Personal robots with autonomy, mobility, and manipulation capabilities have the potential to dramatically improve quality of life for various user populations, such as older adults and individuals with motor impairments. Unfortunately, unstructured environments present many challenges that hinder robot deployment in ordinary homes. This thesis seeks to address some of these challenges through a new robotic sensing modality that leverages a small amount of environmental augmentation in the form of Ultra High Frequency (UHF) Radio-Frequency Identification (RFID) tags. Previous research has demonstrated the utility of infrastructure tags (affixed to walls) for robot localization; in this thesis, we specifically focus on tagging objects. Owing to their low-cost and passive (battery-free) operation, users can apply UHF RFID tags to hundreds of objects throughout their homes. The tags provide two valuable properties for robots: a unique identifier and receive signal strength indicator (RSSI, the strength of a tag's response). This thesis explores robot behaviors and radio frequency perception techniques using robot-mounted UHF RFID readers that enable a robot to efficiently discover, locate, and interact with UHF RFID tags applied to objects and people of interest. The behaviors and algorithms explicitly rely on the robot's mobility and manipulation capabilities to provide multiple opportunistic views of the complex electromagnetic landscape inside a home environment. The electromagnetic properties of RFID tags change when applied to common household objects. Objects can have varied material properties, can be placed in diverse orientations, and be relocated to completely new environments. We present a new class of optimization-based techniques for RFID sensing that are robust to the variation in tag performance caused by these complexities. We discuss a hybrid global-local search algorithm where a robot employing long-range directional antennas searches for tagged objects by maximizing expected RSSI measurements; that is, the robot attempts to position itself (1) near a desired tagged object and (2) oriented towards it. The robot first performs a sparse, global RFID search to locate a pose in the neighborhood of the tagged object, followed by a series of local search behaviors (bearing estimation and RFID servoing) to refine the robot's state within the local basin of attraction. We report on RFID search experiments performed in Georgia Tech's Aware Home (a real home). Our optimization-based approach yields superior performance compared to state of the art tag localization algorithms, does not require RF sensor models, is easy to implement, and generalizes to other short-range RFID sensor systems embedded in a robot's end effector. We demonstrate proof of concept applications, such as medication delivery and multi-sensor fusion, using these techniques. Through our experimental results, we show that UHF RFID is a complementary sensing modality that can assist robots in unstructured human environments.

This work includes formulation of mechanically flexible magnetic composites and application to a quarter-wavelength microstrip patch antenna benchmarking structure operating in the lower UHF spectrum (~300-500 MHz) to investigate capability for miniaturization. A key challenge is to introduce sufficiently low magnetic loss for successful application. Particles of NiZn ferrite and BaCo ferrite, also known as Co2Z, were characterized. Flexible magnetic composites comprised of 40 vol% NiZn ferrite or BaCo ferrite particles in a silicone matrix were formulated. Effects of treating the particles with silane in the formulation process were not detectable, but larger particle size showed to increase complex permittivity and complex permeability. By comparing complex permittivity and complex permeability of the composites, BaCo ferrite was selected for the antenna application. Antennas on the developed magnetic composite and pure silicone substrates were electromagnetically modeled in a full-wave FEM EM solver. A prototype of the antenna on the magnetic composite was fabricated. Good agreement between the simulated and measured results was found. Comparison of the antennas on the magnetic composite versus the pure silicone substrate showed miniaturization capability of 2.4X and performance differences of increased bandwidth, reduced Q, and reduced gain. A key finding of this study is that a small amount of permeability (relative permeability ~2.5) can provide relatively substantial capability for miniaturization, while sufficiently low magnetic loss can be introduced for successful application at the targeted operating frequency. The magnetic composite showed the capability to fulfill this balance and to be a feasible option for RFID applications in the lower UHF spectrum.

Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / A combination of Radio Frequency Identification technology and ubiquitous computing are revolutionising the manner in which we look at simple objects. Radio Frequency Identification (RFID) allows RFID labeled objects to be identified at a distance without physical contact, and ubiquitous computing provides a virtually connected environment for the objects. RFID labels are frequently referred to as the next generation barcodes. RFID Systems provide increased productivity, efficiency, convenience and many advantages over bar codes for numerous applications, especially global supply chain management. RFID labeling has a number of advantages over conventional bar code systems. The optics based bar code systems could be rendered useless by common everyday environments containing dirt, dust, smoke, grease, condensation and by misorientation and misalignment. Furthermore bar codes are subject to fraudulent duplication and counterfeiting with minimal effort. However, there are limitations and constraints inherent to RFID technology: semiconductor thresholds, limits on transmitted power, costs, antenna and coupling inefficiencies. Thus it is important for RFID designers to understand these limitations and constraints in order to optimise system designs and overcome inefficiencies where possible. Therefore the work presented in this dissertation seeks to improve the performance of advanced RFID systems by overcoming a number of these limitations. Prior to a discussion of improving performance, the author's interpretation of a modem RFID system along its evolutionary path as a ubiquitous RFID network and its application to supply chain management is described. Performance improvements are achieved by: the development of electromagnetic theory for RFID system analysis and optimisation; design and development of interrogator antennas; analysis of electrically small and tiny antennas for RFID labels; and development and utilisation of a design methodology for creating high performance label antennas and antennas for tagging metallic objects. Implementations of RFID systems have raised concerns regarding information security and possible violations of end-user privacy. The most profound concerns are raised against low cost RFID technology because of its potential for mass scale deployment, its pervasive nature, and the resource limitations preventing the provision of strong cryptographic solutions. There is a growing need in the RFID community to discover and develop techniques and methods to overcome various hurdles posed by the above-mentioned concerns. Thus, the thesis also considers the vulnerabilities of low cost RFID systems and associated insecurities and privacy concerns resulting from the latter. Prior to addressing such concerns impeding the deployment of low cost RFID technology, a framework within which to provide security services is also detailed. It has become important to both defme and identity a framework based around low cost RFID systems since RFID has become a "catch all" phrase for various other forms of technology. Addressing security and privacy of low cost RFID systems requires novel thinking. The later parts of the thesis outline design considerations for security mechanisms and a number of practicable solutions for providing the features of: mutual authentication; confidentiality; message content security; product authentication; anonymity and untraceability, that are necessary for low cost RFID systems to overcome the weaknesses identified in this dissertation. Implementing these security mechanisms requires the generation of true random tag parameters and true random numbers. Achieving these objectives using a hardware based true random number generator is also described and analysed. A final part of the thesis focuses on active RFID labels and improving their performance. The primary concern with active labels is the life of the onboard battery. Turn-on circuits provide a method of turning "on" and "off" an active label remotely to conserve valuable battery power. Analysis, development and testing of a turn-on circuit concept, based on interrogator field sensing, have provided a means of remotely activating and deactivating active RFID labels and conserving battery power. The final chapter of this thesis provides a detailed analysis, based on coupling relations between electromechanical systems, for evaluating the feasibility of a theft detection sensor, based on a turn-on circuit for an active RFID label, for preventing the theft of high value items. While low cost RFID needs to overcome certain security and privacy related barriers, RFID technology does provide novel and valid approaches to such security related applications as product authentication, anti-counterfeiting and theft detection. It is believed that the contributions from this thesis will extend and elaborate on the existing knowledge base, paving the way forward to allow further significant deployment of advanced RFID techno logy. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1368084 / Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2007

Thesis (M.S.)--Rochester Institute of Technology, 2007. / Typescript. Includes bibliographical references (p. 67-68).

Thesis (M.S.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph.D.)--University of Melbourne, Dept. of Electrical and Electronic Engineering, 2007. / Typescript. Includes bibliographical references (leaves 139-156).

Thesis (Ph.D.)--Mississippi State University. Department of Management and Information Systems. / Title from title screen. Includes bibliographical references.

Research Project (M.B.A.) - Simon Fraser University, 2005. / Research Project (Faculty of Business Administration) / Simon Fraser University. MBA-MOT Program. Senior supervisor : Dr. Jill Shepherd.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains x, 113 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 108-113).

Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Dr. Manos Tentzeris; Committee Member: Dr. Gregory Durgin; Committee Member: Dr. Joy Laskar.