ISBN 9783843914611

978-3-8439-1461-1, Reihe Kommunikationstechnik

Theresa Nick
Advanced Localization Concepts for RFID-based Systems

185 Seiten, Dissertation Technische Universität Dortmund (2013), Softcover, A5

Zusammenfassung / Abstract

Radio Frequency Identification (RFID) is an omnipresent technology because it enables the wireless and therefore contactless identification of objects. This feature is especially desirable in logistics where it is important

to quickly identify many objects in a short period of time. Additionally to the identification also a localization of the objects can be realized via this technology which is beneficial in many scenarios.

Based on the RFID technology this work introduces a variety of advanced localization approaches for moving or stationary objects using Received Signal Strength (RSS) measurements. The recursive algorithms Unscented Kalman Filter and Particle Filter are employed for localization and tracking of these objects. The methods are augmented to include constraints and other available information into the localization process in order to increase positioning accuracy. These constraints are obtained from relative or absolute position information like the fixed height of the RFID tag attached to the object or characteristics of the employed hardware like the antenna’s beam characteristic. Besides the localization accuracy the computational complexity is considered as an additional measure to be able to name benefits as well as disadvantages of the various algorithms. Since the Particle Filter is more computationally demanding compared to the Unscented Kalman Filter, but can achieve a more accurate positioning result under certain circumstances, an approach is introduced that combines both filters to construct a localization algorithm with reasonable computational complexity but good accuracy.

The localization accuracy is still limited by the RSS measurements. Thus, to further improve the localization results of the proposed methods another sensor can be included into the localization system. The usage of one or two inexpensive cameras complementing the RFID-based system leads to more accurate positioning results, but a matching between camera- and RFID-based localization results is required, if more than one tag/object is detected. This matching facilitates a joint RFID- and image-based localization system that can be applied for a wide range of use cases where identification and localization is required simultaneously.