghip i hc


tin, tuy nhin, chng ta khng th gi li quyn s hu b m cho truyn pht v tr v cho cng b m n h thng. Ging nh mt thnh phn khai bo mt b dm bn tin v con tr b m bn tin trong khung ca n. B iu khin handle thay i b m vo v trao i quyn s hu b m vi h thng. Nu b m truyn pht trc ca n vn bn, mt trong hai ton t phi c khia bo. Mt thnh phn ang thi hnh bin dch li t nhiu gi c th c th s hu nhiu b m nh vy. Trong mt vi trng hp, vic qun l lu tr b m run-time c gim nh bng vic hon i con tr n gin. AM Tiny c s dng h tr cc node m mng ng v a trm, nh tuyn ad hoc. Nt m c th c khi to t nhiu node, nhng thng n l cc gc ti cc node gateway cung cp kt ni n mng tho thun. Mi gc truyn dn nh k mt bn tin mang cc ID ca n v khong cch distance, c gi t 0 n khong cch vi node lng ring ca n. B iu khin handle bn tin kim tra d c ngun hay khng l node thn thit m n lng nghe cch y khng lu (v d trong giai on pht hin hin ti) v nu vy, n ghi li ID ngun ging nh gc multi-hop, gia tng khong cch v truyn pht i bn tin vi ID ca ring n ging nh ngun. Thnh phn pht hin tn dng vic hon i b m. Cc gi c nh tuyn ln trn cy sau. Mt node ang truyn pht d liu c nh tuyn ch r mt a trm ang tin vo b iu khin handle v nhn dng cha ca n ging nh ni nhn. B iu khin handle s t chy mt trong cc node bn cnh. Cc node cha truyn pht cc gi n gc ca n, s dng hon i b m. Cc node lng ring khc n gin l loi b gi. Do vy d liu c nh tuyn hop-by-hop n gc. Cc ton t reduction c th c hnh thnh nh tch lu d liu t nhiu node con trc khi truyn i mt gi ln cy. Thut ton pht hin khng ti u bi v c s d tha trong dng sng pht hin hng gi i v c th c ci tin bi qu trnh la chn cluster leaders hoc truyn dn li cnh bo trc vi nhiu xc sut c quan h nghch o vi s lng node con (sibling). Mt khc, pha pht hin c th c loi tr hon ton nh qu trnh mang (piggybacking) thng tin v khong cch trn cc bn tin d liu cm bin. Khi mt node nhn mt gi t mt node, m t hn cc hop t trm gc, n nhn node ngun lm gc ca n. Node gc truyn dn n gin mt gi t chnh chng pht trin cy nh tuyn. Cc node cng phi nh r khong cch hin ti ca chng thch nghi vi nhng thay i trong topology ngc Anh - D2001VT

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n tt nghip i hc


mng v nhng thay i v chuyn ng v truyn pht tn hiu. Cc v d ny minh ha bc truyn thng c bn nh vo cc thut ton phn tn cho cc mng khng dy nhng c da vo: qu trnh nhn mt gi, bin i n, v c kh nng la chn truyn dn li n hoc khng. Qu trnh truyn pht li ngt qung (squelching retransmission) hnh thnh mt dng sng hng gi i trong discovery v hnh thnh mt beam trn nh tuyn multi-hop. Trong cc thut ton ny cu trc d liu cho vic quyt nh quyt nh truyn dn li hay khng l mt b m cache ca cc gi gn y. Mt thch thc l chuyn cc d liu bn tin t b m lu tr n module vt l ca knh khng cn phi to ra ton b cc bn sao, v tng t trong hng ngc li. Mt mu hnh chung m ni ln l mt chic bm d liu cross-layer data pump. Chng ta tm thy iu ny ti mi lp ca ngn xp trong hnh 1.4. Thnh phn cao hn c mt n v ca d liu c phn vng vo trong cc n v con. Thnh phn thp hn c hiu rng n chp nhn n v con v khi n sn sng cho thnh phn k tip, n bo hiu mt s kin n v con. iu ny c thc hin nh gi lnh n v con k tip trong khi b iu khin handle sn sng lm vic. Lp bn tin l mt b m gi hiu qu. Lp packet m ho v sp xp iu chnh gi, bm n theo kiu byte by byte vo lp byte. Trn lp UART, khi nim tru tng byte-by-byte c thc hin trc tip trn phn cng. Ngc li trn knh v tuyn lp byte bm d liu bit by bit ln lp v tuyn. Mt trong s cc thnh phn tn dng khung, lnh, v framework s kin xy dng mt c cu trng thi phn mm bn ng k li. Trong mt mng tp hp d liu a trm, mi mt node truyn pht d liu ca ring n t time to time, v lng nghe trong khong thi gian cn li d liu m n yu cu chuyn theo hng mt node sink. Mc d truyn dn kch hot l ch tp trung ngun nhiu nht, hu ht cc my pht v tuyn tiu th mt phn ng k ngun nng lng truyn dn khi my v tuyn ang hot ng v khng nhn bt k tn hiu no. Trong cc mng c bit, mt thit b truyn dn cho cc chu k thi gian ngn, nhng phi lng nghe lin tc chuyn d liu n cc node lng ring. Mc tiu th nng lng tng ca mt thit b chi phi bi chi ph thu nhn RF. Mc tiu th ngun c th c gim nh s qu trnh thu nhn nh k. Nh to ra chu k thi gian khi qu trnh truyn pht khng c php, cc node phi lng nghe ch trong khong thi gian lm vic. Phng php ny lm vic tt ngc Anh - D2001VT

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n tt nghip i hc


khi di t l thi gian ca cc chu k khng hp l c quan h khng ln lm vi thi gian truyn pht bn tin. Downside ca phng php ny m b gii hn l vic s dng bng tn. Trong mng cm bin, mt node c th lm vic nh mt b nh tuyn hoc im x l d liu, v c th cn thit cho vic s dng y bng tn v tuyn. Qu trnh thu nhn ngun thp tun theo cng khi nim chu k cng sut thu, nhng khng lm gim theo t l thi gian. gim hn na mc tiu th ngun trung bnh ca mng, qu trnh thu nhn ngun thp c th c kt hp vi qu trnh thu nhn tun hon. Thc thi thi c cc k hoc to ra kt qu ng thi trong qu trnh thu nhn ti mc ngun c gim ch cho mt phn thi gian, v cc mc gim ngun nhn ln. K thut ny cung cp mt c cu cho bng tn thng mi v chi ph truyn pht cho mt mc gim trong mc tiu th ngun nhn. Phn cng kt ni trc tip t b vi iu khin trung tm n my thu pht v tuyn. iu ny thay th tt c cc yu cu thi gian thc ca my v tuyn n b vi iu khin, n iu khin tt c cc bit m c truyn pht hoc thu trong thi gian thc. Thm na, n iu khin nh thi mi bit nhng jitter trong cc tn hiu iu khin m n sinh ra c truyn pht thnh tn hiu truyn pht. Ngn xp truyn thng TinyOS iu khin cc rng buc ny trong khi cho php cc chc nng mc cao hn c tip tc thc hin song song. Ti gc ngn xp thnh phn l mt c cu trng thi thc hin nh thi bit. Thnh phn nguyn khi RFM (RF Monolithic) truyn dn mt bit n ti mt thi im i hoc n b thu pht v tuyn RFM. Vi mt kiu truyn pht ng xut hin, bit c truyn dn phi c t v gi trn ng TX (u ra d liu) ca my thu pht v tuyn cho mt khong thi gian bit chnh xc, v d, khong 100 s. Vi hng thu, ng thu RX (u thu d liu) ca my v tuyn phi c ly mu ti im trung bnh ca chu k truyn dn. My thu pht v tuyn khng h tr kh nng quyt nh khi cc khong thi gian bit c hon thnh. Giao din n thnh phn RFM hnh thnh mt b bm d liu thc thi mt kiu truyn dn bit-by-bit t mt thnh phn mc byte (byte-level) n phn cng vt l. bt u qu trnh truyn pht d liu, mt lnh c pht ra t thnh phn RFM n b chuyn mch chn ch truyn dn. Sau mt lnh th hai c s dng truyn mt bit n xung thnh phn RFM. Bit ny

ngc Anh - D2001VT

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n tt nghip i hc


c t ngay lp tc vo ng truyn pht. Sau khong 100 s tri qua, thnh phn RFM bo hiu mt s kin biu th rng n sn sng cho bit khc. p ng ca thnh phn mc byte a ra lnh khc n thnh phn RFM cha ng bite k tip. S tng tc ny gia qu trnh bo hiu mt s kin v qu trnh nhn bit k tip vn tip tc din ra cho n khi qu trnh truyn ton b gi c hon thnh. Thnh phn lp RFM tru tng ha cc gii hn thi gian thc (real-time deadline) ca tin trnh truyn pht t cc thnh phn lp cao hn. Trong sut qu trnh truyn pht, qu trnh m ho phc hp c thc hin trn mi byte trong khi ng thi nhn cc yu cu thi gian thc chnh xc ca lp bit. Qu trnh m ho cho mt byte n chim dng thi gian di hn thi gian truyn dn ca mt bit n. m bo rng d liu m ho sn sng trong khong thi gian nhn gii hn qu trnh truyn pht (transmission deadline). Tin trnh m ho cho cc byte k tip bt u trc khi kt thc qu trnh truyn pht byte hin ti. C cu tc v TinyOS thc thi qu trnh m ho trong khi vn thc hin ng thi qu trnh truyn pht d liu trc. Do qu trnh m ho d liu mt byte trong phn sm pha ca qu trnh truyn pht, b m c s dng tch bit nh thi mc bit t tin trnh m ho byte. Qu trnh nhn d liu mang cng dng ging vi qu trnh pht, tr ra rng ni b nhn u tin phi pht hin ra mt qu trnh truyn trong khong bt u v quyt nh nh thi truyn pht. hon thnh n, khi ch kch hot trn knh v tuyn, thnh phn lp RFM b tr ly mu cc bit trong cc khong thi gian l 50 s, ly mu gp i mi byte. Thnh phn mc byte to ra mt b m con (sliding buffer) cc bit ny c gi tr cha ng 18 bit cui cng. Khi gi tr ca pha nhn 18 bit cui so snh vi k hiu bt u c ch r, im bt u ca mt gi c pht hin. Thm na, nh thi ca gi c quyt nh trong na mt khong thi gian bit. K tip, lp RFM ly mu mt bit n sau 75 s. V mu k tip c sp xp trong phn gia ca s bit k tip, ti na gia ni m ly mu gp i xy ra nu chu k ly mu vn gi nguyn ti 50 s. Sau RFM ly mu c sau mi 100 s cho phn cn li ca gi. Trong cc h thng nhng v tuyn, ng truyn thng n cc thit b l mt knh chia s, n phi c chia s c hiu qu trong ng cnh x l rng buc ti nguyn v nh tuyn Ad hoc multi-hop. Nhiu ng dng yu cu rng cc node phi c kh nng ngang bng nhau chuyn d liu qua mng, m khng quan tm n v tr trong topology mng. Cc thnh phn truyn thng ngc Anh - D2001VT

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TinyOS mc thp c m rng vi mt giao thc iu khin truy nhp mi trng (MAC) nhn bit nng lng (energy-aware) v s dng mt k thut n gin cho iu khin tc tng thch c t ng dng. Cc giao thc MAC phi c thi hnh trn b vi iu khin trng hp vi cc thao tc khc. My thu pht v tuyn RF cn h tr pht hin xung t, v th lc CSMA (Carrier Sense Multiple Access) c s dng, ni mt node thu nhn trn knh v tuyn v ch truyn mt gi nu knh ny ri. C cu cho ng h ng b trong cc bit ti lp vt l cng c s dng cho qu trnh cm bin sng mang. V vy, lp MAC c thi hnh ti c hai mc bit v byte trong ngn xp. Nu qu trnh ly mu lin tc ca knh v tuyn pht hin ra khng c tn hiu no, knh v tuyn c cho rng ri v mt qu trnh truyn gi c gng c th thc hin. Tuy nhin, nu knh v tuyn bn, mt tn hiu back-off ngu nhin xut hin. Ton b tin trnh ny lp li cho n khi knh ri. Mt b ng k dch chuyn feedback tuyn tnh 16 bit n gin c s dng nh mt b to s gi ngu nhin cho chu k back-off. My thu pht v tuyn c tt i trong ch back-off. Nhiu ng dng tp hp v truyn pht d liu mt cch nh k, c th sau khi pht hin mt s kin pht sinh, v th lu lng c th c tng quan rt cao. Qu trnh pht hin knh bn xut mt node lng ring c th ch th rng cc kiu truyn thng ca cc node c ng b. ng dng s dng li gi ging nh phn hi v dch chuyn pha ly mu n b c kh nng gii ng b. Mt yu cu ng dng chung khc l xp x phm vi gi tr ngang nhau ca qu trnh ly mu qua ton b mng. Mi node trong mng c th pht tn ch nh ng bng tn n trm gc. Vi cc lp nh tuyn c bit cc node t t chc thnh mt rng bao trm, ni m mi node to ra v nh tuyn lu lng n mt trm gc. S cnh tranh gia lu lng pht sinh v nh tuyn trn bng tn upstream phi c cn bng tho mn mc ch cng bng. Dung lng mng multi-hop c gii hn, v cc node phi thch ng vi s tr gip ca chng ti ln bng tn sn c, ng hn l thng qua cam kt knh v tuyn v nng lng d tha trong qu trnh truyn pht cc gi c th lin lc n trm gc. Lc truyn pht thch ng l mt thut ton ni b c thc hin trn ln lp bn tin kch hot (active-message) v di lp ng dng. ng dng c mt t l ly mu baseline quyt nh tc truyn pht cc i v truyn dn mt mu vi mt xc sut quyt nh ng. Nh qu trnh truyn pht thnh cng, xc sut c gia tng tuyn tnh, trong khi li trn c gim

ngc Anh - D2001VT

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n tt nghip i hc


nhanh gp nhiu ln. Mt qu trnh truyn dn thnh cng c th biu th bi mt xc nhn hin t b thu hoc mt xc nhn n khi b thu lng nghe gi tin ca n m ang c gi t node cha (node gc). V xc nhn n thng l c trng ng dng, ng dng quyt nh nu qu trnh truyn dn thnh cng, v truyn thng tin xung n lp iu khin truyn dn. Qun trnh loi b lnh truyn dn ca ng dng ti lp iu khin truyn dn khi ng qu trnh thch ng. Phng php TinyOS cung cp hiu qu tng i trong vic h tr truyn thng a nng, kh nng, nhiu thit b m c rng buc rt cao trong cc mi quan h x l, lu tr, bng tn v nng lng vi phn cng nguyn thu h tr I/O. M hnh event driven gip thun tin cho vic xen b vi x l gia nhiu lung d liu v gia nhiu lp trong ngn xp cho mi lung trong khi vn nhn mt vi yu cu thi gian thc ca tin trnh bo dng ca cc my thu pht v tuyn. V b lu tr d liu rt hu hn, n l phn chung x l cc bn tin gia tng ti mt vi mc, ng hn l m cho ton b cc bn tin v x l chng theo mc level by level. Tuy nhin, cc s kin ng mt mnh th khng c kh nng, v bn cht l mt s kin c th loi b tin trnh quan trng mt tc v chy bn ngoi ca s thi gian thc. iu ny cung cp s trng hp logic trong ngn xp v c s dng ti mi mc loi tr lp tru tng phn cng. Nh chp nhn phng php iu khin s kin, nonblocking, cc lung truyn thng khng c h tr, vi cc ngn xp c kt hp ca chng v ng b phc hp. Phng php thnh phn cung cp cch thc hot ng mnh mc d c s gii hn v kh nng g ri, v thun tin cho th nghim. Cc thnh phn gi c th c hon i vi mt mc thay i n gin n lc m t v cc thnh phn tm thi c th c t gia cc thnh phn tn ti, khng cn c nhng thay i cc b xung ni b. Hn na vic s dng cc thnh phn ch php, v c bn, ton b mt cy con ca cc thnh phn c thay th phn cng v ngc li. M hnh lp trnh bn tin kch hot Tiny cho php cc cuc th nghim vi nhiu lp mng mc cao v cc thut ton phn tn ht nh (ne-grained). Cc node c th lp trnh li thng qua mng. Mt node c th thu c bao m (code capsule) t cc node lng ring hoc thng qua cc tuyn multi-hop v tp hp hnh nh thc thi y trong b lu tr th hai ca n l EEPROM. Sau node c th s dng hnh nh ny t lp trnh li. ngc Anh - D2001VT

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n tt nghip i hc


Cc thnh phn lp thp nht ng b tt c cc my thu n my pht trong vng mt phn nh thi gian ca mt bit. V vy, thng tin ng b thi gian rt tt c th c cung cp vi mi gi tin cho cc ng dng iu khin. 1.6.2 H thng Cm bin mng tch hp khng dy WINS Cc mng cm bin vi nh phn tn khng dy bao gm mt tp cc node truyn thng, ti mi node kt hp: Mt hoc nhiu cm bin cho vic o lng mi trng. Kh nng x l x l d liu cm bin vo thng tin c gi tr cao v hon thnh vic iu khin ni b, v Mt knh v tuyn truyn pht thng tin n v i t cc node lng ring v ngi s dng m rng.

Cc chip CMOS ngun mc thp phn cc c th tch hp vo cc my thu pht v tuyn truyn thng, tnh ton s, v cc thnh phn cm bin MEMS, trn mt khi n cung cp trong dung tch cao cho mc ch chi ph thp. iu ny cho php mt s lng ln cc cm bin mng tch hp v tuyn c trin khai tht d dng v nhanh chng (v d, khng kh c tch ra t cc trng battle hoc trin khai trn mt kh cu hoc tu khng gian) hoc hnh thnh cao cc mng cm bin tha, t nh cu hnh, chuyn dng. khng rng buc vi cc nh pht trin, cc node s dng cc truyn thng khng dy, v l nng lc thit lp v vn hnh mng ca ring h. ko di thi hn sng ca ngun pin, tt c cc node v chc nng mng c thit k tiu th cng sut ti thiu. Cc h thng c nng lc v tin cy cao c xy dng ngoi s lng ln cc node nh vy tht r, ring l v s dng s cng tc gia cc node cung cp tin cy cao, thng tin cht lng cao.Node WINS da trn mt thit k module m s dng k thut off-the-shelf thng mi sn c rng ln. Cc node cm bin vi nh khng dy kt hp cc nng lc cm bin (ging nh xung ng, m thanh, t) vi mt my v tuyn in thoi cordless s thng mi v mt b vi x l RISC thng mi nhng trong mt gi nh. Khi cc mng ny c thit k vi mc nh cho ngun thp, qu trnh x l tn hiu nhng c thc hin gim cc yu cu v truyn thng. V d, nhiu nghn byte ca d liu ni tip thi gian th t cc cm bin dung ng c gim xung mt vi byte ca thng tin bin v tn s s dng vi x l onboard. Thng tin c x l truyn thng ch gim bt yu cu v ngun vn chuyn thng tin nh th t cng . Cc node WINS h tr cc th nghim

ngc Anh - D2001VT

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n tt nghip i hc


trong cc giao thc truyn thng d liu a trm, x l tn hiu coopera-tive ng (v d, qu trnh beamforming vi cc node khng gian ngu nhin), v qun l ti nguyn phn tn. a/ Cc yu cu cho mng cm bin vi nh WINS Mt ngoi duy nht ca cc mng cm bin vi nh c th c kim tra vi s lng quan trng ca cc thit b nguyn mu r rng c thit k cho mc ch ny, tri vi cc dng in ton chung, Mt vi trong s cc yu cu cho mng WINS bao gm: Yu t hnh dng nh nh; n nh vi cc di nhit rng v cc iu kin mi trng yu cu khc; Ngun pin hoc cc ngun nng lng ring mt mnh khc; Vn hnh ngun mc thp v truy nhp vi cc my iu khin cng sut ni; Mt my radio ngun thp nh c ri tn Mt mi trng thc thi thi gian thc; C kh nng vit m trong mt ngn ng mc cao cho t chc v kim tra thut ton nhanh chng v; Mt mc chi ph hp l.

Cc node h tr cc ng dng ti chin trng (battle-field), v mt lot qun l y t, phng tin giao thng v cc ng dng bo tr da trn iu kin (condition-based) trong cng nghip, qun i v cc nn tng v khng gian. V d, mt lp kim tra vn ng v tm ti cho qu trnh pht trin gim st v chun on thnh phn, x l, v mc h thng) c xy dng ti Rockwell Science Center. Lp kim tra test bed ny c cung cp vi cc node WINS chng kt hp cht ch vi cc cm bin gia tc, p sut v nhit v cc thut ton cho cc chun on x l v chuyn ng. Cc thut ton x l tn hiu chy trn cc node ring bit cung cp cho pht hin mi bt u ca mt lot cc li. Cc kiu truyn thng mng khng dy cung cp cho vic ci t n gin v cc chun on cng tc trong cc nhm motor, my bm, van trong h thng. Mt trnh duyt da trn web cho php ton b h thng, v nhiu thnh phn trong h thng c gim st t xa. Cc mng cm bin vi nh phn tn s dng kiu x l cng tc v cc giao thc truyn thng ngun mc thp. Vin cnh, ging nh gim st cc vng ln,

ngc Anh - D2001VT

- 27 -

n tt nghip i hc


cc to nh hoc cc i l, c hon thnh nh thit lp b tr cc cm bin thnh cc vng ng c quan tm trong mt dy c cao. Khong ng cho php cm bin ngun thp v cc lin kt v tuyn tm ngn. Cc node c th c nh v chnh xc hoc c phn tn trong cc cu hnh ngu nhin vi kh nng nhn bit trong khng gian (hoc khng cn iu ) c kt hp trong qu trnh x l tn hiu v cc thut ton truyn thng. S linh hot ny to thnh cc node ph hp vi mt phm vi rng ln cc ng dng, v d, an ninh trong cc doanh tri v kho st trc, gim st chuyn ng v cc ti sn khc trong cc nh my cng nghip ln, gim st nhiu h thng con trn cc phng tin giao thng. Cc node WINS truyn thng vi th gii bn ngoi thng qua mt mng mc enterprise, ging nh mt mng iu khin x nghip v/hoc mng Internet nh ch ra hnh 1.5. Truyn thng hai chiu c cung cp thng sut h thng, nh mi node WINS h tr cc truyn thng ngang hng, hai chiu vi cc node lng ring. cc node WINS c th l tnh hoc di ng chm. Nhiu port cho truyn pht thng tin vo trong hoc ra ngoi mng cm bin c th c thit lp. Mt cng port c th c m rng bi cho php kt ni cc my v tuyn tm xa ti mt vi node hoc thng qua mt gateway n mt dng hu tuyn, ging nh Internet, cho php ngi s dng gim st v iu khin mng t xa. Mt ngi s dng WINS c th pht i cc lnh thng qua mt giao din ngi s dng c thit lp trn mt my tnh c nhn hoc iu khin cm tay, cho php ngi s dng iu khin mng cc node, v d thit lp ngng nhy cm cm bin hoc lp trnh li cc node thng qua lin kt v tuyn. Giao din ngi s dng c th hin th kch hot ti mt trong cc node cng vi tnh trng th cht ca chng (v d mc ngun pin). B my v tuyn s tri ph trong mi node WINS cung cp mt lin kt truyn thng v tuyn mnh, v cho php tc d liu t n 100kb/s qua phm vi khng qu 100m. Truyn thng ngang hng hai chiu trong phm vi cc node trong mt vng ln cn nh h tr cc kiu truyn dn d liu multi-hop, trnh yu cu cho tt c cc node nm trong phm vi ca mt trm gc. c im ny a cho ngi s dng mt mc rt cao v tnh mm do trong vic pht trin cc node, v vy cho php vic sp xp cm bin chin lc trong vng quan tm m khng cn rng buc v cc kiu truyn thng line-of-sight n mt tp d liu hoc v tr gateway. Khi nim WINS mang n mt thun li trn thc t l cc hop v tuyn tm ngn c hiu qu v ngun hn cc hop

ngc Anh - D2001VT

- 28 -

n tt nghip i hc


phm vi ln hn theo hm m trong cng mt khong cch. iu khin cng sut trn mi mt my v tuyn c s dng xa hn na ti thiu ho cng sut truyn dn c cn thit cho truyn thng n cc node lng ring.

Hnh 1.5: Mt m t gin ca mt kin trc h thng WINS Mng trong mt h thng WINS c dng v vi mng d liu v tuyn thng thng vi cc l do sau: Cc node c nng lng pin gii hn, to nn cc lc TDMA hp dn, nhng phi yu cu cc lc nh tuyn c bit c ti u ho mc tiu th ngun ti thiu. Cc node cm bin c th yu cu ng b vi cm thi gian thi gian v qu trnh s l tn hiu kt hp c thc hin nh bo tr ngun, cc thut ton phn tn thi gian mng. Cc node c th c nhiu kiu cm bin (v d chn ng, m thanh, IR) mi kiu vi s khc nhau v mc hi t (hay bao ph), chnh xc, v mc tiu th ngun, v s cho php hn lon cm bin ni b. Cc mu truyn lu lng c to ra ca WINS ni chung c th on trc, cho php iu chnh sng hiu qu ca cc giao thc. Trong khi lu lng c to ra nh cc s kin ngu nhin (v d cc pht hin ch, cc lnh ngi s dng), cc ch v v th cc tuyn c rng - 29 -

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ngc Anh - D2001VT

n tt nghip i hc


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buc, nh l dung lng bn tin v cc tim nng cho php. Thng tin pht hin c chuyn tip n cc cng. cng c qu trnh tng hp d liu theo ng nh tuyn mng. X l kt hp, ging nh qu trnh beam-forming, yu cu nhm multicast ng ca cc node cc thit lp cht ch cc s kin. V cc ch hoc cc hin tng khc gy nn cc s kin c th di ng, tp cc node cm bin tch cc chng s thay i, chuyn ng v tr cc pht sinh bn tin.

Yu cu cho vic trin khai node n gin bt buc mng cc node c kh nng t khai ph v t nh cu hnh. Cc th tc t nh cu hnh cho vic boot-up v t ng t chc node vo mng cho php cc node c thm vo mng hot ng cho vic ci tin mc bao ph hoc lp y. Cch thc hot ng cho vic khi phc t cc li node cho php mng t ng phc hi. WINS s dng mt lc hiu qu ngun, a truy nhp phn chia theo thi gian h tr cho vic truyn thng multi-hop. Cc thut ton nh tuyn trnh c vic to ra cc trung tm tiu th ngun rng kt qu ti cc cm bin trong mt vng ln cn lm tiu hao nng lng ngun pin nhiu hn lc mng trong trng thi ngh nhanh chng nguyn nhn l s phn chia khi nng lng ca chng b suy yu. Nghin cu cc thut ton x l tn hiu ngun thp l mt phn khng th thiu ca n lc pht trin h thng v cho cc ng dng qun s (battleeld), vi cc trng tm chnh sau: Pht hin/phn loi ch: Cc node WINS thc hin cc thut ton pht hin rung ng trn c s ngng nng lng. K thut ny l i tng cc cnh bo sai hng n s quan tm ca cc thut ton k hiu ph tinh vi hn. Cc thut ton ngun mc thp phn loi lp s kin pht hin ging nh mt s kin xung (v d nh mt bc chn hoc mt vin n) hoc phng tin giao thng(v d nh bnh xe hoc bnh xch, nh hay nng) c s dng. S hp nht cm bin on-board: Bao gm c rt nhiu cm bin trn mi node cho php hp nht cc hin tng cm bin khc nhau, ch dn cht lng thng tin cao hn v gim t l cnh bo sai. Cc thut ton cho vic gn cc cm bin rung ng, m thanh v t trng trn mt node n c s dng.

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ngc Anh - D2001VT

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S hp nht cm bin multi-node: Cc thut ton tn dng nhng u im ca mt mng ca cc node ring r trong khng gian m rng ra mt di cc behavior cng tc, mi mt trong s cc node t b cht lng tch sng chng li vic tiu th nng lng. Cc v d v s hp nht kt hp c di t chng thc quyt nh mc cao (v d b phiu bu c) n hp nht cc c im, v qu trnh hnh thnh tn hiu radio kt hp y .

b/ Nn tng pht trin Phn cng trong mi node cm bin vi nh s dng kiu thit k m, thnh module cho php st nhp vo mt phm vi cc cm bin. Cc board lin kt uc cung cp bi thit b kt ni nh 40 chn. Cc kt ni hnh thnh mt bus h thng cung cp cc ng cung cp ngun v iu khin cho cc board cm bin, v h tr nhiu giao din m. Node WINS bao gm mt ngn xp cc mch in c bn gm b x l, my v tuyn v h thng cung cp ngun, i cp vi cc cm bin yu cu. Cc thnh phn phn cng gm: Cm bin m hc; Modul v tuyn tri ph DCT (Bin i Cosin ri rc); Modul x l StrongARM; Modul cung cp ngun nhiu mc in p; My d m thanh (cm bin m thanh) Mark 4 Product; Hai ngun chun 9V;

S khi phn cng c bn c ch ra hnh 1.6 ch ra kt ni v phn tn ngun gia cc module ch yu trong h thng. a/ Modul x l: module x l c xy dng da trn b iu khin nhng Strong Arm SA1100 ca Intel. SA1100 l mt chip a nng, b vi x l 32 bit RISC da trn cng ngh ARM. b x l tr gip mt b nh m cu trc lnh 16 bit, mt b nh m d liu 8kb, I/O ni tip v giao din JTAG, tt c c kt hp trn mt chip n. Lu tr chng trnh v d liu c cung cp nh b nh bootable flash 128kb SDRAM v 1Mb. Kt ni vi cc module cm bin c hon tt mt cch d dng nh s dng 4 dy Giao din ngoi vi ni tip SPI. Mt cng RS232 c thm vo module thc hin kt ni vi cc thit b bn ngoi. B x l c 3 trng thi: bnh thng, ri, ng, c th c iu khin gim mc tiu th ngun.

ngc Anh - D2001VT

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n tt nghip i hc


b/ Modul v tuyn: module v tuyn s dng Conexant Systems, RDSSS9M Digital Cordless Telephone (DCT) chip-set b xung thc hin lin kt truyn thng RF tri ph tn s 900MHz. Chipset c mt b vi iu khin nhng 65C02 thc hin tt c cc chc nng iu khin v gim st c yu cu cho truyn thng tri ph chui trc tip (12 chip/bit), rt tt trao i d liu vi module x l. Knh v tuyn hot ng trn mt trong 40 knh ca bng tn ISM, c th la chn nh b iu khin. Lu tr chng trnh v d liu c cung cp vi 32kb SDRAM v 1Mb b nh bootable flash. Vi chng trnh (phn sn) nhng c pht trin h tr mng a truy nhp vi phn h tr b x l ARM cc tiu. Board cng cung cp mt b bin i ADC 4 bit cho vic gim st in th pin. Phn RF ca knh v tuyn c ng gi ging nh mt module a chip nh, giao din vi antenna xon tr khng 50 v kh nng hot ng ti nhiu mc ngun truyn pht 1 n 100 mW, c th s dng cc thut ton truyn thng ti u ho ngun. c/ Modul cm bin rung ng: board cm bin rung ng s dng mt my d Mark IV c thit k cho pht hin tn s thp ca cc s kin rung ng. Kh nng cm bin ca my d ny khong 15g. Mch in tn dng mt b bin i Sigma-delta thit b tng t AD 7714 m kt qu nm trong mt clean, 20dbit tn hiu t 1Hz n 400Hz. Mch in c th lp li thch hp cho php s so khp pha gia cc node cm bin h tr qu trnh x l kt hp cng tc, ging nh qu trnh beamforming. Cc module cm bin khc bao gm: Cm bin m thanh: Board cm bin m thanh tn dng mt microphone nh ging nh phn t microphone Knowles BL1785 c mt ngng tn thp l 4 Hz. Tn s cc i quan tm cho cc ng dng cm bin m thanh l 2kHz. Thc s c mong i duy tr thng pha cho cc ng dng beamforming. T k: mt module t k tn dng Honeywell HMC1001 v c bng tn 10Hz. T l cm bin l 27 microgausss lm n c th pht hin 1lb ca st t 6 feet. Gia tc k: Mt gia gia tc k ch to cho vic s dng trong vic gim st rung ng my. Board ny bao gm mt gia tc c ly mu ti tn s 48 kHz. Board gia tc k WINS cng cung cp u vo cho cc cm bin nhit v p sut.

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ngc Anh - D2001VT

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n tt nghip i hc


Hnh 1.6: Mt s khi phn cng h tr cho vic th nghim v pht trin cc thut ton, mt mi trng phn mm mm do m trong cc ng dng c th c vit bng mt ngn ng bc cao, ging nh C, trong qu trnh bo tr truy nhp n cc chc nng phn cng mc thp, ging nh iu khin ngun, l ch yu. Cc chc nng phn mm WINS chnh c t chc trong cc lp sau: Gim st/Phn lp tru tng phn cng HAL: HAL cung cp thng trnh cho vic ci t ho, truyn thng vi bn ngoi, ti v g ri chng trnh, v x l ngt. Mt phin dch nh chun gi nh tuyn cc gi n t b pht v tuyn hoc t RS-232 bn ngoi vo cc tc c bn trong. Ti chng trnh c th xy ra hoc thng qua mt thit b nh km hoc thng qua b pht v tuyn. Mi trng thi gian thc thi Run-time: Nhn run-time trn mi node cung cp c s h tng mng WINS phn tn mc thp. iu khin mc thp cho cc giao thc truyn thng, tt ging nh cc driver cm bin c t chc ti lp ny. ngc Anh - D2001VT

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Cc ng dng h thng: Cc my tnh x l tn hiu v chc nng lin mng lp cao hn (lp lch, nh tuyn) c chy v vit bng ngn ng lp trnh mc cao ging nh C. Cc ng dng mi c th c download v cc node cm bin m c trin khai trong cc trng cm bin thng qua mng RF. Cc ng dng giao din ngi s dng t chc trn cc my PC cho php ngi s dng chy cc tc v khc nhau v tng tc vi mng cm bin. Mt giao din cho truyn thng vi mng thng qua mt gateway c h tr tt ging nh hin th v logging thng tin mng.

Hnh 1.7: Cc thnh phn mi trng run-time Mt nhn run-time, c quyn u tin, a tc v c port n module x l da trn Micro C/OS, v c thit k chy trn trn mc cao nht ca HAL. HAL cung cp cc chc nng ngn ng bin dch then cht cho Micro C/OS (nh thi thi gian thc, chuyn mch ng cnh, iu khin ngt). Mi quan h gia cc ng dng, h iu hnh v HAL c ch ra ti hnh 1.7 vi nhiu chi tit ca qu trnh thc thi. OS c s dng lp lch cc ng dng, truyn thng lin x l mnh vi my pht v tuyn v cc module thng minh nh km, iu khin qun l ngun mc cao hn, iu khin cc driver thit b cm bin nh km, v iu khin cc bn tin mng v cc chc nng giao thc lin quan. HAL cung cp mt ci nhn chun v cc ngt n OS v truy nhp mc ngc Anh - D2001VT

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thp hn n qun l ngun, cc b download m, chc nng lp trnh b nh Flash, v giao din g ri JTAG. Mt chc nng I/O chun c cung cp h tr g ri ngn ng C v giao din mc C cho qu trnh truyn bn tin mng. Hnh 1.8 ch ra kin trc phn mm tng th vi cc thc th phn mm c t trn module x l ARM, module DCT, cc module cm bin v mt my ch (PC). H tr cho mt my thu pht v cng c cung cp. Mt vi cng c pht trin pht trin trn OC v Arm cho vic s dng trong qu trnh m ho v g ri phn mm. Ngi s dng s dng ARM SDT (System Developers Toolkit) hoc b bin dch tng t pht trin cc ng dng da trn C (Cbased). Mt lc TDMA hiu qu ngun c thi hnh ging nh giao thc lp lin kt WINS c bn. Lc TDMA cho php cc node kho b thu v/hoc b pht ca chng khi chng khng c lp lch truyn thng. Mt lc nh tuyn multi-hop cng c thi hnh thng tin t cc node xa c th c chuyn n cc v tr ch. Cc giao thc lp lin kt c xy dng trn nht ca knh qung b v tuyn tri ph s v cung cp mt tc d liu th khong 100kb/s. Cc loi lc t sa li trc mo u thp cng c thi hnh. Ton b node cm bin WINS tiu th ngun c nh l 1W, vi b x l tiu th 300mW, my pht v tuyn tiu th 600mW trong ch truyn pht v 300mW trong ch thu, thp hn 100mW c tiu th nh cc b transducer cm bin. B iu khin thch hp chuyn bit ca h thng cho php cng sut nh t khi b ph thuc. Mt nng lc ct yu ca cc thit b l chng c th c php t vo trong ch ri hoc ng di s iu khin phn mm mc thp tng thi gian sng hot ng h thng.

ngc Anh - D2001VT

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n tt nghip i hc


Hnh 1.8: Kin trc phn mm WINS

ngc Anh - D2001VT

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Chng 2. Cc ng dng ca mng cm bin khng dy

CHNG 2 CC NG DNG CA MNG CM BIN KHNG DY 2.1 Cc ng dng ca cng ngh mng cm bin khng dy2.1.1 Gim st v iu khin cng nghip Mt nh my cng nghip, c quy m rng in hnh c mt phng iu khin tng i nh, xung quanh c cc thit my mc tng i ln. Phng iu khin c cc ng h ch bo v cc my hin th m t trng thi cc thit b (trng thi cc van, trng thi thit b, nhit v p sut ca nguyn liu c lu tr, v.v), u vo cc thit b iu khin cc b truyn ng trong cc my mc (cc van, cc bp l, v.v) m tc ng n trng thi c theo di ca my mc. Cc cm bin m t trng thi cc my mc, cc kt qu hin th ca chng nm trong phng iu khin, cc thit b u vo iu khin, v cc b truyn ng trong cc my tt c tng i r khi c so snh vi chi ph ca cc ng dy bc kim loi m c s dng truyn thng gia chng. Tit kim chi ph ng k c hon tt nu mt phng tin khng dy r c sn cung cp kiu truyn thng ny. Bi v thng tin c truyn thng l thng tin trng thi, n thng thay i chm. V vy, trong ch vn hnh bnh thng, thng lng d liu c yu cu ca mng tng i chm, nhng tin cy c yu cu ca mng li rt cao. Mng cm bin khng dy ca nhiu node, cung cp nhiu ng dn nh tuyn bn tin ca qu trnh truyn thng multi-hop, c th nhn c cc yu cu ny. Mt v d v iu khin cng nghip khng dy l qu trnh iu khin b tr nh sng qung co. Rt nhiu ph tn trong qu trnh ci t cc bng n trong mt to nh ln lin quan n vic iu khin cc bng n ni m cc chuyn mch c dy, vi cc bng n c bt v tt cng nhau, iu khin bng n, v.v Mt h thng khng dy c tnh mm do c th tn dng mt b iu khin handheld c th c lp trnh iu khin mt s lng cc bng n trong mt theo nhiu cch khc nhau gn nh v hn, trong khi vn cung cp mc an ninh c yu cu bi mt b phn lp t qung co. Thm mt v d na l vic s dng cc mng cm bin khng dy trong cc ng dng an ton cng nghip. Cc mng cm bin khng dy c th tn dng cc cm bin pht hin s hin din ca cc cht c hi hoc cc vt liu - 37 -

ngc Anh - D2001VT

n tt nghip i hc


nguy him, cung cp qu trnh pht hin v nhn dng sm cc khe h hoc pht hin trn cc tc nhn ho hc hoc sinh hc trc khi thit hi nghim trng c xy ra (v trc khi cc cht vt ra ngoi vng kim sot). Bi v mng khng dy c th s dng cc thut ton nh tuyn phn tn, c nhiu ng nh tuyn, v c th t cha tr v t duy tr, chng c th co gin trong mt ngoi ca qu trnh bng n hoc cc thit hi khc n my cng nghip, cung cp cc thm quyn vi thng tin trng thi my quyt nh di cc iu kin rt kh. Qu trnh gim st v iu khin c cu quay hoc chuyn ng l mt lnh vc khc ph hp vi cc mng cm bin khng dy. Trong cc ng dng nh vy, cc cm bin c dy v cc b truyn ng thng khng thc hin c, iu rt quan trng gim st nhit , dao ng, dng bi trn, v.v ca cc thnh phn quay ca cc my ti u ho thi gian gia cc chu k bo tr, khi my phi c gi off-line. lm c iu ny, quan trng l h thng cm bin khng dy c kh nng thc hin cho khong thi gian trn vn gia cc chu k bo tr, nu khng n th tiu mc ch ca cc cm bin. iu ny, trong chuyn ng quay, yu cu s dng mt mng cm bin vi cc yu cu nng lng rt thp. Cc mng cm bin c th s dng ring bit trong qu trnh d bo li cc thnh phn trong aircaft, ni m nhng phn tn ny c th c s dng cho cc ci tin ring bit. Vi ng dng khc trong lnh vc ny ca cc mng cm bin khng dy l hi nng, thng hi v cc iu kin khng kh (HVAC) ca cc to nh. Cc h thng HVAC c in c iu khin bi mt s lng nh cc my n nhit v n m. S lng cc my n nhit v n m ny cng b gii hn, tuy nhin, bi chi ph kt hp vi kt ni hu tuyn n v tr t h thng HVAC. Thm na, cc b iu khin khng kh v chng rung m iu khin trc tip trong mi trng phm vi phng cng c dy; cng vi cc l do ny, s lng ca chng cng b gii hn. Tuy nhin, thn nhit pht sinh do con ngi trong mt to nh cng thay i tng i. Nhng thay i hng ngy, hng tun, theo ma lun xy ra. Nhng thay i ny c kt hp vi qu trnh phn tn con ngi trong to nh sut ngy, sut tun, sut ma, sut nm; nhng thay i quan trng cng nh hng n thn nhit ca to nh ti cc khong khng ng u. V d, khi cc t chc ci t li v sa cha li, khng gian s dng trc y cho cho cc vn phng c th c s dng bi l pht sinh nhit hoc thit b ch to. Nhng ngc Anh - D2001VT

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thay i n ngi nh bn thn chng cng c quan tm: phn kt cu bn trong tng c th c chn vo, chuyn hoc di ri i; cc ca s, cc mn chn, cc mi hin cng c th c thm vo hoc ri i, v.v V tt c nhng bin i c th ny v m gn nh khng c ai lm vic trong vn phng trong to nh ny c th chng nhn chng, nn ci tin c yu cu. Nguyn nhn cn bn ca chc nng HVAC khng tt nh vy lm cc h thng iu khin thiu thng tin chnh xc v mi trng trong to nh duy tr mt mi trng thoi mi cho con ngi. Bi v chng khng yu cu ph tn cc b cm bin v kch thch c dy, mng cm bin khng dy, c th c tn dng gia tng nhanh chng thng tin v gi tr mi trng trong to nh n h thng iu khin HVAC, v gim nhanh chng kh nng to thnh p ng li ca n. B n nhit v n m khng dy c th c t ti mt vi v tr trong mi phng cung cp chi tit thng tin n iu khin h thng. Tng t, cc b gim rung vng v gim dung m lng khng dy c th c s dng to ra mt lng ln tinh chnh p ng ca h thng HVAC n nhiu trm. Khi mi ngi trong mt phm vi vn phng chuyn n phng hi ngh meeting, v d, h thng c th c p ng bi vic ng cc b chng rung m lng trong phm vi vn phng, trong khi m cc b chng rung m lng ti phng hi ngh. Khi mi ngi ri khi to nh, h thng HVAC c th hng dn cc b chng rung vng p ng thay i trong ton b thn nhit to nh. Khi mi ngi tr li trong khi li xe di ma gi, b n m trong v o i ma c th pht hin m trong o ma. H thng HVAC sau c th t c bit ti ni kh ro, khng tc ng n ngi s hu n trong phng. H thng HVAC khng dy cng c th gii thch mt trong nhng vn ln i vi k s HVAC: Cn bng nhit m v tnh trng khng kh. Vi trng hp m cc ngun nhit c phn tn khng u nhau khp to nh. V d trong ngi nh, nh bp c khuynh hng m hn, bi v nhit ca bp nu n, trong khi cc phng ng c khuynh hng lnh hn. Vo ma ng, khng kh m hn yu cu c gi n phng ng, ni m khng kh lnh hn, v ngun nng thp hn yu cu c gi n nh bp, ni khng kh m hn. Trong ma h, tuy nhin, ngc li khng kh lnh hn yu cu c gi n nh bp, ni m khng kh m hn, v khng kh t lnh yu cu c gi n phng ng, ni m khng kh lnh hn. S khc bit ny gia cc qu trnh phn tn khng kh ca nhit m v tnh trng khng kh l mt vn kh v t tin

ngc Anh - D2001VT

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n tt nghip i hc


gii quyt i vi cc h thng iu khin hu tuyn, bi v mt b chng rung m lng n mi phng trong cn nh phi c iu khin c lp. Thng, cc b chng rung c t ti mt v tr n, c nh, ngoi cc vng lnh lin tc v m lin tc. Vi cc cm bin v cc b truyn ng khng dy trong h thng HVAC, tuy nhin, vn ny tr nn tm thng; mt (nhiu) b chng rung trong mi phng c th c iu khin bi mt (nhiu) cm bin trong mi phng, sp t s cn bng h thng hon chnh ti nhng thi im trong nm. Mt h thng HVAC c nhng u im khc. Qu trnh gim st kn ca h thng cho php cc vn c nhn ra v c sa cha trc khi cc phin toi xy ra. b xung n cc cm bin vng c tr cc cm bin khng dy c th c t h thng thay i nhit) khng ph thuc vo t bo tr to cc php o bng tay trn cc khe h. Thm na cc cm bin c th c t trong cc tng thng v cu trt ti b bi m cha ng ng dn; nhit bt thng trong cc vng ny c th ch ra cc l r tai hi lung khng kh nng hoc lnh. V nhng nguyn nhn ny, ton b chi ph HVAC ngi nh s gim, trong khi s thoi mi ca ngi s dng gia tng khi cc cm bin v cc b truyn ng c tn dng. 2.1.2 T ng ho gia nh v in dn dng Gia nh l khng gian ng dng rt ln cho cc mng cm bin khng dy. Nhiu ng dng cng nghip va c m t c mi lin h tng t trong gia nh. V d mt h thng HVAC c trang b vi cc b n nhit v chng rung khng dy c th bo v cc phng di nh nng mt tri ca ngi nh s hiu qu hn mt ngi nh ch trang b mt b n nhit n c dy. Mt ng dng c iu khin chung t xa, mt PDA loi thit b c th ch khng iu khin TV, My nghe DVD, dn m thanh ni v cc thit b in t gia nh khc nhng vi cc bng n, cc cnh ca, v cc kho cng c trang b vi mt kt ni mng cm bin khng dy. Vi iu khin chung t xa, mt b c th iu khin ngi nh t tin ch trn gh. Tuy nhin, kh nng hp dn nht n t s kt hp nhiu dch v, ging nh cc cnh ca t ng ng khi TV c bt, hoc c th t ng ngng h thng gii tr gia nh khi mt cuc c nhn trn my in thoi hoc chung ca ku. Vi chic cn v my tnh c nhn c hai c kt ni vi nhau thng qua mt mng cm bin khng

ngc Anh - D2001VT

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n tt nghip i hc


dy, sc nng ca mt vt c th c t ng ghi li khng cn yu cu s can thip bng tay. Mt mc ch ln ca cc mng cm bin khng dy trong gia nh c mong ch l cc thit b ngoi vi my tnh c nhn, ging nh cc keyboard v mice khng dy. Cc ng dng ny em li u im gi thp v mc tiu th ngun thp l iu kin thit yu ca cc mng cm bin khng dy. ng dng khc trong gia nh l cc dng c thng tin da trn cm bin (sensor-based) m tc ng v lm vic cng sinh r rt cng nhau tho mn ch nh. Cc mng ny l mt m rng ca cc dng c thng tin c xut bi Norman. Cc chi miu t mt th trng ln khc ca cc mng cm bin khng dy. Danh sch cc chi c th c thm hoc cho php nh cc mng cm bin khng dy l b gii hn ch bi sc tng tng ca con ngi, v phm vi t cc xe hi v tu thuyn c iu khin bng v tuyn thng thng n cc tr chi trn my tnh tn dng cc b joystick v b iu khin khng dy. Mt phm vi hp dn c bit l cc my tnh c nhn cc tr chi nng cao, tn dng sc mnh tnh ton ca mt my tnh gn nng cao cht lng ngay ti bn thn tr chi. V d, nhn dng v tng hp ging ni c th c thc hin bi v tr cc microphone v speaker trong tr chi, cng vi cc b bin i analog-to-digital v digital-to-analog ph hp, nhng tn dng mt kt ni khng dy n my tnh, c th thc hin cc chc nng nhn dng v tng hp. Nh thay th cc mch in nhn dng v tng hp n ny cn b gii hn vi gi tng i t, bng vic s dng sc mnh tnh ton (mnh hn nhiu) hin ti trong my tnh, chi ph cc tr chi c th c gim ng k, trong khi ci tin nhanh chng v kh nng v thc thi ca tr chi. N cng c th a ra phc tp ca tr chi m trn thc t khng c b xung trong cc k thut khc. ng dng gia nh ln hn khc l mt m rng ca c im RKE (Remote Keyless Entry) c tm thy trn nhiu t. Vi cc mng cm bin khng dy, kho khng dy, cc cm bin ca ra vo v ca s, v cc b iu khin bng n khng dy, ch nh c mt thit b tng t nh mt key-fob vi mt node bm. Khi bm node, thit b kho tt c cc ca ra vo v ca s trong nh, tt hu ht cc bng n trong nh (tr mt vi bng n ng), bt cc bng n an ton ngoi nh, v thit lp h thng HVAC n ch ng. Ngi s dng nhn mt ting beep mt ln hi p th hin tt c thc hin thnh cng, v ngh ngi hon ton, nh vy ngi nh an ton. Khi mt cnh ca hng khng ngc Anh - D2001VT

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th m, hoc vn tn ti, mt mn hnh hin th trn thit b ch th ni b hng. Mng c thm tr c th tn dng mt h thng an ninh gia nh y pht hin mt ca s b gy hoc ch hng khc. Bn ngoi ngi nh, cc kh nng location-aware ca cc mng cn bin khng dy ph hp vi mt tp khc nhau ca cc hot ng consumer-related, bao gm du lch v mua sm. Trong cc ng dng ny, qu trnh nh v c th c s dng cung cp thng tin context-specific n ngi tiu dng. Trong trng hp ca ngi hng dn vin du lch, ngi s dng ch c cung cp thng tin lin quan n quang cnh hin ti, trong trng hp ca nhn vin bn bn hng, ngi s dng c cung cp thng tin lin quan n sn phm trc mt. bao gm cc khon mua bn v khu hao c bit v tr gip. 2.1.3 Cm bin trong qun s Cc mng cm bin khng dy l mt phn khng th thiu trong cc ng dng qun s ngy nay vi cc h thng mnh lnh, iu khin, thu thp tin tc tnh bo truyn thng, tnh ton, theo di k tnh nghi, trinh st v tm mc tiu. Cc c tnh trin khai nhanh chng, t t chc v kh nng chu ng li ca cc mng cm bin cho thy y l mt cng ngh y trin vng trong lnh vc qun s. V cc mng cm bin da trn c s trin khai dy c vi cc node gi r v ch dng mt ln, vic b ch ph hu mt s node khng nh hng ti hot ng chung nh cc cm bin truyn thng nn chng tip cn chin trng tt hn. Mt s ng dng ca mng cm bin l : kim tra lc lng, trang b, n dc, gim st chin trng, trinh st vng v lc lng ch, tm mc tiu, nh gi thit hi trn nh, trinh st v pht hin cc v kh ha hc sinh hc - ht nhn (NCB). - Kim tra lc lng, trang b, n dc: Cc lnh o v ch huy c th kim tra thng xuyn tnh trng ca qun i, iu kin v kh nng sn sng chin u ca cc trang b, n dc trong mt chin trng bng vic s dng cc mng cm bin. Mi ngi lnh, xe c, trang b u c gn mt cm bin thng bo trng thi. Cc thng bo ny c tp hp ti mt node thu d liu (Sink node) v c gi ti ngi ch huy. Cc s liu ny c th c hng ti cc cp cao hn trong phn cp ch huy cng vi cc s liu t cc n v khc ti mi cp. - Theo di chin trng : Ti cc vng quan trng, cc tuyn tip cn, cc con ng v eo bin, cc mng cm bin c th c trin khai nhanh chng ngc Anh - D2001VT

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theo di hot ng ca i phng mt cch r rng, b mt. Khi bn cng tc c chun b, cc mng cm bin c th c trin khai bt c lc no theo di i phng. - Trinh st vng v lc lng i phng: Khi cc mng cm bin c trin khai ti cc vng chin lc, cc thng tin tnh bo c gi tr, chi tit v kp thi c th c thu thp trong mt vi pht trc khi b i phng ngn chn. - Tm mc tiu: Cc mng cm bin c th c kt hp cht ch vi cc h thng hng o trong cc qun trang thng minh. - nh gi thit hi ca trn nh: Ngay trc hoc sau khi tn cng, cc mng cm bin c th c trin khai trong vng mc tiu tp hp cc s liu nh gi thit hi trong trn nh. - Trinh st v pht hin cc v kh ha hc, sinh hc, ht nhn: Trong cc cuc chin tranh sinh hc v ha hc, vic pht hin chnh xc v kp thi cc tc nhn l iu rt quan trng. Cc mng cm bin c trin khai trong vng chim ng v c s dng nh cc h thng cnh bo v kh sinh ha c th cung cp cho qun i cc thng tin v cc tc nhn c th gy nguy him, thng vong. Cc mng cm bin cn c dng gim st chi tit sau khi cc tn cng sinh, ha v ht nhn c pht hin. Ngi ta c th c c s trinh st v v kh ht nhn m khng phi a cc i trinh st vo vng bc x nguy him. 2.1.4 Cm bin trong y t v gim st sc kho Mt s ng dng trong y t ca mng cm bin l cung cp kh nng giao tip cho ngi khuyt tt; kim tra tnh trng ca bnh nhn; chn on; qun l dc phm trong bnh vin; kim tra s di chuyn v cc c ch sinh hc bn trong ca cn trng v cc loi sinh vt nh khc; kim tra t xa cc s liu v sinh l con ngi; gim st, kim tra cc bc s v bnh nhn bn trong bnh vin. - Kim tra t xa cc s liu v sinh l con ngi: Cc s liu v sinh l thu thp c bng cc mng cm bin c th c lu tr trong thi gian di v c th c s dng kho st y hc. Mng cm bin cn c s dng kim tra v pht hin tnh trng ca ngi cao tui nh s t qu. Cc node cm bin nh ny cho php cc i tng c th di chuyn t do trong phm vi rng v cc bc s c th pht hin cc triu chng c nh ngha trc mt cch d dng. Cc mng cm bin ny to thun li hn cho cc bnh nhn so vi vic ngc Anh - D2001VT

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n cc trung tm iu tr. Mt nhm c tn l Health Smart Home c t chc ti khoa y hc ca Grenoble France nh gi, cng nhn tnh kh thi ca cc h thng ny. - Gim st v kim tra cc bc s v bnh nhn bn trong bnh vin: Mi bnh nhn c cc node cm bin nh v nh c gn vi h. Mi node cm bin c mt nhim v ring. V d, mt node c th theo di nhp tim, trong khi mt node khc theo di huyt p. Cc bc s cng c th mang theo cc node cm bin cc bc s khc bit c v tr ca h trong bnh vin. - Qun l dc phm trong bnh vin: Cc bnh nhn c gn cc node cm bin c th nhn bit cc d ng thuc v cc dc phm cn thit. Nh vy, c th gim ti a cc sai st trong vic k n thuc v s dng thuc ca bnh nhn. 2.1.5 Cm bin mi trng v nng nghip thng minh Mt s cc ng dng v mi trng ca mng cm bin bao gm theo di s di chuyn ca cc loi chim, loi th nh, cn trng; kim tra cc iu kin mi trng nh hng ti ma mng v vt nui; tnh trng nc ti; cc cng c v m cho vic gim st mt t phm vi rng v thm him cc hnh tinh; pht hin ha hc, sinh hc; tnh ton trong nng nghip; kim tra mi trng khng kh,t trng, bin; pht hin chy rng; nghin cu kh tng v a l; pht hin l lt; v bn sinh hc phc tp ca mi trng v nghin cu nhim mi trng. - Pht hin chy rng: V cc node cm bin c th trin khai dy c, t do cc v tr cn thit nn chng c th cung cp tin tc chnh xc v ngun gc pht la trc khi chng pht tn rng khng kim sot c. Hng nghn node cm bin c th c trin khai v tch hp nh cc h thng quang v cc tn s v tuyn. Ngoi ra, cc node cm bin cn c trang b cc phng php thu nng lng, v d nh dng pin mt tri, cc cm bin c th t duy tr trong nhiu thng thm ch nhiu nm. Cc node cm bin s cng tc vi cc node khc phn tn s cm bin v chng li cc tr ngi nh cc cnh cy, khi lm cn tr tm nhn ca cc cm bin. - V bn sinh hc phc tp ca mi trng: Vic lp bn sinh hc ca mi trng i hi phi tip cn mt cch tinh vi kt hp cc thng tin qua cc trc khng gian v thi gian. Cc tin b k thut trong lnh vc cm bin t xa v thu thp d liu t ng cho php phn gii khng gian, quang ph v ngc Anh - D2001VT

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thi gian cao ti mt n v din tch. Da vo cng ngh hin nay, cc node cm bin c th c kt ni Internet, iu ny cho php ngi s dng t xa c th iu khin, kim tra v theo di cc thnh phn sinh hc trong mi trng. Mc d cc h thng cm bin v tinh v trn my bay rt hu ch cho vic theo di tnh a dng sinh hc v m nhng chng khng tinh vi tip cn cc thnh phn sinh hc c kch c nh. Do cn thit phi s dng mng cm bin theo di chi tit cc thnh phn sinh hc mt cch y . - Pht hin l lt: mt v d v ng dng pht hin l lt l h thng ALERT c trin khai ti M. Nhiu kiu cm bin c trin khai trong h thng ALERT l cc cm bin v lng ma, mc nc v thi tit. Cc cm bin ny cung cp thng tin cho h thng c s d liu trung tm. Cc d liu ny c tnh ton, phn tch a ra d bo v tnh hnh nguy c l lt. - Trong nng nghip: Mt v d c bn ca vic s dng cc mng cm bin khng dy trong nng nghip l o c lng ma. Cc trang tri trng trt v cc trang tri chn nui ln c th vt qu vi dm vung, v chng c th ch nhn c lng ma ri rc v ch c mt vi v tr trn trang tri. Ti nc l rt t, v vy quan trng l bit c cc cnh ng no nhn c ma, mc ch l vic ti nc c th b b qua, v ch c nhng cnh ng no khng c v phi c ti. Mt ng dng nh vy l tng cho cc mng cm bin khng dy. S lng d liu gi qua mng c th rt chm (chm bng mt bit yes hoc no - vi p ng l truy vn Hm nay tri c ma hay khng) v tr bn tin c th theo trnh t vi pht. By gi, gi c thp, v mc tiu th ngun phi thp cho mng nguyn khi n cui ma sinh trng. Mng cm bin khng dy l kh nng nhiu hn cc php o lng m ca t, tuy nhin, bi v mng c th c thch hp vi mt s lng cc loi near-inf

DO an TOT NGHIEP DAI HOC Mang Cam Bien Khong Day

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