Cảm biến không dây tự nạp năng lượng

The giai Cam bi^n<br /> <br /> <br /> <br /> <br /> C A M BIEN KHONG D A Y<br /> TU NAP N A N G L U O N G<br /> Ky thuat nap nang luomg dat ra mot sir lira chon trong viec thiet ke nguon cua cam bien,<br /> cho phep khong can dung pin, giam chi phi va co the mo rong cac tien ich cua cam bien<br /> trong nhieu img dung. Edward va Steve da gioi thieu img dung ciia mot loai cam bien ap<br /> suat khong day va bo demo cua no tLrong thich vdi tieu chuan IEEE 802.15.4, dugc cap<br /> nguon bang each lay nang luomg rung tir mot phan tCrsgi gom ap dien.<br /> <br /> <br /> <br /> <br /> N<br /> gay nay ta cd the trien khai eac ung dung Bang each su dung mpt qua trinh da dupc cap bang<br /> <br /> <br /> <br /> giam sat khdng day cd chi phi thap, tudi tho sang che, Advanced Ceramethes san xua't cac sai<br /> cao va tieu thu it dien nang theo tieu chuan piezo gdm dai, linh hoat va re. Op linh hoat dupe cai<br /> IEEE 802.15.4 va cam bien ZigBee. Pin cd thien dang ke bang each them mpt lap dat mdng, cung<br /> tudi tho cao da cho phep cac cam bien tdn tai ddc cap bd chuyen ddi phuc hop rat ben va cd the tao hinh<br /> lap trong nhieu mdi trudng ma khdng can ndi day cap theo dinh dang ciia ngudi diing, cho phep gan chatvao<br /> ngudn. Nhung vdi hang trieu cac cam bien khong cac ca eau ea khi ed su dao ddng. Cac bd chuyen ddi<br /> day se dupc trien khai trong thap ky tdi, viee thay the loai nay da dupe ung dung de chuyen ddi co nang<br /> hang trieu qua pin (hay toan bd eac cam bien) se thanh dien nang vdi hieu suat dat 70%.<br /> phai chju mdt ehi phi Idn, dac biet la eac cam bien<br /> nhimg va cam bien d nhung nai khd tiep can. Cdng nghe Sdi gdm mdj khdi ngudn nang lifdng piezo<br /> Hay thu tudng tupng rang pin dien thoai cd the tu<br /> Cd sd cua Uiec nap nang llfdng nap dien lai khi ban deo no ben hdng. Hoac mpt cam<br /> Viec khai thac cac ngudn nang lupng tu mdi bien khdng day dupe cap dien tu si/ chuyen dpng<br /> trudng xung quanh nhu su dao ddng ed the loai bo eua thie't bj ma nd cam irng. Odng nghe chdng rung<br /> viec phai su dung pin trong cae ung dung giam sat, da duac cap ngudn nhu the nao tu su di chuyen<br /> keo dai tudi thp va giam dang ke chi phi van hanh manh ma chiing dang cd gdng triet tieu?<br /> ciia cam bien. Nang lupng lay dupe do su dao ddng Nhung ung dung kieu nhu vay mdi ehi'la phan ndi<br /> eiia cac spi ap dien gia re trd thanh ngudn cd sin cua tang bang trdi. Advanced Ceramethes cua<br /> thay the cho pin trong eac ung dung giam sat. Cae Lambertville, New Jersey da phat then mdt cong<br /> cam bien dupe cap ngudn tu su dao ddng cd the d l nghe mdi ed the tao ra mdt ngudn dien cd cdng sua't<br /> dang dupc tich hop vao trong ke't eau va may hoac bang 10 lan cua cac dang piezo linh hoat khac.<br /> ed the lap dat trong eac mdi trudng khac nghiet ma Cong nghe nay la mdt bien the hoan toan mdi dua<br /> binh thudng rat khd khan trong viee thay pin. tren phuang tien phat dien eu va dang luu tam la ap dien.<br /> Nang lupng tu su dao dpng ed the dupc khai thac<br /> bang rat nhieu each khae nhau nhu chuyen ddi dien TlTdien nang tdi Cd nang va ngiTdC lai<br /> tu, tinh dien hoac ap dien. Trong phuang phap ap Nam 1880, Pierre va Jacques Oune da phat hien<br /> dien (piezo), dt/a tren co so dao dpng cua cac vat ra rdng cae tinh the phat ra mot dien tu khi bi tac<br /> lieu ap dien, ngudi ta ed the tao nen mdt bd nap de dpng manh. Ho da tudng rdng dd la eac tinh the<br /> phat ra mdt dien^ap co dd Idn tuong ung vdi kich cd piezo, theo tieng Hilap cd nghTa la dp.<br /> va hinh dang cua vat lieu ap dien cung nhu tinh ehu Cae tinh the ap dien ddng vai trd nhu nhi/ng bp<br /> ky va dd Idn cua luc tac ddng. chuyen ddi. Chung bien ca nang thanh dien nang.<br /> 34 : Automdtion Toddy 55 5 (gi) 9007<br />  The giai Cam b i ^ n<br /> <br /> Mpt bd chuyen ddi ca nang sang dien nang thdng Cac ung dung ciia soi PZT duo'c ehia thanh hai<br /> thudng la mdt bd danh lua. Trong dd se cd mdt chiec nhdm chinh: nhdm cd che dp nap nang lupng va nhdm<br /> bua gd vao mdt tinh the ap dien de tao ra tia lua dien ed che dd kich thich. Mdt vai trudng hpp dien hinh la:<br /> lam mdi cho ngpn Ida ga. • Cam bien khong day: Cam bien khdng day nghe<br /> Gidng nhu viee chuyen ddi ca nang thanh dien nang, cd ve nhu la mdt y kien rat hay eho den khi ed<br /> cac tmh the ap dien chuyen ddi dien nang thanh cac ngudi dat ra eau hoi: "Ai la ngudi se thay hang<br /> chuyen ddng. nhung chide loa chinh la cae bd chuyen nghin qua pin?" Nhung neu pin khdng can thay<br /> doi dien nang thanh ca nang. Su thay ddi dien ap se hoac tham chi chiing cdn duoc loai bo di thi cudc<br /> lam eho cac vat lieu ap dien rung len, sau dd duac choi lai trd lai va hua hen ve cam bien khong day<br /> khueeh dai va tao ra am thanh. hoan toan cd the thanh hien thue.<br /> Tuy nhien cac vat lieu ap dien truyen thdng thudng • Cac cam bien khdng can diing pin: cho du dupe<br /> la cdng kenh, de vd va khong hieu qua nen khi chju su' lap dat ben trong mdt dudng dng khdng khi hoac<br /> tac ddng eiJa trudng dien tu hoac ddng dien ehiing se gan tren cae he thdng giam sat thi phan Idn cae<br /> gian no hoac eo lai mdt lupng nhd. cam bien deu d trong mdi trudng ma co nang<br /> Cac soi gdm ap dien eua Advanced Oerametrics giai quanh nd da bj lang phi rat Idn. Cac soi PZT cua<br /> quyet du'o'c tat ea eac han che dd. Chiing kha lmh hoat Advanced Oerametrics se tan dung cac ca nang<br /> do vay rat de dang trong viec trien khai ung dung. dd de nap lai pin hoac cap dien true tiep eho cam<br /> Chung tao ra mdt cdng suat bang 10 lan cong suat do bien ma khong can dung pin,<br /> vat lieu po li me linh hoat truyen thong, Mdt bo chuyen • Cam bien thong minh: Hay tuong tuong cam bien<br /> ddi ed trpng lupng hai gram (Hinh 1) su dung cac soi thdng mmh se nhac ban khi nao can thay hoac cac<br /> gdm ed the de dang tao ra mot dien ap vai tram vdn. dong CO hoac khung may bay ed kha nang thong<br /> bao khi CO cac su cd xay ra - ma khdng can phai gan<br /> pm hoac cap dien ngoai cho cam bien va transmit-<br /> ter, Thay vao dd chung se dupe cap dien tu chinh su<br /> dao dpng ma chiing do duac.<br /> • Chieu sang: Cac sai ap dien cua Advance<br /> Oerametrics cd the chuyen co nang thanh anh<br /> sang ma khong can eac thiet bj dien tu. Chiing tdi<br /> khdng de cap den mdt ngudn sang dac biet nao ca<br /> ma eho bat eu mot loai den phat quang nao, Kha<br /> nang nay md ra ca hpi eho viee cap dien chieu<br /> sang tren nhung chiec cau, den tin hieu va phao<br /> cuu sinh trong cae ung dung khae,<br /> • Chd'ng rung: Ben canh viee khai thac ngudn nang<br /> luong tu su' dao dong ciia mdi trudng xung quanh<br /> Hmh 1. Bo chuyen doi co trong luong hai gram<br /> (theo djnh luat chuyen ddi nang lupng), cac hop<br /> Cae SOI gdm ap dien cua Advance Ceramitries nhan chat PZT cua Advance Ceramethes cdn dupe su<br /> cae dao dpng trong mdt dai tan rpng Idn. Vi du doi vdi dung de chdng rung tich cue. Qua trinh chdng<br /> viec cam nhan tieng ghita dien, ehiing se nhan duac rung su dung ea hai dac tinh cua piezo (tac dpng<br /> nhieu am thanh hon tu eac spi day dang rung. Cdng true tiep va nguoc lai), Khi nhu'ng su dao dong tao<br /> suat ra rat Idn cho phep chiing cd the dupc phat lai ma ra nguon dien, mach dien tao san se chuyen qua<br /> khong can phai khueeh dai trung gian, lam giam trpng trinh nap vao bd vi xu ly de do bien dp eua su dao<br /> luang eua he thdng va tao ra am thanh trung thu'c han. dpng va dua ra mdt tin hieu da dupc khueeh dai tu<br /> Neu dem so sanh vdi cae loai gdm Idn khac, cae spi dd se keo cang hoac tha long co cau chap hanh.<br /> gdm cua Advanced Oerametrics dupe su dung nhu la cac Trong mdt sd ung dung dien hinh cua viee chdng<br /> bo chuyen ddi dien nang thanh ca nang tao ra luc co hpc rung Head Sport AG of Kennelbach, Austria da su<br /> Idn han tren mdt dai chuyen ddng rdng hon - tuang ung dung cac hop chat PZT eiia Advance Oerametrics<br /> 35 % trong lupng. Mot phien tong spi piezo tong hop cd de giam su rung ciJa vat tenis va van trupt tuyet.<br /> trong lupng 2 gram su dung trong che dp kich thich cd the<br /> tao ra mdt sue nang tuang ung vdi 60 pounds. Ha t^ng mang cua cam bidn khdng day<br /> Mang cam bien thong minh khong day va ea cau<br /> Dai ung dung rong Idn chap hanh (WISAN) la mot ha tang mang eho cam bien<br /> Advance Oerametrics san xuat cac spi ap dien dua khdng day tuong thich vdi chuan IEEE 802,15,4 ban<br /> trdn hop chat ziricon-titanic hay cdn gpi la PZT, la loai dau do Dai hoc Ciarkson thiet ke va duoc Ambio<br /> vat lieu piezo co ban su dung trong dien thoai di dong, Systems LLO thuang mai hda, Cac not mang eua<br /> may tmh. Id vi sdng hay may nhan tin. WISAN cd dp tieu thu ngudn rat thap va dupe lua chpn<br /> <br /> <br /> <br /> Tt/ dong ho.i ngdy ndy 35<br /> so ') cm) i'oo/<br />  The gi6i Cam b i ^ n<br /> <br /> <br /> cho cac ung dung tu cap ngudn. WISAN cung cap Can h^ng tai nguyen nang liTdng<br /> dudng truyen 6u lieu lien tuc vdi muc dd suy hao thap Mdt cam bie'n tu nap nang luang can phai can bang tai<br /> va dung luang dudng truyen cao giua cac cam bien ma nguyen nang luang. Chi ed mdt ngudn nang lupng duy<br /> van tuan thu eac yeu cau cua IEEE 802,15.4. nhat trong he thdng WISAN - phan tu d_ao dpng piezo -<br /> Su dung ca ehe truyen xu ly tin hieu tiet kiem nang nhung lai ed nhieu phan tu si; dung, mdi phan tu lai co<br /> luang va bang thdng rdng cho phep nhieu cam bien gang lay mpt luang Idn trong tdng tai nguyen nang lupng.<br /> truyen du lieu tren dudng truyen hPn so vdi giao thuc Mpt trong nhung phan tu su dung ngudn Idn nha't la<br /> truyen eua IEEE. Chipcon radio vdi che dp nhan chiem ddng dien 20mA va<br /> ehe dp truyen chiem ddng dien phu thudc vao muc do<br /> cdng suat truyen. Dieu nay se giu cho sdng radio d muc<br /> tiet kiem dien trong sudt thdi gian va se chi kich hoat len<br /> TIMSPOO ] trong khoang thdi gian rat ngan khi cd du lieu truyen. Chip<br /> cua bd thu cung cap ba ehe dp giam nang lupng;<br /> • Idle; Ca bd dao ddng tinh the eiia bd thu va bd dieu<br /> SmMcLCO<br /> Dado<br /> irtsface<br /> chmh dien ap deu dupe kich hoat (khoang 430 ^A)<br /> CNpcon<br /> CC24»<br /> • Power-down: dung bd dao ddng nhung duy th bp<br /> nhd trong eua chip (khoang 20 uA)<br /> • Power-off; chip bi ngat hoan toan (khoang 2 ).iA)<br /> US8<br /> inerfsce Odi vdi nhung dii lieu truyen khdng theo dinh ky tdt<br /> nhat la ngat hoan toan bd thu. Trong ehe dp power-down<br /> hoac power-off, se cd mdt lupng nang luang dang ke den<br /> Hmh 2. Do khoi cac diem gan cu.i cam bien WISAN<br /> de khdi ddng cae tinh the cao tan ciia bp thu.<br /> Bd vi dieu khien se tieu tdn mdt lupng 4mA d fan so 8<br /> MHz, tuy nhien rat nhieu hpat ddng (nhu lay mau ADC) co<br /> the thuc hien ma ldi ciia bd vi dieu khien khdng can phai<br /> lam viee. Viec tieu ton nang lupng trong qua trinh thu thap<br /> du lieu chil yeu phu thude vao chu ky lay mau do trd<br /> khang ciia cam bien quy djnh. Giii eho trd khang ciia cam<br /> bien cao se giam thieu nang luang tdn that tren cam bie'n<br /> tuy nhien nd se lam tang nang luang tdn that trong qua<br /> trinh lay mau cd thdi gian dai han. Bd vi dieu khien phu<br /> thupc phan Idn vao ehe dp nghi ed ddng hd thdi gian thi/c<br /> tan sd thap 32 kHz (va bd djnh thdi) la dang lam viee.<br /> Viee cam bie'n dupe cap ngudn lien tue khdng phai la<br /> mdt lua chon td't cho he thdng tu cap ngudn. Ddi vdi cam<br /> bien cd kha nang quay vdng ngudn cap (chi cap ngudn tai<br /> thoi diem thue hien phep do), tyje thdi gian khdi ddng ciia<br /> cam bien so vdi chu ky lay mau trd thanh mpt nhan to<br /> Hinh 3. Cac diem gin cam bien quan trpng, Khi ty sd nay dat den gia tri 1:1 Ipi ich tu viec<br /> quay vdng ngudn cap se bj suy giam. Cam bie'n dien trd<br /> Tren Hinh 2 la sa dd khdi cac diem gan eua cam thudng cd thdi gian khdi ddng tue thi va thudng dupe lua<br /> bien WISAN. Cae diem gan cam bien dupe cho tren chpn eho eac he thdng tu cap ngudn,<br /> Hinh 3. Su dung cac bp vi dieu khien tieu thu ngudn Phan tu tieu thu dien nhieu nhat la giao thuc mang<br /> thap ciJa Texas Instruments la MSP430 de giao tiep vdi truyen thdng de duy tri bd thu trong che dd nhan trong<br /> chip Chipcon CC2420 RF. Su ket hop nay eho phep he mdt khoang chu ky thdi gian md rdng. Vi du giao thuc<br /> thdng tieu thu rat it ngudn (< 10 ).LW) trong che dp nghi OSMA cua IEEE 802.15.4 cd the duy tri cam bien trong<br /> (sleep mode) va trong che dp lam viec binh thudng. Bd ehe dd nhan den 2,5 ms trudc khi truyen. Giai phap de<br /> vi dieu khien nay ed thdi gian khdi ddng cue ngan tu giam tdn that nay cd the la dan gian hda giao thuc va<br /> ehe do nghi sang che dp lam viec va cd bd chuyen ddi thuc hien nhung nhiem vu trong tung giai doan nhat<br /> tuong tu sang sd (ADO) va bp chuyen ddi sd sang djnh, eho phep khdi phuc lai nang luang can kiet.<br /> tuang tu cung tieu thu it cdng suat. Cac not mang<br /> WISAN cung ed kha nang giao tiep vdi bd nhd flash Gan kdt cac ph^n lai udi nhau<br /> ngoai la loai 24 bit sigma-delta va loai 16 bit SAR ADOs, He thdng demo cua Ambio Systems lay nang luong<br /> eac sd, man hinh LCD, eong ndi tiep, cdng USB, tu mdt ngudn dao dpng va cung cap mdt ddng du lieu<br /> Bluetooth va cac thief bi khac thong qua eong ket ndi cam bien dn dinh cho may tinh. Ke't qua la mdt bd demo<br /> ben ngoai. de doe tinh hieu ap sua't d tan sd 30Hz va cir sau moi<br /> <br /> Automdtion Toddy<br /> 36 so 5 (81) 2007<br />  The qioi Cam b i e n<br /> <br /> 3 giay lai truyen du lieu den man hinh LCD va may tinh su dung eac cam bien khdng day nhimg cho cae ung<br /> ket ndi thong qua cdng USB, dung giam sat, Tiiy thuoc vao su san ed cua nang lupng<br /> Tren Hinh 4 la bd demo, Cac thanh phan chinh cua mdi trudng xung quanh, ngay ea nhung ludng du lieu lien<br /> nd bao gdm; tuc cung ed the truyen bang eac thief bi tu ddng nap nang<br /> • Ca eau chap hanh piezo. luong,<br /> • Mdt ddng ca kich tu vdi mpt khdi ddi trong. Cac ban cd the tai doan video vi du ve cam bien<br /> • Mdt bd chinh luu, bang tu dien va mach bd dieu WISAN tu nap nang luong tu trang web www,ambiosys-<br /> chinh. tems.eom.<br /> • Mdt cam bien dien tro do ap suat trong mdt not<br /> mang WISAN. Tich hdp thidt kd ciia sdi piezo<br /> Van de mau chdt de tich hop cong nghe soi PZT (zir-<br /> conate titanate) vao trong cac he thdng cudi la xac dmh<br /> yeu eau ngudn cap va xac dmh dupe ngudn ea nang san<br /> cd. Qua trinh thief ke bao gdm cae bude sau:<br /> • Xac dinh nhu cau nang lupng: Yeu cau nang<br /> lupng ma he thdng can dupc cung cap la gi? Ngudn<br /> trong the gidi nang lupng tan dung khai thac can<br /> phai dupe can ddi va dupe giu d hudng tich cue,<br /> • Oanh gia nguon dien san co xung quanh: viee su<br /> dung thief bi giiip xac dinh vj tri san co - may mdc,<br /> ket eau, xe ed, con ngudi va cac thief bj khae, Sau<br /> khi cae dinh dupe vj th, phai xac dinh va kiem chung<br /> ngudn dao ddng va co nang,<br /> • Xac dinh khong gian lap dat yeu cau: khoang<br /> Ddng ca nhd/ddi trpng tac ddng vao ea eau chap hanh khdng gian danh eho cac td hop spi ap dien la nhu<br /> trong tung vdng quay tao nen su' dao ddng, Su dao dpng the nao? Neu nd la mpt thie't bi dien fu ed the di<br /> eiia CO cau chap hanh sinh ra dien ap xap xi tu 20-40 Vac, chuyen duoc, dien tieh danh cho nd khong nen bj<br /> tuy thude vao mue dp eiia su kich thich dupe dieu khien gidi han bdi kich thudc eiia khoang dung pin. Thuc<br /> bdi may do dien ap. Dien ap xoay chieu dupe ehinh luu va su la cae td hop piezo ehi can lay hinh dang cua<br /> tieh tru tren mdt bang tu gdm cd mue phdng dien thap, luu ehinh thief bi dd,<br /> tru dii nang lupng de van hanh hoat ddng ciia niit cam • Mo hinh kha nang caip nguon ciia piezo: cd the<br /> bien vdi mdt giao dien khdng day trong vai ms, Mdt may xac djnh dau ra ngudn ap dien khi fa xac djnh dupc<br /> dieu ehinh tuyen tinh vdi ddng dien tinh khoang 3 pA se kich thudc va nhan fd hinh dang eua vat lieu td hpp<br /> dieu chinh dien ap cung cap. va biet dupe lue eiing nhu fan sd eo hoc.<br /> Cam bien do ap suat la mpt hop chat polyme cd dien • Xac dinh chinh luu, luu trO va yeu cau ciia bp dieu<br /> tra nhay duoc cap ngudn ngay trude khi do va ngat chinh: ddi vdi viee fan dung khai thac nang lupng,<br /> ngudn ngay sau khi chuyen ddi ADO, Dieu nay yeu eau cdng viee thief ke mach dien fu kha don gian. Yeu eau<br /> phai kich hoat bd xu ly trudc va sau khi chuyen ddi, tuy chinh la luu tru dien nang, dien ap dieu chinh va kha<br /> nhien bd xu ly van d trong ehe dp nghi trong qua trinh nang chju dung,<br /> chuyen ddi de tiet kiem nang lupng,<br /> Du lieu cam bien ap suat dupe lay mau 8 bit de giam Kdt luan<br /> thieu tai cho mang va viee tieu tdn nang luang tuang ung. Mdt sd lupng cae san pham mdi va duy nhat ndi len<br /> Du lieu sau dd dupe truyen den mdt thiet bi tren mang ca tren thj trudng dang cd xu hudng han che hoac loai bd<br /> nhan (PAN) de hien thi sdng thdi gian thuc tren man hinh viec su dung pin, Cdng nghe spi su ap dien cung cap mdt<br /> LCD va tiep tuc truyen du lieu qua cdng USB den may tinh giai phap duy nhat cho eac he thdng khai thac nang lupng,<br /> ea nhan ed cai dat phan mem Labview eiia National dieu khien ed cau triic tieh cue va tu cung cap ngudn, Cae<br /> Instrumemt de hien thj va luu tru du lieu. spi fd hpp tich et/e do Advanced Oerametrics san xua't ed<br /> Not mang WISAN truyen du lieu cam bien thdng qua cdng suat ra bang 10 lan cdng suat ctJa cae dang piezo<br /> giao thue gian tien eiia IEEE 802,15.4 MAO. Phan mem not khac va cd dp ben dien hinh bang 200 theu ehu ky. Bang<br /> mang se thuc hien khdi ddng tung giai doan va khdi tao each ke't hpp cae spi fd hop vdi cac thief bj dien fu va ddng<br /> trong dd tung budc khdi tao dupe chuyen tiep theo tung ehu gdi chi phi thap da md ra mpt ky nguyen mdi eho cac san<br /> ky khd phuc. Truyen du lieu khdng day su dung giao thuc pham va ung dung tieu tdn cue ky it nang lupng. Nhung<br /> CSMA gian tien va khdng can cd xac nhan truyen. giai phap mdi nham cung cap cac ngudn ed cdng suat<br /> Ban demo nay cho thay viec khai thac nang lupng moi nho, tuoi tho cao va khong can diing pin eho cae ung dung<br /> truang xung quanh la kha nang hoan toan ed the thue hien ve ngudn cap cung dang ndi len tren thj truang.LJ<br /> duoe a trinh dd cdng nghe hien nay va ed the xem xet khi GIANG LAM - Theo Tap chi Industrial Embedded Systems<br /> <br /> <br /> <br /> SO 5 (81) 900/<br /> TiJ dong<br /> ong Ino<br /> hod ngdy ndy ; 37<br />