Radio-identification

Résumé

La radio-identification, le plus souvent désignée par l'acronyme RFID (de l’anglais « radio frequency identification »), est une méthode pour mémoriser et récupérer des données à distance en utilisant des marqueurs appelés « radio-étiquettes » (« RFID tag » ou « RFID transponder » en anglais). Les radio-étiquettes sont de petits objets, tels que des étiquettes autoadhésives, qui sont collés ou incorporés dans des objets ou produits, et même implantés dans des organismes vivants (animaux, corps humain). Les radio-étiquettes comprennent une antenne associée à une puce électronique qui reçoit et répond aux requêtes radio émises par l’émetteur-récepteur. Ces puces électroniques contiennent un identifiant et éventuellement des données complémentaires. Cette technologie d’identification peut être utilisée pour identifier :

les objets, comme avec un code-barres (on parle alors d’étiquette électronique) ;
les personnes, en étant intégrée dans les passeports, cartes de transport, car

Source officielle

https://fr.wikipedia.org/wiki/Radio-identification

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This thesis is motivated from the four keywords: remanufacturing, quality, multi-agent and intelligence. Recent years' environmental problems caused tightening the regulations and legislations for used products. Therefore remanufacturing is getting more attention. The quality of used products is uncertain and even dynamically changes during the remanufacturing process, and each used product should be individually handled in a different way depending on its quality. Fortunately recent developing wireless technologies like radio frequency identification (RFID) may enable remanufacturing control systems to identify, track, and control each used product and disassembled subassembly/part (PDSP) automatically. The multi-agent approach can be a good solution for the individual control of each PDSP, because a centralized control system is not eligible to managing so many elements in the remanufacturing system. The objective of this thesis is to propose a quality embedded remanufacturing system (QRS) which comprises a multi-agent framework and a scheduling mechanism. First, this thesis discusses the fundamental concepts for the proposed modeling tools and scheduling mechanism: the QRS quality characteristics and the multi-agent framework. As the second step, this thesis proposes QRS modeling tools which support the PDSP/resource quality representation and comprise: intuitive remanufacturing system representation (IRSR) and dynamic token two-level colored Petri-nets (DTPN). The former is designed from the user-side perspective and the latter is from the system-side perspective. The multi-agent framework is constructed based on the model represented with the proposed tools. Last, this thesis proposes a real-time scheduling mechanism for the QRS which enables the constructed framework to execute. The scheduling mechanism embeds a communication protocol among agents and dispatching rules formulated depending on the PDSP/resource quality. A knowledge-based approach is adopted to increase efficiency of the scheduling mechanism, where the knowledge is learned by simulations. A heuristic method is also proposed to reduce the simulation time.

EPFL2009

Chargement

Nano-SAW Devices for Wireless Identification

Florian Bienefelt

Surface Acoustic Wave (SAW) technology is omnipresent in the devices around us today, mainly used as passive bandpass filters in most radio systems like smartphones and TV antennas or as delay lines in telecommunications. More recently, the possibility to use SAW devices for wireless identification has surfaced and generated the first widespread applications such as on the highways in Norway over 2 decades ago. Their environmentally robust structure and passive use is very interesting for many applications in outdoor environments or chemically challenging places. It is possible to read many of them simultaneously and the amount of information that can be carried is much higher than printed barcodes. This semester project was aimed at learning how to design and fabricate an RFID device based on SAW technology in a cleanroom and trying to optimize the parameters of the device while reducing its size. Optical lithography tools with feature sizes down to 2 μm will help achieve this before E-Beam lithography can further decrease the features in scale of the structures involved in a SAW RFID tag. While creating an entire working wireless tag would take more time than available, the objective is to take this project as far as it can to pave the way for future students to search on this topic and increase knowledge about SAW devices.

2014

Chargement

XBAR resonators in 128° Y-cut Lithium Niobate LiNbO3

Manal Zeddoug

The increasing demand of higher frequencies technologies in RF (Radio frequency) components, especially for telecommunication, create a need to develop wider and higher frequency bands filters, with optimal performances. Thus, constant effort are made to develop new resonators that outperform excited technologies mainly in terms of electromechanical coupling and quality factor. Excited Bulk Acoustic Resonator XBAR which are composed of a single piezoelectric crystal layer, with metallic electrodes on the top surface, seem to be an interesting solution. It has indeed been shown that it can achieve higher frequency than others acoustic waves propagation technologies. The different characteristics of these resonators are mainly determined by their dimensions and the properties of the piezoelectric membrane. Lithium Niobate has shown interesting piezoelectric properties such as a high phase velocity and large electromechanical coupling which enable wider filter bandwidths. Therefore, using this material in the XBAR represents an attractive way to respond to this flourishing need. The aim of this project is thus to explore the potential of using LiNbO3 substrate with a new orientation. The case of a 128° Y-cut Lithium Niobate LiNbO3 membrane is going to be studied. For that we are first going to review the proprieties of the 128° Y-cut material and how the resonator composed of this substrate has been modeled. Finally, we will search for the combination of geometrical parameters which permits the optimal performance of the resonator.

2021

Chargement

EPFL2009