This diploma thesis deals with matte coatings for 3D scanning purposes. The coatings are made with spray gun which uses a vibrating membrane atomizer and air blow gun. A suspension of titanium dioxide and alcohol is used as a coating material. This thesis describes the effect of the spray gun process parameters on the deposited coatings. These include, for example type of the coating suspension or setup of the blow gun. Phase Doppler Anemometry was used to measure spray characteristics. Deposited coatings were measured with profilometer and scanned with 3D scanner to study their thickness and effect on the results of 3D reconstruction. The result of this work was the coating with thickness below 1 µm with good optical properties for 3D scanning purposes. Standard deviation of the captured point cloud from the reference plane was below 0.0011 mm.

Im Rahmen einer Diplomarbeit an der TU Bergakademie Freiberg wurden in 2014 die Grundlagen für die Auswertung von 3D-Punktwolken zur automatisierten Nachtragung des Risswerks gelegt. Um die dafür notwendigen 3D-Punktwolken möglichst wirtschaftlich zu erstellen, laufen seit 2015 Untersuchungen und Testmessungen zur Machbarkeit des untertägigen Einsatzes von mobil messenden Laserscannern. Im Folgenden werden verschiedene technische Ansätze sowie die Ergebnisse der Testmessungen und die weiteren geplanten Schritte vorgestellt. / As part of a thesis at the Technical University of Freiberg, a basis for the analysis of 3D point clouds was set for refining the mine map automatically. Since 2015 studies and test measurements have been running to create the necessary 3D point clouds as economically as possible, by using an underground mobile scanning system. Below the different technical approaches will be presented as well as the results of the test measurements and the next planned steps.

3D scanning has grown to become an important tool in a wide variety of applications. Still, acquiring high-quality 3D models using scanning technology is a challenging task. In this thesis, we present various ways that reduce the hurdles of existing 3D scanning pipelines with the ultimate goal of bringing this technology closer to the end user. To achieve this goal, we focus on three sub problems of traditional scanning pipelines: First, we present a novel algorithm that can be used to consistently orient the normals of huge point clouds. We achieve this by formulating the orientation problem as a graph-based energy minimization problem and applying out-of core methods. Second, we introduce interactivity into the scanning pipeline by presenting an online surface reconstruction method that produces high-quality semi-regular meshes. The resulting interactive pipeline is highly efficient because it reduces the turn-around between presentation of the final result and possible corrections by the user. Third, we develop a robust method to texture-map semi-regular meshes. This approach is based on a generalization of motorcycle graphs, which partitions arbitrary meshes into quadrilateral patches. These patches then serve as the parametrization domains of the texture atlas. Finally, we present an application from the area of cave science. The application is targeted at quantitatively and objectively assessing a cave's size. To achieve this goal, we present methods to analyze the structure of caves, especially to distinguish chambers from passages.

Continuous improvements are an integral part for the development of everyday life. These improvements do not only ascertain financial gain but also lessening the environmental impact. The purpose of this study is to gain a deeper understanding of the design process and the decisions required to achieve an optimal design with respect to weight reduction, while retaining the required strength. The study will also investigate the choice of material. This will be done through material and design studies, along with strength calculations of the product in question. The conclusion from this study is that it is possible to save a certain percentage of the material used, while keeping the strength, form, fit and function intact. The material study provided with a recommendation of the zinc alloy ZA-8. It is an alloy with a good combination of great strength, low density and price.

Due to the increasing demand from patients and dentists for highly aesthetic and strong, metal-free restorations there has been a rapid increase in research into dental CAD CAM technique and zirconia based restorations over the last decade. Such new technology has the potential to take the place of conventional techniques and materials for fabricating indirect dental restorations in the future. In this PhD thesis, five laboratory studies were designed to investigate zirconia bridges constructed using dental CAD CAM. The studies concentrated on: 1. Ideal force applied by dentists for cementing zirconia bridges and the impact on seating. 2. The effect of firing cycles and zirconia thickness on the fit of zirconia bridges. 3. The effect of span length on the fit of three and four unit all zirconia bridges. 4. The effect of veneering on the strength of three unit zirconia bridges. 5. The fit of three unit all zirconia bridges produced by digital and conventional techniques. For these laboratory studies an ideal three unit (and four unit for study 3) fixed-fixed all ceramic bridge preparation was carried out on two plastic teeth and all SLA models and zirconia based bridges were made using the Lava COS and Lava™ CAD CAM system (3M, ESPE). In addition to the laboratory studies, a clinical audit was carried out to assess satisfaction (dentist, dental technician and patient) with zirconia based restorations (through a xvi series of questionnaires) made and fitted at Dundee Dental Hospital and School. In addition, as part of this audit a simple cost analysis was carried out to explore the differences in cost between zirconia based restorations and high fusing gold alloy based metal ceramic restorations. Four of the studies (studies 1, 2, 3 and 5) investigated the internal and marginal fit of the zirconia based restorations under differing laboratory and clinical procedures and conditions. It was found that the seating force used to cement a zirconia based bridge had no impact upon fit (Study 1). Whilst the thickness of zirconia (all-zirconia bridge and un-veneered zirconia framework) did not affect the fit of the restoration, veneering the framework did lead to a statistically significant deterioration in fit (Study 2). Although leading to a poorer fit veneering did have a positive effect in strengthening the zirconia framework, but neither un-veneered nor veneered frameworks were as strong as monolithic/all zirconia bridges (Study 4). Despite the high shrinkage during post milling sintering and the potential for greater distortion on longer span bridges, the longer span bridges investigated in Study 3 did not impact upon fit. In study 1, 2, 3 and 4 the Lava COS intra-oral scanner was used to create a digital impression of the tooth preparations and study 5 confirmed that the fit of bridges made from these impressions were better than those made using conventional addition cured silicone putty and wash impressions (Study 5). The results of the questionnaires used in the audit revealed high satisfaction rates with all stake holders and the cost analysis showed that producing zirconia based restorations can be five to six times cheaper than conventional gold based restorations. Despite the variations in fit which were found in Studies 2 and 5, all bridges produced were within what would be regarded as clinically acceptable and comparable to those produced with more traditional techniques.

Die vorliegende Arbeit befasst sich mit der Erfassung von Oberflächen mittels Streifenprojektionsverfahren. Dabei wird ein Berechnungsmodell erarbeitet, welches den durch eine Aufnahme erfassten Bereich der Objektoberfläche berechnet und bewertet. Mithilfe einer optimalen Positionierung von Einzelaufnahmen ist es möglich, ein Objekt bei festgelegten Randbedingungen zeitsparend zu erfassen.

O futebol é o esporte mundial com maior quantidade de praticantes no mundo e suas normas são produzidas pela IFAB (Conselho da Associação Internacional de Futebol) e regulamentadas pela FIFA (Federação Internacional de Futebol Associado), sendo um esporte que gera milhões de reais em patrocínios e propaganda. A antropometria dos atletas praticantes pode variar muito, tanto em nível amador quanto profissional, apesar de estudos demonstrarem que atletas de mesma posição (atacantes, laterais, goleiros e outros), que desempenham a mesma função dentro do jogo, tem a tendência a apresentarem características semelhantes. No caso das caneleiras, esses atletas ainda utilizam, na grande maioria, equipamentos Standard, o que contribui para o elevado número de lesões que ocorrem anualmente com os jogadores de futebol, embora as técnicas de preparação física e testes de esforço tenham evoluído muito nos últimos anos. Em função disso, os equipamentos esportivos utilizados devem evoluir cada vez mais para diminuir a incidência de lesões, aumentando o conforto e a proteção aos atletas. Considerando que a caneleira é o único equipamento de proteção obrigatório exigido pela FIFA, a personalização deste produto se torna uma prática interessante. Nesse trabalho, a obtenção de caneleiras personalizadas ocorre de três maneiras distintas, por modelagem em gesso, digitalização e tomografia. Os resultados indicam que os três métodos são satisfatórios para a produção de uma caneleira personalizável, pois em todos foi possível obter a geometria da canela e reproduzi-la em polipropileno através da termoformagem, desenvolvendo assim um equipamento que se encaixa perfeitamente à canela do usuário. Cada método apresenta uma vantagem especifica frente aos outros, o molde feito em gesso é o método mais barato e fácil, a tomografia computadorizada poderia ser obtida previamente em analises ou previsões de lesões e o jogador poderia aproveitar a mesma para a criação da sua caneleira personalizada economizando tempo ao usuário e por ultimo a digitalização é o método mais preciso com a melhor repetibilidade. / Football is the sport worldwide with the largest number of practitioners in the world and its standards are produced by the IFAB (Council of International Football Association) and regulated by FIFA (Federation Internationale de Football Association), being a sport that generates millions of dollars in sponsorships and advertising. The athletes in the anthropometry can vary greatly, both at amateur and professional, despite studies showing that athletes from the same position (forwards, sides, goalkeepers and others) that perform the same function within the game, you tend to have characteristics similar. In the case of shin guards, these athletes are still using, in most cases, standard equipment, which contributes to the high number of injuries that occur each year with the football players, although the techniques of physical fitness and physical exhaustion tests have evolved in very recent years. As a result, the sports equipment used must evolve more and more to decrease the incidence of injuries, enhancing comfort and protection for athletes. Whereas the shin guard is the only required protective equipment required by FIFA, the customization of this product becomes an interesting practice. In this work, obtaining custom leggings will occur in three ways, by modeling plaster, and CT scan. The results indicate that the three methods are satisfactory for the production of a customizable shin guard, because in all it was possible to copy the geometry of shank and play it through the polypropylene in thermoforming, thus obtaining a device that perfectly fits the shank of the user. Each method has an advantage compared to the other specifies the plaster cast made the method is cheaper and easier, a CT scan could be obtained previously in analysis of injury and the player could use it to create your custom shinguard saving time to user and finally the scan is the most accurate method with the best repeatability.

Doctor of Philosophy / Department of Industrial & Manufacturing Systems Engineering / Chih-Hang John Wu / Quality is a result of product design and production control. Product design must maximize the ability to function across variations in production and environment. Production control must monitor and maintain the key design characteristics necessary for the intended function. Failure to do so results in premature part failure and increased costs. This has occurred in the production of modern cross ties. By designing quality into the product and production process, performance is maximized. This research presents a methodology for incorporating quality into the product design and production process. For product design, a relationship between product performance and design parameters is established by modeling techniques. These models provide a means to redesign the product to maximize performance and to understand the sensitivity of the design to fluctuation in production and environment. These models also establish the key design parameters that are critical for sustaining quality. For production, a method of monitoring the key design parameters is presented that provides an affordable means of automated inspection. Automated inspection removes operator error from the inspection process and allows for greater sampling rates to be achieved. The methodology presented allows for a potential of 100% inspection to be achieved with minimal impact to production costs. The research is applied to the analysis and quality control of pre-stressing steel reinforcement for concrete cross-ties. This application provides an opportunity to test and verify the research findings on a real world problem. Novel automated 3D spatial analysis algorithms are presented. This research furthers the state of the art of performing Geometrical Dimensioning and Tolerancing (GD&T). A cost effective method of non-contact surface profiling was developed with high resolution and high density surface profiles. The combined research findings present a methodology of achieving quality by design.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The aim of this work is to develop a non-contact 3D scanning robot to measure surfaces from objects of small sizes. The 3D scanner is shaped for a mechanical structure and an optic lecture system. The mechanical structure has 5 degrees of freedom. Such system is composed by two kinematic chains used to move the laser sensor and the workpiece respectively. The lecture system is derived from a laser sensor, based on 3D active triangulation technique that acquires the surface workpiece data. This technique assurance the scanning of the workpiece surface with reduced dimensional errors and consequently it makes possible the use less data points. Therefore it is achievable the fast data processing to reverse engineering method. In order to analyze its kinematics and dynamic model, its workspace, error analysis, and efforts at the joints, methods for reading the surface coordinates were proposed. For the analysis were considered the resolution and mechanical characteristics of the components used for the construction of a prototype. / O objetivo deste trabalho consiste no estudo e desenvolvimento de um digitalizador tridimensional robótico que será empregado para adquirir as dimensões superficiais de objetos de tamanho reduzido. O digitalizador é composto por uma estrutura mecânica e um sistema de leitura ótico. A estrutura mecânica do digitalizador possui 5 graus de liberdade e é composta por duas cadeias cinemáticas acopladas cinematicamente, onde uma delas é utilizada para movimentar o sensor laser e a outra para movimentar o objeto. O sistema de leitura é composto por um sensor laser que é baseado no método da triangulação ativa espacial para adquirir as medidas superficiais do objeto. Neste trabalho é utilizado o método da triangulação espacial porque ele garante o acompanhamento superficial do objeto para diminuir os erros nas medições, facilita a redução da quantidade de dados, facilitando o processamento de dados nas tarefas de engenharia reversa. Para permitir analisar os modelos cinemático e dinâmico, com o conseqüente estudo de seu espaço de trabalho de leitura, análise de erros, e dos esforços nas articulações, foram propostas metodologias de leitura da superfície do objeto. Para as análises foram consideradas as características mecânicas e de resolução dos componentes utilizados para a construção de um protótipo. / Doutor em Engenharia Mecânica

O futebol é o esporte mundial com maior quantidade de praticantes no mundo e suas normas são produzidas pela IFAB (Conselho da Associação Internacional de Futebol) e regulamentadas pela FIFA (Federação Internacional de Futebol Associado), sendo um esporte que gera milhões de reais em patrocínios e propaganda. A antropometria dos atletas praticantes pode variar muito, tanto em nível amador quanto profissional, apesar de estudos demonstrarem que atletas de mesma posição (atacantes, laterais, goleiros e outros), que desempenham a mesma função dentro do jogo, tem a tendência a apresentarem características semelhantes. No caso das caneleiras, esses atletas ainda utilizam, na grande maioria, equipamentos Standard, o que contribui para o elevado número de lesões que ocorrem anualmente com os jogadores de futebol, embora as técnicas de preparação física e testes de esforço tenham evoluído muito nos últimos anos. Em função disso, os equipamentos esportivos utilizados devem evoluir cada vez mais para diminuir a incidência de lesões, aumentando o conforto e a proteção aos atletas. Considerando que a caneleira é o único equipamento de proteção obrigatório exigido pela FIFA, a personalização deste produto se torna uma prática interessante. Nesse trabalho, a obtenção de caneleiras personalizadas ocorre de três maneiras distintas, por modelagem em gesso, digitalização e tomografia. Os resultados indicam que os três métodos são satisfatórios para a produção de uma caneleira personalizável, pois em todos foi possível obter a geometria da canela e reproduzi-la em polipropileno através da termoformagem, desenvolvendo assim um equipamento que se encaixa perfeitamente à canela do usuário. Cada método apresenta uma vantagem especifica frente aos outros, o molde feito em gesso é o método mais barato e fácil, a tomografia computadorizada poderia ser obtida previamente em analises ou previsões de lesões e o jogador poderia aproveitar a mesma para a criação da sua caneleira personalizada economizando tempo ao usuário e por ultimo a digitalização é o método mais preciso com a melhor repetibilidade. / Football is the sport worldwide with the largest number of practitioners in the world and its standards are produced by the IFAB (Council of International Football Association) and regulated by FIFA (Federation Internationale de Football Association), being a sport that generates millions of dollars in sponsorships and advertising. The athletes in the anthropometry can vary greatly, both at amateur and professional, despite studies showing that athletes from the same position (forwards, sides, goalkeepers and others) that perform the same function within the game, you tend to have characteristics similar. In the case of shin guards, these athletes are still using, in most cases, standard equipment, which contributes to the high number of injuries that occur each year with the football players, although the techniques of physical fitness and physical exhaustion tests have evolved in very recent years. As a result, the sports equipment used must evolve more and more to decrease the incidence of injuries, enhancing comfort and protection for athletes. Whereas the shin guard is the only required protective equipment required by FIFA, the customization of this product becomes an interesting practice. In this work, obtaining custom leggings will occur in three ways, by modeling plaster, and CT scan. The results indicate that the three methods are satisfactory for the production of a customizable shin guard, because in all it was possible to copy the geometry of shank and play it through the polypropylene in thermoforming, thus obtaining a device that perfectly fits the shank of the user. Each method has an advantage compared to the other specifies the plaster cast made the method is cheaper and easier, a CT scan could be obtained previously in analysis of injury and the player could use it to create your custom shinguard saving time to user and finally the scan is the most accurate method with the best repeatability.