Object localization using RFID

Abstract

-Object localization is a key primitive in pervasive computing environments, where numerous applications depend on the rapid and accurate position estimation of objects. We present a general RFID-based localization framework that reliably determines the positions of objects with unprecedented accuracy and speed. This is achieved by varying the power levels of the RFID readers, calibrated against reference tags of known sensitivity. Our implementation and experiments are able to localize objects to an accuracy of 15 cm within a few seconds, and this compares favorably with previous techniques. We also suggest several practical optimizations for further enhancing the speed and accuracy of the method.

RFID Localization Using Angle of Arrival Cluster Forming

“…The distance is associated with the lowest power level at which the tag is detected. In other words, the power level is mapped to a distance [18].…”

An RFID-based object localisation framework

“…Finally, the above approaches ignore the key issue that the RFID equipment itself can introduce significant amount of experimental errors. For example, previous works ignore the fact that 'identical' tags can have widely varying detection sensitivities, which can greatly affect the experimental outcomes (Chawla et al, 2010a;Chawla et al, 2010b). Thus, instead of addressing and mitigating these basic principles (as we do in our approach), previous research works resort to Herculean efforts in order to reduce the errors on other fronts, while ignoring bigger error sources, resulting in a hodgepodge of ad-hoc and sometimes ineffectual techniques.…”

“…'binning') the tags based on their detection sensitivities. We thus classify tags as 'highly sensitive', 'average sensitive', and 'low sensitive' using read measurements over different power and distance combinations (Chawla et al, 2010a;Chawla et al, 2010b), as detailed in Section 5 below. This enables only uniformly sensitive tags to be deployed in the same experiment, resulting in more consistent and meaningful experimental results.…”

Localization of a Radio-Frequency Identification Tag from Measurements of the Fourier Coefficients of Its Magnetic Flux Density

“…Estimating the position of a radio-frequency identification (RFID) tag has attracted great interest for ubiquitous computing and location-aware systems [1]- [4]. RFID tags can be classified into two groups based on the carrier frequency of their response signals: low/high-frequency (LF/HF) tags with frequencies of 135 kHz and 13.56 MHz and ultrahigh-frequency (UHF) tags with frequencies of 300 MHz, 950 MHz, and 2.45 GHz.…”

“…Bekkali et al [3] proposed to localize a passive UHF tag by measuring the received signal strength of a target and landmark tags with two readers. Chawla et al [4] varied the power level of the UHF RFID readers and infer the distance between the reader and the tag by using reference tags at known locations. Although these systems with UHF tags are suitable for widerange, indoor localization (about 5 m × 5 m), they have limited localization accuracy (about 150 mm at best) due to reflection by metals and absorption by the human body, and are not suitable for applications which require more accurate localization, even in the limited range.…”