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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Utveckling av testsystem för Interface Test Adapter till Gripen ATE

Bäckman, Tobias, Ehmke, Gustav January 2016 (has links)
The work has been carried out as a product development project at Saab AB in Arboga, focusing on construction. Saab in Arboga develops test systems for JAS 39 Gripen, whose purpose is to verify all the contacts. This is done by using the test system, ATE. Before testing can begin, the wiring harness in the ITA must be verified. Currently this is done manually, and due to wiring extent, the risks of incorrect measurements are apparent. In addition to incorrect measuring, the extent of the wiring can also lead to incorrect wiring in production. These errors can result in the test system fails, which means great financial loss for the company. The project's aim was to develop an automated measurement process and produce a prototype, in order to verify that the ITA is correctly connected before the simulation is done. The main issue for the project has been if an automated measurement process can obtain sufficient precision to replace manual measurement. By analyzing the market for automated movement, a number of concepts for the overall measurement process were generated. The concepts were evaluated with decision-matrix method, as well with regard to the complexity of the required software management for each concept. The measurement process that was chosen based on the 3D printer and its underlying mechanics and automation. To realize the concept to a fully working prototype the process of product development was broken down in segments. This reduced the level of complexity, while it contributed to simplify optimization. In order to achieve optimum design every segment consisted of concept generation and concept evaluation. The construction which is the basis for the prototype is an off-the-shelf solution, and based on the parts used in the milling machine x-Carve. The overall structure is based on the milling machine, however modified to the extent that the purpose can be achieved. The choice to base the design on the X-Carve was made against the background that it harmonized well with the overall concept of measuring process, but also well with the concepts generated in the broken down segments, mentioned above. The underlying factor to the use of components which is an off-the-shelf solution to the design is a result of the project vastness and the provided time. The developed prototype lives up to the requirements. Empirical tests indicate that the prototype obtains sufficient precision to perform measurements. The results of the tests carried out shows that manual labor can be replaced, and therefore leads to the conclusion that the prototype proved useful. The prototype has some potential for development, why it is recommended to examine each segment if additional optimizations must be made.
2

Omkonstruktion av främre låsring på högtrycksrotorn i RM12

Eriksson, Lena, Oberlé, Ann-Christin January 2002 (has links)
No description available.
3

Omkonstruktion av främre låsring på högtrycksrotorn i RM12

Eriksson, Lena, Oberlé, Ann-Christin January 2002 (has links)
No description available.
4

Vývoj rychlé metody pro stanovení barvy speciálních sladů

Křepelová, Simona January 2014 (has links)
The aim of this work was to suggest a quicker, technically-undemanding, and easy to use method for measuring the malt colour without congress mashing, and to evaluate the extent how the colour values obtained by this quick method will vary from the values obtained by a standard method. 12 malt samples were used for the experiment (3.1 -- 1320 j. EBC), wort was prepared from them in the standard (congress) way and in the new quicker way. The quick method for wort preparation was based on the extraction of overground malt in hot water. The extraction lasted 5, 10, and 15 minutes. The following properties of wort were measured by the spectrophotometer: clarity (L*) a* and b*. Overall differences in the clarity (L*) and calculated total colour difference (delta E*) between the wort prepared by the tested method and the congress wort were caused by the fact that boiling water, which created conditions for Maillard reactions, was used for the extraction. High-molecular colour components started to be formed in the extract. The suggested method seems to be applicable, but it will be necessary to optimize its conditions, especially to decrease the water temperature for extraction.
5

Pressure Monitoring and Fault Detection of an Anti-g Protection System / Tryckövervakning och feldetektion av ett anti-g-skyddssystem

Andersson, Kim January 2010 (has links)
<p>When flying a fighter aircraft such as the JAS 39 Gripen, the pilot is exposed to high g-loads. In order to prevent the draining of blood from the brain during this stress an anti-g protection system is used. The system consists of a pair of trousers, called the anti-g trousers, with inflatable bladders. The bladders are filled with air, pressing tightly on to the legs in order to prevent the blood from leaving the upper part of the body.</p><p>The purpose of this thesis is to detect if the pressure of the anti-g trousers is deviating from the desired value. This is done by developing a detection algorithm which gives two kinds of alarm. One is given during minor deviations using a CUSUM test, and one is given at grave deviations, based on different conditions including residual, derivative and time. The thresholds, in which between the pressure should lie in a faultless system, are calculated from the g-load value. The thresholds are based upon given static guidelines for the pressure tolerance area and are modified in order to adapt to the estimated dynamics of the system.</p><p>The values of the input signals, pressure and g-load, were taken from real flight sessions. The validation has been performed using both faultless and faulty flight sequences, with low false alarm rate and no missed detections. All together the detection system is considered to work well.</p>
6

Design and Validation of Configurable Filter for JAS 39 Gripen Mission Planning Data

Flodin, Per January 2009 (has links)
<p>Saab Aerosystems, a part of Saab AB, has the overall responsibility for the development of the fourth generation fighter aircraft JAS 39 Gripen. When planning a mission for one or more aircrafts, a computer program called Mission Support System is used. Some of the data from the planning is then transferred to the actual aircraft. Today there are some unwanted restrictions in the planning software. One of these restrictions is about the fact that a number of parameters that controls the output from a planned mission are not configurable runtime, i.e. a reinstallation at customers location is needed to change this. The main purpose of this thesis was to propose a new design and a new framework that solves the inflexibility described above. The design should also be validated by a test implementation. A number of different designs were proposed and four of these were selected to be candidates for being implemented. An important tool used when developing the designs was the theory of design patterns. To choose one of the four a ranking system, based on both measurable metrics and non-measurable experience, was used. One design was selected to be the best and after implementing of the design it was considered to be valid. Future work can consist of rewriting all modules in the software to use the new framework.</p>
7

Pilotmodeller till flygmekanisk simulator för JAS 39 Gripen

Ajdén, Per, Backlund, Carl January 2010 (has links)
<p>Abstract</p><p>SAAB has for a long time used user controlled pilot models in ARES. ARES is a simulation tool used in the desktop environment for simulations and calculations of the JAS 39 Gripen fighter and other aircraft. ARES stands for ”Aircraft Rigid body Engineering Simulation”. To work with these pilot models has been both time-consuming and inefficient. In this master thesis, new pilot models are developed, where parameters are automatically generated, this will result in that the user doesn’t have to put a lot of work into adjusting the gains for different manoeuvres. This is called gain scheduling.</p><p>To make this possible, simple models of the aircraft were created at different points in the envelope. These models were then used to calculate optimal controllers using LQ-control and pole placement techniques. These models and controllers were then implemented in Simulink. Simulink was then used to test the controllers before they were implemented in ARES.</p><p>Control in all modes except roll attitude and speed by throttle are based on LQ-control in pitch-, roll- and yaw-angular velocity. And through these angular velocities the other angles are controlled by simple controllers, who is generating a reference in angular velocity. The roll attitude controller is based on direct pole placement based upon desired damping and undamped natural frequency, and the speed controller is based upon a model of throttle positions in trimmed states.</p><p>The new pilot models are usable to control:</p><ul><li>Roll rate</li><li>Roll attitude</li><li>Pitch rate</li><li>Pitch attitude</li><li>Angle of attack</li><li>Load factor</li><li>Yaw attitude</li><li>Course angle</li><li>Climb angle</li><li>Mach number</li><li>Climb rate</li></ul><p>These controllers can be combined so that the aircraft can perform desired maneuvers.</p>
8

Dimensionering av momentskärmstativ : Analys med finita elementmetoden / Dimensioning of safety chute frame : Analysis with Finite Element Method

Jonsson, Ida, Öhrn, Robin January 2013 (has links)
På uppdrag av Saab har en grupp studenter på Linköpings tekniska högskola utvecklat ett skärmstativ för nya generationens JAS 39 Gripen E. Vid testflygning är stativet placerat vid planets stjärtkon och på stativet ska en skärm fästas. Skärmens funktion är att stabilisera flygplanet genom att ge det ett tippmoment vid okontrollerade spinnfall. Detta kandidatarbete hade till uppgift att designa och dimensionera ett stativ efter givna lastfall, begränsad volym, deformationskrav och givna infästningspunkter, samtidigt som fokus skulle ligga på viktreducering. För att möjliggöra detta togs en CAD-modell fram i Creo Parametric 2.0, som sedan exporterades till Ansys Workbench 14.0 där det utfördes beräkningar enligt finita elementmetoden. Under projektets gång testades olika material, tvärsnitt och konstruktioner, vilka utvärderades för att få fram en så lätt och hållbar konstruktion som möjligt.   Resultatet blev ett stativ med fackverksstruktur, som är gjord av fyrkantiga balkar med yttermått 70 mm och innermått 63,8 mm. Den maximala spänningen blev 883 MPa och maximal deformation var 53,1  mm. Stativets totalvikt blev 60,5 kg.
9

Pilotmodeller till flygmekanisk simulator för JAS 39 Gripen

Ajdén, Per, Backlund, Carl January 2010 (has links)
Abstract SAAB has for a long time used user controlled pilot models in ARES. ARES is a simulation tool used in the desktop environment for simulations and calculations of the JAS 39 Gripen fighter and other aircraft. ARES stands for ”Aircraft Rigid body Engineering Simulation”. To work with these pilot models has been both time-consuming and inefficient. In this master thesis, new pilot models are developed, where parameters are automatically generated, this will result in that the user doesn’t have to put a lot of work into adjusting the gains for different manoeuvres. This is called gain scheduling. To make this possible, simple models of the aircraft were created at different points in the envelope. These models were then used to calculate optimal controllers using LQ-control and pole placement techniques. These models and controllers were then implemented in Simulink. Simulink was then used to test the controllers before they were implemented in ARES. Control in all modes except roll attitude and speed by throttle are based on LQ-control in pitch-, roll- and yaw-angular velocity. And through these angular velocities the other angles are controlled by simple controllers, who is generating a reference in angular velocity. The roll attitude controller is based on direct pole placement based upon desired damping and undamped natural frequency, and the speed controller is based upon a model of throttle positions in trimmed states. The new pilot models are usable to control: Roll rate Roll attitude Pitch rate Pitch attitude Angle of attack Load factor Yaw attitude Course angle Climb angle Mach number Climb rate These controllers can be combined so that the aircraft can perform desired maneuvers.
10

Modellering av reserv- och nödkraftsystem i JAS 39 Gripen / Modeling of Auxiliary and Emergency Power System in JAS 39 Gripen

Eilertsen, Adrian January 2010 (has links)
Simulation is a vital tool during development of JAS 39 Gripen, since money and time can be saved. The Auxiliary and Emergency Power System, AEPS, is a subsystem of the secondary power system in Gripen. It has the function of providing the aircraft with electrical and hydraulical power before activation and after deactivation of the main engine. The system also functions as backup in case of a safety critical problem in the main power supply system. The system basically consists of a control unit and an auxiliary gearbox. The gearbox is driven by an air turbine. An auxiliary generator and a hydraulic pump are mounted on the gearbox to provide the aircraft with electrical and hydraulical power. The airflow to the turbine is regulated by an Air Modulating Valve, AMV. This report describes a new model of the AEPS. The model encompasses the logical control unit and a physical description of AMV, air turbine, auxiliary gearbox, auxiliary generator and the auxiliary hydraulic pump. The logical model is connected to the physical model whereby simulation of the whole system is made possible. The model is implemented in Matlab/Simulink. This work provides a complete model of the AEPS which enables simulation of the dynamical processes. Verification was done by comparing simulation results with measurements from the real physical system. Satisfactory results are achieved, especially for inlet pressure for the air turbine and the speed of the auxiliary generator. / Simulering är ett viktigt verktyg under utveckling av JAS 39 Gripen, eftersom detta möjliggör att både pengar och tid kan sparas. Reserv- och nödkraftsystemet Auxiliary and Emergency Power System, AEPS, som är en del av Gripens hjälpkraftsystem, har till uppgift att försörja flygplanet med el- och hydraulkraft före uppstart och efter nedstängning av huvudmotor. Systemet fungerar även som backup vid bortfall av ordinarie kraftförsörjning. Grovt förenklat består systemet av en logisk kontrollenhet och en turbindriven reservväxellåda. På reservväxellådan finns en reservgenerator och en reservhydraulpump för elkraft respektive hydraulkraftförsörjning. Luftflödet till turbinen regleras av en så kallad Air Modulating Valve, AMV. Den här rapporten beskriver en ny modell av AEPS. Modellen omfattar den logiska kontrollenheten och en fysikalisk beskrivning av systemets reglerventil, turbin, växellåda, reservgenerator och reservhydraulpump. Den logiska modellen kopplas samman med den fysikaliska och möjliggör simulering av hela systemet. Implementeringen görs i Matlab/Simulink. Arbetet leder fram till en komplett modell för AEPS där dynamiska förlopp beskrivs. Verifiering görs genom att jämföra simuleringar med mätningar från det fysiska systemet. Tillfredställande resultat uppnås, speciellt för tryck in till turbin och varvtal för reservgenerator.

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