This thesis is the result of the investigation and solution of a mechanicalproblem regarding flywheel malfunctions. A flywheel is, in short, a devicethat relies on a rotating object?s moment of inertia to store energy overshort time spans. This project is part of the development of a fourthflywheel prototype at the division for electricity at Uppsala university,which uses magnetic levitation to keep a hollow cylinder rotating at veryhigh speeds inside a vacuum chamber. Should the magnets fail however, orsome other error occur that leads to an uncontrolled state of rotation, thecylinder needs to be stabilized mechanically by a device usually referredto as ?back-up bearing?.

Good comfort for the driver of a construction machine is crucial. Gearshift comfort is an important part of the total comfort. Volvo Construction Equipment Components has a simulation environment of the powertrain, SimPow, which is implemented in Matlab/Simulink. SimPow is mostly used for simulation of control strategies and performance. In order to be able to study gearshifting comfort, Volvo has an interest in developing new models for SimPow.

Nordic Light AB tillverkar armaturer för bland annat butiker och utställningar. För att kunna avgöra vilken armatur som behövs för en viss applikation och för att se hur en viss armatur lyser har kunder efterfrågat fotometriska filer av formatet EULUMDAT. Fotometriska filer innehåller bland annat information om armaturers ljusfördelning. Den utrustning som Nordic Light AB använder i sitt ljuslabb kan mäta belysningsstyrkan i lux på en kvadratisk yta och sedan sparas mätvärden i en textfil med x- och y- koordinater samt belysningsstyrkor. Detta examensarbete har utförts för att ta reda på vad en fotometrisk fil av formatet EULUMDAT innehåller och om det med Nordic Light AB: s befintliga utrustning går att ta fram en sådan fil.

Detta examensarbete är utfört på ITT W&WW i Sundbyberg, Sverige, i samarbete med KTH, Instutitionen för Maskinkonstruktion. Arbetet har gått ut på att finna parametrar som kan användas för att detektera sörpling i en pump. Arbetet har fokuserat på att undersöka om vibrationer och ljud kan ge information om när pumpen sörplar eller ej, samt att utveckla en algoritm baserat på dessa parametrar.När en pump pumpar en blandning av luft och vatten kallar man det att den sörplar. Detta innebär slitage på pumpen samt energiförluster, då verkningsgraden minskar betydligt. Detta är ett problem för bland annat dräneringspumpar inom gruv- och byggindustrin där permanenta installationer och externa sensorer för att undvika sörpling ofta saknas.

Today small metal parts are mass-produced as for example rollers in cylinder bearings. At high velocity cutting the metal is cut with a great force in a scissor-like device. Both precision and repeatability is important to be able to guarantee good quality, but from an economical point of view it is also important to keep a great manufacturing capacity. The part of the process that is most time consuming is when the metal bar, that is about to be cut, is fed to the right position. Therefore it is interesting to examine if the time used for positioning can be reduced.

This thesis work has been performed at the department of diagnosis and dependability at Volvo Car Company, Torslanda. The background of this project is based on interest in ascertaining how different factors possibly can affect a diagnosis method, which has been developed to find leaks in the fuel tank and evaporation system. According to the OBD II requirements leaks with an orifice diameter larger or equal to 0,5 mm, must be detected. The idea of the diagnosis method is to create an over pressure in the system with an air-pump. The current through the pump is measured and correlates to the power consumed by the pump.

This is a thesis presents a differential gear which is found in a tracked vehicle called BvS10. The tracked vehicle is manufactured by BAE Systems Hägglunds AB in Örnsköldsvik, Sweden. The differential gear has a bolted house. The differential meets the requirement specifications, but the problem is that the bolts are sheared off because of the extreme torque that the differential is exposed to resist.Previous report on the differential show pictures of bolts which have been sheared off at the threads. This report is also includes three lists that explain seven different proposals which some are approved and some are not, and the report also presents the force, tensile, and shear stress.In a bolted connection there is both axial tension stress and radial shear stress, which can lead to wear out and broken bolts.

Långtidsbehandling med ventilator utan tillräcklig befuktning kan torka ut en patients luftvägarmed olika komplikationer som följd. Målet för detta examensarbete var att utveckla en ny teknikför att befukta och värma inandningsgasen. Ett fungerande koncept och en prototyp som styrkerkonceptet skulle tas fram.Marknaden för befuktare studerades och de vanligast använda befuktningsmetoderna granskadesför att hitta svagheter som behövde åtgärdas. De två vanligaste befuktartyperna är HeatedHumidifier och Heat and Moisture Exchanger. Den främsta nackdelen med Heated Humidifiervar dess tendens att övermätta luften med kondensutfällning som följd, och med Heat andMoisture Exhanger att inte tillräckliga fukt- och temperaturnivåer nåddes.Därför togs en ny design fram med målet att kunna styra fukt och temperatur oberoende avvarandra.

To achieve the requirements to decrease emissions of greenhouse gases by 20 % by 2020, Swedenneeds to increase its use of bioenergy. In doing so it seems natural that those who already haveaccess to large amounts of biofuels in the form of by-products such as straw, wood chips anddigestible materials take advantage of these assets locally. By combining production of heat withpower production at the farm it may be possible to not only reduce the direct use of fossil fuel forheating but also reduce energy costs.The purpose was to simulate different cases of using a small scale biofueled combined heat andpower plant for farm-based systems. A Matlab-model was developed and used to draw conclusionsabout the costs for production of heat and electricity with different conversion technologies.The model uses climate data to simulate the variations in heat energy demand on a day-to-day basis.The given heat demand is the base of the simulation and from this the possible electric output iscalculated. This study has focused on the impact of the following properties: electric-, heat- andtotal efficiency, fuel, fuel price and specific fuel requirements.

Unmanned aerial vehicles (UAV?s) are nowadays greatly appreciated. The advantage over manned airplanes are great since UAV?s can be much smaller and therefore lighter. The goal of this project is to evaluate the performance of an environmentally friendly UAV using only lithium-ion batteries.

Detta examensarbete har utförts på Saab Training Systems (STS) AB i Huskvarna. Arbetet handlar om metodik och utrustning för mätning av ström och energiförbrukning på Saabs batteridrivna apparater, nämligen SAT och SAAD.Nuvarande mätutrustning klarar inte av de tekniska kraven som STS ställer. Därför behövs det ett instrument eller en metod som generellt kan mäta energiförbrukningen på Saabs batteridrivna enheter. Problemet är att strömmen till apparaterna varierar kraftigt från några mikroampere till flera hundra milliampere i en väldigt kort tidsperiod.Arbetet har genomförts som en teoretisk utredning men innehåller också praktiska mätningar på Saabs SAT och SAAD för att undersöka vilka svårigheter som kan uppstå vid mätning. Dessutom har två förslag på lösningar presenterats.

We have different kinds of signal processing everywhere around us in our everyday life, in our cellphones, when we are listening to music, watching TV etc. This makes signal processing a very interesting and important technical area, where the demand of skilled engineers sets the limit of what is possible.Working with signal processing requires in-depth knowledge in areas such as mathematics, physics, electronics, and other related areas. For this, it has traditionally been demanded by a talented developer to also master the advanced programming languages such as C / C + + and Assembler.This has begun to change; today there are several companies that offer graphical development environments for signal processing, environments where programming skills are not needed anymore, and the focus can be on signal processing instead.The goal with this project is to build a corresponding graphical development environment to reach an understanding of what is required of these systems, and also to grasp what opportunities that are available within graphic programming. Inspiration for the work has partly arise from some of the tools available on the market, and partly from previous theses that have been written about graphic programming.The challenge lies in creating a program that can execute signal diagrams in real time from given signal blocks, and be able to handle feedback loops in an efficient way and to do so at the lowest "cost" in terms of clock cycles as possible. This should also be compared against to code, compile and run a complete signal diagram directly.To increase the usability it should also be possibility to externally manage in real time the parameters of the signal diagram during execution.The interface is a separate program, which is to some extent similar to Matlab Simulink, where a signal diagram is drawn up graphically by connecting wires between different signal blocks.

I detta examensarbete har ett problem som varit en del av ett pågående projekt på ElektaInstrument AB undersökts och en lösning har föreslagits.Problemet har varit att utveckla och modellera en servoenhet som med hög precision kanpositionera ett instrument i fem dimensioner (tre translaterande och två roterande) och som kanhålla instrumentet på sin position med hög styvhet.Problemet löstes genom att först specificera kraven på servoenheten, sedan undersöktes olikabefintliga koncept för att uppnå kraven. Det bästa konceptet, en Stewart-Gough plattform, valdesoch studerades och analyserades sedan i detalj.Analysen gjordes i två steg, det första steget var att göra beräkningar av krafter och benlängdersom en funktion av positionen för en Stewart-Gough plattform. Det andra steget var att realiseraberäkningarna och implementera dessa i kod och hårdvara för att styra fysiska motorer och fådem att bete sig som önskat enligt beräkningarna.Resultatet av första delen av analysen är ett Matlab program som kan beräknainverskinematiken och benkrafterna för en godtycklig Stewart-Gough plattform som belastasmed en godtycklig kraftvektor och en godtycklig momentvektor. Programmet kan även itereraberäkningarna för olika lägen för Stewart-Gough plattformen och för olika belastningar ochskriva ut extremvärdena som beräknats.Den andra delen av analysen resulterade i ett LabView program för simultan styrning av sexmotorer och hårdvara för att driva sex motorer. Styrningen har testats på befintliga motorer medlyckat resultat.Resultaten av examensarbetet visar att Stewart-Gough plattformen kan uppfylla kraven som ärställda på servoenheten.

ITT Flygt is a world leading company that mainly manufactures submersible pumps. A problem of ITT Flygt is that product development projects rarely manage to hold the estimated project time. It shows that something unexpected occurs in projects quite often, which results in delays. The delays can both be due to an optimistic time plan of projects and risks in product development projects which are not discovered at an early stage. This added with unforeseen delays makes it difficult for ITT Flygt to estimate the duration of their projects.The goal with the Master thesis is to examine a suitable method for simulation of project time.

This thesis has been a part of Forsmarks Kraftgrupp AB's evaluation of a turbulencemodel used in simulation of turbulent flow called PRNS (Partially Resolved NumericalSimulation). This model has promising properties and may be of use in savingcomputational resources. The purpose of this thesis was to analyze this model andcompare it with industrially applied models such as k-omega SST and LES (Large EddySimulations).PRNS works as a hybrid of the k-omega SST and DNS (Direct Numerical Simulation)where a constant, RCP (Resolution Control Parameter) with a value between 0 and 1are selected. This constant is then used in the calculations and determines thebehavior of the simulation. When RCP is set to zero the equation are the same as fora DNS simulation and when RCP is set to one the equations for k-omega SST issolved.