Design and Completion of the Indoor Positioning System Based-on Taylor Iterative Liyan FAN1, a, *, Song CHEN2, b, Shuang WAN3, c, Shilei ZHU4

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1 rd Iteratoal Coferece o Macher, Materals ad Iformato Techolog Applcatos (ICMMITA 05) Desg ad Completo of the Idoor Postog Sstem Based-o Talor Iteratve La FAN, a, *, Sog CHEN, b, Shuag WAN, c, Shle ZHU4 Isttute of Navgato ad Space Target Egeerg, Iformato Egeerg Uverst, Zhegzhou Hea, 45000, Cha Isttute of Navgato ad Space Target Egeerg, Iformato Egeerg Uverst, Zhegzhou Hea, 45000, Cha Isttute of Iformato Scece ad Egeerg, Southwest Jaotog Uverst, Chegdu Schua, 6756, Cha 4 Isttute of Navgato ad Space Target Egeerg, Iformato Egeerg Uverst, Zhegzhou Hea, 45000, Cha a emal:076596@6.com, bemal:wrelessmacs@6.com c emal:05979@qq.com,*correspodg author Kewords: LBS, Idoor Locato Sstem, CSS, WSN, Talor Iteratve Algorthm Abstract. Developmet belogg to Locato-Based Servce (LBS) makes people s dal lves more coveece. Compared wth Outdoor Locato Sstem, whch developg more ad more mature, Idoor Locato Sstem acheves much more atteto from commut. I ths paper, b comparg the advatages ad dsadvatages of estg Idoor Locato Sstem comprehesvel, the Idoor Wreless Sesor Network (WSN) Postog sstem based o Chrp Spread Spectrum (CSS) s chose as studg target. Talor teratve algorthm, whch ehaces the postog accurac effectvel, s appled to calculate posto coordates. Itroducto Wth the populart of wreless etworks, Locato-Based Servce has acheved more ad more atteto showg great vtalt emergec relef, trasportato, polce ad fre departmets, persoalzed servce ad other areas []. Accordg to the sttuto predcted, Global LBS market would grow rapdl at the rate of 80% per ear. Vsble, LBS deserves to be studed. At preset, the Idoor Navgato Sstem s ot et mature because of a varet of comple techcal sstems. So how to break though the problems of Idoor Postog feld wll be a hotspot. The paper [] troduces the ke techologes of Idoor Postog based o WLAN wth two ma postog method, lke paper [] metos fgerprt localzato algorthm havg relatvel hgh postog accurac ad paper [4] metos a kd of Idoor Posto based o receved sgal stregth dcator (RSSI) though flter algorthm ad teratve algorthm; the paper [5] metos a techolog about Idoor Postog based o Bluetooth 4.0 to solve the tradtoal problem of hgh power cosumpto of Bluetooth devces. Because of hgh cost ad tesve odes, ths algorthm whose postog accurac s m, s lmted to popularze ma felds; the paper [6] metos a techolog about Idoor Postog based o Ultra-Wde Bad (UWB) wth a hgh accurac at cetmeters. Smlarl, t ca t be popularzed because of hgh hard-ware cost ad algorthm complet. After a comprehesve comparatve aalss, ths paper adopts a modfed WSN based o CSS sgal Idoor Postog techolog[7] wth accurac less m. I a rage of 00m*00m, four statos are eeded justl to complete posto, whch reduces hard-ware cost largel. The smulato proves that postog accurac ca be ehaced further though adoptg Talor terato. 05. The authors - Publshed b Atlats Press 69

2 Postog Prcple Geerall, the locato sstem obtas the measured dstace b estmatg TOA [8] ad multpled b sgal trasmsso speed. I order to makg sure the result s veract, the tme of trasmtg termal ad recevg termal s asked to be schroous strctl ths process,whch leads to the dffcult lag schrozg etwork, hgh cost ad adequac faceg to populart. Because of these dsadvatages, we promote a aschroous measuremet method [9], amel blateral TOA estmato method. The steps are as follows. ) Postog Label seds ragg request to Measurg Stato ad marks the tme as t ; ) Measurg Statos mark the tme as t ad produces resposes ACK after recevg the request from Postog Label; ) Measurg Statos sed ACK, mark the tme as t, ad calculate T t t ; 4) Postog Label marks the tme as t ad calculate T t t after recevg ACK; 5) Measurg Statos lauch the same measurg dstace flow ad calculate T, T 4, where T t t 4, T4 t4 t ; 6) Postog Label calculates the TOA as follows: T-T+ T-T4 T-T4+ T-T = = 4 4 T () The completg measurg dstace. Ths measurg method does t eed schrozato mechasm, elmates error caused b clock, ad promotes the measurg accurac. Locato solver prcple The Postog Cotrol Ceter ca calculate label s coordate b combg the dstace betwee the Postog Label ad the Measurg Statos wth the Measurg Statos coordates. The cocrete prcple s as follows. Settg the Postog Label ad the Measurg Statos coordates as (, ), (, ),let f (, ) as: f (, ) () ( ) () where,,, N, N s the umber of statos. Igore the secod ad hgher compoets, After spreadg the coordate (, ) accordg to Talor, we ca receve f f f f (, ) () (, ) (, ) where f (, ) ( ) ( ),the f f (, ) e e (4) e, e f (, ) f e e f f f f (, ) e e f f e e f4 f4 (, ) e 4 e 4 where Let,ow (5) 60

3 e e f (, ) f e e f (, ) f E L f (, ) f (6) e e f4 (, ) f4 e 4 4 e D,, The L = ED s a group of overdetermato equato, whch ca be solved b the Least Squares: T T T D = E E E L (7) The, the coordate (, ) s D (8) Repeat the above steps, f, reach the preset threshold, amel ( 0),the * * curret coordate (, ) s the fal label s coordate. Postog Accurac Aalss I order to testg the postog accurac of the sstem, the posto of the measurg statos eed to be calbrated frstl. Trmble S8 Total Stato (show below), whch has a agle measuremet accurac of ± " ad ragg accurac of ± (mm + ppm) uder the drect reflecto mode, s used to calbrate the measurg statos. I the test, a room wth.5m heght, m legth ad 7.m wdth was chose, ad four measurg statos were hug four corers of t. Ne labels were placed e radom chose postos, ad beg measured respectvel b usg the proposed Idoor Locato Sstem ad total stato. Though cotrastg betwee the measured data ad real data, the statstcal cumulatve error curve of the postog sstem s obtaed as follows: As ca be see from the fgure, the probablt of the postog error less tha 0.8m ca reach 90%, so a cocluso that the postog accurac of the postog sstem s better tha m ca be got. Test results Fg.8. Cumulatve error curve Pla a rectagular path wth a wdth of 4.8m ad 9.6m legth the room above, hold the posog label ad move alog the path wth a speed at about 0.8m / s adoptg the metoed CSS 6

4 door postog techolog to locate, the calculate the orgal posto b usg the mamum lkelhood algorthm. The orgal result ad the fltered result though Kalma are show below: (a) the mamum lkelhood algorthm (b) Mamum lkelhood +Kalma Fg.. Orgal result ad fltered result The calculated result of the Talor terato algorthm ad The fltered result though Kalma are show as below. Cocluso (a) Talor terato algorthm (b) Talor terato + Kalma Fg.. Result of Talor terato algorthm ad fltered result As ca be see from the above test results, the solvg effect of the postog coordate based o Talor terato s much better tha solutos based o mamum lkelhood algorthm; the smoothess of the postog trajector has bee sgfcatl mproved after addg the Kalma flter, whch also leaded to a serous formato loss ad creased the complet of the algorthm. Therefore, although we use Talor teratve algorthm based soluto to esure the postog accurac ad projects mplemetablt ths paper, the areas eed further mprovemet s eeded the respect of track smoothe, whch wll be part of the cotet of the et research. Refereces [] L L Zhag, E S Zhog. Proceedgs of the 8th Cha Assocato of GIS Aual Meetg [C]. 04, 0(): [] Yag Q, Che Y, Y J, et al., LEAPS: A Locato Estmato ad Acto Predcto Sstem a Wreless LAN Evromet. I Proceedgs of NPC. LNCS,Wuha, Cha: 004, [] Bah P, Padmaabha V N. RADAR: A I-Buldg RF-Based User Locato ad Trackg Sstem[C]. 9th IEEE Computer ad Commucatos Socetes Coferece, Tel Avv, Israel: IEEE. 000: [4] J Wag, H Q Zhag. Research o RSSI-based locato Techolog for Idoor Evromets [A]. Computer Measuremet ad Cotrol, 009, 7(): [5] H S Ba. Research of Idoor Locato Techolog Based o Bluetooth Low Eerg 4.0[D]. Master degree theses. Bejg uverst of posts ad telecommucatos. 05: [6] Zhogjua Zhag. Stud o Idoor Locato Techolog Based o UWB [D]. Taj: Master's degree thess of Taj Uverst. 0: [7] Japg Luo, Ypg Lu, Mahe Xao. Real Tme Locato Sstem Based o CSS techologd [J]. SCIENCE & TECHNOLOGY INFORMATION. 04, 0(0): 5-7 [8] Bgbg QI, Chagq WU. TOA estmated b combg matched flter ad cross correlato [J]. Audo Egeerg. 0, 0():

5 [9] Fagao Che. Research ad Implemetato o UWB Idoor Postog Sstem Based o schroous TOA Estmato [D]. Haerb: Master's degree thess of Harb Isttute of Techolog. 0.: 6