1. IEEE International Symposium on Wireless Pervasive Computing Object Localization Using RFID Kirti Chawla, Gabriel Robins, and Liuyi Zhang Department of Computer Science University of Virginia, Charlottesville, USA {kirti, robins, lz3m}@virginia.edu Palazzo Ducale, Modena, Italy, May 5-7, 2010 This work is supported by U.S. National Science Foundation (NSF) grant: CNS-0716635 (PI: Prof. Gabriel Robins) For more details, visit: www.cs.virginia.edu\robins

2. Kirti Chawla, Gabriel Robins, and Liuyi Zhang 2 Analysis Overview Future Directions Proposed Approach RFID Localization

3. Overview: Application Scenarios Kirti Chawla, Gabriel Robins, and Liuyi Zhang 3 RFID Localization Spatio-temporal Inferences Fine-grained Object Lookup Smart Ambience Novel Environments

4. Overview: RFID Localization Kirti Chawla, Gabriel Robins, and Liuyi Zhang 4 RFID Localization Reader Localization Tag Localization Stationary Reader Localization Mobile Reader Localization Stationary Tag Localization Mobile Tag Localization

5. Overview: Contentious Issues Kirti Chawla, Gabriel Robins, and Liuyi Zhang 5 RFID Localization Issues Ambient InterferenceOcclusionsReader LocationTag OrientationTag SpatialityTag Sensitivity

6. Proposed Approach: Underlying Principles Kirti Chawla, Gabriel Robins, and Liuyi Zhang 6 Power Distance Relationship PTPT PRPR D

7. Proposed Approach: Basic Concept Kirti Chawla, Gabriel Robins, and Liuyi Zhang 7 Calibrated TagsPower-Distance Relationship Tag Placement SchemesLocalization Algorithms Localization Coarse-grained Location Estimate Fine-grained Location Estimate Error Reduction Heuristics Localization Framework

8. Proposed Approach: Algorithm I Kirti Chawla, Gabriel Robins, and Liuyi Zhang 8 Start Algorithm I For each Tag T Linear Search for PL O of T Report PL O Stop PL O FOUND ? YESNO YES NO PL C > Threshold ? Time Complexity: O(N  P)

9. Proposed Approach: Algorithm II Kirti Chawla, Gabriel Robins, and Liuyi Zhang 9 Time Complexity: O(N  logP) Start Algorithm II For each Tag T Binary Search for PL O of T Report PL O Stop PL O FOUND ? YESNO YES NO PL C > Threshold ?

10. Proposed Approach: Algorithm III Kirti Chawla, Gabriel Robins, and Liuyi Zhang 10 Start Algorithm III Initialize PL of all tags to MAX_POWER_LEVEL Linearly increment PL for all tags Stop PL = 0 ? PL of tag “fixed” ? YESNO YES NO Tag has OPT PL Time Complexity: O(P)

11. Proposed Approach: Localization Error Kirti Chawla, Gabriel Robins, and Liuyi Zhang 11 Source of Localization Error Radio Wave Target Tag Reference Tag Antenna RFID Reader

12. Proposed Approach: Heuristics I Kirti Chawla, Gabriel Robins, and Liuyi Zhang 12 Heuristics: Absolute Difference

13. Proposed Approach: Heuristics II Kirti Chawla, Gabriel Robins, and Liuyi Zhang 13 Heuristics: Minimum Power Reader Selection

14. Proposed Approach: Heuristics III Kirti Chawla, Gabriel Robins, and Liuyi Zhang 14 Heuristics: Root Sum Square Absolute Difference

15. Proposed Approach: Meta-Heuristic Kirti Chawla, Gabriel Robins, and Liuyi Zhang 15 Heuristics Architecture Localization Error Heuristics: Root Sum Square Absolute Difference Meta-Heuristic Heuristics: Minimum Power Reader Selection Heuristics: Absolute Difference Other Novel Heuristics

16. Experimental Setup Kirti Chawla, Gabriel Robins, and Liuyi Zhang 16 1 Linear Antenna Region Area: 6 m 2 32 Reference Tags Room Volume: 41 m 3 S Q Data Logging BackendRFID Reader

17. Results: Tag Sensitivity I Kirti Chawla, Gabriel Robins, and Liuyi Zhang 17 Constant Distance Variable Power

18. Results: Tag Sensitivity II Kirti Chawla, Gabriel Robins, and Liuyi Zhang 18 Variable Distance Constant Power

19. Results: Localization Speed Kirti Chawla, Gabriel Robins, and Liuyi Zhang 19 Localization Speed

20. Localization Accuracy Results: Localization Accuracy Kirti Chawla, Gabriel Robins, and Liuyi Zhang 20

21. Results: Localization Visualization Kirti Chawla, Gabriel Robins, and Liuyi Zhang 21 Heuristics Accuracy Work Area Antenna Control

22. Comparative Analysis Kirti Chawla, Gabriel Robins, and Liuyi Zhang 22 Speed / Accuracy Comparison TechniqueAverage Time (min)Test Area (m 2 ) Error (m) Setup Stage Localization Stage Ni et al [10]NR ~2 Alippi et al [1]NR 200.68 Joho et al [8]~27NR 0.375 Zhou et al [16]NR 0.19 Bechteler et al [2]NR 0.2 Wang et al [15]NR 0.1 – 0.9 Bekkali et al [3]NR 90.5 – 1.0 Proposed Approach (I, II, III) 19.3, 14.7, 3.6 0.72, 0.48, 0.9160.08 – 0.31 Avg. Localization Error = 0.15 m Localization Time = 0.43 min.

23. Future Directions Kirti Chawla, Gabriel Robins, and Liuyi Zhang 23 Open Research Problems Reduce Average Localization Time Improve Localization Accuracy Testing in Different Scenarios Novel Applications

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25. References D. Joho, C. Plagemann, and W. Burgard, “Modeling RFID Signal Strength and Tag Detection for Localization and Mapping”, IEEE International Conference on Robotics and Automation (ICRA 2009), Kobe, Japan, May 2009, pp. 3160-3165. X. Liu, M. Corner, and P. Shenoy, “Ferret: RFID Localization for Pervasive Multimedia”, Lecture Notes in Computer Science, Berlin, Germany, Springer Press, Sep. 2006, Vol. 4206/2006, pp. 422-440. L. Ni, Y. Liu, Y. Lau, and A. Patil, “LANDMARC: Indoor Location Sensing Using Active RFID”, 1st International Conference on Pervasive Computing (PerCom 2003), Arlington, Texas, Dec. 2003, pp. 407-415. D. Papadogkonas, G. Roussos, and M. Levene. “Discovery and Ranking of Significant Trails”, 2nd International. Workshop on Exploiting Context History in Smart Environments (ECHISE 2006), Irvine, CA, Sep. 2006. T. Sanpechuda and L. Kovavisaruch, “A Review of RFID Localization: Applications and Techniques”, 5th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology (ECTI-CON 2008), Krabi, Thailand, Vol. 2, May 2008, pp. 769-772. P. J. Sweeney, “RFID for Dummies”, Wiley Publishing, New Jersey, 2005. T. Wada, N. Uchitomi, Y. Ota, T. Hori, K. Mutsuura, and H. Okada, “A Novel Scheme for Spatial Localization of Passive RFID Tags; Communication Range Recognition (CRR) Scheme”, IEEE International Conference on Communications (ICC 2009), Dresden, Germany, IEEE Press, Jun. 2009, pp. 1-6. Kirti Chawla, Gabriel Robins, and Liuyi Zhang 25

26. References C. Wang, H. Wu, and N. Tzeng, “RFID-Based 3-D Positioning Schemes”, IEEE International Conference on Computer Communications (INFOCOM 2007), Alaska, May 2007, pp. 1235-1243. J. Zhou and J. Shi, “RFID Localization Algorithms and Applications—a Review”, Journal of International Manufacturing, Netherlands, Springer Press, Aug. 2008, pp. 695-707. Kirti Chawla, Gabriel Robins, and Liuyi Zhang 26

27. Questions ? Kirti Chawla, Gabriel Robins, and Liuyi Zhang 27