교차로 환경에서 Range-based와 Range-free 위치측정기법을 혼합한 개선된 차량위치추적기법

An Improved Vehicle Tracking Scheme Combining Range-based and Range-free Localization in Intersection Environment

  • 박재복 (전북대학교 컴퓨터공학부) ;
  • 고광신 (성화대학 사회복지계열) ;
  • 조기환 (전북대학교 컴퓨터공학부 영상정보신기술연구센터)
  • Park, Jae-Bok (Division of Computer Science & Engineering, Chonbuk National University) ;
  • Koh, Kwang-Shin (Department of Social Welfare, Sunghwa College) ;
  • Cho, Gi-Hwan (Division of Computer Science & Engineering, Chonbuk National University)
  • 투고 : 2010.10.29
  • 심사 : 2010.02.28
  • 발행 : 2011.03.25

초록

USN(Ubiquitous Sensor Network) 환경은 언제, 어디서나 정보를 이용할 수 있게 한다. 이러한 환경의 기반이 되는 기술은 타겟의 정확한 위치설정을 전제로 한다. 특히 ITS(Intelligent Transportation Systems)는 USN 기술을 적용함으로써 쉽게 구축 될 수 있다. 위치측정은 Range-based 방식과 Range-free 방식으로 나눌 수 있다. Range-based 방식은 전파의 불규칙하고 추가 장비가 필요로 센서네트워크기반 위치측정에 적합하지 않은 것으로 알려져 있다. 반면에 Range-free 방식은 능동적인 통신을 수단으로 위치를 측정하므로 자원제약적인 센서네트워크에서는 적합한 것으로 알려져 있다. 그러나 Range-free 방식은 일반적으로 정확성이 부족하며, 특히 밀집도가 낮은 환경에서는 정확성이 매우 낮다. 따라서 이 두 기법은 장단점을 가지고 있다. 그러므로 두 기법을 혼합하여 위치추적의 정확성을 개선할 수 있는 새로운 기법이 요구된다. 본 논문은 Range-free 방식을 개선할 수 있도록 추가 장비가 요구되지 않은 RSSI(Received Signal Strength Indication) 신호 값을 분류하고 주변노드의 위치와 통신범위 및 세기정보를 최대한 활용하여 이동차량을 보다 정확하게 추적할 수 있는 Range-hybrid 기반의 위치추적기법을 제시한다. 추가적으로 예측기법을 활용하여 위치추적의 정확성을 획기적으로 개선할 수 있는 방안을 제시한다. 그리고 시뮬레이션 결과, 제안된 기법이 기존 위치추적 알고리즘 보다 교통 환경에서 위치추적의 정확도가 우수함을 증명하였다.

USN(Ubiquitous Sensor Network) environment permits us to access whatever information we want, whenever we want. The technologies to provide a basement to these environments premise an accurate location establishment. Especially, ITS(Intelligent Transportation Systems) is easily constructed by applying USN technology. Localization can be categorized as either Range-based or Range-free. Range-based is known to be not suitable for the localization based on sensor network, because of the irregularity of radio propagation and the additional device requirement. The other side, Range-free is much appropriated for the resource constrained sensor network because it can actively locate by means of the communication radio. But, generally the location accuracy of Range-free is low. Especially, it is very low in a low-density environment. So, these two methods have both merits and demerits. Therefore, it requires a new method to be able to improve tracking accuracy by combining the two methods. This paper proposes the tracking scheme based on range-hybrid, which can markedly enhance tracking accuracy by effectively using the information of surrounding nodes and the RSSI(Received Signal Strength Indication) that does not require additional hardware. Additionally, we present a method, which can improve the accuracy of vehicle tracking by adopting the prediction mechanism. Simulation results show that our method outperforms other methods in the transportation simulation environment.

키워드

참고문헌

  1. A. Bharathidasan and V. A. S. Ponduru, "Sensor Network: An Overview," IEEE Infocom 2004.
  2. 공현민, 성태경, 권영미, "UWB 실내 측위를 위한 TDOA 위치결정기법," 전자공학회논문지, 제 42권 TC편, 제 1호, 9-15쪽, 2005년.
  3. M. Heidari, N. A. Alsindi and K. Pahlavan, "UDP Identification and Error Mitigation in ToA-based Indoor Localization Systems using Neural Network Architecture," IEEE Transactions on Wireless Communications, Vol.8 No.7, p.3597-3607, July 2009. https://doi.org/10.1109/TWC.2009.080415
  4. X. Ding, H. Li, F. Li, and J. Wu, "A novel infrastructure WLAN locating method based on neural network," Proc. on the 4th Asian Conference on Internet Engineering, Pratunam, Bangkok, Thailand. November 18-20, 2008.
  5. A. Savvides, H. Park and M Srivastava, "The Bits and Flops of the N-hop Multilateration Primitive for Node Localization Problems," Proc. on First ACM International Workshop on Wireless Sensor Networks and Applications, Sep 28, 2002.
  6. A. Savvides, C.C. Han and M.B. Srivastava, "Dynamic Finegrained Localization in Ad-hoc Networks of Sensors," Proc. on the 7th ACM International Conference on Mobile Computing and Networking (Mobicom2001), July, 2001.
  7. L. Doherty, K. Pister, and L. Ghaoui, "Convex Position Estimation in Wireless Sensor Networks," Proc. on the 20th Annual Joint Conference of the IEEE Computer and Communications Societies (INFOCOM 2001), April 22-26, 2001.
  8. S. Capkun, M. Hamdi and J. Hubaux, "GPS-free Positioning in Mobile Ad-hoc Networks," Proc. on the 34th Annual Hawaii International conference on System Sciences, Jan 3-6, 2001.
  9. D. Niculescu and B. Nath, "DV Based Positioning in Ad-Hoc Networks," Telecommunication Systems, Vol. 22, No. 1-4, pp. 267-280, 2003.
  10. N. Bulusu, J. Heidemann and D. Estrin, "GPS-less Low Cost Outdoor Localization for Very Small Devices," IEEE Personal Communications Magazine, Vol. 7, No. 5, pp. 28-34, October 2000. https://doi.org/10.1109/98.878533
  11. T. He, et al, "Range-free Localization Schemes for Large Scale Sensor Networks," Proc. on the 9th ACM International Conference on Mobile Computing and Networking (Mobicom2003), Sep 2003.
  12. Y. Kwon, K. Mechitov, S. Sundresh, W. Kim and G. Agha, "Resilient Localization for Sensor Networks in Outdoor Environments," Proc. on 25th IEEE International Conference on Distributed Computing Systems (ICDCS2005), June 6-10, 2005,
  13. T. Instruments, CC2420 Datasheet, 2004. [Online]. Available:http://focus.ti.com/lit/ds/symlink/cc2420 .pdf
  14. The Network Simulator, ns-2, http://www.isi.edu/ nsnam/ns/
  15. R. Crepaldi, P. Casari, A. Zanella and M. Zorzi, "Testbed Implementation and Refinement of a Range-based Localization Algorithm for Wireless Sensor Networks," Proc. on the 3rd International Conference on Mobile Technology, 2006.