abstract: Metal castings are selectively machined-based on dimensional control requirements. To ensure that all the finished surfaces are fully machined, each as-cast part needs to be measured and then adjusted optimally in its fixture. The topics of this thesis address two parts of this process: data translations and feature-fitting clouds of points measured on each cast part. For the first, a CAD model of the finished part is required to be communicated to the machine shop for performing various machining operations on the metal casting. The data flow must include GD&T specifications along with other special notes that may be required to communicate to the machinist. Current data exchange, among various digital applications, is limited to translation of only CAD geometry via STEP AP203. Therefore, an algorithm is developed in order to read, store and translate the data from a CAD file (for example SolidWorks, CREO) to a standard and machine readable format (ACIS format - *.sat). Second, the geometry of cast parts varies from piece to piece and hence fixture set-up parameters for each part must be adjusted individually. To predictively determine these adjustments, the datum surfaces, and to-be-machined surfaces are scanned individually and the point clouds reduced to feature fits. The scanned data are stored as separate point cloud files. The labels associated with the datum and to-be-machined (TBM) features are extracted from the *.sat file. These labels are further matched with the file name of the point cloud data to identify data for the respective features. The point cloud data and the CAD model are then used to fit the appropriate features (features at maximum material condition (MMC) for datums and features at least material condition (LMC) for TBM features) using the existing normative feature fitting (nFF) algorithm. Once the feature fitting is complete, a global datum reference frame (GDRF) is constructed based on the locating method that will be used to machine the part. The locating method is extracted from a fixture library that specifies the type of fixturing used to machine the part. All entities are transformed from its local coordinate system into the GDRF. The nominal geometry, fitted features, and the GD&T information are then stored in a neutral file format called the Constraint Tolerance Feature (CTF) Graph. The final outputs are then used to identify the locations of the critical features on each part and these are used to establish the adjustments for its setup prior to machining, in another module, not part of this thesis. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2016

Ingeniero Civil Industrial / Durante los últimos 20 años se ha observado un incremento en el interés por aplicar analytics (análisis de datos) en la toma de decisiones en deporte. Un ejemplo reciente es la planificación del fixture para las Eliminatorias al Mundial de Rusia 2018 en la Conmebol en la que se utilizaron modelos de optimización. En la presente memoria se analizan dos casos a la toma de decisiones vinculadas al fútbol: (1) predicciones de resultados si se cuenta con información secuencial y (2) orden de partidos en el fixture de un torneo y su impacto en la posición final de un equipo. Es por ello que se realizan dos experimentos, en el primero, a través de una plataforma online de crowdsourcing, se invita por medio de incentivos a un grupo de personas a que participen en el pronóstico de partidos para la Eurocopa realizada en Francia. Se contrastan dos grupos: uno solo tiene una instancia para hacer las predicciones de todos los partidos a considerar, mientras que el otro grupo debe efectuar predicciones todos los días. Por lo tanto, en este escenario, se examina cómo la presencia o ausencia de decisiones secuenciales afecta la certeza en predicciones de partidos de fútbol. En el segundo experimento, se aprovecha el orden aleatorio de la secuencia de partidos que se da en ciertos campeonatos de fútbol, con el objetivo de medir el impacto de la dificultad del equipo rival a comienzos del torneo (experimento natural). Se utiliza los datos recogidos de los partidos de la Liga Inglesa de fútbol en un período de 10 años (2005-2015). A través de técnicas econométricas se evalúa el efecto de la dificultad inicial, controlando por factores inherentes a cada equipo y temporada. En término de conclusiones, en el primer experimento se encuentra que no existen diferencias significativas entre los dos grupos, aun cuando un grupo tenía mayor información al momento de hacer predicciones. En el segundo experimento, se infiere que la dificultad de los primeros partidos de una temporada, medida a partir de las posiciones de los equipos rivales en temporadas pasadas, afecta significativamente la posición final de un equipo, es decir, los equipos que enfrentan mayor dificultad en estos partidos tienen más chances de ver afectada negativamente su posición final. Además, al analizar la heterogeneidad de este efecto, no se encuentran diferencias dependiendo si la dificultad inicial del rival es asignada a mejores o peores equipos, según sus posiciones en temporadas pasadas. Finalmente, para investigaciones futuras se propone expandir el estudio con muestras de mayor tamaño, para el primer experimento, y al mismo tiempo, buscar formas de evitar sesgos de selección entre grupos experimentales. En el segundo experimento se sugiere incluir más temporadas y realizar comparaciones con otras ligas de fútbol. / Este trabajo ha sido parcialmente financiado por Corporación ISCI

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The target of Master Thesis with theme „The innovation of production technologie of pressure reservoir“, is a description of manufacturing technologie currently in use and design a new technologie. Part of new development of technologie is a selection of suitable spectrum of rails (pressure reservoir), design invention of appropriate machine loading system and clamping fixture placed into machine. Also the comparison of technologckl and economical parameters of proposed designed technologies and technologie currently in use - the final evaluation included.

Sequential single-axis vibration testing strategies often produce over-testing when qualifying system hardware. Multi-axis excitation techniques can simulate realistic service environments, but the hardware and testing strategies needed to do so tend to be costly and complex. Test engineers instead must execute sequential tests on single-axis shaker tables to excite each degree of freedom, which the previous two decades of vibration testing literature have shown to cause extensive over-testing when considering cross-axis responses in assessing the severity of the applied test environments. Traditional assessments assume that the test article responds only in the axis of excitation, but often significant response occurs in the off-axes as well. This paper proposes a method to address the over-testing problem by approximating a simultaneous multi-axis test using readily-available, single-axis shaker tables. By optimizing the angle of excitation and the boundary condition through dynamic test fixture design, the test article can be tested using a Single-Input, Multiple-Output (SIMO) test in a way that approximates a Multiple-Input, Multiple-Output (MIMO) test. This paper shows the proposed method in simulation with a 2D finite element box assembly with removable component (BARC) model attached to springs with variable stiffness. The results include quantified test quality assessment metrics with comparison to standard sequential testing. The proposed method enables access to rapid, approximate, multi-axis testing using existing hardware, thereby reducing the over-conservatism of sequential single-axis tests and requisite over-design of systems.

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No description available.

The advent of finite element methods has changed the tire industry's design process over the past three decades. Analyses, previously impractical using analytical methods and physically limited by experimental methods, can now be performed using computational methods. This decreases the cost and time associated with bringing a new design to the marketplace; however some physical testing is still required to validate the models. The design, fabrication, installation, and operation of a tire, suspension, and chassis test fixture (TiSCTeF) is detailed as part of this study. This fixture will support the validation of effective, parametric finite element models currently under development, as well as the design and testing of suspension and chassis components for the Virginia Tech Formula SAE team. The fixture is designed to use the Formula SAE race car as the test platform. Initially, the fixture is capable of performing static load-deflection and free-rolling tire tests. Provision has been made in the design for incremental upgrades to support cornering tests and additional instrumentation. An initial load-deflection test has proven that the fixture is capable of creating reproducible data sets. Specific recommendations are made concerning the improvement of data quality for future tests. This study also presents a process for analyzing existing tire cornering data and eliminating anomalies to improve the effectiveness of normalization techniques found in the literature. The process is shown to collapse tire cornering data, which is partially ill- conditioned, onto master curves that consistently display the effect of inclination angle and tire inflation pressure on tire response. / Master of Science

Samhällets ständiga utveckling och utbyggnad kräver en mer ändamålsenlig användning av mark, anläggningar och byggnader. Ett steg i den riktningen togs den 1 januari 2002 då möjligheten att överföra och frigöra fastighetstillbehör infördes i svensk lagstiftning. Överföring av fastighetstillbehör från en fastighet till en annan görs enligt fastighets-bildningslagen eller anläggningslagen. Ett frigörande innebär att fastighetstillbehöret istället blir lös egendom och det genomförs med stöd av ledningsrättslagen. 13 år har nu gått sedan införandet och syftet med denna studie är att kartlägga hur reglerna har använts mellan den 1 januari 2007 och den 31 december 2014. Studiens avgränsning i tid beror på att en liknande studie gjordes 2006. För att svara på studiens frågeställningar används två metoder. Den första är intervjuer med nio sakkunniga inom området som ska klargöra bl.a. varför de har använt reglerna och om de kan förbättras. Den andra metoden är en statistisk analys av ett utdrag från fastighetsregistret där alla åtgärder med anmärkningen "fastighetstillbehör" är med. Den statistiska analysen ska visa på hur ofta reglerna används, om detta förändras över tid och vad som överförts och frigjorts. Totalt har minst 4 014 fastighetstillbehör överförts eller frigjorts i 897 lantmäteriförrättningar. Antalet sådana åtgärder per år har halverats från 2007 till 2014. De fastighetstillbehör som är vanligast att överföra eller frigöra är sådana med ändamål vatten och avlopp vilka utgör ca 38 % av alla åtgärder. Starkström är en annan vanligt förekommande anläggning som dock har minskat med 80 % under studiens tidsintervall. Andra fastighetstillbehör som är vanliga att överföra och frigöra är jordvärmeanläggningar, byggnader och fjärrvärmeledningar. Motiven till att överföra och frigöra fastighetstillbehör är framförallt att klargöra de äganderättsliga förhållandena så att de inblandade parter vet vem som är ansvarig för drift och försäkring av byggnaden eller anläggningen. Vad gäller förbättringspotentialen för reglerna så skulle en enhetlig registrering av sådana åtgärder i FR underlätta för lantmätarna när äganderätten till ett fastighetstillbehör ska klargöras. Ett förtydligande av ansökan där man skiljer på överförande och frigörande av fastighetstillbehör skulle underlätta för fastighetsägarna att få upp ögonen för denna möjlighet. Studien visar tydligt att användandet av reglerna minskar men att den trenden sakta planar ut. Det är troligt att det kommer minska i ytterligare några år till det stannar på det grundbehov som studien tyder på finns. / Society's constant development and expansion requires a more efficient use of land, facilities and buildings. A step in this direction was taken on January 1, 2002 when the possibility of transmit and release property fixture was introduced into Swedish legislation. The transmission of a property fixture from one property to another is done according to the Real Property Formation Act or the Joint Facilities Act. With a release we mean that the property fixture becomes personal property which is carried out in accordance with the Utility Easements Act. Thirteen years have now passed since the introduction. The aim of this study is to identify how the rules have been implemented between 1 January 2007 and 31 December 2014. The study's time interval was decided upon due to the fact that a similar study had been carried out in 2006. In order to reply to the purpose of the study, two methods were used. The first method was to carry out interviews with nine experts within the field in order to clarify the motives and the rules where used and if they can be improved. The second method was a statistical analysis of an extract from the real property register where all the cadastral dossiers marked "property fixture" were included. The statistical analysis showed to which extent the rules were used, if the usage changed over time and what was transmitted and released. In total some 4 014 property fixtures were transmitted or released which have been implemented within 897 cadastral procedures. The number of such actions on an annual basis has decreased by 50 % from 2007 to 2014. The property fixture that were most commonly transmitted or released were those with water and sewerage purposes which form approx. 38 % of all actions made. High voltage electricity facilities were also common to be transmitted or releases, but this category's usage of the rules has decreased by 80 % during the study's interval. The motives for transmit or release a property fixture is mainly to clarify the ownership conditions so the parties involved know who is responsible for insuring and maintaining the building or the facility. An improvement of the rules would to get a unified registration of such actions in the real property register. It would simplify the cadastral surveyors work when the freehold of a property fixture needs to be clarified. A clarification of the application where transmit and release of property fixture where separated would make it easier for property owners and open their eyes for this opportunity. The study clearly shows that the uses of the rules were decreasing during the period but the trend slowly flattens. It is likely that it will decrease a few more years until it stops on a basic need which this study thinks exist.

This dissertation addresses the development of a telemanipulation system using intelligent mapping from a haptic user interface to a remote manipulator to assist in maximizing the manipulation capabilities of persons with disabilities. This mapping, referred to as assistance function, is determined on the basis of environmental model or real-time sensory data to guide the motion of a telerobotic manipulator while performing a given task. Human input is enhanced rather than superseded by the computer. This is particularly useful when the user has restricted range of movements due to certain disabilities such as muscular dystrophy, a stroke, or any form of pathological tremor. In telemanipulation system, assistance of variable position/velocity mapping or virtual fixture can improve manipulation capability and dexterity. Conventionally, these assistances are based on the environment information, without knowing user's motion intention. In this dissertation, user's motion intention is combined with real-time environment information for applying appropriate assistance. If the current task is following a path, a virtual fixture orthogonal to the path is applied. Similarly, if the task is to align the end-effector with a target, an attractive force field is generated. In order to successfully recognize user's motion intention, a Hidden Markov Model (HMM) is developed. This dissertation describes the HMM based skill learning and its application in a motion therapy system in which motion along a labyrinth is controlled using a haptic interface. Two persons with disabilities on upper limb are trained using this virtual therapist. The performance measures before and after the therapy training, including the smoothness of the trajectory, distance ratio, time taken, tremor and impact forces are presented. The results demonstrate that the forms of assistance provided reduced the execution times and increased the performance of the chosen tasks for the disabled individuals. In addition, these results suggest that the introduction of the haptic rendering capabilities, including the force feedback, offers special benefit to motion-impaired users by augmenting their performance on job related tasks.