Smart Parking Management System Based on RFID

Transcription

1 Intrnational Journal of Elctrical Enrgy, Vol. 1, No. 3, Sptmbr 2013 Smart Parking Managmnt Systm Basd on Wiwi Wang Bijing Univrsity of Posts and Tlcommunications, Bijing, China Pngfi Ma Duk Univrsity, Durham, NC, Amrica principls. Nxt, in sction 3, w prsnt th structur of smart parking managmnt systm and th rsults of simulation in sction 5, and conclud in sction 6. Abstract This papr prsnts th dsign of a smart parking managmnt systm which consists of non-stop automatic gat guard paymnt systm and parking spot dtction systm. W first brifly introduc tchniqu and discuss its oprating principls. Thn w propos a dsign for controlling and managing parking systm using tchniqu which is abl to automatically calculat th parking f of vhicls and show th numbr of unoccupid parking spac in th scrn at th ntranc. Finally, w simulatd th anti-intrfrnc ability of Manchstr coding and dcoding in this systm, th radio-frquncy intrfrnc circuit of RF tag and th transmission and rciving modul of th RF radr using th simulation softwar Simulink. II Radio-frquncy idntification achivs non-contact and bidirctional communications btwn th radr and a radio-frquncy card through using radio-frquncy lctromagntic filds. A systm consists of four componnts: lctronic tag, radr, computr communication ntwork and antnna. As w can s from Fig. 1, to achiv automatic idntification and tracking, a tag is attachd to th objct. Whn th objct with th tag gos into th signal rang that th antnna covrs, a wirlss communication link is built btwn th radr and th objct. Thn th tag transmits th srial numbr and data stord in it to th radr. Bfor th data is transmittd to th radr, it will b ncodd by th antnna. Upon rciving th signal, th radr will dmodulat it and thn transmit th rsults to background computr systm, which handls th analysis of data [3]. Indx Trms, parking managmnt systm, simulink I INTRODUCTION With th rapid dvlopmnt of socity, th numbr of various vhicls significantly incrass. In som citis, th xisting parking managmnt systm cannot fficintly oprat thus raiss congstion problm. Morovr, drivrs cannot b notifid about th numbr of parking spacs in th sparking lot bfor thir ntranc, which xacrbat th congstion problm. To circumvnt this problm, w propos a smart parking managmnt systm, which is composd of two aspcts: automatic collction of parking f and dtction of th numbr of availabl parking spacs [1]. To nabl th systm to fficintly oprat, w mploys radio frquncy idntification tchniqu (). As a wirlss data transmission tchniqu, is usd in smart parking managmnt systm with multipl advantags[2]: (1) at last 9 mtrs idntification distanc and capability to idntify static and high-spd mobil objcts at a spd of 100 km/h; (2) th capability to idntify multipl radio-frquncy cards with diffrnt srial numbrs; (3) no lctromagntic pollution; (4) high scurity and privacy; (5) asy to install and maintain. Th rmaindr of this papr is organizd as follows. First, in sction 2, w dscrib tchniqu and its Figur 1. III SYSTEM STRUCTURE In this sction, w dscrib how our smart parking managmnt systm oprats. Th whol systm consists of non-stop automatic gat guard paymnt systm and parking spot dtction systm. Whn th vhicl ntrs th parking lot, th paymnt systm uss radr to collct th information via th tag on th vhicl, Manuscript rcivd Fbruary 25, 2013; rvisd July 18, 2013 doi: /ijo structur and oprating principl 117

2 thn snd th information to control computr, storing vhicl information, ntranc tim and pictur into th databas. At th tim th vhicl xits, rlativ information is obtaind via tag and th parking tim is calculatd and stors th pictur again. Parking spot dtction systm: ach parking spot rquirs a tag and an ultrasonic prob, which srvs to dtct th availability of th parking spot and th tag is rsponsibl for snding th status of parking spot and its squnc numbr to control computr through RF ntwork. Th backnd control computr communicat with RF tag by RF radr and updat th databas whn tag information is rcivd. Fig. 2 shows th structur of th hardwar of parking managmnt systm, two ntranc channls ar dsignd and on for long trm card holdrs who hav RF tags attachd on thir vhicls and anothr for tmporary card holdrs. Th ntranc and xit controllr connct th control computr and ar rsponsibl for managing th camra, radr and barrir. Th radr is usd to obtain both th vhicl information from th tag on th vhicl and th parking spot status information. Two camras ar installd at th ntranc and xit, taking picturs of th vhicls. Morovr, th control computr snds th parking situation to th scrns which ar installd both insid and outsid th parking lot. Databas parking ara. Othrwis, th drivr will b notifid th card is invalid and th barrir kps closing, suggsting using th tmporary ntranc channl. In th first cas, th computr kps rcords of ntranc tim, pictur of vhicl, tag srial numbr and vhicl plat numbr. For tmporary card holdrs, th drivr obtains th tmporary parking card at th tmporary ntranc channl and th barrir will rais, simultanously, th ntranc tim, pictur of vhicl and plat numbr will b rcordd. Insid th parking lot, a LED scrn is installd showing th position of th availabl parking spacs. B. Exit Dsign Similarly, th validation of th tag on long trm card holdrs will b chckd by th RF radr. If valid, th barrir will rais and th vhicl lavs th parking ara without having to stop, and simultanously parking f will b chargd from th holdr s account; othrwis, whn th tmporary card holdr xits, th drivr nds to stop and rturn th tmporary card and pay th parking f. In both cass, th xit tim, pictur of vhicl and card numbr will b rcordd into th computr and th barrir rturns to its original position. Fig. 3 shows th flow chart of th ntranc and xit dsign as follows. (parking situation) Entranc (mpty spot) Exit Control Computr Entranc Controllr Hub Exit Controllr invalid Long trm card/ Gt tmporary card Logical Judgmnt valid Tak imags Sav information Ys pay automaticly Long Trm Tak imags & Sav information No Giv back Card And pay Camra Barrir Opn barrir Vhicl passs Opn barrir Vhicl passs Figur 2. tag 1 A. Entranc Dsign tag 2 tag n Structur of th parking managmnt systm Bfor th vhicl ntrs th parking lot, th drivrs ar abl to know th numbr of availabl parking spacs in th parking lot through looking at th scrn outsid th parking lot. For long trm card holdrs, whn th vhicl ntrs th signal rang, th radr automatically rads th RF tag and chcks th validation of th tag through communications with th computr databas. Simultanously, th camra will tak photos of th vhicl for rcords. If th tag is idntifid as valid, th barrir will rais, allowing th vhicl to ntr th Figur 3. clos barrir C. Dtction Systm Dsign clos barrir Flow chart of ntranc and xit dsign Aftr initiation of dtction systm, th parking spot availability flag is st to b zro. Thn ultrasonic transmitting and rciving circuit is usd to dtct whthr th parking spot is occupid, if so st th flag 1 othrwis th flag rmains 0. Aftrwards, th squnc numbr of th tag, th availability flag and rlativ information ar ncapsulatd into a datagram, which will b snt to th radr via th tag. Upon rciving th datagram, th radr transmits th information to th control computr which updats th databas. Fig. 4 shows th flow chart of vhicl dtctor systm. 118

3 Systm Initialization availability flag 0 Ultrasonic Vhicl Dtctor Y Empty? availability flag 1 Figur 4. N D. Softwar Structur Non-stop Automatic Gat Guard Paymnt Systm Vhicl Information Collction Modul Protocol Layr Middlwar Bottom-Drivn Figur 5. Snd Status Information Control Computr Databas Updat Ultrasonic Vhicl Dtctor Empty? Y availability flag 0 Flow chart of vhicl dtctor systm Smart Parking Managmnt Systm Parking Information Managmnt Modul Srvic Proxy Basic Information Managmnt Spot Status Managmnt Opration Log Managmnt Databas Implmntation Srvic Intrfac Layr Dtction Systm Spot Dtction Modul Protocol Layr Middlwar Bottom-Drivn Systm softwar function structur N LED Display Modul Function Library Rfrsh Clar LED Opration Implmntation LED Bottom-Drivn Th softwar structur consists of application layr, srvic intrfac layr and bottom-drivn layr and ach layr is composd of multipl softwar moduls. As w can s in Fig. 5, application layr is rsponsibl for communication with usrs, consisting of non-stop automatic gat guard paymnt systm and parking spot dtction systm. Ths two systms us a parking information managmnt modul to control th databas of th intrfac layr. Non-stop automatic gat guard paymnt systm obtains and stors th information of th vhicl, including plat numbr, ntranc tim and pictur in th databas through vhicl information modul. Whn th vhicl xits th parking lot, corrsponding information is obtaind from th databas to calculat th parking tim and parking f, simultanously, rlativ information is stord in th databs for latr us whn ncssary. Parking spot dtction systm is rsponsibl for dtcting th occupation information of th parking lot and it uss parking spot dtction modul to collction th status of all th parking spacs. Th status information will b snt to th parking information managmnt modul which snds th numbr of availabl parking spacs and th position of th availabl parking spot to LED display modul. IV SIMULATION As th main componnts of our smart parking managmnt systm ar RF tag and RF radr, w implmnt and simulat th following four parts: (1) dsign and simulation of th radio-frquncy intrfac circuit of th RF tag; (2) dsign of th transmission circuit of th RF radr with working frquncy 915MHz undr ISO Typ B protocol; (3) dsign and simulation of th rciving circuit of RF radr; (4) simulation of th anti-intrfrnc ability of Manchstr coding and dcoding that th systm mploys. A. RF Intrfac Circuit Simulation of RF Intrfac Circuit Th ISO Typ B[4] protocol rgulats that th systm adopts ASK modulation, th modulation dpth is 11% or 99% and bit rat is 10 kb/s or 40 kb/s. Th radio-frquncy intrfac circuit consists of four circuits: sin-wav carrir modulation circuit, DC powr supply gnration circuit, nvlop gnration and dtction circuit and rst signal gnration circuit. To obtain sin-wav modulation circuit, w us a sin wav as th carrir wav and multiply it by digital signal and thn adapt th gain of th digital signal via adding a constant if ncssary. DC powr supply gnration circuit is achivd by obtaining th absolut valu of th signal and thn putting th signal into a low pass filtr. Envlop gnration circuit consists of a nonlinar dvic that is ralizd by absolut valu and a low pass filtr that is simulatd by a transfr function [5]. Dtction circuit consists of a narrow-band filtr and a voltag dcision unit, narrow-band filtr is simulatd by a transfr function and voltag dcision unit is simulatd by a comparator. Envlop gnration circuit and dtction circuit togthr form th nvlop modulation circuit thus can rcovr th digital signal. Rst signal is obtaind by using a voltag comparator and whn th supply voltag riss up to a valu that is abl to support th opration of RF tag, th rst signal kps this valu to nsur stady opration of th circuit. W hav implmntd simulation of th four parts abov and obtaind idal rsults. Hr w prsnt th rsult of th intgratd circuit consisting of th four parts w hav dscribd as in Fig

4 B. Simulation of Transmission and Rciving Circuit Figur 6. RF intrfac circuit achiving th dmodulation signal. Finally, th ncoding signal is obtaind by shaping th signal, putting th dmodulation signal into a voltag comparator. Figur 7. Typ B protocol transmission modul W hav simulatd th tim-domain charactristics of th 915MHz radr. ISO Typ B radr transmission intrfac consists of Manchstr ncoding, ASK modulation (modulation dpth 11% or 99%), and powr amplification [6]. In th simulation, w us dmodulation in ordr to prcisly th chang of th data flow. W conduct tsts for both 11% and 99% modulation dpth and hr w prsnt th tst rsults for modulation dpth 99%. As w can s in Fig. 7, puls gnrator is usd to gnrat raw data or command and a XNOR opration is conductd btwn th raw data and scond frquncy multiplication signal to raliz Manchstr ncoding. Thn th basband signal is modulatd by th ASK modulation and powr is amplifid to achiv th transmission signal. Whn dmodulation, transmission signal and carrir signal is procssd by a down convrtr and low pass filtr thus Figur 8. Simulation wavform of th transmission modul undr Simulink (99%) Th simulation rsult of th wavform is shown in Fig. 8; w can s that transmission signal is obtaind by Manchstr ncoding, modulation and powr amplification. Th signal can b rcovrd by passing a low pass filtr, dmodulation and shaping [7]. Thus, th dsign of transmission signal modul can produc dsirabl rsult. As in Fig. 9, to simulat th rciving circuit, w us Buttrworth fourth-ordr low pass filtr, th transfr function of which is A( S) A0 ( S s / c ) B( S) whr B (S) is Buttrworth polynomial. (1) 120

5 S 3.414S 2.613S (2) B( S) S In simulation, w st c 100Hz. original signal is 1, Manchstr cod is 10 and if th original signal is 0, Manchstr cod is 01. Thus, w can implmnt Manchstr coding by a XNOR opration btwn th original data and a rctangl wav with th frquncy qual to doubl th original frquncy. Rvrsly, Manchstr dcoding is implmntd by a XNOR opration btwn th data and a rctangl wav with th frquncy qual to half of th original wav frquncy. Th Manchstr coding and dcoding circuit is thn obtaind by conncting th coding modul to th dcoding modul. Figur 9. Rciving modul From th simulation wavform in Fig. 10, w can s that th signal is ncodd by FM0 and modulatd, thn is transmittd to th rcivd. At th rcivr, w can obtain FM0 basband signal by low pass filtr dmodulation. Th sourc signal is finally obtaind by FM0 ncoding and dmodulation. C. Simulation of Anti-infrnc Ability of Manchstr Coding adopts Manchstr coding to ncod transmission data. According to Manchstr coding, if th Figur 10. Rciving circuit simulation wavform Figur 11. Simulation modl of anti-intrfrnc ability of Manchstr Coding TABLE I. SIMULATION RESULTS OF MANCHESTER ERROR DETECTION RATE Coding Simulation tims Total rrors Dtctd rrors 1 Error Dtction Rat Omission Rat 1 Manchstr coding % 6.13% W hav conductd simulation of th anti-intrfrnc ability of Manchstr ncoding in our systm nvironmnt. W us a signal sourc to gnrat a random clustr of binary array, which rprsnts th 121

6 Intrnational Journal of Elctrical Enrgy, Vol. 1, No. 3, Sptmbr 2013 command of th RF radr or th data transmittd by th RF tag to th radr. Thn Manchstr coding tchniqu is usd to ncod th binary array and th rsult is transmittd through binary symmtric channl. Bfor dcoding, th data is chckd whthr rror xists in th squnc. Thn th anti-intrfrnc ability can b xamind by comparing th dcodd wav to th original wav. Fig. 11 shows th simulation modl of anti-intrfrnc ability of Manchstr coding tchniqu. Sinc th siz of th fram data is approximatly svral to tns of byts, w dtrmin th lngth of ach fram to b 100 byts in simulation. Morovr, w mak th rror probability of th binary symmtric channl chang btwn 1% and 50% and rpat th simulation 1000 tims. Thn w compar th signal at th rcivr nd to th original signal and rcord th numbr of dtctd rrors. According to th formula blow, th rror dtction rat can b computd by Eq. (3) % (3) whr dnots th rror dtction rat, and 1 dnot th numbr of dtctd rrors and th numbr of mad-up rrors rspctivly. As w can s in Tabl I, th rror dtction rat is 93.9%, which indicats th ability to dtct rror is good. Morovr, Manchstr coding can satisfy data transmission for th following rasons. First, whn th vhicl ntrs th radio-frquncy rang, th RF radr can rad th signal continuously such that a small amount of rrors can b tolratd. Scond, th absnc of clock circuit in RF tag rquirs RF tag to ftch clock information from th signal transmittd from th radr. Th ftch of th clock information can b asily achivd sinc ach cod lmnt in Manchstr coding has jumps intrnally. Finally, most tag has no powr supply itslf, which rquirs th RF tag to xtract nrgy from th lctromagntic wav that RF radr mits. This mchanism rquirs th cod pattrn to vary, which Manchstr coding can satisfy. Thrfor, Manchstr coding schm can b mployd as th data transmission ncoding tchniqu in. V CONCLUSION This papr focuss on improving th infficint problm of currnt parking managmnt systm, proposing a dsign of a smart parking managmnt systm that can solv th congstion and unrasonabl parking chargs problm,and also shows th numbr of availabl parking spacs and th position of thm for th drivrs. Morovr, this papr prsnts th simulation rsults of svral important componnts of th systm. Th simulation rsult is also shown to hav rfrnc valu to som application systms basd on, which nabls this smart systm to hav broadr us in practic. REFERENCES [1] H. T. Du, Th Parking managmnt systm basd on, Computr Knowldg and Tchnology: Acadmic Exchang 6, pp , [2] B. Liu, Q. H. Song, and S. Q. Hu, Intllignt parking managmnt systm basd on, Computr & Digital Enginring, vol. 36, no. 5, pp , [3] Z. Q. You, K. S. Liu, t al. Radio Frquncy Idntification () and Bar Cod Tchnology, China Machin Prss, [4] Joint Tchnical Committ, ISO standard, May [5] Y. Sun and L. Wu, Simulink Communication Simulation Dvlopmnt Handbook, 1 st d, Bijing: National Dfnc Industry Prss, [6] J. Wi and S. C. H. Lung, A simulation modling and analysis for -nabld mixd-product loading stratgy for outbound logistics: A cas study, Computrs & Industrial Enginring, vol. 61, no. 1, pp , August [7] X. G. Zhou, Radio frquncy idntification () systm dsign, in Th Simulation and Application, Posts and Tlcom Prss, Wiwi Wang was born in Panjin city of Liaoning Provinc, China on th day of Jan 20th, In Jun 2011, Wiwi arnd bachlor dgr in Sichuan Univrsity, Chngdu, China, majoring in communication nginring. Sh will arn hr Mastr of Scinc Dgr in Bijing Univrsity of Posts and Tlcommunications in March 2014, majoring in communication and information systm. Currntly, sh is a graduat studnt in Bijing Univrsity of Posts and Tlcommunications and an intrn in China Tlcom Group in Bijing. As th third author, sh has anothr publishd papr: Stadium Travrsal Algorithm on Simulation Robot Platform, which is includd in IEEE indx. Pngfi Ma was born in Langfang city of Hibi Provinc, China on th day of Dc 1st, In Jun 2011, Pngfi arnd bachlor dgr in Sichuan Univrsity, Chngdu, China, majoring in automation. H arnd Mastr of Scinc Dgr in Duk Univrsity, Durham, North Carolina, USA, majoring in lctrical and computr nginring. Currntly, h is working as a product managr in Lnovo Group in Bijing, China. As th first author, h has anothr publishd papr: Stadium Travrsal Algorithm on Simulation Robot Platform, which is includd in IEEE indx. 122