Orientadores: Katia Lucchesi Cavalca, Rainer Nordmann / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-12T14:22:54Z (GMT). No. of bitstreams: 1 Furtado_RogerioMendonca_D.pdf: 2160863 bytes, checksum: 4c54a9ce5fcded113554dc24287e591a (MD5) Previous issue date: 2008 / Resumo: Um atuador magnético como fonte de excitação em sistemas rotativos é desenvolvido para emprego na análise modal e em outros estudos, envolvendo a excitação sem contato. Embora os sistemas magnéticos para aplicação de forças em máquinas rotativas sejam empregados com alto desempenho (como por exemplo os mancais magnéticos), o desenvolvimento de um sistema simples, para aplicações laboratoriais, se apresenta como uma contribuição experimental útil, para ser empregado numa bancada de testes utilizada no desenvolvimento de projetos de máquinas rotativas. O conceito apresentado é simples, mas permite a excitação externa sem contatos ou mesmo o controle das amplitudes de vibração, quando associado a um sistema de controle. Contudo, a calibração e o estudo do desempenho dinâmico do sistema não são análises simples. Neste sentido, o trabalho apresenta uma experiência prática e discussões sobre o desenvolvimento do atuador magnético utilizado para testes em máquinas rotativas. A influência da corrente elétrica, entreferro, superfície do pólo do atuador e também da freqüência de excitação, são apresentadas. A força magnética é estimada, baseando-se na medida da densidade de fluxo magnético, medida por sensores hall. / Abstract: A magnetic actuator as excitation source in rotating systems is developed, in order to accomplish modal analysis and other studies involving contacless excitation. Although the use of magnetic systems to apply forces onto rotating machinery has been carried out with high performance level (for example, magnetic bearings), the development of a conveniently easy and simples device for laboratory application presents interesting contribution to experimental methods used in test rigs based on similarity design to rotating machinery. The initial concept of the magnetic actuator proposed here is simple, but enables either the external excitation without contact or the vibration control when associated with a controller system. However, the performance characteristics tunning to attend the dynamic demand of the system is not so trivial. Following this focus, the work brings practical experience and discussion about the development and performance analysis of a magnetic actuator used for rotating machinery tests. The influence of the electrical current in the actuator coils, the air-gap between actuator and rotative system, thetype of surface of the actuator poles (flat or curved) as well as excitation frequency was verified. Force estimation was based on the magnetic flux density, measured by hall sensors. / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutor em Engenharia Mecânica

This thesis attempts with the design of a device for contactless control of the computer presentation. In the first part there are theoretically described the methods of contactless computer control. The second part is focused on the description of different types of sensors and also the key elements for this thesis – the development board TinyPICO ESP32 and sensor BNO055. Finally, in the third part there is described the design of the device and gestures.

Cílem této práce bylo implementovat emulaci tagu MIFARE Classic na NFC-A periferii vestavěné v mikrokontroléru. K implementaci řešení byl použit mikrokontrolér nRF52832 vyráběný firmou Nordic Semiconductor. Byla implementována základní sada příkazů MIFARE Classic (autentizace, čtení, zápis). Implementace byla otestována s několika čtečkami, za pomoci různých aplikací. Výsledné řešení bylo porovnáno s existujícími, jako je Proxmark a Chameleon Mini.

The first part of thesis is theoretical and it is the introduction into conductometry. It defines the essential terms of this field as well as contact and contactless methods of measurement of fluid conductivity and also the influential parasitic phenomena and possibilities of their elimination. The second part is dealing with design of the contactless transformer conductivity probe. The characteristics of designed probe are verified in the practical part of the thesis. The final part of the thesis is dealing with measurement according to the defined points in the assignment. The characteristics of several contact probes are verified and also the characteristic of the contactless transformer probe, which was implemented according to the design from the second part. Outcomes of these measurements establish the suitable power supply frequencies and currents for all these probes.

The aim of this work is to prove the practical applicability of the concept of contactless energy transfer using induction coils. The first part deals with the mathematical model and theoretical proof of the concept being able to work in practice and describes the process of detecting resonance of receiver circuit on transmitter side. Next chapter describes hardware solution of the experimental prototype. The last part contains measurement results of a coupling coefficient of coils and discusses performance and notable features of the prototype.

The objective of my thesis is description of contactless measuring methods, their principle and distribution. There are compiled basic facts about the measurement of laser and ultrasound. In this work is also described non-contact temperature measurement. Part of thesis is non-contact flow measurement on the model.

This work deals with the calibration of contact and contactless thermometers. The theoretical part describes physical laws, which are important for contact and contactless measuring of temperature, requirements for thermometers, suitability of use different types of thermometers and materials used for construction of temperature sensors. The following part describes metrology with the focus on metrology system of the Czech Republic. This thesis also describes errors and uncertainties of measurments, especially on their division, sources of uncertainties and methodology of type A and type B uncertainty determination. The practical part is focused on the calibration of thermometers within the Czech Metrological Institute and the Faculty of Electrical Engineering and Communication in Brno.

Contactless cards are everywhere nowadays due to their ease to use and low price to produce. In addition, their reliability is excellent. That is why they are used in systems where security is essential within a low price. To develop the associated systems (cards, readers, terminals), efficient tools are needed. These tools can be a spy analyzing any communication or an emulator that can act and answer exactly as a real contactless card. The objective of this thesis was to develop a contactless card emulator on a product that is currently only spying, the NomadLAB of KEOLABS. The emulator feature is based on a discontinued product, the ProxiCARD, and it has for main objective to be compliant with the ISO 14443 standard. Through the analysis of its architecture and its current performance, I have developed a complete system that can be integrated into the ecosystem of the KEOLABS products. The features I developed take place into the source code of the NomadLAB, at the level of its ARM microcontroller in language C, and in its FPGA in language VHDL. The ARM is here to handle all the smart part of the transmission, while the FPGA to handle the coding and decoding process. In addition, I developed an antenna able to on one hand receive the signal from a reader and on the other hand to reply to it by modulating the magnetic field. I also developed and added my controls to the current computer software. Finally, I have written a lot of testing to make sure that this new system is reliable. The NomadLAB is now able to emulate a contactless card complying with ISO14443 standard, while keeping its spy features, and its control through a computer.

Researchers today anticipate that in the near future, the majority of the owners of a smartphone will use it as a wallet, i.e. for contactless payment. The technology that enables contactless payment today is “Near Field Communication” (NFC), which is increasingly embedded in smartphones. Applications like mobile payment between a phone and a terminal use NFC. With Mobile payment the user’s credit and banking information gets saved and it’s extremely important for a user that the saved data doesn’t fall into the wrong hands. How should then a user of an NFC equipped device ensure that end-to-end security is strong enough when they use NFC technology? Can user feel safe enough to keep their private documents on the phone without getting “robbed”? NFC uses a security element “Secure Element” (SE) that offers the user safety for their mobile purchases but also in other applications such as transportation tickets. The security element comes in three forms: SD card based, SIM card based or embedded in the smartphone. Over time, the technology behind the secure element is further developed and a new phenomenon has emerged, a new type of secure element. The new technology is an application based secure element: “Software Emulation Card” (Soft-SE), which offers security without a physical SE This thesis will deal with the Secure Element’s area to see if the Soft-SE are so confident that we can count it as an option when we do our mobile purchases in the store. A number of threats and attacks that an SE or generally an NFC device can be exposed to will be mentioned and some will also be described and some possible threats and attacks against Soft-SE. In addition, a few pros and cons of applying Soft-SE will be discussed. The analysis is based on how a user can get more out of the existing SE instead of applying the Soft-SE. Based on the facts, pros and cons, and the analysis that has been treated, it has been concluded that the Soft-SE is not a more secure alternative than the SE that is already used by NFC phones. Since Soft-SE is still new, it has not yet developed to protect themselves against the possible attacks that they may be exposed to. It is strongly recommended that users of Google Wallet adhere to the Secure Element that the smartphone use instead of applying Soft-SE. / Dagen forskare förutser att inom en snar framtid kommer majoriteten av ägarna till smarttelefon använda den som sin plånbok, det vill säga använda sig utav kontaktlös betalning. Tekniken som möjliggör kontaktklös betalning idag är närfältkommunikation (Engelska: “Near Field Communication” - NFC) som finns inbäddad i smarttelefoner. Applikationer som mobila betalningar mellan en telefon och terminal använder sig av NFC. Vid mobila betalningar sparas användarens kredit- och bankinformation och det är ytterst viktigt för en användare att dess sparade data inte kommer i fel händer. Hur ska då en användare av NFC vara säker på att säkerhetsutvecklingen går hand i hand med NFC-tekniken? Kan en användare känna sig tillräckligt säker för att spara sina privata handlingar på telefonen utan att bli bestulen? NFC använder sig utav ett säkerhetselement (Engelska: “Secure Element” - SE) som erbjuder användaren säkerhet vid alla mobilköp men även i andra applikationer som till exempel färdmedelsbiljetter. Säkerhetselementet kommer i tre olika former: SD-kortbaserat, SIM-kortbaserat eller inbäddad i smarttelefonen. Med tiden har tekniken bakom SE vidareutvecklats och ett nytt fenomen har uppstått, nämligen ett nytt slags säkerhetselement. Den nya tekniken är ett applikationsbaserat säkerhetselement: mjukvarubaserad kortemulering (Engelska: “Software Card Emulation” - Soft SE), som erbjuder säkerhet utan ett fysiskt SE. Denna avhandling kommer behandla säkerhetselementets område och se över om Soft-SE är så pass säker att vi kan räkna det som ett alternativ vid våra mobilköp i affären. Ett antal hot och attacker som ett SE eller allmänt en NFC-enhet kan utsättas för kommer att nämnas och en del kommer även att beskrivas samt möjliga hot och attacker mot Soft-SE. Utöver det kommer ett par för- och nackdelar med att tillämpa Soft-SE att diskuteras. Analysen är baserat på hur en användare kan få ut mer av den existerande SE istället för att tillämpa Soft-SE. Utifrån fakta, för- och nackdelar och analysen som har behandlats drogs slutsatsen att Soft-SE inte är ett säkrare alternativ än den SE som redan används av NFC-telefoner. Eftersom Soft-SE fortfarande är något nytt har den inte ännu utvecklats tillräckligt för att skydda sig mot de möjliga attacker som den kan utsättas för. Det är starkt rekommenderat att användarna av Google Wallet håller sig till det säkerhetselement som smarttelefonen använder sig utav istället för att tillämpa Soft-SE.

New environmental regulations as well as the increasing industrial competitiveness have set new more demanding rules on the manufacturing industry. In order to abide by those rules not only from the legal point of view but also to be able survive, manufacturing has to be more sustainable from many aspects, especially the economical one. One way to achieve the previous target is an unfortunately often oversighted aspect of the industry sector, the maintenance strategy. Condition based maintenance, CBM, can be used successfully in the industry and accurate estimation of spindle life time can lead to large savings in downtime and cost. CBM requires accurate sensors and equipment in order to get the right indicators whether equipment performance is deteriorating or not. One performance factor when planning a machining process is chatter vibration and one way to avoid this deteriorating phenomenon is to choose cutting parameters that allow stable machining. Various types of sensors are available for vibration and other CBM related measurements. Depending on the situation, the most applicable sensor is selected. The core of this thesis is to investigate the usefulness of measurements with the contactless excitations and response unit in terms of condition based maintenance. In the first part of the thesis, some of the theoretical aspects of maintenance are extensively elaborated upon and later on, the experimental part is presented along with the results’ discussion. The hardware required by the experiments has been provided by KTH and the experiments took place in two of an automotive industry’s production sites. There have been two visits at site A and one at site B, apart from the initial meetings. The measurements have been analyzed with the use of MATLAB. / Nya miljöregler samt ökande industriell konkurrens har satt nya mer krävande regler för tillverkningsindustrin. För att följa dessa regler, inte bara ur rättslig synpunkt utan också för att kunna överleva, behöver tillverkningen ske mer hållbar ur många aspekter, särskilt den ekonomiska. Ett sätt att uppnå målen är via, en tyvärr ofta underskattad metod, underhållsstrategin. Tillståndsbaserat underhåll, CBM, kan användas med framgång inom branschen och korrekt uppskattning av spindellivstid kan leda till stora besparingar genom minskade driftstopp och kostnader. CBM kräver noggranna sensorer och utrustning för att få rätt indikatorer för att avgöra om utrustningens prestanda försämras eller ej. En prestationsavgörande faktor vid planering av bearbetningsprocesser är vibrationer. Ett sätt att undvika dessa försämrade fenomen är att välja skärparametrar som tillåter stabil bearbetning. Olika typer av sensorer finns tillgängliga för vibrations- och andra CBM-relaterade mätningar. Beroende på situation, väljs den mest lämpliga sensorn. Kärnan i denna rapport är att undersöka nyttan av mätningar med en beröringsfri excitations- och mätenhet för tillståndsbaserat underhåll. I de första avsnitten av rapporten redogörs några av de teoretiska aspekterna av underhåll och i de senare är den experimentella delen presenterad, tillsammans med diskussion kring resultat. Hårdvaran som krävs för experimenten har tillhandahållits av KTH och experimenten ägde rum på två produktionsanläggningar hos en fordonstillverkare. Det har varit två besök på plats A och ett besök på plats B, bortsett från inledande möten. Mätningarna har analyserats med hjälp av MATLAB.