In Guinea Bissau, one of the third most underdeveloped countries, there are many areas that are hard to reach by any other kind of vehicles than motorcycles – cars struggle with the poor road conditions. This means that many smaller communities, that are at a considerable distance from a larger road or city, become isolated and vulnerable. When the water pumps break down, one of the main issues in the repair process is that the pump mechanics simply struggle to transport their tools and spare parts to these areas. The consequence is that the water pumps are left broken and out of use and people go back to using the water holes instead, where the water normally is of significantly worse quality and often contaminated. This leads to sickness, diseases and loss of workforce in the entire country. This project aims to develop a prototype of a monotrailer that can be used by the pumpmechanics in Guinea Bissau. A monotrailer is a transport vehicle which is attached behind a motorcycle. Motorcycles have very limited loading options, but with a monotrailer the possibilities can be extended. The road conditions are rough, the area of usage is hard to define and the manufacturing possibilities are limited. Given this, the challenges of this project is to develop the monotrailer in a way that it can be manufactured on site and fulfil its purpose. The project has been carried out in both Stockholm aa well as in Guinea Bissau and is acooperation between KTH and Unicef Wash Section. / I Guinea Bissau, som är ett av världens tredje mest underutvecklade länder, finns många landområden som är svåra att nå med något annat fordon än motorcyklar – vägarna är så undermåliga att bilar har stora svårigheter att ta sig fram. Det innebär att många mindre samhällen och byar som ligger på betydande avstånd från en större väg eller stad, blir isolerade och lätt hamnar i en sårbar position. När vattenpumpar i byarna går sönder, har det visat sig att ett av de största problemen kring reparationsprocessen är att pumpmekanikerna helt enkelt har svårt att transportera sina verktyg och reservdelar till dessa platser. Påföljden blir att vattenpumparna står oanvända och befolkningen återgår till att hämta vatten i vattenbrunnarna, där vattnet är av betydligt sämre kvalitet och ofta kontaminerat. Detta ledertill ohälsa, sjukdomar och bortfall av arbetskraft i hela landet. Detta projekt syftar till att utveckla en prototyp av en monotrailer för bruk av pumpmekaniker i Guinea Bissau. En monotrailer är ett transportfordon som fästs bakom en motorcykel. Motorcyklar har väldigt begränsade lastmöjligheter och med en monotrailer kan dessa utökas. Vägförhållandena är tuffa, användningsområdet för monotrailern är svårt att definiera och tillverkningmöjligheterna är begränsade. Givet detta, ligger därför utmaningen i detta projekt att utveckla monotrailern så att den går att tillverka på plats och fyller sitt syfte. Projektet har utförts både i Stockholm och på plats i Guinea Bissau och är ett samarbetemellan KTH och Unicef Wash Section.

One of the weapons used on the Visbykorvett is a machine gun (KSP 88). The machine gun need’s regular maintenance and that is usually done on the floor at shooting platform or the weapon is carried down into the ship to a suitable location. This is both unergonomic and impractical, which is why the Swedish Armed Forces have built a prototype of a weapons service table. This prototype does not meet all the requirements, but it was used extensively and it confirmed that a weapon service table is needed. That is why the Swedish Armed Forces, the Swedish Defence Materiel Administration and the company Mildef have created this opportunity for a master thesis. In this project, two research questions have been formulated that’s going to be answered: How can a table be designed to handle heavy loads while still being portable?  How should a table be designed to be transported by one person? To answer these research questions, several concepts were developed and two of these were worked on for a longer period of time. What became clear towards the end of the project was that there was an optimal design for each research question and the requirement to handle high load was given the highest priority when design was chosen. / En av vapnerna som används på Visbykrovetterna är ett maskin gevär (KSP 88). Maskin geväret är i behov av regelbunden service och det görs oftast på durken vid skjutplattformen eller så bärs vapnet ner i skeppet till en lämplig plats. Detta är både oergonomsikt och opraktiskt därför har Försvarsmakten byggt en prototyp på ett vapenvårdsbord. Denna prototyp uppfyller inte alla de krav som ställs på bordet, men det har används flitigt och det har bekräftat att ett vapenvårdsbord behövs. Därför har Försvarsmakten, Försvarets materielverk och företaget Mildef skapat denna möjlighet för ett examensarbete. I detta projekt har det formulerats två stycken forskningsfrågor som ska besvaras:  Hur bör ett bord konstrueras om den ska hantera hög belastning och samtidigt vara portabelt? Hur ska ett bord utformas för att transporteras av en person?  För att besvara dessa forskningsfrågor togs det fram flera koncept och två av dessa arbetades med under längre tid. Det som framgick i mot slutet av projektet var att det fanns en optimal design för vardera forskningsfråga och kravet på att hantera hög belastning fick högst prioritering när designen valdes.

Traffic congestion in large urban and metropolitan areas is a substantial problem plaguing these areas. Not only are commuters losing valuable time, but greenhouse gas emissions are substantially worse because of congestion. Considerable research and development into next generation electrified aircraft is ongoing to introduce air mobility as a viable new means of transporting people and goods across long commutes. This development extends into commercial aviation as a whole as a means of reducing the industry’s carbon footprint with new aircraft designs that employ electrified propulsion systems. Many electrified aircraft projects are currently underway, ranging from small commuter aircraft all the way to large twin-aisle aircraft, and part of the development scope for alot of these projects is creating highly robust and power dense electric machines that replace the current state-of-the-art. The axial flux permanent magnet synchronous machine is an exciting candidate for aircraft propulsion due to its exceptional torque density and compact axial nature. In this thesis, the mechanical design for three generations of axial flux permanent magnet synchronous machines is discussed. These machines serve as development phase prototypes for machines that are ultimately intended for propulsion applications in commercial aviation, particularly for eVTOL aircraft. The motivation for electrification in the commercial aviation industry is discussed, followed by an overview of the development landscape for electrified propulsion systems in commercial aviation, focusing primarily on electric machines that are currently state-of-the-art or are set to be in the near future, as well as what is required for future electric machines in terms of power output and power density. The axial flux architecture is then presented, including a high-level comparison to the radial-flux architecture, an overview of the various axial flux machine designs and topologies, and a discussion of the inherent mechanical design challenges associated with the axial flux architecture. The yokeless and segmented armature axial flux permanent magnet synchronous machine design was selected for the machines developed as part of the research for this thesis, and the discussion of the mechanical design of these machines is broken up into the two core sub assemblies: stator assembly and rotating assembly. High-level design methodologies are introduced for both sub-assemblies, which is further broken down into different approaches pertaining to each generation. The first and second generation designs are presented at a high level, followed by deep-dives into the complete mechanical design for the third generation stator, the bearing selection, arrangement, and analysis for the third generation rotating assembly, and adhesive characterization trials used to guide adhesive selection for rotor magnetics retention in the second and third generation machines. The current status of the machines and any outcomes from testing that has been conducted thus far, particularly with respect to performance, is presented at the end. / Thesis / Master of Applied Science (MASc)

No description available.

Novige develops a wave energy converter (WEC) concept that utilizes wind-generated wave to create electricity. The system uses a float and a hydraulic cylinder to pump water up to a turbine, similar to an inverted hydro power plant. The penstock system that delivers the fluid to the turbine was optimized for efficiency and a theoretical efficiency of the penstock was calculated. The penstock and the surrounding components were updated to a commercial size. The longer cylinder resulted in a larger loss from the hydrostatic pressure. The optimal pipe diameter was calculated by comparing the friction loss and the additional weight resulting from a larger pipe. For the penstock the piping elements were compared and chosen for a higher efficiency. The penstock system can be optimized for efficiency by using pipe elements with lower coefficients of loss. It is more efficient to divert the flow as little as possible, while maintaining the same flow velocity throughout the system. Losses can be reduced by choosing the optimalpipe diameter size, therefore making the penstock as light as possible, while also reducing thepipe friction. The hydrostatic pressure from the height of the cylinder is the largest source of lossin the system. The efficiency of the redesigned penstock was found to be 93.7%. / Novige utvecklar ett vågkraftverks koncept som utnyttjar vindvågor för att generera elektricitet. Systemet använder sig av en flotte och en hydraulisk cylinder för att pumpa vatten upp till en turbin, det kan liknas vid ett inverterat vattenkraftverk. Tilloppstuben som leder vattnet till turbinen optimerades för effektivitet och den teoretiska effektiviteten av tilloppstuben beräknades. Tilloppstuben och de omgivande komponenterna uppdaterades för den kommersiella varianten. Den längre cylindern resulterade i större förluster på grund av det hydrostatiska trycket. Den optimala rör diametern beräknades genom att jämföra friktions förlusterna och de förluster som uppstår på grund av större rör vikt. Olika rörelementen i tilloppstuben jämfördes och valdes med avsikt på effektivitet. Effektiviteten i tilloppstuben kan optimeras genom att välja rörelement med lägre förlustfaktor. Det är mer effektivt att dela på flödet så lite som möjligt och behålla samma flödeshastighet genom hela systemet. Förlusterna kan minskas genom att välja den optimala rördiametern, vilket ger en så låg vikt som möjligt samtidigt som friktionsförlusterna i röret reduceras. Det hydrostatiska trycket från höjden av cylindern är den största orsaken till förlust i systemet. Effektiviteten av det nya tilloppstubs systemet är 93.7%.

<p>As a cost-effective, healthy, and environmentally friendly personal mode of transportation, electric bicycles (E-bikes) are gaining an increasing market share from conventional bicycles and automobiles. Considering the legal rules in Ontario, Canada, a 500W motor makes the E-bike more attractive for travelling use. At the same time, the simple structure, high torque and power density, as well as the low cost of the switched reluctance machine (SRM) makes it a strong candidate for E-bikes.</p> <p>In this thesis, a 3-phase, external-rotor SRM with 6 stator poles and 10 rotor poles is designed for E-bike. The design of an external rotor arrangement of the 6-10 SRM topology has not previously been reported, hence it offers a new contribution to the published works. The machine design is initiated by the output power equation and is followed by a comprehensive finite element analysis (FEA). The external-rotor arrangement is chosen to facilitate ease of integration into the wheel hub structure of a typical pedal bicycle. The increasing rotor poles yield improved torque ripple reduction than more conventional (i.e. 6-4, 12-8 etc.) SRM design, which is an essential feature for low speed rider comfort.</p> <p>A new torque ripple reduction control scheme is investigated. Although the comparison shows that the torque sharing function has more positive result than angular position control with regards to torque ripple, this is at the expense of higher losses. Detailed thermal analysis ensures this machine is suitable to require no additional cooling system. The final machine design is experimentally tested via a full system prototype. Results highlight some limitation of the 2-D FEA in terms of the winding inductance calculation. Here, the end winding introduce more influence on short thickness machine, which will reduce its output power. However, its power-speed curve shows that this prototype machine has very strong overload ability.</p> / Master of Applied Science (MASc)

O objetivo do trabalho é apresentar o funcionamento de um gerador a relutância chaveado monofásico. Para isso, foi desenvolvido um modelo computacional em ambiente Matlab Simulink, fazendo-se a comunicação entre diferentes partes do sistema. O comportamento da dinâmica de geração é apresentado para diferentes pontos do sistema, e testes experimentais realizados em um pequeno protótipo confirmam as características funcionais desta máquina. Ensaios realizados comprovam sua funcionalidade e simplicidade de operação, tendo estabilidade de geração para ampla faixa de velocidade de funcionamento, caracterizando uma máquina promissora, robusta e eficiente para aplicações especiais. / This work presents a single-phase switched reluctance machine operating as a generator. For that purpose, a computational model was developed in Matlab Simulink environment, wherein all the system components, such as voltage source, drive and machine model, and load were integrated. The current and voltage behavior for several points of operations are presented. Furthermore, experimental tests were also carried out in a simple prototype to validate its functionality and simplicity of operation, providing a stable power generation over a wide range of speed. The results showed that the single-phase switched reluctance generator can be robust, efficient, and promising for especial applications.

Computer aided process planning (CAPP) is generally acknowledged as a significant activity to achieve Computer Integrated Manufacturing (CIM). In coping with the dynamic changes in the modern manufacturing environment, the awareness of developing integrated and intelligent CAPP systems has been raised in an attempt to generate more successful implementation of intelligent manufacturing systems. The main objective of this research work has been to develop an integrated intelligent process planning system that helps designers and process planners to improve their design and planning in the early stages of the product life cycle. In order to achieve this goal, the following specific objectives have been accomplished: (1) Developed a STEP-based feature modeler for building mechanical parts using high-level 3D solid features as the basic design entities. The modeler is capable of generating high-level product data in XML format according to ISO 10303-AP224 standard. This file can be used to integrate into CAPP/CAM systems without using a complex feature recognition process. (2) Developed a STEP-based intelligent process planning system for prismatic parts. The system maps STEP AP224 XML data file and produces the corresponding machining operations to generate a digital process plan in XML format according to ISO 14649 (STEP-NC) standard. A Hybrid approach of most recent techniques of artificial intelligence (neural networks, fuzzy logic and rule-based) is used as the inference engine of the developed system. Three neural network models are implemented to select machining operations, cutting tools, and machine tools. Several fuzzy logic models are utilized to select machining parameters for different machining operations, work material, and tool material combinations. The rule-based functions are utilized to perform operation sequence and setup planning. An object-oriented approach has been used in the definition and implementation of the developed system. This approach offers advantages of incremental system development and reusability. The developed system is integrated with AutoCAD using Activex automation interface. Several examples have been presented to demonstrate and verify the applicability of the developed system. Finally, this research will contribute significantly to the applicability of advanced artificial intelligent techniques in CAPP systems. The implementation of STEP technology in this research will support the integration of CAPP system with other systems in CIM environment. The developed system is intended to be an effective concurrent engineering tool that bridges the gap between design and manufacturing.

O objetivo do trabalho é apresentar o funcionamento de um gerador a relutância chaveado monofásico. Para isso, foi desenvolvido um modelo computacional em ambiente Matlab Simulink, fazendo-se a comunicação entre diferentes partes do sistema. O comportamento da dinâmica de geração é apresentado para diferentes pontos do sistema, e testes experimentais realizados em um pequeno protótipo confirmam as características funcionais desta máquina. Ensaios realizados comprovam sua funcionalidade e simplicidade de operação, tendo estabilidade de geração para ampla faixa de velocidade de funcionamento, caracterizando uma máquina promissora, robusta e eficiente para aplicações especiais. / This work presents a single-phase switched reluctance machine operating as a generator. For that purpose, a computational model was developed in Matlab Simulink environment, wherein all the system components, such as voltage source, drive and machine model, and load were integrated. The current and voltage behavior for several points of operations are presented. Furthermore, experimental tests were also carried out in a simple prototype to validate its functionality and simplicity of operation, providing a stable power generation over a wide range of speed. The results showed that the single-phase switched reluctance generator can be robust, efficient, and promising for especial applications.

Orientador: Gilmar Barreto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-09T16:50:00Z (GMT). No. of bitstreams: 1 Giesbrecht_Mateus_M.pdf: 3904732 bytes, checksum: 55e43903b08b7c8d770f9120fb071c40 (MD5) Previous issue date: 2007 / Resumo: A motivação para este estudo é criar um modelo computacional capaz de prever se o regime de trabalho a que um motor monofásico de indução é submetido implica ou não em um aquecimento que comprometa os materiais isolantes do mesmo. A solução apresentada busca encontrar uma equação a diferenças em que a saída do sistema (temperatura do motor no instante k+1) é calculada como uma combinação linear das entradas (temperatura do motor, valor RMS da corrente e temperatura ambiente no instante k). Para conhecer os coeficientes desta combinação linear, foram realizados alguns ensaios e, a partir de seus resultados, foi aplicado o método dos mínimos quadrados para a obtenção do modelo computacional que representa o sistema. Os resultados computacionais obtidos com o modelo proposto refletem com exatidão o comportamento do sistema real. O modelo desenvolvido também é útil para outras aplicações em que se utilize um motor de indução monofásico em regime intermitente periódico com partida / Abstract: This study motivation was finding a computer-based model that was able to foresee if the duty cycle applied in a single-phase induction motor implies or not in an overheating that can compromise the motor insulation. The solution presented here is based on finding a difference equation in which the system output (motor temperature at time k+1) is calculated as a linear combination of the input (motor temperature, RMS current and ambient temperature at time k). The Mean Square Method was applied to find the coefficients of this linear combination, resulting in the final computational model that represents the system. The computational results found with the proposed model reflect exactly the real system behaviour. This model is also useful to other applications in which a single-phase induction motor during intermittent periodic duty with starting is used. / Mestrado / Automação / Mestre em Engenharia Elétrica