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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.
1

STEP-NC enabled cross-technology interoperability for CNC machining

Safaieh, Mehrdad January 2014 (has links)
In recent decades there has been a rapid development of technology in manufacturing industries, in particular through the increasing use of ever more powerful and sophisticated Computer Numerical Controlled (CNC) machines to manufacture complex parts. These machines are supported by a chain of computer based software solutions amongst which manufacturing information is exchanged. With the need for information exchange, interoperability between various computer-aided systems (CAx) has become an important research area. In CNC part programing, innovations by various hardware manufacturers and their reflection in their software have led to the necessity for the existence of different part programs for each machine. Creating these is a time consuming and economically inefficient activity. Implementing genuine interoperability between CNC machines is a way of eliminating this deficiency but, to achieve this, CNC programmers must be able to write a CNC program for a specific machine and effortlessly convert that program to work for other machines. The aim of this research was to enable the exchange of CNC programmes across machines with different technologies and demonstrate this between a C-axis CNC turn-mill machine and a 4-axis CNC machining centre. This has been achieved by designing a cross-technology interoperability framework that is capable of supporting systems that can work with the different types of CNC machines. This framework is the core contribution to knowledge from this PhD research. In order to fully identify the context for the research, this thesis presents a review of existing literature on machining of turn-mill parts and interoperability for CNC manufacturing. This is followed by the specification and realisation of a novel framework for cross-technology interoperability for CNC manufacturing. The demonstration is conducted using test components that can be manufactured using different CNC technologies.
2

A novel methodology for modelling CNC machining system resources

Vichare, Parag January 2009 (has links)
No description available.
3

Proposition de chaîne numérique pour la fabrication additive

Bonnard, Renan 12 October 2010 (has links) (PDF)
Les procédés par ajout de matière sont soumis à des changements majeurs depuis ces dernières années. En effet, ils sont passés de procédés de prototypage rapide, à des procédés de fabrication additive pour la réalisation de pièces fonctionnelles. Ces changements ont entraîné de nouvelles attentes en termes de maîtrise de ces procédés. Dans le même temps, il subsiste certains problèmes dus à leur non-intégration dans une chaîne numérique complète et robuste. Ce point ne leur permet pas à l'heure actuelle de rattraper leur retard en terme de développement par rapport aux procédés plus traditionnels. Les limites de la structure actuelle au niveau de la commande numérique (s'appuyant sur le STL) des machines de fabrication additive ont été identifiées par les travaux de recherche de plusieurs groupes internationaux. La grande majorité a conclu au nécessaire développement d'une nouvelle structure de données basée sur le format STEP, qui apparaît comme étant un format adapté pour obtenir une chaîne numérique complète, robuste et s'appuyant sur des données de haut niveau conceptuel. Le but des travaux de thèse est donc de proposer une nouvelle structuration des données pour le procédé par ajout de matière basée sur le format STEP-NC puis dans le même temps de mettre en place une nouvelle chaîne numérique STEP-NC s'appuyant sur des DCN génériques du même type que ceux utilisés en usinage. La première partie du travail est la mise en place d'un modèle hiérarchisé des données nécessaire pour la description des procédés par ajout de matière. Ce modèle hiérarchisé permet d'identifier et de hiérarchiser toutes les données utiles à l'élaboration d'un projet de fabrication additive. La seconde étape consiste à partir des données du modèle hiérarchisé à la proposition d'un modèle de données STEP-NC pour l'introduction des procédés de fabrication additive dans la norme ISO 14649. Pour réaliser une chaîne numérique complète basée sur le STEP-NC, les travaux de l'équipe (qui concernent non seulement la fabrication additive mais aussi l'usinage) ont conduit à la mise en place d'une plateforme appelée SPAIM (STEP-NC Platform for Advanced and Intelligent Manufacturing). Dans cette plateforme la chaîne numérique complète (CAO-FAO-DNC) est intégrée autour d'un unique fichier STEP-NC sans perte d'information. Cette plateforme a de plus l'avantage de pouvoir être intégrée sur toutes les machines de nouvelle génération de fabrication additive équipées avec des DCN génériques.
4

A novel method for information rich costing in CNC manufacture

Taiwo, Ayobamidele January 2013 (has links)
Reliable cost estimation is important for economic production, cost control and maintaining competitive advantage in manufacturing contract bidding. Therefore, estimating the manufacturing cost of a machined part is of critical importance in CNC manufacture. Computers aided systems the link to manufacturers CAD systems and databases have been used since the 1980’s to identify product cost and enable a company to evaluate resource utilisation. While the concept of an integrated costing system has made significant advances in integrating the design function with the cost estimation process, there are still major gaps in acquisition and application of detailed product data for generation of timely and reliable costing information feedback to engineers. Integrated costing systems are information intensive and require significant manufacturing data support. A major obstacle is the bespoke nature of the available cost relevant data and their storage in company specific database tailored to individual company practices. Thus there is need to consider standardisation of information from the design of component through to their process planning and manufacture. This will allow seamless exchange of detailed, cost relevant, information between other computers aided systems and costing systems to facilitate automatic and reliable cost information feedback. In this research a novel framework is specified and designed for enabling detailed product information that exists across CNC manufacturing, to be utilised for generation of reliable cost estimates. The standards based costing proposed in this thesis framework facilitates high-level integration of various CAx resources and increases the availability of product creation process (PCP) data that are applicable in costing process. A prototype implementation of the unified costing framework is utilised to demonstrate the capabilities of the framework. The demonstration is conducted using two industrially inspired prismatic test components where the components machining cycles were timed with a stop watch and the actual result compared with the prototype system estimated result to determine its reliability. The research shows that implementation of manufacturing standard that contain structured representation PCP information together with an effective data retrieval mechanism and computational algorithms can provide a standard compliant framework to realise an information rich (detailed) costing system. The potential of the proposed framework is not limited to enabling the use of detailed information that exist within manufacturing facility to generate cost information; it also provides a standard compliant approach for the development of future generations of costing systems.
5

Desenvolvimento de uma fresadora CNC aderente à norma STEP-NC baseado no controlador de máquina avançado (EMC2)

Gutierrez Paredes, Miguel Eduardo 03 September 2013 (has links)
Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia Departamento de Engenharia Mecânica, 2013. / Submitted by Alaíde Gonçalves dos Santos (alaide@unb.br) on 2013-11-29T11:04:04Z No. of bitstreams: 1 2013_MiguelEduardoGutierrezParedes.pdf: 15355916 bytes, checksum: 1e77add6f0b92d80f9670d197374f50e (MD5) / Approved for entry into archive by Guimaraes Jacqueline(jacqueline.guimaraes@bce.unb.br) on 2014-02-28T12:16:20Z (GMT) No. of bitstreams: 1 2013_MiguelEduardoGutierrezParedes.pdf: 15355916 bytes, checksum: 1e77add6f0b92d80f9670d197374f50e (MD5) / Made available in DSpace on 2014-02-28T12:16:20Z (GMT). No. of bitstreams: 1 2013_MiguelEduardoGutierrezParedes.pdf: 15355916 bytes, checksum: 1e77add6f0b92d80f9670d197374f50e (MD5) / Este trabalho apresenta o desenvolvimento e a validação de uma arquitetura de um controlador numérico computadorizado (CNC) aderente à norma STEP-NC por médio de um adaptador de STEP-NC a Código G. O CNC está associado ao processo de fresamento. O controlador STEP-NC desenvolvido é baseado no controlador de código aberto EMC (Enhanced Machine Controller) aderente à norma RS-274, que originalmente trabalha com programa NC (Numerical Control) usando códigos G e M. Para validação da arquitetura do controlador foi desenvolvida uma máquina-ferramenta controlada numericamente com topologia tipo Router (fresadora com estrutura em portal) com três graus de liberdade tendo como controlador o EMC em plataforma x86 (computador pessoal) usando o sistema operacional Ubuntu/Linux. O controlador EMC foi integrado com o modelo de dados STEP-NC Parte 21 utilizando um adaptador do arquivo físico p21 a código G, permitindo que o EMC receba como entrada um programa de comando numérico em formato STEP-NC Part-21. O formato se baseia no conceito de workingsteps, features de usinagem e operações de usinagem, entre outras entidades descritas pela norma; ou seja, o programa STEP-NC foca-se em uma descrição de alto nível baseada em features de usinagem e em um modelo de dados mais sofisticado, mas não na movimentação dos eixos da máquina. O comando numérico com código STEP-NC é gerado pelo sistema integrado de projeto, planejamento de processo e manufatura auxiliado por computador (CAD/CAPP/CAM) denominado STEP Modeler (http://www.grima.ufsc.br/stepnc_project/), desenvolvido pelo GRIMA/UFSC, que permite a modelagem de uma peça prismática via Web baseada em features de usinagem, tendo um modelo de dados aderente ao projeto STEP, viabilizando a integração do ciclo de vida de uma peça, do projeto à fabricação, via Web. O controlador EMC com o adaptador STEP-NC utiliza o código gerado pelo STEP Modeler e o executa de forma transparente para o operador da Router CNC, especialmente desenvolvida para validação da arquitetura idealizada. Este desenvolvimento permitiu a validação do conceito de integração do ciclo de vida do projeto à fabricação baseado no modelo de dados STEP-NC, utilizando os conceitos de features de projeto e usinagem. A arquitetura é apresentada usando modelos IDEF0 (Integration Definition for Function Modeling) e UML (Unified Modeling Language), mostrando a especificação do sistema integrado CAD/CAPP/CAM, em especial a etapa associada ao CAM Execução, ou seja, o controlador/adaptador STEP-NC desenvolvido baseado no EMC. O projeto detalhado da Router é apresentado de forma resumida. Os resultados obtidos são mostrados através de estudo de caso com a fabricação de peças exemplos, contemplando sua medição e análise. O ambiente STEP-NC foi concebido para um contexto Web sendo também usado em disciplinas de Automação da Manufatura de graduação e pós-graduação da UnB e da UFSC, visando à apresentação dos conceitos e modelos de dados baseados em STEP, que será o futuro da Automação da Manufatura, estando a cada ano mais madura. _______________________________________________________________________________________ ABSTRACT / This document describes the development and validation of the architecture of a numerical computer controller that is adherent to the standard STEP-NC by means of an adapter of STEP-NC to G-Code. The CNC is associated with the milling process. The STEP-NC controller development is based on the open source driver EMC (Enhanced Machine Controller) adherent to the standard RS-274 that originally works with the NC program using G/M codes. In order to validate the controller architecture, the NC machine-tool topology type Router (portal structure) was developed with three degrees of freedom to have the EMC controller in x86 platform (personal computer) using the operating system Ubuntu/Linux. The EMC controller was integrated using an adapter to the Data Model STEP-NC Part- 11, allowing the EMC to receive as an input a numerical control program in a format STEP-NC Part-21 also called STEP. The format is based on the concept of workingsteps, machining features and machining operations, among others that are described by the standard, i.e., the STEP program focuses on a high-level description based on machining features and a more sophisticated data model but not the movement of the machine axes. This numerical control program with STEP-NC code is generated by the integrated design, process planning and computer-aided manufacturing (CAD / CAPP / CAM) called STEP Modeler (http://www.grima.ufsc.br/stepnc_project/), developed by GRIMA/UFSC, that allows the modeling of a prismatic part web-based machining features, having a data model adhering to the STEP project, enabling the integration of the life cycle of a piece, from design to manufacturing, via Web. The EMC controller with STEP-NC adapter uses codes generated by STEP Modeler and runs transparently to the operator of specially developed CNC Router to validate the architecture conceived. This development allows the validation of the concept of integration lifecycle from design to manufacturing based on the data model of STEP-NC, using the concepts of design and machining features. The architecture is presented to use models IDEF0 (Integration Definition for Function Modeling) and UML (Unified Modeling Language), showing the specification of integrated system CAD / CAPP / CAM, particularly the stage associated with CAM Execution, i.e., the controller/adapter STEP-NC developed based on EMC. The detailed project of the Router CNC is presented in a summarized way. The results are shown through study of cases, process planning and manufacturing parts examples, with measurement and analysis. The environment STEP-NC has been designed for Web context being also used in the disciplines of the Manufacturing Automation of graduate and postgraduate of UNB and UFSC, aiming at presentation of concepts and data models based on STEP, which will be the future of Automation Manufacturing, maturing through time and technological improvements.
6

CNC-C2: um controlador aderente às normas ISO 14649 E IEC 61499 / CNC-C2: um controlador aderente às normas ISO 14649 e IEC 61499

Harbs, Eduardo 09 October 2012 (has links)
Made available in DSpace on 2016-12-12T17:38:31Z (GMT). No. of bitstreams: 1 Eduardo Harbs.pdf: 12792734 bytes, checksum: b505810b68894ae2924a805e7f89d032 (MD5) Previous issue date: 2012-10-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The industry has found difficulties towards CNC machines flexibility, due to the CNC programming current standard, the ISO 6983 or G/M code. The ISO 14649 or STEP-NC was developed to replace the current standard. It is a new unified data transfer model between CAD/CAM and CNC systems. To satisfy the new automation and control systems requirements, the IEC 61499 standard was developed, aiming the use of software objects, called function blocks (FBs). In this work, the standards STEP-NC and IEC 61499 were integrated to build a new generation of CNC, where STEP-NC supplies the complete data model without functionality, and the FBs provide the functionalities to the data model for the machine tool command. In this context, a controller for a CNC machine prototype, compliant to STEP-NC and IEC 61499 standards was developed. The prototype consists of a 2,5D milling machine, driven by a group of three servomotors drivers with integrated PLCs. A set of software was developed for compiling STEP-NC files and the automatic generation of IEC 61499 models, viewing, editing and executing FBs and FB networks, and further a library with IEC 61499 models. Test on software and prototype was performed machining an example workpiece, achieving the proposed goal and providing the individual characteristics of the standards in the controller, such as: interoperability, portability, use of features, configurability, distribution and adaptability. / A indústria tem enfrentado dificuldades quanto à flexibilidade das máquinas CNC, devido à norma utilizada atualmente para a programação CNC, a ISO 6983 ou código G/M. Com objetivo de substituição desta norma, desenvolveu-se a ISO 14649 ou STEP-NC, que é um novo modelo de transferência de dados unificado entre sistemas CAD/CAM e CNC. Para atender os novos requisitos de automação e controle de sistemas, desenvolveu-se a norma IEC 61499, visando o uso de objetos de software, os function blocks (FBs). Neste trabalho integraram-se as normas STEP-NC e IEC 61499 para a construção de uma nova geração de CNCs, onde STEP-NC fornece o modelo de dados completo, porém sem funcionalidade, e os FBs fornecem as funcionalidades ao modelo de dados para o controle da máquina-ferramenta. Para tal, foi desenvolvido um controlador para uma máquina CNC protótipo aderente às normas STEP-NC e IEC 61499. Este protótipo é constituído de uma fresadora 2,5D, acionada por um conjunto de três servoacionamentos com CLPs integrados. Um conjunto de software foi desenvolvido para compilação do arquivo STEP-NC e geração automática de modelos IEC 61499, visualização, edição e execução de FBs e rede de FBs além de uma biblioteca de modelos IEC 61499. Teste do software e do protótipo foi realizado com a usinagem de uma peça exemplo, alcançando o objetivo proposto e provendo as características individuais das normas no controlador, como: interoperabilidade, portabilidade, uso de features, configurabilidade, distribuição e adaptabilidade.
7

Optimisation de la programmation des MOCN - Application aux machines à structure parallèle

Rauch, Matthieu 10 December 2007 (has links) (PDF)
Les travaux de recherche présentés visent à définir des voies d'optimisation concernant la programmation des MOCN liées au développement des machines à structure parallèle. Nous avons identifié quatre axes de recherche permettant d'adapter la programmation de la machine à l'application visée. Le premier axe traite de la préparation de la fabrication, en particulier le choix de la stratégie d'usinage, en évaluant le potentiel de nouvelles trajectoires (tréflage et usinage trochoïdal) et en définissant des fenêtres de performance pour les principales stratégies d'usinage en fonction des aptitudes de la machine employée. Le deuxième axe se focalise sur le formage incrémental, procédé émergent. Nous montrons que le recours à une programmation adaptée améliore la mise en oeuvre de ce procédé et que les voies d'optimisation sont fonction des capacités de la MOCN choisie. Au cours du troisième axe, nous proposons une nouvelle approche de programmation avancée des parcours d'outil, la méthode ICAM (Intelligent Computer Aided Manufacturing). Elle permet d'optimiser la programmation implémentée en s'appuyant sur une évaluation par le DCN de données process en cours de fabrication. Le quatrième axe porte enfin sur les évolutions à moyen terme de la programmation en s'intéressant d'un côté aux mutations de l'environnement des MOCN générées par le développement de l'e-manufacturing et d'un autre côté à la mise en place d'un nouveau standard de programmation des machine outils, le format Step_NC. Ce dernier constitue un cadre idéal aux optimisations proposées pour les autres axes de recherche, en plus de conduire à de nouvelles avancées en programmation des MOCN.
8

Intégration de la programmation basée entités pour la fabrication sur machines à commandes numériques dans un contexte multi-process

Laguionie, Raphael 17 November 2010 (has links) (PDF)
Les travaux présentés portent sur l'intégration de la programmation basée entités des machines-outils à commande numérique (MOCN). Cette programmation émergente s'appuie sur les concepts véhiculés par le standard STEP-NC et la norme ISO 14649. Quatre axes de recherche sont proposés. Le premier concerne l'évolution de la programmation actuelle vers la programmation basée entités et l'enrichissement du standard STEP-NC. Pour ceci, nous proposons deux contributions principales au standard STEP-NC dans le cadre de notre participation au comité normatif de l'ISO 14649 : l'intégration de stratégies d'usinage à motifs avec pour application l'usinage trochoïdal et le tréflage, et l'élaboration d'un modèle fonctionnel STEP-NC des MOCN. Le deuxième axe se focalise sur l'évolution du système de fabrication pour tirer profit de la programmation basée entités. Nous proposons un concept de système étendu de fabrication intégrée XMIS (eXtended Manufacturing Integrated System) ainsi qu'une déclinaison concrète à travers la CAO étendue et la CN étendue. Au cours du troisième axe, nous étendons l'étude à l''intégration de plusieurs procédés au sein d'une même gamme de fabrication STEP-NC et étudions l'organisation des outils de simulation dans ce contexte multi-process avec la description d'espaces de simulation. Le quatrième axe porte sur la validation et la mise en œuvre des concepts proposés avec le développement de la plate-forme SPAIM (STEP-NC Platform for Advanced and Intelligent Manufacturing) qui intégre la programmation basée entités du modèle à la pièce usinée sur des moyens industriels et montre l'impact multidirectionnel des modifications tout au long de la chaîne numérique.
9

Development Of A Step Feature-based Intelligent Process Planning System For Prismatic Parts

Amaitik, Saleh Mohammed 01 June 2005 (has links) (PDF)
Computer aided process planning (CAPP) is generally acknowledged as a significant activity to achieve Computer Integrated Manufacturing (CIM). In coping with the dynamic changes in the modern manufacturing environment, the awareness of developing integrated and intelligent CAPP systems has been raised in an attempt to generate more successful implementation of intelligent manufacturing systems. The main objective of this research work has been to develop an integrated intelligent process planning system that helps designers and process planners to improve their design and planning in the early stages of the product life cycle. In order to achieve this goal, the following specific objectives have been accomplished: (1) Developed a STEP-based feature modeler for building mechanical parts using high-level 3D solid features as the basic design entities. The modeler is capable of generating high-level product data in XML format according to ISO 10303-AP224 standard. This file can be used to integrate into CAPP/CAM systems without using a complex feature recognition process. (2) Developed a STEP-based intelligent process planning system for prismatic parts. The system maps STEP AP224 XML data file and produces the corresponding machining operations to generate a digital process plan in XML format according to ISO 14649 (STEP-NC) standard. A Hybrid approach of most recent techniques of artificial intelligence (neural networks, fuzzy logic and rule-based) is used as the inference engine of the developed system. Three neural network models are implemented to select machining operations, cutting tools, and machine tools. Several fuzzy logic models are utilized to select machining parameters for different machining operations, work material, and tool material combinations. The rule-based functions are utilized to perform operation sequence and setup planning. An object-oriented approach has been used in the definition and implementation of the developed system. This approach offers advantages of incremental system development and reusability. The developed system is integrated with AutoCAD using Activex automation interface. Several examples have been presented to demonstrate and verify the applicability of the developed system. Finally, this research will contribute significantly to the applicability of advanced artificial intelligent techniques in CAPP systems. The implementation of STEP technology in this research will support the integration of CAPP system with other systems in CIM environment. The developed system is intended to be an effective concurrent engineering tool that bridges the gap between design and manufacturing.
10

Projeto e implementação de um controlador numérico computadorizado aberto baseado em STEP-NC

Pacheco, Nazareno de Oliveira 18 February 2009 (has links)
Made available in DSpace on 2016-12-12T17:38:36Z (GMT). No. of bitstreams: 1 Nazareno.pdf: 5066639 bytes, checksum: d126b9cbc310906e85db744b2286d806 (MD5) Previous issue date: 2009-02-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / No trabalho desenvolvido foi utilizada a Norma ISO 14649 (STEP-NC) que é o novo pa¬rão para interface de dados de manufatura entre os sistemas CAM/CNC. Atualmente a oca dessas informações é feita usando a linguagem da Norma 1S06983, conhecida como ódigo-G/M. Isto significa que partes das informações geradas no ciclo de Desenvolvimento, notadamente a geometria do produto e dados de ferramentas, são perdidas ao se gerar o programa em codigo G/M Para a prova de conceito da funcionalidade desse novo padrão no controle e acionamento direto de maqumas ferramenta CNC foram projetados construidos software, hardware e uma estrutura mecânica simples de uma fresadora/¬:radeira CNC. A arquitetura de software e hardware é aberta e aderente à STEP-NC. sistema desenvolvido faz uso de arquivos ISO14649 para programação da maquina sem o de linguagens legadas Isto permitiu a validação do uso da norma no acionamento de quinas CNC, provando a flexibilidade e eficacia para a troca de informações e controle maquinas-ferramenta.

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