Browsing by Subject "Manufacturing"
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Item Automated conceptual design of manufacturing workcells in radioactive environments(2013-08) Williams, Joshua Murry; Landsberger, Sheldon; Pryor, Mitchell WayneThe design of manufacturing systems in hazardous environments is complex, requiring interdisciplinary knowledge to determine which components and operators (human or robotic) are feasible. When conceptualizing designs, some options may be overlooked or unknowingly infeasible due to the design engineers' lack of knowledge in a particular field or ineffective communication of requirements between disciplines. To alleviate many of these design issues, we develop a computational design tool to automate the synthesis of conceptual manufacturing system designs and optimization of preliminary layouts. To generate workcell concepts for manufacturing processes, we create a knowledge-based system (KBS) that performs functional modeling using a common language, a generic component database, and a rule set. The KBS produces high-level task plans for specific manufacturing processes and allocates needed material handling tasks between compatible human and/or robotic labor. We develop an extended pattern search (EPS) algorithm to optimize system layouts based on worker dose and cycle time minimization using the functions and sequencing of generated task plans. The KBS and EPS algorithm were applied to the design of glovebox processing systems at Los Alamos National Laboratory (LANL). Our computational design tool successfully generates design concepts with varied task allocation and processing sub-tasks and layouts with favorable manipulation workspaces. This work establishes a framework for automated conceptual design while providing designers with a beneficial tool for designing manufacturing systems in an interdisciplinary and highly constrained domain.Item Automated estimation of time and cost for determining optimal machining plans(2012-05) Van Blarigan, Benjamin; Campbell, Matthew I.; Li, WeiThe process of taking a solid model and producing a machined part requires the time and skillset of a range of professionals, and several hours of part review, process planning, and production. Much of this time is spent creating a methodical step-by-step process plan for creating the part from stock. The work presented here is part of a software package that performs automated process planning for a solid model. This software is capable of not only greatly decreasing the planning time for part production, but also give valuable feedback about the part to the designer, as a time and cost associated with manufacturing the part. In order to generate these parameters, we must simulate all aspects of creating the part. Presented here are models that replicate these aspects. For milling, an automatic tool selection method is presented. Given this tooling, another model uses specific information about the part to generate a tool path length. A machining simulation model calculates relevant parameters, and estimates a time for machining given the tool and tool path determined previously. This time value, along with the machining parameters, is used to estimate the wear to the tooling used in the process. Using the machining time and the tool wear a cost for the process can be determined. Other models capture the time of non-machining production times, and all times are combined with billing rates of machines and operators to present an overall cost for machining a feature on a part. If several such features are required to create the part, these models are applied to each feature, until a complete process plan has been created. Further post processing of the process plan is required. Using a list of available machines, this work considers creating the part on all machines, or any combination of these machines. Candidates for creating the part on specific machines are generated and filtered based on time and cost to keep only the best candidates. These candidates can be returned to the user, who can evaluate, and choose, one candidate. Results are presented for several example parts.Item Dynamic modeling of membrane swelling in fuel cell manufacturing(2010-12) Silverman, Timothy J.; Beaman, Joseph J.; Meyers, Jeremy P.; Chen, Dongmei; Edgar, Thomas F.; Fahrenthold, Eric P.Fuel cells are promising energy conversion devices, but they have not been widely adopted because of their very high cost. The most expensive component of a fuel cell is the membrane electrode assembly, a polymer film coated with catalyst material. The catalyst layer is fabricated by depositing and drying a liquid ink on the membrane. The membrane can rapidly absorb water from the ink, causing swelling strain sufficient for wrinkling, which can cause defects in the finished product. These challenges limit most catalyst layer fabrication to individual preparation by hand. We seek to understand the swelling phenomenon in a way that enables the control of defects during mass production. Membrane swelling is a transient, three-dimensional, coupled mass transfer, heat transfer and solid mechanics problem. Existing models describe the membrane in fuel cell operating conditions, making use of simplifying assumptions that are not valid for predicting manufacturing defects. We present a new model incorporating effects that are missing from other models. We present simulation results for scenarios relevant to the control of defects. Simple spatial variations in water content can cause curl and wrinkling; we establish criteria for the formation of these defects by simulating the membrane's response when subjected to the full pre-swollen coating and drying process. We investigate the sensitivity of wrinkling to nonuniformity in the coating and to processing conditions in the coating line. We propose a rationale for controlling wrinkling caused by these effects and for diagnosing coating defects using the membrane's wrinkling response. We show how the membrane behaves differently depending on whether the coating is applied to one side or to both sides simultaneously. We have designed and constructed a machine to pre-swell the membrane, apply a coating and then dry the coating under controlled tension, speed, temperature and humidity. We present the design and discuss how the machine may be used, together with the membrane model, to predict and control defects in catalyst-coated membranes.Item How technical standards are developed for global engineering and manufacturing organizations(2010-08) Bauer Bailey, Alyssa Kay; Seepersad, Carolyn C.; Ambler, TonyThis paper explores how corporations can choose technical standards used throughout its organization. A methodology for choosing the standard is introduced. It is based on the methods that professional standards organizations use to create new standards for industries. The steps to choose an external standard as well as create new internal standards are consensus, development, approvals, and maintenance. Questions about standards from Applied Materials are answered: what technical standard should be used for engineering drawings, should the company use metric units, what tolerance scheme should be used, and how are standards chosen when a merger or acquisition is performed? Applied Materials should use the ASME Y14.5M-1994 standard. The move to metric should be done if the customers request it. Simple parts and complex assemblies should not be toleranced the same way. When mergers and acquisitions are done, the consensus, development, approval, and maintenance method should be used to choose which standards should be used.Item Lithography variability driven cell characterization and layout optimization for manufacturability(2011-05) Ban, Yong Chan; Pan, David Z.; Abraham, Jacob; Touba, Nur; Lucas, Kevin; Orshansky, MichaelStandard cells are fundamental circuit building blocks designed at very early design stages. Nanometer standard cells are prone to lithography proximity and process variations. How to design robust cells under variations plays a crucial role in the overall circuit performance and yield. This dissertation studies five related research topics in design and manufacturing co-optimization in nanometer standard cells. First, a comprehensive sensitivity metric, which seamlessly incorporates effects from device criticality, lithographic proximity, and process variations, is proposed. The dissertation develops first-order models to compute these sensitivities, and perform robust poly and active layout optimization by minimizing the total delay sensitivity to reduce the delay under the nominal process condition and by minimizing the performance gap between the fastest and the slowest delay corners. Second, a new equivalent source/drain (S/D) contact resistance model, which accurately calculates contact resistances from contact area, contact position, and contact shape, is proposed. Based on the impact of contact resistance on the saturation current, robust S/D contact layout optimization by minimizing the lithography variation as well as by maximizing the saturation current without any leakage penalty is performed. Third, this dissertation describes the first layout decomposition methods of spacer-type self-aligned double pattering (SADP) lithography for complex 2D layouts. The favored type of SADP for complex logic interconnects is a two-mask approach using a core mask and a trim mask. This dissertation describes methods for automatically choosing and optimizing the manufacturability of base core mask patterns, generating assist core patterns, and optimizing trim mask patterns to accomplish high quality layout decomposition in SADP process. Fourth, a new cell characterization methodology, which considers a random (line-edge roughness) LER variation to estimate the device performance of a sub-45nm design, is presented. The thesis systematically analyzes the random LER by taking the impact on circuit performance due to LER variation into consideration and suggests the maximum tolerance of LER to minimize the performance degradation. Finally, this dissertation proposes a design aware LER model which claims that LER is highly related to the lithographic aerial image fidelity and the neighboring geometric proximity. With a new LER model, robust LER aware poly layout optimization to minimize the leakage power is performed.Item Relevant factors in the path of successful implementation of Lean(2011-12) Carroll, Benjamin Todd; Lewis, Kyle, 1961-; Kutanoglu, ErhanIn any business environment companies experience challenges and competition. In this current worldwide economic crisis, the stakes are now higher. With every crisis comes opportunity. The best companies with the best methods and processes that create highest quality product for less money will have an extraordinary advantage over their less efficient, lower quality competition. The term ‘Lean’ describes how Toyota does business: fewer humans, less effort, less investment, fewer defects, less time to develop, less inventory. For companies that have truly understood and implemented these principles the effects are significant; but many others have failed Lean initiatives. What factors are necessary for a company to successfully adopt the processes proven by over 50 years of success in Toyota? Using both primary and secondary research, I compared attributes of four companies, three of which were successful, and one that did not make the conversion. Three main factors emerged, the Technical Factor -- knowing both your core business and having a deep understanding of Lean principles, the Management Factor -- strong leadership operating within Lean principles and with hands-on approach, and the Human Factor -- approaching the workforce with respect and employee engagement in problem-solving process. The following is a brief review of these factors and the tools and concepts that undergird them.Item Semiconductor manufacturing dashboard(2012-12) Collier, Scott Allen; Barber, K. Suzanne; Graser, ThomasThe semiconductor manufacturing process is a complex process that can consist of hundreds if not thousands of steps. During this process an enormous amount of data is generated and collected by several different systems. Analyzing this data can be complicated and time consuming. But, in order to optimize the manufacturing process, it is important to be able to process data quickly and provide data consumers an easy, meaningful way to view the data. Data consumers at a management level need to view data differently than someone who works in the semiconductor fabrication plant (FAB) operating the manufacturing equipment or a maintenance technician who fixes and maintains the equipment. So, it is important to provide these different data views to the users in a logical, organized way. This paper will discuss what a dashboard is, an overview of the semiconductor manufacturing process, and one implementation of a dashboard for the semiconductor industry, the Semiconductor Manufacturing Dashboard (SMD). An explanation of the systems involved in collecting and loading the data, the database structures, and the web servers used for development and production will also be discussed.Item The use of personality profiles in personnel selection: an exploration of issues encountered in practical applications(Texas A&M University, 2004-11-15) Shelton, Matthew LarrenceThe purpose of this study was to explore the issues that are typically encountered when using personality instruments for personnel selection. Cattell's Sixteen Personality Factor Questionnaire (16PF) was used in the study to predict job performance in a small team-based manufacturing organization. Issues including the utility of the 16PF in this setting, the bandwidth fidelity argument (to use narrow or broad traits), and whether job-specific versus company-wide profiles provide better prediction success were addressed. The usefulness of the organization's current selection process of using the 16PF to generate interview questions was also investigated. Results indicate that the 16PF can be a useful tool for personnel selection in this setting and that the 16PF was able to correctly classify if an applicant was going to be successful over 86% of the time. Evidence for using narrow factors instead of broad factors was also presented, and the benefits of using job specific profiles were discussed. The limitations of this study were addressed, which included conducting this type of research with relatively small sample sizes. Additionally, this study provides suggestions for additional research in the future.Item Using the FRDPARRC design methodology to drive innovation in the HETDEX PFIP support adjustable strut assembly(2010-12) Molina, Homar; Nichols, Steven P.; Beno, Joseph H.This thesis provides background information on the Hobby-Eberly Telescope (HET), HET Dark Energy Experiment (HETDEX), Gough-Stewart platforms (GSP), the Prime Focus Instrument Package (PFIP) support structure, and the design methodology used to design said support structure. Each component is analyzed from the point of view of Professor Alex Slocum’s FRDPARRC design methodology. Each aspect of the design is shown to have been derived by following the steps of Slocum’s design method. Material selection, manufacturing techniques, and integration of off-the-shelf components into the support system are also discussed in reference to FRDPARRC. The assembly procedure for the PFIP structure is outlined. Finally, using specific examples from the detailed design, the FRDPARRC method itself is analyzed and its ability to drive innovation in design is evaluated.