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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.
71

Método de resolução de deadlocks no controle de produção de sistemas de manufatura automatizados utilizando redes de Petri coloridas

Souza, Wesley Willy Oliveira de 01 July 2011 (has links)
Made available in DSpace on 2016-06-02T19:06:03Z (GMT). No. of bitstreams: 1 4911.pdf: 4490259 bytes, checksum: 94cfbdb804ef2f55cb81e1163b1c6ad4 (MD5) Previous issue date: 2011-07-01 / Universidade Federal de Sao Carlos / Resources sharing is one of the main characteristics of Automated Manufacturing Systems (SMA), this characteristic can be a synonym of advantages but on the other hand it may lead to the problem of deadlock. Several papers have suggested methods and techniques to reduce or eliminate the occurrence of deadlocks in SMA systems. The deadlock resolution strategies suggested in the literature can be classified into the following types: deadlock detection and recovery, deadlock prevention and deadlock avoidance. This work proposes a resolution method for the control of automated manufacturing systems using colored Petri nets, the main goal of the proposed method is to provide a deadlock-free production controller. To model, simulate and implement the technique in a production controller a dedicated software is used to model the Petri Nets. Initially, a model using Colored Petri Nets is proposed, then changes in the model are introduced in order to eliminate the deadlocks, resulting in a Colored Petri net control model of the SMA. Finally the model is implemented in the scenario of a Flexible Manufacturing System for testing and validation of the method. / O Compartilhamento de recursos é uma das principais características dos Sistemas de Manufatura Automatizados (SMA), esta característica pode ser um sinônimo de vantagens, mas por outro lado pode levar ao problema de deadlock. Diversos trabalhos têm sugerido métodos e técnicas para reduzir ou eliminar a ocorrência de deadlocks em SMA. As estratégias de resolução de deadlock sugerido na literatura podem ser classificados nos seguintes tipos: detecção e recuperação de deadlocks, prevenção de deadlocks e de deadlock. Este trabalho propõe um método de resolução para o controle de sistemas de manufatura automatizados utilizando redes de Petri coloridas, o principal objetivo do método proposto é obter um controlador da produção livre de deadlocks. Para modelar, simular e implementar a técnica em um controlador de produção um software dedicado é usado para modelar a rede de Petri. Inicialmente, um modelo usando Redes de Petri Coloridas é proposto, então mudanças são introduzidas, a fim de eliminar os deadlocks, resultando em um modelo de rede de Petri de um SMA livre de deadlock. Finalmente o modelo é implementado no cenário de um Sistema de Manufatura Flexível para testes e validação do método.
72

Redução automatizada de redes de petri baseada em algoritmos genéticos

Bevilaqua, André 26 June 2014 (has links)
Made available in DSpace on 2016-06-02T19:06:15Z (GMT). No. of bitstreams: 1 6263.pdf: 2838494 bytes, checksum: 852261a244b09c47cc828522a799cc8d (MD5) Previous issue date: 2014-06-26 / Petri Net (PN) is a graphical mathematical tool used to create models that provide a formal specification of systems, creating the possibility of running behavior analysis and property verification. PN models can be used to model several system types, for example, Manufacturing Systems. In general, using PN to model systems with too many characteristics cause the so-called state-space explosion problem, in other words, a great element profusion in the model. In order to mitigate the referred problem researchers developed reduction rules to synthetize models. Reduced models maintain original system properties and can be easily analyzed and simulated. A method to automate reduction rules application is proposed on the present research. A Genetic Algorithm heuristic is responsible for applying six reductions rules on Place-Transition Petri Nets given as input. The proposed algorithm, presented as a Matlab toolbox, may contribute when simulating and running property verification methodologies on Petri Net models. / Rede de Petri (RP) é uma ferramenta de modelagem com rigor matemático usada para especificar e formalizar sistemas e suas características. Modelos de RP podem ser avaliados quanto à seu comportamento dinâmico e suas propriedades estruturais. Diversos tipos de modelos podem ser especificados usando RP s, por exemplo, modelos de Sistemas de Manufatura. De maneira geral, modelos de sistemas complexos sofrem do problema da grande profusão de elementos. Esse problema é um limitante para diversas metodologias de verificação de propriedades e simulação de comportamento dinâmico dos modelos. Frequentemente metodologias baseadas em regras de redução são propostas para superar o problema da grande profusão de elementos. O presente trabalho apresenta uma ferramenta para automatizar a aplicação de regras de redução em modelos de RP. Um conjunto de regras foi selecionado para montar uma base de regras de redução e uma heurística baseada em algoritmos genéticos foi criada para aplicar reduções em modelos de RP Lugar-Transição. Os resultados obtidos mostraram que a ferramenta proposta, apresentada como uma toolbox do Matlab, pode ser utilizada para auxiliar no processo de análise, simulação e verificação de propriedades de sistemas modelados por meio de RP s.
73

Análise da variabilidade de vibração em atuadores elétricos

Rocha, Clayton Gilnei Martins January 2016 (has links)
Em sistemas modernos de manutenção inteligente a qualidade de uma máquina ou equipamento depende do suporte que é fornecido junto com esse produto, com a confiabilidade e segurança na utilização do mesmo. Estas exigências, por vezes, não são cumpridas e podem estar indisponíveis em algumas máquinas. Este trabalho descreve uma abordagem utilizando sinais de vibração coletados em tempo real com falhas como estudo preliminar para uma abordagem mais profunda como estudo dametodologia de testes de vida acelerado para auxiliar durante a fase de vida operacional permitindo ao fabricante a determinação dos ciclos de vida do produto. A abordagem proposta construída em cima de experiências anteriores em desenvolvimento no projeto Integração de Sistemas Inteligentes de Manutenção e Cadeia de Fornecimento de Peças Sobressalentes. O objetivo deste trabalho é apresentar resultados preliminares analisando a variabilidade das assinaturas de falhas das engrenagens danificadas de maneira a permitir a identificação dos ciclos de vida do produto para partes específicas de um atuador elétrico. / In modern systems of intelligent maintenance the quality of a machine or equipment depends on the support that comes with this product, with the reliability and safety in the use of it. These requirements are sometimes not met and may be unavailable on some machines. This paper describes an approach using vibration signals collected in real-time with faults as a preliminary study for a deeper approach with the study of the methodology of accelerated life tests to assist during the operational life stage allowing the manufacturer the determination of the life cycles of product. The proposed approach built on previous experiences under development in the project Integration of Intelligent Systems of Maintenance and Chain of Supply of Spares. The objective of this work is to present preliminary results analyzing the variability of failure signatures of the damaged gears in order to allow the identification of product life cycles for specific parts of an electric actuator.
74

Controle de sistemas reconfiguráveis de manufatura. / Control of reconfigurable manufacturing systems.

Robson Marinho da Silva 01 August 2016 (has links)
A capacidade de reconfiguração de sistemas de manufatura tem sido procurada pelas empresas para assegurar características de agilidade, eficiência e exibilidade para atender as mudanças de tipo/quantidade de produtos, processos, recursos e, além disso, para assegurar a devida reação à ocorrência de falhas. Por outro lado, a Indústria 4.0\" impõe novos desafios para os sistemas de controle, tais como a integração de tecnologias de interação entre homem e máquina em cadeias de valor compondo uma rede de plantas industriais geograficamente dispersas. O controle de sistemas reconfiguráveis de manufatura deve considerar: (i) funcionalidades de sistemas distribuídos e dispersos, tais como agilidade de resposta às mudanças, autonomia e colaboração entre os componentes para alcançar os objetivos do sistema de forma conjunta; (ii) interfaces para sua interoperabilidade e portabilidade; (iii) modularização para facilitar a manutenção, expansão e atualização do sistema, evitando a sobreposição de escopos; e (iv) mecanismos de controle para supervisionar as ações e interações dos componentes, o diagnóstico e a tomada de decisão. O pleno atendimento a estes requisitos não é trivial e formalismos para o desenvolvimento de soluções devem ser adotados. Uma solução é combinar técnicas voltadas para sistema multiagente e holon com arquitetura orientada a serviço através de uma adequada técnica de modelagem usando extensões de rede de Petri: Production Flow Schema e Input Output Place Transition. Portanto, este trabalho prop~oe uma arquitetura de controle e o método de modelagem de seus componentes para sistemas reconfiguráveis de manufatura combinando estas técnicas e considerando os aspectos de personalização, convertibilidade, escalabilidade, modularidade, integrabilidade, diagnosticabilidade, interoperabilidade e colaboração entre os componentes do sistema de controle, inclusive do homem. Um exemplo de aplicação é apresentado para demonstrar a viabilidade da proposta e comprovar os resultados alcançados. / The reconfiguration ability of the manufacturing systems has been approached by companies to ensure agility, efficiency and exibility characteristics to address the changes of type/quantity of products, processes and resources and, furthermore, to ensure proper reaction to the fault occurrence. On the other hand, the\"Industry 4.0\" imposes new challenges for control systems, such as interaction between man and machine into value chains composing a network of geographically dispersed industrial plants. The control of reconfigurable manufacturing systems should consider: (i) functionalities requirements of distributed and disperse systems, such as responsiveness to changes, autonomy and collaboration among components to achieve the global system aim; (ii) interfaces for interoperability and portability; (iii) modularity to facilitate maintenance, expansion and upgrade of the system, avoiding the overlapping of scopes; and (iv) control mechanisms to supervise the actions and interactions among components, diagnosis and decision making. The compliance with these requirements is not trivial and formalisms to develop solutions must be adopted. A solution is combining techniques based on holonic and multi-agent system with service-oriented architecture through appropriate modeling using Petri net extensions: Production Flow Schema and Input Output Place Transition. Therefore, this paper proposes control architecture and a method to model components for reconfigurable manufacturing systems, combining these techniques and considering aspects of customization, convertibility, scalability, modularity, integrability, diagnosability, interoperability and collaboration among control system components, including humans. An application example is presented to demonstrate the feasibility of the proposal and verify the results.
75

Metodologia de implementação de planejamento de vendas e operações : estudo de caso em manufatura de produção para estoque / Sales and operations planning implementation methodology : case study in make to stock manufacturing

Barbeiro, Francisco Miguel 21 December 2005 (has links)
Orientador: Antonio Batocchio / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-06T08:19:28Z (GMT). No. of bitstreams: 1 Barbeiro_FranciscoMiguel_M.pdf: 3666365 bytes, checksum: 90bcb4b2a8648ea08f9f8360c1b7ed50 (MD5) Previous issue date: 2005 / Resumo: O Planejamento de Vendas e Operações é um processo integrado de gerenciamento do negócio, que pode gerar vantagem competitiva através de uma visão e entendimento do cenário futuro e do envolvimento de um time multifuncional para definir e executar um conjunto de planos operacionais alinhados de modo a maximizar os resultados do negócio e melhor atender os clientes. Este trabalho tem como objetivo apresentar uma metodologia que suporte a implementação de um Processo de Planejamento de Vendas e Operações e testá-la através de sua aplicação prática numa Divisão de Negócios que atende o mercado de consumo a partir de uma manufatura de produção para estoque. Identifica os fatores relevantes para uma implementação de sucesso, abordando os três elementos básicos do S&OP: i) Pessoas - Uma vez que o processo é gerenciado e operacionalizado por pessoas, estas precisam estar conscientes, treinadas, além de entender o que se espera delas. Precisam, também, operar o processo em conformidade com os princípios aprovados, políticas e procedimentos; ii) Processo - Um processo precisa estar formalizado, com etapas, entradas, saídas, definição de responsabilidades e de medidas de desempenho; iii) Ferramentas - Devem estar disponíveis para suportar as pessoas na execução de suas atividades. Podem incluir hardware, software, manuais e sistemas de comunicação. O trabalho aborda, também, os potenciais benefícios de um processo eficaz de S&OP, bem como suas limitações, demonstrando a melhoria do trabalho em equipe, do serviço aos clientes e da gestão de ativos, obtidos pela implementação do processo na Divisão de Negócio analisada / Abstract: Sales and Operations Planning is an integrated business management process to generate competitive advantage by looking forward, understanding future scenarios and involving a multifunctional team to define and execute a set of operational plans, aligned to maximize the business results and best attend the customers. This project aims to present a methodology to support a Sales and Operations Planning Process implementation and test it through a practical application in Business Division that attends consumer market through make to stock manufacturing. Identifies the relevant factors to a well succeeded implementation, covering S&OP basic elements: i) People - Whatever is a process managed and operated by people, they need to be acknowledgeable, trained and understand what is expected of them. They also need to operate the process in accordance with agreed-upon principles, policies and procedures; ii) Process - A process needs to be formalized, defining process steps, inputs, outputs, roles, responsibilities, and measurements; iii) Tools - Need to be available allowing people to fulfill their part in the process. These tools may include hardware, software, manual and communication systems. This project also wants to discuss Sales and Operations Planning potential benefits and limitations, demonstrating the improvements the Business Division achieved related to teamwork, customer service and asset management, due to the S&OP process implementation / Mestrado / Planejamento e Gestão Estrategica da Manufatura / Mestre em Engenharia Mecânica
76

Reengenharia de um SFM didático com o desenvolvimento de um sistema supervisório e a automoção de um AGV / Reengineering of an didactic FMS with the of development a supervisory system and automation of an AGV

Sérgio Ricardo Pacheco 30 April 2011 (has links)
Este trabalho tem por objetivo atualizar um Sistema Flexível de Manufatura, (SFM) didático, que devido às suas características construtivas apresentava inúmeras dificuldades de operação e manutenção, necessitando sempre de mão de obra altamente especializada. As dificuldades com a manutenção tornavam o SFM totalmente inoperante para a utilização nas aulas de uma das unidades da escola SENAI, o que prejudicava as atividades práticas, em laboratório, das disciplinas do curso técnico da área de produção. O projeto deste trabalho consistiu em uma reengenharia completa da parte elétrica de um Veículo Guiado Automaticamente (AGV) como também no desenvolvimento de um sistema supervisório, que comanda a comunicação entre os CNCs, AGV e computadores. Após as modificações efetuadas, os alunos das disciplinas da área de produção poderão interagir com o sistema, modificando a logística de produção conforme as necessidades didáticas a serem estudadas. Por outro lado os alunos de automação, por meio do acesso à documentação e à estrutura do sistema de manufatura, poderão desenvolver estudos e possíveis modificações, uma vez que o sistema se tornou mais didático e amigável. / This paper aims to update a didactic Flexible Manufacturing System (FMS) that due to their construction had numerous difficulties in operation and maintenance, and so constantly require manpower to operate and maintain highly specialized. The difficulties with maintaining the SFM became totally irrelevant, for use in the classroom of an unit school SENAI, would hinder the practical activities in the disciplines of laboratory technician course from the production area. The design of this work consisted in re-engineering of the complete electrical part of an Automatically Guided Vehicle (AGV) and development of a supervisory system and communication between the CNCs, AGV and computers. After the modifications to the students of the disciplines of production may interact with the system by modifying the production logistics as required didactic to be studied. Furthermore students automation through access to documentation and structure of the manufacturing system can develop studies and possible changes, since the system became more didactic and friendly.
77

Conception et déploiement des Systèmes de Production Reconfigurables et Agiles (SPRA) / Design and deployment of Reconfigurable and Agile Manufacturing Systems (RAMS)

Chalfoun, Imad 26 September 2014 (has links)
L'industrie est aujourd'hui, comme elle a toujours été, une pierre angulaire de l'économie pour chaque pays développé. Avoir une base solide en entreprises industrielles est très important parce qu’elles poussent et stimulent tous les autres secteurs de l'économie, et offrent également une grande variété d'emplois qui apporte des bonnes conditions de vie dans de nombreux secteurs de la société. L’augmentation de la concurrence mondiale, l’évolution rapide du marché, la nécessité de créer des entreprises stables avec des usines rentables obligent la mise en oeuvre d’une démarche globale prenant en compte à la fois les aspects techniques, économiques, logistiques et sociétaux lors de la conception d’un système de production innovant. L’objectif de cette thèse est de contribuer au développement d’un concept innovant de Systèmes de Production Reconfigurables et Agiles (SPRA) permettant de s'adapter rapidement et efficacement aux exigences imposées du marché, des clients, de la technologie des procédés, de l’environnement et de la société afin que l’entreprise soit dynamique, compétitive et rentable. Dans ces travaux de thèse, la proposition d'un modèle générique et la caractérisation de ce nouveau type de système de production ont été décrits en utilisant le langage de modélisation des systèmes complexes (SysML : Systems Modeling Language). Ensuite, nous avons développé un processus de reconfiguration qui représente une démarche à suivre pour concevoir et implanter une nouvelle configuration. De plus, un pilotage opérationnel adapté au SPRA a été introduit. Enfin, quelques travaux développés au cours de cette thèse ont été partiellement déployés sur un démonstrateur industriel au sein de la plate-forme AIP-PRIMECA Auvergne. / Industry is, today as it has always been, a cornerstone of the economy for any developed country. Having a strong manufacturing base is very important because it impels and stimulates all the other sectors of the economy. It provides a wide variety of job, which bring higher standards of living to many sectors of society, and builds a strong middle class. Increasing global competition, rapid changes in the marketplace and the need to create stable companies with profitable plants require the implementation of a global approach, taking into account technical, economic, logistic and societal aspects in the design of an innovative manufacturing system. The aim of this dissertation is to contribute to the development of an innovative concept of Reconfigurable and Agile Manufacturing Systems (RAMS) to adapt quickly and effectively to the requirements imposed by markets, customers, technology processes, the environment and society, to ensure that the enterprise is dynamic, competitive and profitable. In this thesis work, the characterization and proposal of a generic model for this new type of manufacturing system have been described using the language of complex systems modeling (SysML: Systems Modeling Language). We have developed a reconfiguration process that represents the approach to follow in the design and implementation of a new configuration. In addition, the operational control of a RAMS has been introduced. Finally, some works developed in this thesis have been partially deployed on an industrial demonstrator within the AIP-PRIMECA Auvergne organisation.
78

Projekt výrobního systému ve vybraném výrobním úseku / The Project of Production System in Selected Manufacturing Segment

Liška, Radomír January 2015 (has links)
This Master’s thesis is focused on the production system design, analysis material flow of the production system in the company ABC Ltd. Part of it is detection of critical places and proposal for their elimination. The theoretical part contains the basic concepts of production. In the analytical part, there is described a current situation in selected manufacturing segment of company. In the final part, the solutions are designed to help improve the business.
79

Conceptual decision support tool for RMS-investments : A three-pronged approach to investments with focus on performance metrics for reconfigurability

Eriksson, Gustav, Isendahl, Johan January 2020 (has links)
Today's society is characterized by a high degree of change where the manufacturing systems are affected by both internal and external factors. To adapt to current manufacturing requirements in the form of short lead-time, more variants, low and fluctuating volumes, in a cost-efficient manner, new approaches are needed. As the global market and its uncertainties for products and its lifecycles change, a concept called 'reconfigurable manufacturing system' has been developed. The idea is to design a manufacturing system for rapid structural change in both hardware and software to be responsive to capacity and functionality. A company's development towards the concept is often based on a strategy of incremental investments. In this situation, the challenges are to prioritize the right project and maximize the performance as well as the financial efficiency of a multi-approach problem. The report is based on three different issues. Partly how to standardize relevant performance-based metrics to measure current conditions, how new performance-based metrics can be developed in collaboration with reconfigurability characteristics, and set a direction for how decision models can be used to optimize step-based investments. The study is structured as an explorative study with qualitative methods such as semi-structured interviews and document study to get in-depth knowledge. Related literature addresses concepts in search areas such as reconfigurable manufacturing system, key performance indicators, investment decisions, and manufacturing readiness levels. The findings are extracted from interviews and document studies that generate a focal company setting within the automotive industry, which acts as the foundation for further analysis and decisions throughout the thesis. The analysis results in sixteen performance measurements where new measures been created for product flexibility, productionvolume flexibility, material handling flexibility, reconfiguration quality and diagnosability using reconfigurability characteristics. A conceptual decision support model is introduced with an underlying seven-step investment process, analyzing lifecycle cost, risk triggered events in relation to cost, and performance measurements. The discussion chapter describes how different approaches are used during the project that has been revised by internal and external factors. Improvement possibilities regarding method choice and the aspects of credibility, transferability, dependability, and conformability are discussed. Furthermore, the authors argue about the analysis process and how the result has been affected by circumstances and choices. The study concludes that a three-pronged approach is needed to validate the investment decision in terms of system performance changes, cost, and uncertainty. The report also helps to understand which performance-based metrics are relevant for evaluating manufacturing systems based on operational goals and manufacturing requirements.
80

Simulation-based multiobjective optimization and availability analysis of reconfigurable manufacturing systems

Del Riego Navarro, Andrés, Rico Pérez, Álvaro January 2021 (has links)
Due to the changes and improvements that have occurred over the years, the manufacturing sector has evolved. Companies in the 21st-century face changes in the marketplace that are difficult to predict due to international competition and the rapid emergence of new products. To cope, companies must reinvent themselves and design manufacturing systems that seek to produce quality and low-cost products, and respond to the changes that must be faced. These capabilities are encompassed in reconfigurable manufacturing systems (RMS), capable of dealing with uncertainties quickly and economically. On the other hand, production planning with this type of system presents a significant challenge. Although simulation-based optimization techniques have been applied to address certain RMS challenges, only a few studies have applied simulation-based multi-objective optimization to simultaneously address several conflicting design objectives, as is the case in this project. This project aims to investigate some aspects using SBMO that directly affect the performance of a plant and demonstrate the usefulness of the method. / <p>Det finns övrigt digitalt material (t.ex. film-, bild- eller ljudfiler) eller modeller/artefakter tillhörande examensarbetet som ska skickas till arkivet.</p>

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