published_or_final_version / Industrial and Manufacturing Systems Engineering / Doctoral / Doctor of Philosophy

No description available.

Layered manufacturing plays important role in industry. Conventional pro-cess planning takes polygon soup as input and has high quality requirements on these polygonal model such as no self-intersection, no degenerate polygon et al. A growing number of models, especially for those in complex shape are acquired from reverse engineering. Implicit representation always serves as intermediate representation and ¯nally need to be tesselated into polygonal mesh for layered manufacturing applications. However, the present tessellation techniques have difficulties to provide topologically faithful and self-intersection free polygonal mesh from implicit model. On the other hand, implicit representation are mathematically compact and robust, which is important for presenting complex freeform models. / I develop a robust and efficient approach to directly slicing implicit solids. Different from prior slicing techniques that reconstruct contours on the slicing plane by tracing the topology of intersected line segments, which is actually not robust, I generate contours through a topology guaranteed contour extraction on binary images sampled from given solids and a subsequent contour simplification algorithm which has the topology preserved and the geometric error controlled. The resultant contours are free of self-intersection, topologically faithful to the given r-regular solids and with shape error bounded; therefore, correct objects can be fabricated from them by layered manufacturing. Moreover, since I do not need to generate the tessellated B-rep of given solids, my direct slicing approach is memory efficient - only the binary image and the finest contours on one particular slicing plane need to be stored in-core. My method is general and can be applied to any implicit representations of solids. / Moreover, I also investigate techniques for support generation for layered manufacturing in image space. Region subtraction is a crucial operation for support generation. I develop a robust and reliable region subtraction method on implicit solid slicing. Compared with the conventional approach in which support regioncontours are produced from part slicing contours by polygonal operations, my approach calculates reasonable support region on binary image for each layer. I investigate a conservative growing-swallow technique to remove as much as possible the support material for self-support region while still guarantee the safety of building process. My region subtraction can serve as core technique for many layered manufacturing processes. In my research, I demonstrate region subtraction technique in both Fused Decomposition Modeling(FDM) and Stereolithography(SLA). A region cleaning technique which can reduce topology complexity of calculated support structure region is developed to fulfil specific requirement of FDM. With all the operations involved being discrete on binary image, my approach is more robust compared with the polygonal operations which are based on numerical computation. Moreover, processing on binary image makes my approach highly parallelizable. My self-intersection free contour extraction technique used in direct slicing can also be adopted to extract support structure contour on binary image if necessary. / Huang, Pu. / "October 2012." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 80-84). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract --- p.i / Chinese Abstract --- p.iii / Acknowledgements --- p.iv / List of Figures --- p.vii / List of Tables --- p.ix / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Contribution --- p.4 / Chapter 1.3 --- Organization --- p.5 / Chapter 2 --- Literature Review --- p.7 / Chapter 2.1 --- Direct Slicing on Implicit Solid --- p.7 / Chapter 2.2 --- Slicing based Support Generation --- p.9 / Chapter 3 --- Problem Definition --- p.10 / Chapter 4 --- Topologically Faithful Slicing Contour Generation --- p.12 / Chapter 4.1 --- Introduction --- p.12 / Chapter 4.2 --- Sampling and Contour Generation --- p.15 / Chapter 4.2.1 --- Sampling --- p.16 / Chapter 4.2.2 --- Topologically faithful contouring --- p.17 / Chapter 4.2.3 --- r-Regularity and Accuracy in Layered Manufacturing --- p.19 / Chapter 4.3 --- Constrained Smoothing --- p.20 / Chapter 4.4 --- Contour Simplification --- p.24 / Chapter 4.4.1 --- Variational segmentation --- p.25 / Chapter 4.4.2 --- Topology and distortion verification --- p.27 / Chapter 4.4.3 --- Hausdorff Error Analysis --- p.31 / Chapter 4.5 --- Results and Discussion --- p.33 / Chapter 5 --- Reliable and Robust Region Subtraction for Support Generation --- p.43 / Chapter 5.1 --- Introduction --- p.43 / Chapter 5.2 --- Preliminary --- p.46 / Chapter 5.3 --- Region Subtraction --- p.48 / Chapter 5.3.1 --- Binary Image Grid-width and Self-support Feature Threshold --- p.48 / Chapter 5.3.2 --- Conservative Growing-swallow Method --- p.50 / Chapter 5.4 --- Region Cleaning Technique for FDM --- p.53 / Chapter 5.5 --- Anchor Support Generation for SLA --- p.57 / Chapter 5.6 --- Result and Discussion --- p.60 / Chapter 6 --- Conclusion --- p.71 / Chapter 6.1 --- Summary and Discussion --- p.71 / Chapter 6.2 --- Future Work --- p.73 / Chapter A --- Inconsistent Contouring Problem Analysis --- p.76 / Bibliography --- p.80

published_or_final_version / abstract / toc / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

Economic and productive utilization of natural resources are central to fundamental Industrial Engineering science, whereas capitalistic corporate strategy is aimed at growth of shareholders capital investments made into capitalistic systems of organizations and industries. In this thesis it is established that Industrial Engineering principles are applicable, as a strategic tool, in the economic and productive utilization of corporate resources such as organizations within unrelated industries aimed at achieving the capitalistic corporate goal. In this expanded field of Industrial Engineering termed Strategic Industrial Engineering, scientific engineering knowledge is therefore applied to capitalistic systems with the strategic aim of accumulating capital for the corporate shareholders. The proposition of this thesis, termed A Strategic Industrial Engineering Philosophy, is primarily justified by applying the philosophical principle of sufficient reasoning. Secondary to this, scientific frameworks are proposed that support this expanded philosophy of Industrial Engineering by demonstrating the achievement of the capitalistic corporate goal. This is achieved through the following: -- Setting return on equity (ROE) as the scientific measure of capital accumulation; -- proposing a Strategic Industrial Engineering Process, aimed at achieving the capitalistic corporate goal, for further research. This process is based on the following: --- the relationship between the fundamental strategy and engineering processes; and --- fundamental corporate performance-regulating principles. -- demonstrating the validity of these performance-regulating principles through explorative statistical analyses. The proposed Strategic Industrial Engineering Process, to be fully defined through further research, is illustrated in Figure 1. See figure 1 in 00front Fundamental corporate strategies are proposed based on applying the Strategic Industrial Engineering Process as a strategic tool. These corporate strategies are based on the following, as indicated in Figure 2. -- Organisational competitiveness -- industry competitiveness; and -- cost of equity. See figure 2 in 00front In figure 3 it is illustrated that the following performance-regulating principles influence the accumulation of capital (ROE) for the benefit of capitalistic corporate shareholders. -- The competitiveness of its individual organizations; -- The individual organisations’ accumulation of capital relative to the cost of equity; -- The competitiveness of the industry structures that the corporation is exposed to; and -- Strategic fit benefits that improve the corporate performance too more than the average performance of its individual organizations. See figure 3 in 00front A corporation’s accumulation of capital is influence by the positions of its individual organizations on the industry ROE life cycle. The proposed industry ROE life cycle is illustrated in Figure 4. See figure 4 in 00front Lastly, the foremost intent with this thesis is to establish and demonstrate a specific way of thinking about the role of Industrial Engineering in corporate strategy. / Thesis (PhD)--University of Pretoria, 2005. / Industrial and Systems Engineering / unrestricted

Cutting and packing problems are combinatorial optimisation problems. The major interest in these problems is their practical significance, in manufacturing and other business sectors. In most manufacturing situations a raw material usually in some standard size has to be divided or be cut into smaller items to complete the production of some product. Since the cost of this raw material usually forms a significant portion of the input costs, it is therefore desirable that this resource be used efficiently. A hybrid general genetic algorithm is presented in this work to solve one and two dimensional problems of this nature. The novelties with this algorithm are: A novel placement heuristic hybridised with a Genetic Algorithm is introduced and a general solution encoding scheme which is used to encode one dimensional and two dimensional problems is also introduced.

Thesis (MEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Artificial intelligence has provided several techniques with applications in manufacturing. Knowledge based systems, neural networks, case based reasoning, genetic algorithms and fuzzy logic have been successfully employed in manufacturing. This thesis will provide the reader with an introduction and an understanding of each of these techniques (Chapter 2 & 3). The intelligent manufacturing process can be a complex one and can be decomposed into several components: intelligent design, intelligent process planning, intelligent quality management, intelligent maintenance and diagnosis, intelligent scheduling and intelligent control. This thesis will focus on how each of the artificial intelligence techniques can be applied to each of the manufacturing process fields. Chapter 5 Chapter 6 Chapter 7 Knowledge based systems Neural networks Fuzzy logic Case based reasoning Genetic algorithms Chapter 8 Chapter 9 Chapter 10 Manufacturing intelligence can be approached from two main directions: theoretical research and practical application. Most of the concepts, methods and techniques discussed in this thesis are approached from a theoretical research point of view. This thesis is also aimed at providing the reader with a broader picture of manufacturing intelligence and how to apply the intelligent techniques, in theory. Specific attention will be given to intelligent scheduling as an application (Chapter 11). The application will demonstrate how case based reasoning can be applied in intelligent scheduling within a small manufacturing plant. / AFRIKAANSE OPSOMMING: Kunsmatige intelligensie bied 'n verskeidenheid tegnieke en toepassings in die vervaardigingsomgewing. Kennis baseerde sisteme, neurale netwerke, gevalle basseerde redenasie, generiese algoritmes en wasige logika word suksesvol in die vervaardigingsopset toegepas. Dié tesis gee die leser 'n inleiding en basiese oorsig van metodes om elk van die tegnieke te gebruik (hoofstuk 2 & 3). Die intelligente vervaardigingproses is 'n komplekse proses en kan afgebreek word in verskeie komponente: intelligente ontwerp, intelligente prosesbeplanning, intelligente gehaltebestuur, intelligente onderhoud en diagnose, intelligente kontrole en intelligente skedulering. Hierdie tesis sal fokus op hoe elk van die kunsmatige intelligente tegnieke op elk van die vervaardigingprosesvelde toegepas kan word. Hoofstuk 5 Hoofstuk 6 Hoofstuk 7 Kennis gebaseerde sisteme Wasige logika Neurale netwerke Gevalle baseerde redenasie Generiese algoritmes Hoofstuk 8 Hoofstuk 9 Hoofstuk 10 Vervaardigingsintelligensie kan vanuit twee oogpunte benader word, naamlik 'n teoretiese ondersoek en 'n praktiese aanslag. Die meeste van hierdie konsepte, metodes en tegnieke word in hierdie tesis vanuit 'n teoretiese oogpunt benader. Die tesis is daarop gerig om die leser 'n wyer perspektief te gee van intelligente vervaardiging en hoe om die intelligente tegnieke, in teorie, toe te pas. Spesifieke aandag sal gegee word aan intelligente skedulering as 'n toepassing (Hookstuk 11). Die toepassing sal demonstreer hoe gevalle baseerde redenasie toegepas kan word in intelligente skedulering.

A partir dos anos 2000 houve uma significativa mudança no cenário global da manufatura, no sentido de induzir as empresas a trabalhar dentro de ambientes colaborativos, os quais necessitam de soluções mais integradas ao \'modelo de empresa estendida\' para colaborar a organização como um todo, incluindo parceiros, fornecedores e clientes. Na atualidade, as atividades de planejamento e gerenciamento dos processos de manufatura necessitam levar em consideração a dispersão de recursos (do ponto de vista sistema), que engloba inclusive o conhecimento e a informação. Um problema de grande importância está na \'conexão\' (interface) entre as engenharias, os ambientes de produção e os ambientes de operações comerciais, principalmente na precisão do compartilhamento de dados. Como proposta de solução deste problema a pesquisa tem como contribuição a criação do modelo de referência denominado PLM2M (PLM to Manufacturing), suportado pelas iniciativas da manufatura digital DM (Digital Manufacturing) do PLM (Product Lifecycle Management), que envolvem \'simulação\' e \'procedimentos colaborativos\', principalmente para as atividades de planejamento e gerenciamento de processos de manufatura, consideradas o \'elo\' entre o desenvolvimento de produtos, o gerenciamento do chão de fábrica e o planejamento e controle da produção. O modelo de referência PLM2M tem como objetivo integrar as áreas que participam do processo de manufatura. Está fundamentado em um conjunto de procedimentos que explora estratégias de modelagem de fluxos de trabalho WfMS (Workflow Management System) e arquitetura TIC (Tecnologia da Informação e Comunicação), a modelagem de processos de negócios, as definições de produto, o layout de plantas industriais, os recursos (máquinas e dispositivos, matéria-prima e pessoas), o sequenciamento das operações de produção (que releva a demanda e envolve volume, variedade e prazos), e ainda, o controle e gerenciamento das informações de chão de fábrica. O modelo PLM2M estabelece relação com a gestão de portfólio de programas e projetos no ciclo de vida de produtos (PLM) e tem o propósito de oferecer melhoria de produtividade, ajuste de capacidade de produção e melhor reuso dos ativos da planta, proporcionando melhores \'time-to-market\' de produtos. Para implementar o modelo PLM2M considera-se a hipótese de que esse modelo deve ser aplicado em cenários de planejamento e gerenciamento de processos de manufatura para ambientes complexos e dispersos e que estejam engajados dentro de critérios de avaliação (assessment) de modelos de maturidade e capabilidade em relação ao uso do PLM e Manufatura Digital. / Since 2000, there has been a significant change in the global scenario of manufacturing, in order to induce companies to work within collaborative environments, which require more integrated solutions to the \'extended enterprise model\' to collaborate the organization as a whole, including partners, suppliers and customers. In the current days, the activities of manufacturing process planning and management need to take into account the dispersion of resources (from the point of view system), which includes the knowledge and information. A problem of great importance is the \'connection\' (interface) among the engineering, the production environments and the commercial operations environments, mainly in the accuracy of the data sharing. As a proposal for solve this problem the research presents as a contribution the creation of the reference model called PLM2M (PLM to Manufacturing), supported by initiatives of Digital Manufacturing (DM) of PLM (Product Lifecycle Management), that involves \'simulation\' and \'collaborative procedures\', principally for activities of manufacturing processes planning and management, considered the \'link\' among the products development, the shop floor management and the production planning and control. The PLM2M reference model has as objective to integrate the areas that participate in the manufacturing process. It is based on a set of procedures that explores workflows modeling strategies WfMS (Workflow Management System) and ICT (Information and Communication Technology) architecture, the business processes modeling, the product definitions, the layout of industrial plants, the resources (machines and devices, raw materials and people), the sequencing of production operations (which takes into account the demand and involves volume, variety and lead-time), and yet, the shop floor information control and management. The PLM2M model establishes relationship with the portfolio management of programs and projects in the product lifecycle management (PLM) and has the purpose to provide productivity improvement, adjustment of production capacity and better reuse of plant assets, providing better \'time-to-market\' of products. To implement the PLM2M model, it is important to consider the hypothesis that this model should be applied in manufacturing process planning and management scenarios for complex and dispersed environments and that are engaged within assessment criteria of maturity and capability models in relation to the use of PLM and Digital Manufacturing.

A partir dos anos 2000 houve uma significativa mudança no cenário global da manufatura, no sentido de induzir as empresas a trabalhar dentro de ambientes colaborativos, os quais necessitam de soluções mais integradas ao \'modelo de empresa estendida\' para colaborar a organização como um todo, incluindo parceiros, fornecedores e clientes. Na atualidade, as atividades de planejamento e gerenciamento dos processos de manufatura necessitam levar em consideração a dispersão de recursos (do ponto de vista sistema), que engloba inclusive o conhecimento e a informação. Um problema de grande importância está na \'conexão\' (interface) entre as engenharias, os ambientes de produção e os ambientes de operações comerciais, principalmente na precisão do compartilhamento de dados. Como proposta de solução deste problema a pesquisa tem como contribuição a criação do modelo de referência denominado PLM2M (PLM to Manufacturing), suportado pelas iniciativas da manufatura digital DM (Digital Manufacturing) do PLM (Product Lifecycle Management), que envolvem \'simulação\' e \'procedimentos colaborativos\', principalmente para as atividades de planejamento e gerenciamento de processos de manufatura, consideradas o \'elo\' entre o desenvolvimento de produtos, o gerenciamento do chão de fábrica e o planejamento e controle da produção. O modelo de referência PLM2M tem como objetivo integrar as áreas que participam do processo de manufatura. Está fundamentado em um conjunto de procedimentos que explora estratégias de modelagem de fluxos de trabalho WfMS (Workflow Management System) e arquitetura TIC (Tecnologia da Informação e Comunicação), a modelagem de processos de negócios, as definições de produto, o layout de plantas industriais, os recursos (máquinas e dispositivos, matéria-prima e pessoas), o sequenciamento das operações de produção (que releva a demanda e envolve volume, variedade e prazos), e ainda, o controle e gerenciamento das informações de chão de fábrica. O modelo PLM2M estabelece relação com a gestão de portfólio de programas e projetos no ciclo de vida de produtos (PLM) e tem o propósito de oferecer melhoria de produtividade, ajuste de capacidade de produção e melhor reuso dos ativos da planta, proporcionando melhores \'time-to-market\' de produtos. Para implementar o modelo PLM2M considera-se a hipótese de que esse modelo deve ser aplicado em cenários de planejamento e gerenciamento de processos de manufatura para ambientes complexos e dispersos e que estejam engajados dentro de critérios de avaliação (assessment) de modelos de maturidade e capabilidade em relação ao uso do PLM e Manufatura Digital. / Since 2000, there has been a significant change in the global scenario of manufacturing, in order to induce companies to work within collaborative environments, which require more integrated solutions to the \'extended enterprise model\' to collaborate the organization as a whole, including partners, suppliers and customers. In the current days, the activities of manufacturing process planning and management need to take into account the dispersion of resources (from the point of view system), which includes the knowledge and information. A problem of great importance is the \'connection\' (interface) among the engineering, the production environments and the commercial operations environments, mainly in the accuracy of the data sharing. As a proposal for solve this problem the research presents as a contribution the creation of the reference model called PLM2M (PLM to Manufacturing), supported by initiatives of Digital Manufacturing (DM) of PLM (Product Lifecycle Management), that involves \'simulation\' and \'collaborative procedures\', principally for activities of manufacturing processes planning and management, considered the \'link\' among the products development, the shop floor management and the production planning and control. The PLM2M reference model has as objective to integrate the areas that participate in the manufacturing process. It is based on a set of procedures that explores workflows modeling strategies WfMS (Workflow Management System) and ICT (Information and Communication Technology) architecture, the business processes modeling, the product definitions, the layout of industrial plants, the resources (machines and devices, raw materials and people), the sequencing of production operations (which takes into account the demand and involves volume, variety and lead-time), and yet, the shop floor information control and management. The PLM2M model establishes relationship with the portfolio management of programs and projects in the product lifecycle management (PLM) and has the purpose to provide productivity improvement, adjustment of production capacity and better reuse of plant assets, providing better \'time-to-market\' of products. To implement the PLM2M model, it is important to consider the hypothesis that this model should be applied in manufacturing process planning and management scenarios for complex and dispersed environments and that are engaged within assessment criteria of maturity and capability models in relation to the use of PLM and Digital Manufacturing.

Made available in DSpace on 2016-06-02T19:51:51Z (GMT). No. of bitstreams: 1 3829.pdf: 4230286 bytes, checksum: 57d5e0c531823572429b3f117b7809fb (MD5) Previous issue date: 2011-06-21 / A necessary condition for the economic efficiency of modern plants is the ability to adjust - as quickly and effectively as possible - the performance of manufacturing process for demand request decisions. In this sense, the research emphasized the importance of understanding the best practices in Information Technology (IT) and the trade scenario of solutions using shopfloor real data in virtual environments for simulation and many achieved benefits. The highlights of this research focused on exploring the collaboration (practice of skills for the achievement of mutually beneficial results) between the MES (Manufacturing Execution Systems) and the digital manufacturing systems (also called virtual manufacturing systems) of PLM (Product Lifecycle Management), in a scenario where the manufacturing processes require high flexibility, reliability and lower delivery times, extensive combination of variants and lower life-cycle of products. The research - in an exploratory and descriptive way, which identified the available knowledge on the subject more sharply between the years 2006 and 2010 - was grounded in the practices of world-renowned companies and institutions and considered opinions and evaluations of renowned researchers and professionals with expertise in initiatives to support the use of MES solutions data in systems of digital manufacturing of PLM to manufacturing processes planning. As a result of the studied scenarios and covered concepts, the research has consolidated a "diagram of information collaboration", with the aim of providing better decision choices within the framework of shop-floor project, processes planning and production management. The research also concluded that the MES systems may have their value extended if integrated within the characteristics of functionalities of the PLM concept. It also brought some recommendations and limitations on the portability of information, commented on the learned lessons and suggestions for future tasks that include the BPM (Business Process Management). / Uma condição necessária para a eficiência econômica das fábricas modernas é a habilidade de adequar - de forma mais rápida e melhor possível - o desempenho dos processos de manufatura às decisões de solicitação de demanda. Nesse sentido, ressaltou-se a importância de compreender as melhores práticas de Tecnologia da Informação (TI) e o cenário comercial de soluções que utilizam dados reais de chão-de-fábrica em ambientes virtuais de simulação e os vários benefícios obtidos. O destaque desta pesquisa ficou por conta de explorar a colaboração (prática de competências para a obtenção de resultados mutuamente vantajosos) entre os sistemas MES (Manufacturing Execution Systems) e os sistemas de manufatura digital (também chamada fábrica virtual) do PLM (Product Lifecycle Management), num cenário onde os processos de manufatura impõem alta flexibilidade, confiança e menores tempos de entrega, ampla combinação de variantes e menores ciclos de vida de produtos. A pesquisa - de forma exploratória e descritiva, que identificou o conhecimento disponível sobre o tema mais acentuadamente entre os anos de 2006 e 2010 - foi embasada nas práticas de instituições e empresas mundialmente reconhecidas, e considerou opiniões e avaliações de profissionais e pesquisadores renomados nas iniciativas que apóiam a utilização de dados das soluções MES em sistemas de manufatura digital do PLM para o planejamento de processos de manufatura. Como resultado dos cenários estudados e conceitos abordados, a pesquisa consolidou um diagrama de colaboração da informação , com o propósito de auxiliar melhores tomadas de decisão no âmbito do projeto de chão-de-fábrica, planejamento de processos e gerência da produção. A pesquisa ainda concluiu quanto os sistemas MES podem ter seu valor ampliado se integrados dentro das características de funcionalidades do conceito PLM, trouxe algumas recomendações e limitações sobre a portabilidade das informações, comentou sobre as lições aprendidas e apresentou sugestões de trabalhos futuros que inclui o gerenciamento de processos de negócios BPM (Business Process Management).