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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Real-time simulation of advanced manufacturing systems

Edinburg, Ari January 1991 (has links)
A project report submitted to the Faculty of Engineering. University of the Witwatersrand, Johannesburg, in Partial fulfilment of the requirements for the. degree of Master of Science in Engineering, Johannesburg. 1991 / In order to analyse and optimize the design and Operation of Advanced Manufacturing Systems (AMS) various simulation techniques are currently in use. However, these methods are' generally inflexible and are used off-line in this project report, a modular, modelling approach is adopted to investigate the requirements of shop floor device models which operate in real-time. The models when connected together, simulate the Operation of the AMS. A suitable technique for the development of these models is proposed. A simulation architecture to support the models is discussed. It is intended that the models are connected on-line to the AMS control system via a local Area Network (LAN). [Advantages and - applications of this approach to AMS simulation are discussed. / MT2017
122

Benefits & barriers of implementing reconfigurable jigs : A study in offsite manufacturing of unique house elements in Sweden

Sege, Victoria, Balta, Pelda January 2019 (has links)
The aim of this paper is to identify the enablers, barriers and benefits of implementing reconfigurable jigs in the off-site manufacturing of unique house elements. Due to de- mands on customization, volume and lowering the cost, there is a need to increase flex- ibility in the industry. The paper focuses on mainly two phases of implementation, which are manufacturing, design and engineering. The research questions are answered by applying a single case study method, taking place in a Swedish house manufacturing company. The study consists of four different techniques – interviews, time study, observations, and questionnaire which are sup- ported with an additional literature review. Hence, research questions are answered from a triangulation approach providing nuanced and dynamic perspectives. From observations and time study it is concluded that in current situation, changeover in manufacturing is time-consuming due to the difference in complexity of product var- iants, along with a complex and inefficient setup process that is not responsive to a changeable environment. Findings imply that the barriers in both phases include lack of knowledge about reconfigurability, communication, current capabilities of CAD sys- tems as well as training and education. Enablers are found to be awareness of the needs of improvements, long-term mindset and working with product platforms. The benefits of implementing reconfigurable jigs include a reduction of setup time in manufacturing, better storage and sharing of information along with a better interpretation of that in- formation, a better structure in the organisation.
123

Método de apoio à decisão de escolha de tecnologia em sistemas flexíveis de manufatura: estudo de caso

Mâncio, Vagner Gerhardt 03 July 2015 (has links)
Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-02-15T15:42:38Z No. of bitstreams: 1 Vagner Gerhardt Mâncio_.pdf: 2330651 bytes, checksum: 51d1129f6c7064f70ea101a75bca32d1 (MD5) / Made available in DSpace on 2016-02-15T15:42:38Z (GMT). No. of bitstreams: 1 Vagner Gerhardt Mâncio_.pdf: 2330651 bytes, checksum: 51d1129f6c7064f70ea101a75bca32d1 (MD5) Previous issue date: 2015-07-03 / Nenhuma / A competição entre as empresas é cada vez mais um fator de sobrevivência, e a busca de diferenciais é o principal objetivo para que as empresas tornem-se destaques no mercado e se mantenham competitivas. Com o objetivo de contribuir para a evolução das empresas com variedade de produtos e uma taxa média de produção, desenvolveu-se esta pesquisa sobre a viabilidade de altos investimentos em automação e a criação de um método para a escolha de equipamentos a partir de uma visão estratégica, considerando as principais dimensões de competição: custo, qualidade, flexibilidade, entrega. A pesquisa delimita-se no campo de Sistemas Flexíveis de Manufatura – do inglês Flexible Manufacturing System (FMS) –, cujas análises estratégicas e de equipamentos de automatização tenham características de sistemas flexíveis. A pesquisa foi desenvolvida na metodologia de modelagem quali-quantitativa, na qual, através da modelagem dos cenários, puderam ser realizadas avaliações qualitativas e quantitativas; o Método de Análise Hierárquica – do inglês Analytic Hierarchy Process (AHP) – foi utilizado para determinar o cenário que melhor combina com a principal variável competitiva. Para o desenvolvimento da pesquisa, foram coletadas opiniões de especialistas de empresas sobre os pesos comparativos do método AHP e sobre os equipamentos de automação que fazem parte dos cenários criados. O cenário 1 possui layout escada com a movimentação dos materiais realizado por esteiras através de pallets, cuja manipulação é realizada por sistemas pneumáticos. O cenário 2 possui layout campo aberto com a movimentação dos materiais realizado por veículos guiados automaticamente – do inglês Automated Guided Vehicle (AGV), capazes de abastecer e descarregar os equipamentos. O cenário 3 possui layout centrado no robô, com 3 robôs que se movimentam em uma esteira para abastecer e desabastecer os equipamentos. Foram propostos dois métodos de cálculo do mérito final dos cenários, e, para ambos, o melhor cenário foi o 3. Adicionalmente, concluiu-se que adotar o cenário 3 é melhor do que não fazer nada, ou seja, continuar com a instalação atual da célula estudada. / The competition between companies is increasingly a factor of survival, and the search for differential is the main objective for companies to become highlights in the market and remain competitive. In order to contribute to the development of companies with a variety of products and an average rate of production, this research was carried out on the feasibility of large investments in automation and the creation of a method for choosing equipment from a vision strategic, considering the main dimensions of competition: cost, quality, flexibility, delivery. The research is delimited in the Flexible Manufacturing Systems field (FMS) whose strategic analysis and automation equipment have flexible systems characteristics. The research was conducted in the qualitative and quantitative modeling methodology, in which, through the modeling of scenarios, could be carried out qualitative and quantitative assessments; the Analytic Hierarchy Process (AHP) was used to determine the setting that best suits the key competitive variable. For the development of research, business expert opinions were collected on the comparative weights of AHP and on the automation equipment that are part of the created scenarios. Scenario 1 has ladder layout with the movement of the materials carried by pallets through mats, in which the handling of materials is achieved by pneumatic systems. Scenario 2 has the open layout with the movement of materials held by Automated Guided Vehicle (AGV), able to supply and unloading equipment. Scenario 3 has focused on the layout robot, in which there are three robots, moving on a conveyor and load and unload the equipment. Two methods of calculating the final merit of the scenarios were proposed. By both methods, the best scenario was the 3. Additionally, the conclusion is that adopting the scenario 3 is better than doing nothing, that is, continue with the current installation of cell studied.
124

On the Micro-Precision Robotic Drilling of Aerospace Components

Newberry, John Christopher, john.newberry@rmit.edu.au January 2007 (has links)
This dissertation describes research concerned with the use of advanced measurement techniques for the control of robotic manufacturing processes. The work focused on improving the state of technology in the precision robotic machining of components within the aerospace manufacturing industry within Australia. Specific contributions are the development of schemes for the use of advanced measurement equipment in precision machining operations and to apply flexible manufacturing techniques in automated manufacturing. The outcome of the research enables placement of a robotic end effector to drill a hole with a positional accuracy of 300 micron, employing an Indoor Global Positioning System for control of the drilling process. This can be accomplished within a working area of 35 square metres where the robot system and/or part positions may be varied dynamically during the process. Large aerospace structures are capable of flexing during manufacturing operations due to their physical size and low modulus of rigidity. This research work provided a framework for determining the appropriate type of automation and metrology systems needed for dynamic control suited to the precision drilling of holes in large aerospace components.
125

Complex materials handling and assembly systems.

January 1979 (has links)
Report covers June 1, 1976-July 31, 1978. / Each v. has also a distinctive title. / National Science Foundation. Grant NSF/RANN APR76-12036 National Science Foundation. Grant DAR78-17826
126

Complex materials handling and assembly systems.

January 1979 (has links)
Report covers June 1, 1976-July 31, 1978. / Each v. has also a distinctive title. / National Science Foundation. Grant NSF/RANN APR76-12036 National Science Foundation. Grant DAR78-17826
127

Complex materials handling and assembly systems.

January 1979 (has links)
Report covers June 1, 1976-July 31, 1978. / Each v. has also a distinctive title. / National Science Foundation. Grant NSF/RANN APR76-12036 National Science Foundation. Grant DAR78-17826
128

Complex materials handling and assembly systems.

January 1979 (has links)
Report covers June 1, 1976-July 31, 1978. / Each v. has also a distinctive title. / National Science Foundation. Grant NSF/RANN APR76-12036 National Science Foundation. Grant DAR78-17826
129

Complex materials handling and assembly systems.

January 1979 (has links)
Report covers June 1, 1976-July 31, 1978. / Each v. has also a distinctive title. / National Science Foundation. Grant NSF/RANN APR76-12036 National Science Foundation. Grant DAR78-17826
130

Complex materials handling and assembly systems.

January 1979 (has links)
Report covers June 1, 1976-July 31, 1978. / Each v. has also a distinctive title. / National Science Foundation. Grant NSF/RANN APR76-12036 National Science Foundation. Grant DAR78-17826

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