This licentiate thesis is devoted to shape measurements using two different optical methods. The first one is a classical triangulation method, which uses projected fringes. The second one is a new interferometric method, which uses wavelength scanning. Both are whole field measuring methods. The main goal of the project has been to analyse the performance of an analysis scheme for absolute shape measurements called temporal phase unwrapping. This method permits the user to determine the absolute distance from the detector (usually a CCD-detector) to the object. A generalised version of the temporal phase unwrapping scheme is called reduced temporal phase unwrapping. The scheme uses an arbitrary number of fringe maps with varied fringe pitch, to calculate phase (shape). A thorough investigation is made of the performance of this algorithm. A single channel and a multi channel approach is considered. Expressions are found that relates the physical quantities to phase errors. In these simulations the single channel approach was found to be the most robust one. Expressions that relate the measurement accuracy and the unwrapping reliability, respectively, to the reduction of the fringe sequence were also found. As expected the measurement accuracy is not affected by a shorter fringe sequence while a significant reduction in the unwrapping reliability is found, as compared to the complete negative exponential sequence. The strength of reduced temporal phase unwrapping is demonstrated experimentally, in a projected fringe three-channel system. Instead of letting each channel carry phase-stepped images each channel can carry images with a change in fringe pitch. This significantly reduces noise, but at least three images needs to be acquired. It is also shown that the temporal phase unwrapping analysis scheme can be used to evaluate experimental data from wavelength scanning interferometry. Two unwrapping strategies are considered: fitting to a reversed exponential sequence and complex Fourier-transform ranging. The achievable accuracy for both methods ultimately depend on the tuning width, the speckle correlation, and random noise in the optical setup. / Godkänd; 2000; 20070318 (ysko)

<p>Godkänd; 1998; 20070404 (ysko)</p>

Godkänd; 1998; 20070404 (ysko)

No description available.

Godkänd; 1995; 20080330 (ysko)

Statistics shows that most traffic accidents with fatal outcome can be related to slippery road conditions. The most hazardous road conditions are the ones that are hard for the driver to detect and that appears sudden on the road. A sensor that classify the road condition in front of the vehicle, warning both the driver and the systems in the vehicle that are incorporated to help the driver, like the electronic stability program (ESP), anti-lock brake system (ABS) or the traction control system (TCS), could help to reduce these accidents. There are several prototypes for classification of road conditions available but they are not yet fully functional. In this thesis a method that makes it possible to classify the four distinct road conditions dry asphalt and asphalt covered with water, ice and snow, respectively, with a low probability of wrong classification using three wavelengths is presented. A prototype sensor built on the a technique using two laser diodes and a photo detector is tested in a real environment and compared with laboratory measurements which shows a promising result characterizing dry asphalt and asphalt covered with ice and snow. Both theory and experiments are presented. The most difficult road conditions to classify from each other are water and clear ice for which a method using polarized light is investigated. The investigation shows that using polarized light for illumination and a polarizer as an analyzer for classification of water and ice on asphalt is a more reliable method than using unpolarized light. All three investigations show promising results in developing an actual sensor to reduce fatal accidents in traffic. / Godkänd; 2007; 20071011 (ysko)

Arbetet utfördes i Vindeln hos Indexator Rotator Systems AB som är ett världsledande företag inom rotatorer. Mellan kran och rotator monteras ofta en länk, en del av dessa länkar erbjuder en viktfunktion, dessa kallas våglänk. I detta examensarbete togs en alternativ våglänk fram. Arbetet är en fortsättning på tidigare arbeten utförda av Indexator. Våglänken som togs fram använder sig av en lastcell för att mäta belastningen som uppstår när virke och dylikt lastas. Projektet kommer vara uppdelat i två delar. Den första delen handlar om att verifiera den elektriska lastcellens prestanda och funktion när den är monterad i våglänken. Här skapas en verifieringsplan och en del av verifieringen utförs även under arbetets gång. För att kontrollera lastcellens funktion så kopplas den upp mot en Arduino och en accelerometer. All programmering och tillhörande kod presenteras i rapporten. I den andra delen ritas våglänk 80–80 5t om för att acceptera den elektriska lastcellen. Innan våglänken ritas om skapas en jämförelse mellan tänkbara lastceller sett till prisbild, form samt funktion. Dessa presenteras med tillhörande offerter. Två lastceller valdes ut och två prototyper per lastcell ritades i Siemens NX. Ritningar tas fram till varje koncept för framtida prototyptillverkning. Resultatet är en jämförelse av två olika lastceller, en verifieringsplan där en del av verifieringen är utförd och CAD-filer med tillhörande ritningar. / The work was carried out in Vindeln at Indexator Rotator Systems AB, which is a world-leading company in rotators. Between the crane and the rotator a link is often mounted, some of these links offer a weight function, and are called weighing links. In this thesis, an alternative weighing link was constructed. This work is a continuation of previous work done by Indexator themselves. The weighing link developed uses a load cell to measure the load that occurs when timber and such are lifted. The project will be divided into two parts. The first part is about verifying the performance and function of the electric loadcell when mounted in the weighing link. Here, a verification plan is created and parts of the verification is also done during the work. To check the function of the load cell, it is connected to an Arduino and an accelerometer. All programming and associated code are presented in the report. In the second part, changes are made to the weighing link 80-80 5t to accept the electric load cell. Before drawing the weighing link, a comparison is made between possible load cells with regards to price, form and function. These are presented with related quotes. Two load cells were selected and two prototypes per load cell were drawn in NX. Drawings are developed for each concept for future prototype production. The result is a comparison of two different load cells, a verification plan with some verification performed and cad files with associated drawings.

Additive Manufacturing (AM) is gaining popularity in aerospace and automotive industries. This is a versatile manufacturing process, where highly complex structures are fabricated and together with topology optimization, a powerful design tool, it shares the property of providing a very large freedom in geometrical form. The main focus of this work is to introduce new developments of Topology Optimization (TO) for metal AM. The thesis consists of two parts. The first part introduces background and theory, where TO and adjoint sensitivity analysis are described. Furthermore, methodology used to identify surface layer and high-cycle fatigue are introduced. In the second part, three papers are appended, where the first paper presents the treatment of surface layer effects, while the second and third papers provide high-cycle fatigue constraint formulations. In Paper I, a TO method is introduced to account for surface layer effects, where different material properties are assigned to bulk and surface regions. In metal AM, the fabricated components in as-built surface conditions significantly affect mechanical properties, particularly fatigue properties. Furthermore, the components are generally in-homogeneous and have different microstructures in bulk regions compared to surface regions. We implement two density filters to account for surface effects, where the width of the surface layer is controlled by the second filter radius. 2-D and 3-D numerical examples are treated, where the structural stiffness is maximized for a limited mass. For Papers II and III, a high-cycle fatigue constraint is implemented in TO. A continuous-time approach is used to predict fatigue-damage. The model uses a moving endurance surface and the development of damage occurs only if the stress state lies outside the endurance surface. The model is applicable not only for isotropic materials (Paper II) but also for transversely isotropic material properties (Paper III). It is capable of handling arbitrary load histories, including non-proportional loads. The anisotropic model is applicable for additive manufacturing processes, where transverse isotropic properties are manifested not only in constitutive elastic response but also in fatigue properties. Two optimization problems are solved: In the first problem the structural mass is minimized subject to a fatigue constraint while the second problem deals with stiffness maximization subjected to a fatigue constraint and mass constraint. Several numerical examples are tested with arbitrary load histories.

This thesis is intended primarily as estimating the technical feasibility of aninvention while achieving product development for a company as a project. Theproject tries to use the invention for covering the market of urban wind turbines.Because it is a safe device for the environment and has no noise, it will beinteresting to use it in residential areas even by a low power coefficient.The project covers a wide range of readers from those who are new in the windindustries with mathematics and mechanics background until professionals. Also,consultants and wind turbine companies will be interested in, such as new ideasand solutions. The project estimates location, height, mechanical principles, andthen it evaluates feasibilities. The design distributed in three phases, head, bracingstructure, and foundation.The head consists of two counter-rotating turbines, one inside to the other and in avertical position. Generally, the mechanism of turbines follows the Savoniusturbine. However, the curved profile of the blades does not follow the semicircularfunction but is of the improved type curve. The bracing structure hasenough height to provide the specified wind speed and keep it against a strongstorm and with enough safety. The foundation has a modern structure to carryforces and momentum.The whole structure match in a triangle profile to spend low components againstthe weight, costs and life cycle energy. At the same time, the used methods in thethesis are matched to academic and industrial procedures to carry out this kind ofinvention according to product development. The main parts of the thesis arefocused on the introduction of wind turbines, methods, theory, and results. Theresults consist of designs, calculations. Finally, a conclusion, critical review, andfurther activities presented.

As the frontier of technology is pushed ever farther, the need for new and improved materials is always present. This thesis investigates the mechanical properties of compacted graphite iron (CGI) as it has been suggested as an alternative to traditional lamellar iron in truck cylinder blocks. The obtained values are compared to the mechanical properties predicted by a commercially available casting simulation software. This thesis shows that the mechanical properties vary within each CGI- cylinder block with respect to position and that the technology of casting several cylinder blocks with similar properties already exists. The casting simulation software used in this thesis was found to give conservative predictions of the evaluated mechanical properties. / i takt med att den tekniska utvecklingen går framåt ställs allt högre krav på konstruktionsmaterial. Inte minst gäller detta cylinderblock i lastbilar. Ett intressant alternativ till traditionellt lamellärt grafitjärn är kompaktgrafitjärn (CGI), som i flera avseenden har mekaniska egenskaper som är bättre lämpade för cylinderblock än det traditionella alternativet. I detta arbete kartläggs mekaniska egenskaper hos cylinderblock gjutna i CGI. De uppmätta värdena används sedan för att utvärdera ett kommersiellt gjutsimuleringsverktyg. Arbetet visar på att det är möjligt att erhålla låg spridning i mekaniska egenskaper mellan individuella block givet att ingångsparametrarna är likartade. Samtidigt går det att konstatera att det föreligger viss spridning i mekaniska egenskaper inom varje cylinderblock. Simuleringsprogrammet som utvärderats överskattade aldrig någon av de undersökta hållfasthetsparametrarna för någon av de positioner som undersökts i detta arbete. Detta är betryggande då det borgar för att simuleringsprogrammet kan komma att utgöra ett pålitligt verktyg i framtida utvecklingsarbeten.