The Switched Reluctance Motor (SRM) inherits a simple and reliable structure with an economical manufacturing cost. The DC power output supplies the unipolar converter to control the pulses sent to SRM. Thus, the velocity and torque are controllable for various velocity commands, and the SRM is gaining more and more applications on high torque requirement field with constant power. This paper proposes a DSP based hybrid sensor for switched reluctance motor with easy implementation. The current transducer is used to monitor the energized current and proximity sensors for rotor salient. The signals are then fed back to DSP. This design will improve the performance of SRM to operate more smoothly.

Magnesium alloys have one of the highest specific strengths of all construction metals used. Specifically, magnesium alloy castings are used in the aerospace industry to reduce the weight of aerospace vehicles. Coating systems must be employed to prevent corrosion of these magnesium alloys as they are also the most corrosion prone construction metals. The use of chromium is employed for the conversion coating which forms the foundation of many of these coating systems. In an effort to phase these harmful chromates out of the coating system and continue to use magnesium alloys, an environmentally friendly conversion coating has been developed. This paper explores the best types of methods used to evaluate the thickness and coating coverage of the environmentally friendly conversion coating. Destructive and nondestructive techniques are developed to examine the thickness and surface coverage of this environmentally friendly coating. Specifically an eddy current measurement technique, light, confocal, scanning electron and transmission electron microscopy techniques are used to determine the coating thickness of the environmentally friendly coating through destructive evaluation. Three nondestructive evaluation techniques, including polarized light microscopy, infrared spectroscopy (Fourier Transform and Raman) and an infrared proximity sensor are used to determine surface coverage of the environmentally friendly coating.

Observing the relative state of two space vehicles has been an active field of research since the earliest attempts at space rendezvous and docking during the 1960's. Several techniques have successfully been employed by several space agencies and the importance of these systems has been repeatedly demonstrated during the on-orbit assembly and continuous re-supply of the International Space Station. More recent efforts are focused on technologies that can enable fully automated navigation and control of space vehicles. Technologies which have previously been investigated or are actively researched include Video Guidance Systems (VGS), Light Detection and Ranging (LIDAR), RADAR, Differential GPS (DGPS) and Visual Navigation Systems. The proposed system leverages the theoretical foundation which has been advanced in the development of VisNav, invented at Texas A & M University, and the miniaturized commercially available Northstar sensor from Evolution Robotics. The dissertation first surveys contemporary technology, followed by an analytical investigation of the coarse sun sensor and errors associated with utilizing it in the near-field. Next, the commercial Northstar sensor is investigated, utilizing fundamentals to generate a theoretical model of its behavior, followed by the development of an experiment for the purpose of investigating and characterizing the sensor's performance. Experimental results are then presented and compared with a numerical simulation of a single-sensor system performance. A case study evaluating a two sensor implementation is presented evaluating the proposed system's performance in a multisensor configuration. The initial theoretical analysis relied on use of the cosine model, which proved inadequate in fully capturing the response of the coarse sun sensor. Fresenel effects were identified as a significant source of unmodeled sensor behavior and subsequently incorporated into the model. Additionally, near-field effects were studied and modeled. The near-field effects of significance include: unequal incidence angle, unequal incidence power, and non-uniform radiated power. It was found that the sensor displayed inherent instabilities in the 0.3 degree range. However, it was also shown that the sensor could be calibrated to this level. Methods for accomplishing calibration of the sensor in the near-field were introduced and feasibility of achieving better than 1 cm and 1 degree relative position and attitude accuracy in close proximity, even on a small satellite platform, was determined.

Abstract Users of mobile devices induce detrimental electrical effects on the antenna when devices are operated in close proximity to either the head, hand or fingers. A totally covered antenna can suffer over 10 dB gain loss and force an increase in the output power of the device, which additionally causes shorter battery life and higher emissions in terms of the specific absorption rate (SAR) and hearing aid compatibility (HAC). The user effect can be minimized with compensation methods such as active antenna tuning or a spatial antenna selection. In this thesis, capacitive proximity sensors are investigated in order to provide new characteristics for user effect compensation. The thesis has three parts. In the first, hand positions along the device chassis are measured with the antenna integrated capacitive sensor. The results are in proportion to the induced hand loss in the antenna. Secondly, discrete electrode sensors are studied as hand and single finger proximity recognition and are found to have a good performance in applications. Thirdly, weaknesses of integrated and discrete sensors are evaluated. The discrete sensor had an induced low antenna loss of 0.05–0.20 dB in the 1–2 GHz bands. In contrast, the integrated sensor caused radio interference in proper GSM channels, decreasing the sensitivity of the radio receiver. The capacitive sensor is able to sense the user proximity effect regardless of antenna matching, which may be changed in a complex manner when more than one electrical resonance is used in the same frequency band or when the matching is modified mainly by the resistive component. In multiple-antenna applications, capacitive sensors are able to maintain up-dated information of user loads of all antennas. Combining the results, the discrete electrode sensors fulfilled the technical and operational objectives of this thesis. They are able to detect a single finger or other user objects, they have low losses and they can be located in such a way that will not consume extra room in mobile devices. / Tiivistelmä Kannettavien päätelaitteiden käyttäjät aiheuttavat sähköisiä häviöita laitteen antennissa kun laitetta käytetään käden, pään tai sormien läheisyydessä. Kokonaan peitetyn antennin häviö voi olla yli 10 dB, mikä johtaa laitteessa lisääntyneeseen tehontarpeeseen, lyhyempään pariston kestoon ja korkeampiin haitta-arvoihin SAR ja HAC mittauksissa. Käyttäjän vaikutusta voidaan minimoida kompensaatiotekniikoilla kuten antennin säädöllä ja -valinnalla. Tässä työssä kapasitiivisia antureita tutkittiin uusien käyttäjävaikutuksen kompensaatiotekniikoiden löytämiseksi. Työ jakaantuu kolmeen osaan. Ensimmäiseksi käden sijainti laitteen rungon suhteen on mitattu kapasitiivisella anturilla. Nämä tulokset ovat verrannollisia käden aiheuttamaan kuormaan antennissa. Toiseksi erillisiä antureita tutkittiin käden ja sormien havaitsemiseksi hyvällä menestyksellä eri sovelluksissa. Kolmanneksi arvioitiin antennin integroidun ja erillisen anturin heikkouksia. Erillisen anturin aiheuttama häviö antenniin oli 0.05–0.20 dB 1–2 GHz taajuuskaistalla. Vastaavasti integroitu anturi aiheutti radiohäiriöitä tietyillä radiokanavilla, mikä heikentää vastaanottimen herkkyyttä. Kapasitiivinen anturi havaitsee käyttäjän läheisyyden riippumatta antennin sovituksesta. Sovitus voi muuttua monimutkaisesti kun useampaa sähköistä resonanssia käytetään samalla taajuuskaistalla tai sovitukseen vaikuttaa sähköisesti resistiivinen kuorma. Moniantennirakenteissa kapasitiiviset anturit voivat tuottaa jatkuvaa informaatiota käyttäjän aiheuttamasta kuormasta eri antenneissa. Erilliset kapasitiiviset anturit täyttivät ne tekniset ja toiminnalliset vaatimukset, jotka työlle aluksi asetettiin. Niillä voidaan havaita yksittäinen sormi tai muu kohde, ne ovat pienihäviöisiä, ja ne voidaan sijoittaa tilaa säästävällä tavalla nykyisiin päätelaitteisiin.

There has been an enormous growth in the usage of smartphones in recent times. Smartphones are not limited to communication purposes. It has various applications designed as per the daily requirements of humans such as web-searching, online shopping, bank transactions, games, etc. With the increase in the usage of the smartphone, the more useful information is captured and stored by it, which raises the question of security. The goal of this research is to develop two android applications. One is a sensor detector application and the second is a screen lock application. The first application will help the user to identify all the hidden sensors and working sensors on the mobile phone. This application even describes the features and usage of every sensor in detail. Using a graphical description of each sensor which depicts the behaviour of each sensor as per environment/movement. The second application is designed using a combination of two sensors. Screen lock applications contain two main factors. One is to work properly in all cases and efficiently do the functions that are required to do. The second is to maintain a smooth inner system interaction because in addition to locking the screen this application should make sure to hide the display of all the other applications without closing the process of these applications. With the increase in the usage of the smartphone, it becomes difficult for older generations to memorize the security pattern techniques and use them. This thesis develops a simple technique in the mobile authentication android application. The thesis is developed on the Android studio platform. The background functionality of the app is coded in java using android SDK tool and frontend of the application is designed using XML files. The GENYMOTION emulator and a mobile phone are used to test the output.

We use autonomous line-following robots in various industrial environments, surveillance applications, and construction and mining industries for object transportation tasks where rail, conveyer, and gantry solutions are unavailable. They help us reduce the work process and improve efficiency. In this report, we will illustrate how a 2WD robot can move on a predefined path and detect obstacles along the way. In this project, we have used a proximity sensor to detect the obstacle in the path and turn the robot from the obstacle. Also, we used an IR sensor so that robot could follow along the predefined path. The used in the project sensors were connected to Arduino UNO, which was programmed to control the robot's movements and decisions. By employing these two techniques, we can efficiently use such robots in various scenarios. For example, in the current Covid scenario, physical contact has become minimal, so if we use this line-following robot to deliver medicines to the patient, the physical contact between people can be reduced. The obstacle avoidance robot technique can be used in cars to improve safety. If an obstacle is detected in the path of the car and the driver does not apply the brakes, this type of technique can be used to bring the car to a stop by applying breaks. Using the proposed robotic techniques we can save time and work efficiently with minimal physical touch. Overall, the project achieved its primary goal of moving the robot on a predefined path and detecting obstacles on the path

Our earths resources are not endless, so it is important to avoid wasting our planets natural resources. Recycling metal saves 95% more energy than producing new metal from ore, which is why it is necessary to reuse metal. Waste sorting is very important in today’s modern society as the demand for metals is increasing at a rapid rate. Landfills are overfilled, lots of energy is required to mine ore and produce metal’s, thus metals should be used sparingly and recycled. Considering all these aspects, we felt an urgent need to look into other methods to make recycling metal easier. The most common way waste sorting is done in today’s society is manually. We are trying to make it automatic to have a higher percentage of correct sorts and to make it easier and faster for consumers to sort their waste. The purpose of this project is to construct a prototype which will automatically sort metal and non-metal waste. By using an inductive proximity sensor, the prototype will be able to distinguish if the object is made of metal. Using a stepper motor, two waste bins, one for metal objects and the other for non-metal objects, will rotate depending on if the inductive proximity sensor gives a signal or not. Ultrasonic sensors were used to detect if an object was present and needed to be sorted. Two ultrasonic sensors gave an increase of 118% accuracy in comparison to using only one ultrasonic sensor. The purpose of the project is achieved, resulting in an automatic waste sorter that is user-friendly and can assist the user in daily waste sorting. However this prototype is limited to objects smaller than 65 millimeters in diameter, and in future work the prototype could be expanded. / Vår planets resurser är inte oändliga och därför är det nödvändigt att undvika slöseri av vår planets naturresurser. Att återvinna metall sparar 95% mer energi än att producera ny metall från malm, därför är det nödvändigt att återanvända metall. Avfallssortering är mycket viktigt i dagens samhälle då efterfrågan på metaller ökar i snabb takt. Deponier är överfyllda, mycket energi krävs för att bryta malm och producera metaller, därför bör metaller användas sparsamt och återvinnas. Med tanke på alla dessa aspekter kände vi ett akut behov av att undersöka andra metoder för att göra återvinning av metall enklare. Det vanligaste sättet att sortera avfall i dagens samhälle är manuellt. Vi försöker göra det automatiskt för att få en högre andel korrekta sorteringar och för att göra det enklare och snabbare för konsumenterna att sortera sitt avfall. Syftet med detta projekt är att konstruera en prototyp som automatiskt sorterar metall- och icke-metall avfall. Genom att använda en induktiv närhetssensor kan prototypen urskilja om föremålet är gjort av metall eller inte. Med hjälp av en stegmotor kommer två avfallskärl, en för metallföremål och en för icke-metallföremål, att rotera beroende på om den induktiva närhetssensorn ger en signal eller inte. Ultraljudssensorer användes för att upptäcka om ett föremål fanns i behållaren och behövde sorteras. Två ultraljudssensorer gav en ökning på 118% noggrannhet jämfört med att endast använda en ultraljudssensor. Syftet med projektet har uppnåts, vilket har resulterat i en automatisk avfallssorterare som är användarvänlig och kan hjälpa användaren i dens dagliga sopsortering. Denna prototyp är dock begränsad till föremål som är mindre än 65 millimeter i diameter, och i framtida arbeten kan prototypen utökas.

[pt] Este trabalho apresenta resultados do comportamento do sensor de proximidade indutivo em medição de oscilação de geradores hidroelétricos do sistema de geração de FURNAS CENTRAIS ELÉTRICAS S.A. Para o desenvolvimento deste estudo, foram utilizados dois (2) sensores de proximidade indutivos. A metodologia consistiu em calibrar estaticamente e dinamicamente o sensor de proximidade indutivo. Para isto, foi utilizada a giga de teste: um sistema composto por um motor com velocidade variável e tendo acoplado a seu eixo um disco com excentricidade variável e controlada. Ajustou- se a excentricidade da giga de teste e foram marcados pontos no disco de 30° em 30°. Foi feita a calibração estática da giga de teste, medindo o deslocamento em cada um destes treze (13) pontos com um relógio comparador calibrado. Para a calibração estática do sensor, este foi posicionado à frente do disco da giga de teste a uma distância conhecida, deslocou-se o eixo manualmente para cada um dos pontos e obteve-se o sinal de saída do sensor com o analisador de sinal calibrado. A curva de calibração estática foi então determinada com a respectiva incerteza de medição. Para a calibração dinâmica, o mesmo sistema foi posto em rotação nas velocidades nominais dos geradores hidroelétricos de FURNAS CENTRAIS ELÉTRICAS S.A. (90 rpm, 120 rpm, 150 rpm e 180 rpm). A resposta do sensor foi então comparada nas diferentes rotações, com o que se determinou a atenuação do sinal devido ao aumento da freqüência de operação. Os dados obtidos estaticamente e dinamicamente foram avaliados, e as incertezas determinadas. As calibrações estáticas realizadas pelo procedimento de FURNAS e deste trabalho produziram os mesmos resultados, considerando a faixa de incerteza de medição. Para reduzir a incerteza de calibração do procedimento de FURNAS, propõe-se que seus resultados sejam ajustados por um polinômio do segundo grau. A calibração dinâmica realizada em várias freqüências mostrou que não existe diferença entre os valores obtidos estaticamente e dinamicamente, muito embora esta tenha uma incerteza mais elevada. Para simplificação da calibração dos sensores, propõe-se que ela seja, portanto, realizada estaticamente. / [en] This work presents the results of the behavior of the inductive proximity sensor at the measurement of oscillation in hydroelectric generators from the generation system of Furnas Centrais Elétricas S.A.. To develop this study, two (2) inductive proximity sensors were used. The methodology consisted of calibrating statically and dynamically the inductive proximity sensor. For this, it was used a test mockup: a system composed by an engine with variable speed and a disc with variable and controlled eccentricity connected to the axle. The eccentricity of the test mock-up was adjusted and thirteen (13) points were marked on the disc, every 30°. The static calibration of the test mock-up has been made, by measuring the displacement in each one of these thirteen (13) points with a calibrated dial indicator. For the static calibration of the sensor, the sensor itself was positioned in front of the test mock-up disc at a known distance, the axle was dislocated manually for each one of the points and the output signal of the sensor was measured with a calibrated signal analyzer. The curve of the static calibration then was determined with the respective uncertainty of the measurement. For the dynamic calibration, the same system was run in the nominal speeds of the hydroelectric generators from Furnas Centrais Elétricas S.A. (90 rpm, 120 rpm, 150 rpm and 180 rpm). The response of the sensor was then compared at the different rotations, being determined the attenuation of the signal due to the increase of the operation frequency. The static and dynamic data were evaluated, and the uncertainties determined. The static calibrations carried through by the procedure of FURNAS and by this work produced the same results, considering the range of measurement uncertainty. To reduce the calibration uncertainty of the FURNAS procedure, it is proposed that its results be adjusted by a polynomial of second degree. The dynamic calibration carried at several frequencies showed that there is no difference between the static and dynamic values, even though the dynamic calibration has a more elevated uncertainty. To simplify the calibration of the sensors, it is proposed then that it is carried statically only.

Clinical trials are experiments or observations on a patient’s responses of different medical treatments to cure diseases. Such trials are heavily regulated and must achieve a certain quality standard of the trial and clinical adherence is a determining factor on the success of a study. However, it has historically been difficult to systematically follow and understand patient adherence to medical ordinations, predominately due to lack of proper tools. One new type of tools is a digital pillbox that can be used to supply pills to participants in clinical trials. This paper examines implementing two supervised machine learning models to detect if an object (a pill) is found in an encapsulated compartment (pillbox) based on electromagnetic radiation data from a proximity sensor. Support Vector Machine (SVM) and Random Forest (RF) were evaluated on a data set of N=1,485 observations, consisting of five classes: four different pills and ‘no pill’. RF performs best with accuracy of 98.0% and weighted average precision of 98.0%. SVM had 97.3% accuracy and 97.6% weighted average precision. Best performance was achieved at N=1,000 for RF and 1,100 for SVM. The conclusion was that a high accuracy and precision can be achieved using either RF or SVM. The classification model strengthens the value proposition of a digital pillbox and can improve clinical trials to achieve better data quality. However, for the model to contribute actual economical value, digital pillboxes must be a common practice in clinical trials. / Kliniska studier är experiment eller observationer av en patients reaktion på olika typer av medicinsk vård för behandling sjukdomar. Sådana studier är tungt reglerade och behöver uppnå en viss kvalitésstandard och klinisk följsamhet är en avgörande faktor för en studies framgång. Trots det har det historiskt varit svårt att systematiskt mäta och förstå en patients följsamhet av en medicinsk ordination, primärt på grund av brist av användbara verktyg. En ny typ av verktyg är en digital  pillerbox som försörjer piller till deltagare i kliniska studier. Denna studie undersöker implementation av två bevakade maskininlärningsmodeller för detektion om ett objekt (ett piller) befinner sig i ett slutet fack baserad på elektromagnetisk strålning från en närhetssensor. Support Vector Machine (SVM) och Random Forest (RF) utvärderades på ett dataset av N=1 485 observationer utgjort av fem klasser: fyra piller och ’inget piller’. RF presterar bäst med 98,0% i träffsäkerhet och 98,0% i viktad medelprecision. SVM fick 97,3% träffsäkerhet och 97,6% viktad medelprecision. Bäst prestation uppnåddes vid N=1 000 för RF och N=1 100 för SVM. Slutsatsen var att en hög träffsäkerhet och precision kan uppnås genom antingen RF eller SVM. Klassificeringsmodellen förstärker en digital pillerbox värdeerbjudande och kan hjälpa kliniska studier att uppnå högre datakvalité. Däremot, för klassificeringsmodellen ska bidra med faktiskt ekonomiskt värde, behöver digitala pillerboxar vara en vedertagen praxis.

The objective of this work is to enhance and advance sensing technologies with the design and development of novel radio frequency (RF) sensors based on far-field and near-field principles of the electromagnetic (EM) resonances. In the first part of this thesis, original design and development of a passive RF temperature sensor, a passive RF strain sensor, and a passive RF pressure sensor are presented. The RF temperature sensor is presented in Chapter 3. It is based on split ring resonators loaded with bimorph cantilevers. Its operating principles and equivalent circuits are discussed in Chapter 4, where the design concept is illustrated to be robust and highly adaptable to different sensing ranges, environments, and applicable to other type of sensing beyond temperatures. The passive RF strain sensor, based on a patch antenna loaded with a cantilever-integrated open loop, is presented in Chapter 5, where it is demonstrated to have the highest strain sensitivity in the same remote and passive class of sensors in the state-of-the-art. Chapter 6 describes the passive RF pressure sensor, which is based on a dual-band stacked-patch antenna that allows both identification and sensing to be embedded in its unique dual resonant responses. In the second part of this thesis, an original and first-of-its-kind RF transducer is presented that enables non-touch sensing of human fingers within 3 cm of proximity (based on one unit sensor cell). The RF transducer is based on a slotted microstrip patch coupled to a half-wavelength parallel-coupled microstrip filter operating in the frequency range of 6 – 8 GHz. The sensing mechanism is based on the EM near-field coupling between the resonator and the human finger. Fundamentally different from the electric field capacitive sensing, this new method of sensing, the first of its kind, based on near-field interference that produces a myriad of nonlinearities in the sensing response, can introduce new capabilities for the interface of electronic displays (the detection is based on pattern recognition). What set this sensor and its platform apart from previous proximity sensors and microwave sensing platforms is the low profile planar structure of the system, and its compatibility with mobile applications. The thesis provides both breadth and depth in the proposed design and development and thus presenting a complete research in its contributions to RF sensing.