E. M. Tapia, S. S. Intille, and K. Larson, "Portable wireless sensors for object usage sensing in the home: Challenges and practicalities," in Proceedings of the European Ambient Intelligence Conference. vol. LNCS 4794 Berlin Heidelberg: Springer-Verlag 2007, pp. 19-37.[PDF]


A low-cost kit of stick-on wireless sensors that transmit data indicating whenever various objects are being touched or used might aid ubiquitous computing research efforts on rapid prototyping, context-aware computing, and ultra-dense object sensing, among others. Ideally, the sensors would be small, easy-to-install, and affordable. The sensors would reliably recognize when specific objects are manipulated, despite vibrations produced by the usage of nearby objects and environmental noise. Finally, the sensors would operate continuously for several months, or longer. In this paper, we discuss the challenges and practical aspects associated with creating such "object usage" sensors. We describe the existing technologies used to recognize object usage and then present the design and evaluation of a new stick-on, wireless object usage sensor. The device uses (1) a simple classification rule tuned to differentiate real object usage from adjacent vibrations and noise in real-time based on data collected from a real home, and (2) two complimentary sensors to obtain good battery performance. Results of testing 168 of the sensors in an instrumented home for one month of normal usage are reported as well as results from a 4-hour session of a person busily cooking and cleaning in the home, where every object usage interaction was annotated and analyzed.


Sensors, home, stick-on, accelerometer, ubiquitous, wireless.


This work was supported by National Science Foundation grant #0313065 and the MIT House_n Consortium.