Abstract
Location-aware systems are systems where location information is used as a rich source of context to enable computers to interact and react to their environment. To date, research involving such systems in the indoor environment has concentrated on the development of cheap, realisable, accurate location systems rather than the continued maintenance of the associated world model needed to derive context. This paper characterises the problems relating to world models that have been observed in a real deployment of a location-aware system. It develops a framework that separates the task of synchronising the real and virtual worlds into two—first monitoring to identify coarse regions of inconsistency, and the second accurate updating of these regions. The paper details methods by which the monitoring can be achieved without the cost of deploying specialised sensors, but rather through collating and analysing human movement patterns and raw location data. It presents an overview of the framework for monitoring, an in-depth case study with experimental results from a deployed system, and a discussion of how accurate updates could be achieved once inconsistent regions are identified.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Want R, Hopper A, Falcao V, Gibbons J (1992) The active badge location system. ACM Trans Inf Syst January:
Want R, Schilit B, Adams N, Gold R, Petersen K, Ellis J, Goldberg D, Weiser M (1995) The PARCTAB ubiquitous computing experiment. Technical report CSL-95-1, Xerox Palo Alto Research Center, March 1995
Addlesee M, Curwen R, Hodges S, Newman J, Steggles P, Ward A, Hopper A (2001) Implementing a sentient computing system. IEEE Comput 34(8):
Richardson T, Stafford-Fraser Q, Wood KR, Hopper A (1998) Virtual network computing. IEEE Internet Comput 2(1):
Harle RK, Hopper A (2005) Deploying and evaluating a location-aware system. In: Proceedings of the third international conference on mobile systems, applications, and services, Seattle, WA, USA (Mobisys 2005)
Bobick A, Intille S, Davis J, Baird F, Pinhanez C, Campbell L, Ivanov Y, Schutte A, Wilson A (1996) The kidsroom: a perceptually-based interactive and immersive story environment. Technical report 398, MIT Media Lab, December 1996
Krumm J, Harris S, Meyers B, Brumitt B, Hale M, Shafer S (2000) Multi-camera multi-person tracking for easy living. In: Proceedings of the third international workshop on visual surveillance, July 2000
Kato H, Billinghurst M, Poupyrev I, Imamoto K, Tachibana K (2000) Virtual object manipulation on a table-top AR environment. In: Proceedings of ISAR 2000, October 2000
Jun Rekimoto (1998) Matrix: a realtime object identification and registration method for augmented reality. In: Proceedings of Asia Pacific computer human interaction, July 1998, pp 63–68
Moravec HP (1988) Sensor fusion in certainty grids for mobile robots. AI Mag 9:61–74
Martin MC, Moravec HP (1996) Robot Evidence Grids. Technical report CMU-RI-TR-96-06, Carnegie Mellon University, 1996
Thrun S (1998) Learning maps for indoor mobile robot navigation. Artif Intell 99(1):21–71
Arbuckle A, Howard A, Mataric M (2002) Temporal occupancy grids: a method for classifying the spatio-temporal properties of the environment. In: Proceedings of the IEEE/RSJ international conference on intelligent robots and systems (IROS 2002), EPFL, Switzerland, 2002
Ward AMR (1998) Sensor-driven computing. PhD thesis, Cambridge University, August 1998
Harle RK, Hopper A (2003) Using personnel movements for indoor autonomous environment discovery. In: Proceedings of the first IEEE international conference on pervasive computing and communications, Fort Worth, TX (PerCom 2003), March 2003, pp 125–132
Harle RK, Hopper A (2003) Building world models by ray-tracing within ceiling-mounted positioning systems. In: Proceedings of UbiComp, Seattle, WA, October 2003
Harle RK, Hopper A (2004) Dynamic world models from ray-tracing. In: Proceedings of the second IEEE international conference on pervasive computing and communications, Orlando, FL (PerCom 2004), March 2004
Harle RK, Ward A, Hopper A (2003) A novel method for discovering reflective surfaces using indoor positioning systems. In: Proceedings of the first international conference on mobile systems, applications, and services, San Francisco, CA (Mobisys 2003), 2003
Borriello G, Brunette W, Hall M, Hartung C, Tangney C (2004) Reminding adbout tagged objects using passive RFIDs. In: Proceedings of the 6th international conference on ubiquitous computing (UbiComp 2004), Nottingham, September 2004
Hahnel D, Burgand W, Fox D, Fishkin K, Philipose M (2004) Mapping and localization with RFID technology. In: Proceedings of the 2004 IEEE international conference on robotics and automation (ICRA ’04), 2004
Brusey J, Floerkemeier C, Harrison M, Fletcher M (2003) Reasoning about uncertainty in Location identification with RFID. In: Workshop on reasoning with uncertainty in robotics, August 2003
Acknowledgments
The authors would like to thank the reviewers for their comments and suggestions. In addition, they wish to thank all those who have contributed to the systems and the location data collection over the years at Cambridge, of which there are too many to mention. Special thanks also go to Andy Ward, Pete Steggles, Rupert Curwen and the other members of the Sentient Computing project at AT\&T Research, Cambridge: their guidance was invaluable.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Harle, R.K., Hopper, A. Towards autonomous updating of world models in location-aware spaces. Pers Ubiquit Comput 12, 317–330 (2008). https://doi.org/10.1007/s00779-006-0103-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00779-006-0103-6