Radio-frequency identification(RFID)is the wireless use of electromagnetic fields to transfer data, for the purpose of automatically identifying and tracking tags attached to objects. It is one of hot topics recently. The power supply is one of key factors restricting the lifetime and performance of RFID. The main focus is to power RFID system with clear power source. In this work, a harvester consisting of a matching network, a rectifier and a load is investigated. The operation of a Schottky diode based rectifier which is the core part inthe harvester is researched seriously. The Schottky diode based rectifier consistingof single-stage or multi-stage of voltage doublers is applied in radio frequency (RF) power harvesting.Analytical modeling of the equivalent circuits composedof a resistor and a capacitor. The resistor and the capacitor from the analytical modeling are applied in the simulation of impedance matching. The design trade-off among the stages of the voltage doubler, load of the harvester, the output voltage and the efficiency is discussed owing to the variation of input impedance with the input power. Moreover, a trade-off betweenthe load inthe harvester and the stages of the voltage doubler is stated based on the analysis of the simulation resultsby Advanced Design System (ADS)with the criteria that the output voltage is higher than 1V.Some conclusions about the harvester are obtained by the simulation and analysis. The sensitivity of the harvester is around -23dBm. Rectifiers with more stages have lower input impedance and lower speeds of variation in input impedance. Larger loading impedance in the harvester leads to higher output voltage but lower conversion efficiency. Four-stage voltage doubler and 5M ohm load should be chosen when the input power ranges from -23 to -20dBm. Two-stage voltage doubler with 500k ohm load is a better choice with input power between -20 and -15dBm. For input power from -15 to -5dBm, single-stage voltage doubler and 50k ohm are utilized. When the input power is larger than -5dBm, two-stage voltage doubler and 50k ohm should be chosen.

Articulated vehicles are widely used in the economically vital cargo industry as they provide a greater maneuverability than their rigid counterparts. Hence, autonomous driving systems for articulated vehicles have become the subject of intense research in the robotic community. This thesis analyzes the reverse motion of an articulated vehicle, namely a tractor-trailer with one on-axle hitched semitrailer, and develops a full autonomous driving system that enables reverse parking in the presence of static obstacles. The motion controller used in the autonomous driving system is based on a two-level feedback control system, with a path stabilization controller in the first level and a hitch angle controller in the second level. The path planner used is a modified RRT planner where the Dubins path has been incorporated in order to enable the planning towards a goal pose rather than merely a goal region. The modifications made have resulted in several improvements, such as more accurate planning and higher computational efficiency. Using a 1:32 scale remote controlled tractor-trailer, and a Qualisys motion capture system for pose estimation, the autonomous driving system was successfully implemented and validated.

In this thesis two cooperative control strategies are designed for a team of two indoorquadrotors and some human-vehicle interaction tasks are developed. First, theprocess of assembling a quadrotor from parts is undertaken. Then, a controller for asingle quadrotor is designed, and implemented using LabView software. Matlab softwareis used to generate the desired trajectories. A LabView software module actsas a supervisor, allowing the coordination between the two vehicles. Two types ofcooperative control are developed: position-based, and position/velocity-based. Bothcontrol strategies allow the quadrotors to follow a reference trajectory while maintaininga specified formation. Furthermore, some tasks are developed where one quadrotorresponds to online stimuli given by a human via a user-friendly interface.

In this work, a mathematical model of a quadrotor’s dynamics is derived, usingNewton’s and Euler’s laws. A linearized version of the model is obtained, andtherefore a linear controller, the Linear Quadratic Regulator, is derived. Afterthat, two feedback linearization control schemes are designed. The first one isthe dynamic inversion with zero dynamics stabilization, based on Static FeedbackLinearization obtaining a partial linearization of the mathematical model.The second one is the exact linearization and non-interacting control via dynamicfeedback, based on Dynamic Feedback Linearization obtaining a total linearizationof the mathematical model. Moreover, these nonlinear control strategiesare compared with the Linear Quadratic Regulator in terms of performances.Finally, the behavior of the quadrotor under the proposed control strategies isobserved in virtual reality by using the Simulink 3D Animation toolbox.

The current trend in the cellular networks to reduce the amount of spectrum dedicated toGSM networks put a burden on the radio access part to keep the promised quality of service.In addition to the focus of operators on other radio access technologies and data networkshave raised the need to direct most of the effort towards other activities. Subsequently newtechniques are needed to compensate for the lack of time and resources to keep GSMnetworks as optimized as possible.The handover functionality is in the heart of any cellular system. It is more important whendelay is not tolerated. Therefore, the choice of its parameters is important. These parametersare chosen based on network performance and traffic load patterns among other criteria. It isa time consuming task, and investigating in a way to automatically choose appropriatesettings for its parameters is desired.This work investigates the possibility of such an automated procedure. A simulationenvironment is developed in order to run simulations. An automated function that utilizesthe principles of control theory, optimization, and live networks statistics is developed andused to build an algorithm to regulate the settings of the handover procedure.By regulating four parameters from the handover procedure, and by introducing differenttraffic loads, frequency reuse and mobility patterns, while testing the results against a set ofperformance metrics in the simulator. The results show better network performance in termsof performance metrics when the regulating algorithm is applied than when manuallychoosing values of these four parameters. However, further investigation shows that thealgorithm under an aggressive mobility pattern imitating a high speed moving users, mightneed a stopping rule. The algorithm tries to find a better network performance even if thecurrent metrics are acceptable. This appears to be invalid approach under some aggressivemodels.

This thesis presents a Multi-Stage Network Processor as part of independentsupervisory control in HVDC grid connecting AC areas.The proposed Network Processor finds the topology of the grid building the AdjacencyMatrix, identifies islands and assigns DC slack bus. The approach consists of twolevels: 1) process of DC substation topology locally and 2) the secondary process atHVDC grid central supervisory controller.At the substation level, the Local Processor determines the branch/bus model of thesubstation including the possible standalone HVDC converters using breakers’ status.Substation Matrix holds information regarding the model of the part of substationconnected to DC grid, while Standing Alone Matrix is created when the converter inthe substation is not connected to DC grid. The same analysis is performed on all thesubstations locally and then the Substation Matrixes are sent to the Central Processorat SCADA level.At central level, the processor creates the global Adjacency Matrix for the wholeHVDC grid.For the islands detection, the corresponding Laplacian Matrix is built from theAdjacency Matrix and a clustering method is used to analyze eigenvectors of theLaplacian Matrix.The proposed Network Processor has been successfully tested using a 7-terminalsHVDC grid model.Besides, an extended version of current algorithm has been studied for the integratedand, with some restriction, for the distributed HVDC supervisory control architecture. This master thesis project has been completely studied and developed at the departmentof Industrial Information and Control Systems at KTH - Royal Institute of Technologyin Stockholm.

unicationtechnologies, the millimeter wave (mmWave) bands are consideredas a promising candidate to extremely high data rate access in futurewireless networks. MmWave communications exhibit high attenuations,vulnerability to obstacles, and sparse-scattering environments. The smallwavelengths of mmWave signals make it possible to incorporate many antennaelements both at the transmitters and at the receivers, which lead tohigh antenna gains. This demands a reconsideration of almost all designaspects in mmWave networks compared to the traditional networks, especiallyat the medium access control (MAC) layer. Blockage affects heavilythe performance of mmWave networks. How to model blockage and itsimpacts on the key performance indicators are largely open problems.In this thesis, a new blockage model is introduced, which allows evaluatingthe impact of penetration loss due to obstacles on the fundamental performanceindicators including achievable throughput and delay. Using thisblockage model, the achievable throughput and delay of two solution approachesto overcome blockage, namely fallback and relay, is investigated.The analysis highlights an interesting correlation between blockage periodand the importance of using one technique or the other one. Afterwards, adelay analysis is proposed to focus on more realistic scenarios. Such an analysisis then used to characterize the throughput-delay tradeoff. The lattersection allows to explore the impact of the main network parameters suchas beamwidth, obstacle occurrence, blockage period, transmission time andalignment overhead. A general framework is proposed, in which it is shownunder which condition which option is preferable, from throughput-delayperspective, at the transmitter to mitigate the blockage problem. Moreover,it shows the situations under which these two techniques are notfeasible in order to fulfil some throughput-delay requirements. Simulationsare presented in order to validate the equations used at the performanceanalysis.

Detta examensarbete kommer att studera hur en virtuell driftsättning skulle skapas till Gävle högskolans Kuka robotar, var två stuider utförs. Den första studien skapar olika simuleringar med industriprocesser genom att använda Offline programmerings (OLP) programmen KukaSim 4.0 och Visual Components Premium 4.4. Dessa simuleringar överförs till en Virtual reality (VR) simulering genom att använda högskolans Oculus rift VR-utrustning och installera mjukvarorna SteamVR, Oculus och Visual Components Experience 1.6 (VC Exp) där det blir möjligt att kunna interagera och se simuleringen genom VR, se Fig. (1). Sedan till den andra studien har man utrett hur själva simuleringen ska kunna kopplas upp till den fysiska Kuka roboten där man går in på kommunikations-gränssnitt. Med Visual Components Premium 4.4 som har tillgång till Open Platform Communications Unified Architecture (UPC UA) klient som sedan kopplas upp till UPC UA server genom Siemens SIMATIC TIA Portal V16. Från UPC UA nätverket installerar man JOpenShowVar vilket gör det möjligt att kommunicera med en Java-klienten och UPC UA nätverket, därefter installeras KukaVarProxy till Kukas robotkontrollern som kommunicera med Java-klienten. Genom dessa steg kommer dataövering ske från simuleringen till den fysiska Kuka roboten.

The term reliability is related with the adequacy and security during operation of theelectric power system, supplying the electricity demand over time and saving thepossible contingencies because every inhabitant needs to be supplied with electricity intheir day to day. Operating the system in this way entails spending money. The first partof the project is going to be an analysis of the reliability and the economic impact of it.During the last decade, electric utilities and companies had been forced to change theiroperations from vertically integrated to open market systems. With the deregulation ofthe electricity industry, the way of operating the system has changed. During the pastyears the idea was basically to supply the demand required from the costumers, but theworld ideas are becoming more ecological, where every process is trying to beoptimized, in this case the emissions are more controlled and the resources are usedwith more efficiency. Nowadays the new wave of ideas is making the costumersparticipants of the electric power systems. This can be done by the participants by4reducing their load, or by a reschedule in their activities, being rewarded withincentives. Thus, during this research an electric power system is going to be assessed,evaluating if it is feasible to include demand response in the electricity market.The project includes a simulation with GAMS of an electric power system, and therewill be six different programs being developed with the same network. Firstly, the threeproblems are going to be developed including reliability, and the second step will bewhen DR is included. The aim of the thesis it is an assessment of the reliabilityeconomic impact and an analysis of the outcomes when demand response it is included.

The eciency of today's aftertreatment system relies on the exhaust gas temperature.The Selective Catalytic Reduction system, which is a part of theaftertreatment system has an operating temperature window which starts atapproximately 200C in order to work as eciently as possible. Rolling downhillwithout burning fuel could cause the exhaust aftertreatment system to cooldown below this window, which gives higher emissions when burning fuel again.This thesis focuses on investigating the potential of using the exhaust brake, athrottle between the turbine and the exhaust aftertreatment system, in slopesand investigates and evaluates possible strategies. The exhaust brake is controlledusing Model Predictive Control with models of acceleration and temperaturewith respect to exhaust brake pressure, mass and road incline. Dierentstrategies are investigated and it is concluded that controlling the exhaust braketo keep constant velocity down the slope gives the highest temperature at theexhaust aftertreatment system. It is also concluded that there is no strategywhich could guarantee the exhaust aftertreatment temperature to stay withinthe temperature window just using the exhaust brake. / Eektiviteten av dagens efterbehandlingssystem forlitar sig pa att avgasernaar inom ratt temperaturomrade. SCR-katalysatorn, som ar en del av efterbehandlingssystemet,har en arbetstemperatur som borjar vid ca 200 C. Narfordonet rullar utfor utan att forbranna bransle sa kan efterbehandlingssystemetkylas ner under arbetstemperaturen, vilket ger hogre utslapp vid forbranningav bransle igen. Detta examensarbete fokuserar pa att undersoka mojligheternaatt anvanda avgasbromen, en ventil mellan turbin och avgasefterbehandlingssystemet,i sluttningar och undersoka mojliga strategier. Avgasbromsen styrs medhjalp av prediktiv modellbaserad reglering vilket innehaller modeller av accelerationoch temperatur i forhallande till avgasbromstryck, massa och vaglutning.Olika strategier utreds och slutsatsen ar att det basta resultatet uppnas genomatt styra avgasbromsen for att halla konstant hastighet i backen. Men det nnsingen strategi dar endast avgasbromsen anvands som kan garantera att efterbehandlingtemperaturenhaller sig inom arbetsomradet.