<p>State estimation deals with estimation of the state of an object of interest by observing noisy measurements. The process to obtain the state estimations is called filtering. In this report several filters are compared to an existing one. The new filters deal with nonlinear process and measurement models in a different way than the existing filter. Instead of approximating the nonlinear transformations the probability densities are approximated by a set of points which undergo the nonlinear transformation.</p><p>The application for which the filters will be used is to estimate the position and orientation of a camera in a markerless environment, using data from an inertial measurement unit and a camera. It is found that the corresponding process and measurement models contain nonlinearities and therefore an accuracy improvement is expected with the new filters.</p><p>The new filters are variations of the so-called unscented Kalman filter. Also a discussion on the marginalized particle filter is presented. Instead of using randomly chosen samples as in the particle filter methods, the unscented Kalman filter uses deterministically chosen points. The marginalized particle filter partitions the variables of the system in a linear and a nonlinear part. Linear Kalman filters are applied to the linear variables and a particle filter to the nonlinear variables, thus reducing the computational load. Details of various implementations of the filters are given, as well as the motivation for the specific implementations.</p><p>Tests are carried out to assess the performance of the filters. This is done with both simulation data and real measurements. A comparison is made to the original extended Kalman filter. The tests are focussed on accuracy and computational load.</p><p>Results showed that the use of the new filters did not improve accuracy. This is mainly due to the fact that the nonlinearities are not so severe. Furthermore the filters had a higher computational load, which is an important aspect in the system reviewed in this report. Therefore the current filter need not to be replaced. The unscented Kalman filter is a good alternative to the EKF in case of new applications, since it can handle the system in a black-box manner in contrast to the EKF.</p>

<p>Under examensarbetet på Luftfartsverket i Norrköping har beräkningar, mätningar och teoretiska analyser gjorts på parallella seriesystem. Detta har givit kunskap om kablarnas uppbyggnad och användning samt induktiva kopplingen mellan de parallella kablarna. All nödvändiga fakta bygger på mina observationer och anteckningar från dessa beräkningar och teoretiska analyser. Utifrån teoretiska analyser och Maxwellsekvationer skall flera frågeställningar besvaras under förutsättningen att undersöka de för- och nackdelar som skärmade kablar ger gentemot oskärmade kablar i ett personsäkerhetsperspektiv och med avseende på störningskänslighet. Kalkyler har tagits ifrån olika litteratur, vilket har resulterat till olika uträkningar på skärmade kablar och oskärmade kablar. Sedan har de olika beräkningarna jämförts med praktiska mätningar som utfördes ute på två flygplatser, nämligen Norrköpings flygplats (med typen oskärmade kablar) och Jönköpings flygplats (med typen skärmade kablar). Personsäkerheten kunde sedan klarläggas utifrån resultaten av såväl beräkningar som mätningar. Resultaten och slutsatser har tagits fram enligt olika matematiska presentationer och teoretiska analyser, då jämförandet mellan skärmade och oskärmade kablar har gjords. Reduktionsfaktor ger en storlek på hur effektivt skärmen är, dvs. för en kabel utan metallmantel är reduktionsfaktorn k=1. Om kabel däremot omsluts av en metallskärm, är reduktionsfaktorn kə. Reduktionsfaktor: 0.9995 (Utan jordade brunnar) Reduktionsfaktor: 0.91 (Med jordade brunnar) Reduktionsfaktor: 0.82 (Mätningar) Med hänsyn till resultaten ser man att reduktionsfaktorn är mindre än 1 för alla tre ovan nämnda, vilket innebär att kabeln är en ganska bra skärm. Samtidigt är reduktionsfaktorn ganska nära 1, vilket indikerar att skillnaden mellan skärmade och oskärmade kablar inte är stort. Detta leder till att man i praktiken inte bör räkna med någon reduktion. Beräkningarna och mätningar som har gjords på inducerad spänning och inducerad ström indikerar att den induktiva kopplingen mellan de parallella kablarna är låg. Den inducerade spänningen blev 14V och inducerade strömmen 156mA för oskärmad kabel och 12V samt 80mA för skärmad kabel.</p>

<p>Skew in telecommunication normally means the difference in arrival time of bits transmitted at the same time in differential transmission. As an increasing of transmission data bit rate and more importantly, a data and clock signal rise time of become faster, digital system interconnects became behaving as transmission line. The high speed signals become microwave in nature. The problem is that modern digital designs and verifications require knowledge that has formerly not been needed for a data bit rate of below than 100Mbit but also at the higher frequency range as 5 to 15GHz, however, most references on the necessary subjects are too abstract to be immediately applicable to the skew. For this reason a new method to investigate the skew were introduced, and with which, test board were measured. Since the test boards are made in devise material, and lines on the boards are configured out in distinct structures. In this paper, several methods were applied to find out the skew, and by comparing the results, it could be found that how factors affect the skew, not only the material factor, but some manufactory reason.</p>

<p>This study was initiated to investigate if it could be feasible to supply offshore oil installations in the North Sea with electrical power from land. A prestudy of alternative converter topologies indicated that the most promising solution would be to investigate a conventional system with reduced synchronous compensator rating.</p><p>The study starts with a summary of the state of power supply to offshore installations today, and a short review of classical HVDC transmission. It goes on to analyse how a passive network without sources influences the inverter. The transmission, with its current controlled rectifier and large inductance, is simulated as a current source. Under these circumstances the analysis shows that the network frequency has to adapt in order to keep the active and reactive power balance until the controllers are able to react. The concept of firing angle for a thyristor is limited in a system with variable frequency, the actual control parameter is the firing delay time.</p><p>Sensitivity analysis showed some astonishing consequences. The frequency rises both by an increase in the active and in the reactive load. The voltage falls by an increase in the active load, but rises by an increase in the inductive load.</p><p>Two different control principles for the system of inverter, synchronous compensator and load are defined. The first takes the reference for the firing delay time from the fundamental voltage at the point of common coupling. The second takes the reference for the firing delay time from the simulated EMF of the synchronous compensator. Of these, the second is the more stable and should be chosen as the basis for a possible control system.</p><p>Two simulation tools are applied. The first is a quasi-phasor model running on Matlab with Simulink. The other is a time domain model in KREAN. The time domain model is primarily used for the verification of the quasi-phasor model, and shows that quasi-phasors is still a valuable tool for making a quick analysis of the main features when the details of the transients are of less importance.</p><p>The study indicates that power supply by HVDC transmission from land to offshore oil installations could be technically feasible, even without the large synchronous compensators normally required. It has been shown that in a network only supplied by an inverter, variations of active and reactive loads have significant influence on both voltage and frequency. Particularly it should be noted that the frequency shows a positive sensitivity to increases in load. This could make the system intrinsically unstable in the case of a frequency dependent load such as motors.</p><p>It was not a part of the study to optimize controllers, but even with simple controllers it was possible to keep the frequency within limits given by norms and regulations, but the voltages were dynamically outside the limits, though not very far. These voltage overswings take place in the first few instances after a disturbance, so it takes unrealistically fast controllers to handle them. They are partly due to the model, where the land based rectifier and the DC reactors are simulated by a constant current source, but partly they have to be handled by overdimensioning of the system.</p><p>The simulations indicate that it should be technically possible to supply an oil platform with electrical power from land by means of HVDC transmission with small synchronous compensators. Whether this is financially feasible has not been investigated. Neither has it been considered whether the necessary equipment can actually be installed on an oil platform.</p><p>Recently both ABB and Siemens have presented solutions for HVDC transmission in the lower and medium power range based on voltage source converters based on IGBTs. Fully controllable voltage source HVDC converters have properties that may be better suited than conventional line commutated current source thyristor inverters, to supply weak or passive networks, such as offshore oil installations, with electrical power. But they also have some disadvantages, and a complete technical and financial comparison must be performed in order to decide about any potential project.</p>

<p>An effective way to extract combustion parameters from a spark ignited engine is to measure the level of ionization. One way to do this is to use the spark plug as a sensor.</p><p>Until now this has been achieved by applying a DC voltage over the spark gap which causes an electrical field. The electrical field together with the ionization process gives cause to an ion current which can be measured and analyzed. Previous research suggests that it would be beneficial to replace the DC voltage with an AC voltage.</p><p>The focus in this thesis is on the hardware and how to best implement an AC voltage to the existing ion sensing system. Both simulation- and hardware models will be constructed. These models will be tested and analyzed to evaluate both benefits and drawbacks of an AC ion current sensing system.</p>

<p>Detta projekt är utfört vid Kvaerner Kamfab AB i Karlstad och beskriver hur strukturering av företagets elsystem har utförts i form av uppmärkning och dokumentation. Detta skall ligga till grund för en effektivisering vid ombyggnation av ställverket.</p> / <p>The assignment has been to label and document Kvaerner Kamfab’s electrical system. This is the first phase of reconstructing the switchgear in order to increase the efficiency.</p>

<p>Vår uppgift var att ta fram en algoritm för hur lastens massa förhåller sig till hydraultrycket i ett hydraulsystem för en truck. Algoritmen skulle sedan implementeras i en vågprototyp. Lösningen skulle vara kostnadseffektiv.</p><p>För att undersöka sambandet utfördes mätserier där vi provade olika komponenter. Resultatet av mätserierna analyserades och vi fann ett samband mellan massan och hydraultrycket. Med hjälp av sambandet kunde sedan programkod för en vågprototyp skrivas tillsammans med tillhörande funktioner.</p><p>Resultatet blev en fungerande vågprototyp för trucken som användes. Denna prototyp behöver dock testas och utvärderas ytterligare på fler truckar innan en eventuell slutprodukt kan bli aktuell.</p> / <p>Our task was to develop an algorithm for the relationship between mass and hydraulic pressure in a hydraulic system in a forklift. The algorithm was then to be implemented in a prototype of a forklift scale. The solution had to be cost-effective.</p><p>To examine the relationship we performed series of measurements in which various components were tested. The results of the measurements were analyzed and we found a correlation between mass and hydraulic pressure. Due to this we could write a code for a forklift scale prototype with features.</p><p>The forklift scale prototype worked on the forklift that we used but it needs to be tested and evaluated further in more forklifts before a final product can be made.</p>

Currently there are very significant interests in printed electronics in the world. The possibility to produce electronics in a roll to roll printing process will considerably reduce the cost of the electronic devices. However, these new devices will most probably not replace the traditional silicon based electronics, but will be a complement in low cost applications such as in intelligent packages and other printable media. One interesting area is printable low cost sensors that add value to packages. In this thesis a study of the performance of low cost sensors is presented. The sensors were fabricated using commercial printing processes used in the graphical printing business. The sensors were characterized and evaluated for the intended application. The evaluated sensors were moisture sensing sensor solutions and touch sensitive sensor solutions. A printable touch sensitive sensor solution is presented where the sensor is incorporated into a high quality image such as in point of sales displays. The sensor solution showed good touch sensitivity at a variety of humidity levels. Four printed moisture sensor concepts are presented and characterized. Firstly, a moisture sensor that shows good correlation to the moisture content of cellulose based substrates. Secondly, a sensor that measures the relative humidity in the air, the sensor has a measuring accuracy of 0.22% at high relative humidity levels. Thirdly, a moisture sensor that utilizes unsintered silver nano-particles to measure the relative humidity in the air, the sensor has a linear response at very low relative humidity levels. And fourth, an action activated energy cell that provides power when activated by moisture. A concept of remote moisture sensing that utilizes ordinary low cost RFID tags has also been presented and characterized. The remote sensor solution works both with passive and semi-passive RFID systems. The study shows that it is possible to manufacture low cost sensors in commercial printing processes. / Det är för närvarande ett stort intresse för tryckt elektronik. Att kunna tillverka elektroniska komponenter i en rulle till rulle process möjliggör en reducering av tillverkningskostnaden. Dessa nya komponenter kommer sannolikt inte konkurrera ut den traditionella kiselbaserade elektroniken utan kommer att kunna komplimentera kiselelektronik i segment där kostnaden är väldigt viktig som i intelligenta förpackningar och andra tryckta medier. Ett intressant område är tryckta sensorer som kan addera värde till förpackningar. I denna avhandling presenteras en studie kring tryckta sensorer som kan tillverkas till låg kostnad. Sensorerna är tillverkade i kommersiella grafiska tryckpressar. Sensorerna karakteriseras och utvärderas för de applikationer som de är tänkta för. I denna avhandling har fuktsensorer och beröringskänsliga sensorer undersökts. Det presenteras en tryckt beröringskänslig sensor som integreras i ett högkvalitativt grafiskt tryck. Denna sensor är tänkt att användas i reklamskyltar för att skapa interaktivitet. Sensorn har en bra känslighet vid varierande fukthalter. Även fyra fuktsensorer presenteras och utvärderas. Den första sensorn mäter fukthalten i cellulosabaserade substrat och visar en bra korrelation till fukthalten i substratet. Den andra sensorn mäter den relativa fukten i luften, denna sensor har en mätnoggrannhet på 0.22% för höga fukthalter. Den tredje sensorn använder partiklar i nanostorlek för att mäta fukthalten i luften. Denna sensor fungerar väldigt bra vid låga fukthalter. Den fjärde sensorn är en energicell som producerar el när den blir fuktig. Även en fuktsensor som kan läsas av på håll utvärderas. Detta sensorkoncept är baserad på vanliga RFID taggar och kan användas med både passiva och semi-passiva taggar. Denna avhandling visar att det är möjligt att tillverka sensorer till en låg kostnad in en traditionell grafisk tryckpress.

This study was initiated to investigate if it could be feasible to supply offshore oil installations in the North Sea with electrical power from land. A prestudy of alternative converter topologies indicated that the most promising solution would be to investigate a conventional system with reduced synchronous compensator rating. The study starts with a summary of the state of power supply to offshore installations today, and a short review of classical HVDC transmission. It goes on to analyse how a passive network without sources influences the inverter. The transmission, with its current controlled rectifier and large inductance, is simulated as a current source. Under these circumstances the analysis shows that the network frequency has to adapt in order to keep the active and reactive power balance until the controllers are able to react. The concept of firing angle for a thyristor is limited in a system with variable frequency, the actual control parameter is the firing delay time. Sensitivity analysis showed some astonishing consequences. The frequency rises both by an increase in the active and in the reactive load. The voltage falls by an increase in the active load, but rises by an increase in the inductive load. Two different control principles for the system of inverter, synchronous compensator and load are defined. The first takes the reference for the firing delay time from the fundamental voltage at the point of common coupling. The second takes the reference for the firing delay time from the simulated EMF of the synchronous compensator. Of these, the second is the more stable and should be chosen as the basis for a possible control system. Two simulation tools are applied. The first is a quasi-phasor model running on Matlab with Simulink. The other is a time domain model in KREAN. The time domain model is primarily used for the verification of the quasi-phasor model, and shows that quasi-phasors is still a valuable tool for making a quick analysis of the main features when the details of the transients are of less importance. The study indicates that power supply by HVDC transmission from land to offshore oil installations could be technically feasible, even without the large synchronous compensators normally required. It has been shown that in a network only supplied by an inverter, variations of active and reactive loads have significant influence on both voltage and frequency. Particularly it should be noted that the frequency shows a positive sensitivity to increases in load. This could make the system intrinsically unstable in the case of a frequency dependent load such as motors. It was not a part of the study to optimize controllers, but even with simple controllers it was possible to keep the frequency within limits given by norms and regulations, but the voltages were dynamically outside the limits, though not very far. These voltage overswings take place in the first few instances after a disturbance, so it takes unrealistically fast controllers to handle them. They are partly due to the model, where the land based rectifier and the DC reactors are simulated by a constant current source, but partly they have to be handled by overdimensioning of the system. The simulations indicate that it should be technically possible to supply an oil platform with electrical power from land by means of HVDC transmission with small synchronous compensators. Whether this is financially feasible has not been investigated. Neither has it been considered whether the necessary equipment can actually be installed on an oil platform. Recently both ABB and Siemens have presented solutions for HVDC transmission in the lower and medium power range based on voltage source converters based on IGBTs. Fully controllable voltage source HVDC converters have properties that may be better suited than conventional line commutated current source thyristor inverters, to supply weak or passive networks, such as offshore oil installations, with electrical power. But they also have some disadvantages, and a complete technical and financial comparison must be performed in order to decide about any potential project.

Although photonic devices have experienced a rapid development lately, there is still room for substantial improvements in performance. From a telecommunications perspective, improvements in speed, size, integration and power consumption are desired. There is also a general interest in photonic devices with new functionalities. Being a key component in fiber-optic systems, high-speed optical modulators often initiate the development towards higher bit-rates. The technology of current state-of-the-art modulators has matured suggesting new paths of development. In this thesis we investigate the potential of modulators based on intersubband (IS) transitions in quantum wells (QWs). Specific QW designs are suggested and complete modulator structures are simulated. IS absorption is also experimentally characterized. Absorption linewidth is critical for IS modulator performance since narrow linewidth implies high bandwidth and/or small driving voltage. High material quality is important, since linewidth is typically limited by well-width fluctuations and interface roughness. A mid-IR AlGaAs/GaAs-modulator is proposed having a RC-limited bandwidth of 130 GHz and a peak-to-peak voltage of 0.9 V. Experimentally, Stark shift is measured in InAlAs/InAlGaAs/InGaAs step QWs at λ ~ 6 μm predicting that an IS modulator based on this material would have a bandwidth of 90 GHz and a peak-to-peak voltage of 0.9 V. IS absorption at 1.55 μm requires material combinations with high conduction-band offset. Simulations of an InGaAs/InAlAs/AlAsSb-modulator predict a bandwidth of 90 GHz and a peak-to-peak voltage of 2.0 V. Experimental studies of IS absorption in AlN/GaN QWs are presented. IS absorption at 1.5-3.4 μm with linewidth below 100 meV is measured for well widths between 15-54 Å. Subpeaks corresponding to well-width fluctuations on the monolayer scale are identified with linewidths of ~60 meV. Agreement between theoretical calculations and measured spectra is encouraging. Theoretical simulations together with measured absorption linewidths suggest that high performance IS modulators operating at 1.55 μm are realizable. Photonic devices with new functionalities are addressed by investigating electromagnetically induced transparency (EIT) theoretically and considering potential applications based on EIT. Simulations of two-dimensional pulse-propagation based on the Maxwell-Bloch equations are performed with a focus on storing and reading out optical pulses. We explicitly formulate the phase-matching conditions for reading out stored pulses in a new direction and propose a serial-to-parallel converter based on this. For slow-light devices, e.g. optical buffers, we identify and analyze two main limitations on the medium bandwidth; the frequency dependent absorption and the group velocity dispersion. Since large bandwidth and large delay are contradictory requirements, the delay bandwidth product is considered. Analytical expressions are derived and analyzed and verified by simulations on pulse propagation. Insertion of parameters relevant for semiconductors indicates that development of materials with long coherence times are necessary for realizing optical buffers based on EIT. / QC 20100903