The servosystems which drive a milling table must be capable of asymptotic tracking and disturbance rejection, and must be robust. The internal model principle is a general method developed by Davison, Desoer and Wonham which achieves asymptotic tracking and disturbance rejection, and is robust. In this thesis, a state-variable control system for the positioning of a milling table is designed by using the internal model principle. The control system is simulated as both a continuous-time system and as a discrete-time system. Results of the simulation indicate that a microprocessor-driven version of the state-variable discrete-time control system is a feasible and practical method of control. / M.S.

Orientador: Amauri Hassui / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-21T02:13:50Z (GMT). No. of bitstreams: 1 Castro_MarceloHirai_M.pdf: 4008200 bytes, checksum: a0c71450e4b5c3ac934e22f6e3cc9f4b (MD5) Previous issue date: 2012 / Resumo: A inovação é a chave para o diferencial da indústria no mercado competitivo atual. Fazer diferente, melhor e mais barato sempre agrega valor ao produto. Por outro lado, a resistência às mudanças faz parte do comportamento humano, seja na sociedade, ou na indústria. O objetivo principal deste trabalho é estudar a viabilidade de se fazer furos não cilíndricos com uma ferramenta em rotação utilizando máquinas-ferramenta CNC. Estes sempre foram obstáculos na indústria de fabricação pela dificuldade de obtenção. Sendo assim, o processo apresentado nesse trabalho busca usinar um furo quadrado com a mesma configuração de ferramentas e fixação de peças utilizadas para um furo cilíndrico, tão comum à indústria. Isso visa reduzir custos de fabricação e facilitar a obtenção de furos não cilíndricos com os recursos de equipamentos programáveis existentes no chão de fábrica. A partir de um modelo matemático, a máquina é programada para executar movimentos sincronizados entre a rotação e os deslocamentos do eixo da ferramenta. Diversas programações foram testadas em diferentes máquinas ferramenta CNC, com diferentes comandos, com e sem recursos de alta velocidade, com diferentes quantidades de pontos programados, interpolações lineares e circulares. A partir dos experimentos, foram analisadas as configurações das máquinas, a capacidade de execução do controlador numérico instalado, a velocidade desenvolvida pela máquina na operação e a geometria obtida dos furos quadrados. Os experimentos apontam que para executar o furo quadrado, os comandos devem ser capazes de controlar um eixo rotativo como eixo propriamente dito, além de sincronizarem mais três eixos lineares. O crítico para este tipo de operação é a velocidade desempenhada pela máquina, sendo o fator mais significativo, o tempo que o comando precisa para o processamento do bloco de programação, independentemente da ativação de recursos de alta velocidade, interpolações lineares ou circulares. Verificou-se também que quanto maior a quantidade de pontos para compor a trajetória do centro da ferramenta, melhor será a geometria obtida do furo. Sendo assim, as máquinas ferramenta CNC que estão em operação na indústria são capazes de realizar a furação não cilíndrica de forma muito próxima à furação cilíndrica quanto ao tempo de usinagem e ao sistema de fixação da ferramenta e da peça, sendo necessária uma programação sincronizada do eixo spindle presente em toda e qualquer máquina ferramenta / Abstract: The innovation is the key for the differential of the industry on the competitive market nowadays. To make different, better and cheaper always it is worth a lot to the product. By the other side, the resistance to changes makes part of the human behavior, in society, or in the industry. The main goal of this work is to study the feasibility to machining of non-cylindrical holes by a tool in rotation using CNC machine tools. That always has been offering obstacles to manufacturing industry by the difficulty of fabrication. Thus, the process presented on this work will machining a square hole with the same configuration of tools and systems for fixation of the parts, used for a cylindrical drilling, so common to industry. This intends to reduce the costs of fabrication and make easier to get non-cylindrical drilling using resources of the programmable equipment which are working at the shops. From a math model on, the machine is programmed to execute synchronized movements between the rotation and the displacements of the axis of the tool. Different programs were tested in different CNC machine tools, with different controllers, with and no resources for high speed, with different quantity of programmed points, with linear and circular interpolations. From the experiments, it was analyzed the configuration of the machines, the capacity for execution of the controller installed, the speed developed by machine at the operation and the geometry of the square holes. The experiments show that to machine a square hole, the controllers must be able to control a rotating axis itself, beyond to synchronize three axis. The critical to this kind of operation is the speed developed by the machine, being the most significant factor, the time the controller needs to process the block of programming, independently the activation of resources for high speed, linear or circular interpolations. It was verified than as larger the amount of points to compose the trajectory of the center of tool, better will be the geometry of the hole. Thus, the CNC machine tools in operation in the industry are able to machine the non-cylindrical drilling in a way very closely the cylindrical drilling as the time of machining and the fixing system of the tool and parts, requiring a programming that synchronizes the main spindle installed in any machine tool / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

The objective of the study is to utilize the cross-sectional computation capabilities of a computer to calculate the revolutions per minute, to determine the volume of metal being removed by the machine cutter at any point in the programmed path, and to output the feed rate that the particular situation requires. The six chapters which present the information are as follows: Chapter I, introduction; Chapter II, analysis of factors affecting the computation of speed and feed rate parameters; Chapter III, organization of the input by the numerical control programmer; Chapter IV, modifications to the computer software; Chapter V, evaluation of the benefits of utilizing computed speed and feed rates; Chapter VI, summary, findings, conclusions, and recommendations.

Baigiamojo darbo tikslas – dvikoordinačiui įtaisui suprojektuoti skaitmeninio programinio valdymo sistemą bei ištirti jos veikimą. Šio darbo įvadinėje dalyje suformuluojamas darbo tikslas ir uždaviniai, taip pat aptariamas temos aktualumas. Literatūros analizės dalyje analizuojami straipsniai, kuriuose pateikti naujausi skaitmeninio programinio valdymo įrengimų programavimo metodai ir tendencijos. Teorinėje dalyje sudaroma sistemos funkcinė ir principinė elektrinė schemos, sukuriamas sistemos kompiuteris modelis bei programinė įranga. Tiriamojoje dalyje vykdomas sistemos imitavimas, patikrinamas suprojektuotos sistemos darbingumas bei braižomos ir tiriamos sistemos koordinačių formavimo laikinės ir tikslumo charakteristikos. Darbą sudaro 8 dalys: įvadas, literatūros analizė, tyrimo tikslas ir uždaviniai, teorinė dalis, tiriamoji dalis, išvados, literatūros sąrašas bei priedai. Darbo apimtis – 53 p. teksto be priedų, 32 paveikslėlis, 2 lentelės, 25 literatūros šaltiniai. / The goal of this master thesis is to design a computer numerical control system for a two – coordinate device and to do a research of its characteristics. The main tasks are formed, as well as the urgency of the topic is being discussed in the introduction of this thesis. The gathered material about the programming of computer numerical control devices is systemized in the literature analysis part. In the theoretical part of this thesis, a functional and principal electric schematics, models and software are created. In the research part, the system is being simulated and graphic data of coordinates change in time and other precision characteristics are being analyzed. In the conclusion of this master thesis the results are discussed and suggestions are offered. There are eight parts of this master thesis: Introduction, Literature analysis part, The Goal and main tasks of this thesis, Theoretical part, Research part, Conclusions and Suggestions, List of Literature used and Additives. Work size – 53 p. without additives, 32 illustrations, 2 tables, 25 bibliographical sources.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Bibliography: leaves 164-168. / by Joseph Githu Kimemia. / Ph.D.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Plastic is widely used to shape many of the daily goods produced and consumed today. Compared to wood and metal, this versatile material was recently introduced to society. The technical advances that began in the mid 1850's led to the invention of the first cellulose plastic polymers - a naturally occurring or synthetic compound consisting of large molecules made up of a linked series of repeated simple monomer (One Look on line Dictionary, 2009) - to be used at an industrial level. Inaugurating a period in which objects could have the strength of metal or wood, while also being lighter, colorful and cheaper to be manufactured. Plastics are a material that has the ability to be easily shaped (Lefteri, 2008). For me, plastic is ideal to work with, not only because its eclectic applications in product design and manufacture, but also due to its ordinary use in our globalized society. My master's research is to design functional objects using different types of plastics. My goal is to experiment with this material and understand the industrial production process behind the manufacture of the daily functional objects that surround us. Each plastic polymer has its proper usage and constraints. These characteristics are taken into account in my design process. Conceptually I allow myself to have freedom in exploring the object's form by respecting the material`s limitations as well as the techniques I have available to design and make my pieces. In conjunction with this creative research, I am using Computer Aided Design and Computer Aided Manufacturing through Computer Numerical Control and Rapid Prototyping technologies to design and produce the pieces. Furthermore, my intention is to have a deep understanding of the uses, production, discard and, recycling procedures of plastics goods. I am interested in knowing more about biodegradable, compostable and recyclable polymers in order to enjoy this great material that is evolving rapidly (Lefteri, 2008) in the contemporary society without causing environmental damage and preserve good conditions to future habitants of the Planet.

Η παρούσα διπλωµατική εργασία πραγµατεύεται την κατασκευή µιας εργαλειοµηχανής µε αρθµητικό έλεγχο µέσω Η/Υ (CNC router) , ικανής για την κατασκευή ηλεκτρονικών πλακετών για τις ανάγκες του εργαστηρίου. Η εργασία αυτή εκπονήθηκε στο Εργαστήριο Ηλεκτροµηχανικής Μετατροπής Ενέργειας του Τµήµατος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής Σχολής του Πανεπιστηµίου Πατρών. Σκοπός είναι η κατασκευή της µηχανικής διάταξης της εργαλειοµηχανής µε επιφάνεια κατεργασίας πλακέτας µεγέθους τουλάχιστον Α4, των ηλεκτρονικών διατάξεων οδήγησης των κινητήρων, της διάταξης και της διασύνδεσης µε τον υπολογιστή, καθώς και των απαραίτητων προγραµµάτων για την ανάγνωση και επεξεργασία των σχεδίων και τη δηµιουργία και διαβίβαση των εντολών ελέγχου από και προς το µηχάνηµα ώστε να υλοποιηθεί το σχέδιο. Αρχικά έγινε η ανάλυση των απαιτήσεων του εργαστηρίου, επιλέχθηκε η συγκεκριµένη µέθοδος και αναλυθήκαν οι προδιαγραφές που πρέπει να έχει το µηχάνηµα. Έπειτα, έγινε η επιλογή της τοπολογίας και του υλικού του µηχανήµατος, των κατάλληλων κινητήρων, του συστήµατος ολίσθησης και του συστήµατος µετατροπής της κίνησης από περιστροφική σε γραµµική, έτσι ώστε να καλύπτονται µε το, χαµηλότερο δυνατό κόστος, οι απαιτήσεις µεγέθους, δύναµης πρόωσης, επιτάχυνσης, ανάλυσης, ακρίβειας, στιβαρότητας και ταχύτητας κίνησης που αναλύθηκαν στο πρώτο στάδιο, µε το χαµηλότερο δυνατό κόστος. Στη συνέχεια σχεδιάστηκε σε πρόγραµµα τρισδιάστατου σχεδιασµού η µηχανική κατασκευή της διάταξης και ανατέθηκε σε κατάλληλο εργαστήριο η κατασκευή των κοµµατιών και η συναρµολόγηση της. Το επόµενο βήµα ήτανε να σχεδιαστούν και να κατασκευαστούν τα κυκλώµατα για την οδήγηση των κινητήρων και η κεντρική πλακέτα που αναλαµβάνει την οµαλή διασύνδεση τους µε τον υπολογιστή. Τέλος, γράφτηκαν κατάλληλα προγράµµατα τα οποία αναλαµβάνουν την ανάγνωση του σχεδίου της πλακέτας και παράγουν και διαβιβάζουν τις κατάλληλες εντολές στους οδηγούς των κινητήρων, ώστε να γίνουνε οι απαραίτητες κινήσεις από αυτούς και να υλοποιηθεί το σχέδιο στην πλακέτα. / This thesis is about designing and building a fully functional CNC machine, capable of building printed circuit boards.

Η παρούσα διπλωματική εργασία πραγματεύεται την μελέτη και την κατασκεύη μιας αυτοματοποιημένης διάταξης επίστρωσης ηλεκτροδίου σε στερεό ηλεκτρολύτη για εφαρμογή σε κυψέλες καυσίμου.Η εργασία εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής Σχολής του Πανεπιστημίου Πατρών. Σε αυτό το πλαίσιο,σχεδιάστηκε μια εργαλειομηχανή τύπου CNC(Computer Numerical Control),υψηλής ακρίβειας,ικανή να εκτελέσει κινήσεις σε τρείς άξονες,ελεγχόμενη από μικροελεγκτή και οδηγούμενη από βηματικούς κινητήρες. Αν και ο απώτερος στόχος της εργασίας είναι η κατασκευή της διάταξης που επιτελεί το επιθυμητό έργο,προηγήθηκε εκτενής θεωρητική μελέτη και ανάλυση όλων των χαρακτηριστικών και παραγόντων του συστήματος. Αρχικά,γίνεται αναφορά στις κυψέλες καυσίμου,στους διάφορους τύπους της συγκεκριμένης τεχνολογίας καθώς και στις εφαρμογές που αυτή ενσωματώνεται. Οι κυψέλες καυσίμου,ως αντικείμενο επιστημονικής μελέτης αλλά και ως εμπορευματικό προϊόν παρουσιάζει εξαιρετικό ενδιαφέρον και έχει απασχολήσει σε μεγάλο βαθμό την επιστημονική κοινότητα τα τελευταία χρόνια λόγω της μεγάλης αποδοτικότητάς τους στην παραγωγή ενέργειας αλλά και της φιλικής προς το περιβάλλον λειτουργίας τους. Εν συνεχεία,αναλύεται ο όρος αριθμητικός έλεγχος και αναλύονται οι εφαρμογές στις οποίες αυτός χρησιμοποιείται ενώ παράλληλα γίνεται αναφορά στο μηχανολογικό τμήμα της κατασκευής,στα υλικά και στο σχεδιασμό τέτοιων διατάξεων. Σημαντικό μέρος της εργασίας αφιερώθηκε στους βηματικούς κινητήρες που επελέχθησαν ως κινητήρες προώσεως της εργαλειομηχανής.Αναλύονται τόσο οι τύποι βηματικών κινητήρων όσο και ο έλεγχος τους ενώ ακόμα παρουσιάζεται και η στατική αλλά και η δυναμική τους συμπεριφορά σε ένα σύστημα. Τον ‘’εγκέφαλο’’ της διάταξης αποτελεί ο μικροεπεξεργαστής που ενσωματώνει το πρόγραμμα λειτουργίας της εργαλειομηχανής,ο οποίος αναλύεται σε μεγάλο βαθμό ξεκινώντας από τον ορισμό του,τη φύση της λειτουργίας του και καταλήγωντας στον ειδικότερο ρόλο που διαδραματίζει στο κύκλωμα ελέγχου της διάταξης. Ακόμα, περιγράφεται η αρχή λειτουργίας και η κατασκευαστική λογική της πλακέτας ελέγχου και οδήγησης του συστήματος.Τα συμπεράσματα της εργασίας και οι μελλοντικές επεκτάσεις που πιθανώς η διάταξη επιδέχεται παρουσιάζονται ως επίλογος. / The purpose of this thesis is the construction of an automated device that coats electrodes in to solid electrolyte for application in fuel cells. The project was conducted in Electromechanical Energy Conversion Laboratory, at Department of Electrical and Computer Engineering of the University of Patras. In this context, a CNC (Computerized Numerical Control) machine, capable of carrying out movements in three axes, controlled by stepper motors was designed. Although the ultimate purpose is the construction of such a device, an extensive theoretical study and analysis of all parameters and characteristics of the system was preceded. Initially, a reference to fuel cells is being made, describing the different types of the technology and the applications which fuel cells are incorporated. In general, fuel cell technology as an object of theoretical study and as a commodity product as well, is considered to be of high scientific interest, due to its high efficiency and it’s environmental friendly operation. In addition, a general definition of numerical control is being given relatively to its applications, providing a special interest in the mechanical design of systems that incorporate this particular method of control. A significant part of the project was consumed by the analysis of stepper motor behavior, both static and dynamic. Different types of stepper motors are being described along with several types of control schemes. Extensive description of the system’s incorporated micro-controller has been made, from its general description down to its specialized role to the system. Finally, the basic principles of operation are being described, given a special interest in to the board of control and drive of the system. The evaluation of the project’s status as well it’s future development were given as final conclusions.

Orientador: Amauri Hassui / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-25T20:35:42Z (GMT). No. of bitstreams: 1 Oliveira_JoaoPaulode_M.pdf: 2286790 bytes, checksum: ca7af2ca9f54e30cbe97dca258b4870d (MD5) Previous issue date: 2014 / Resumo: Para as indústrias aumentarem a produtividade, se faz necessário buscar melhorias contínuas e muitas vezes radicais em seus processos de fabricação. Uma das maneiras de obter êxito e melhorar os processos existentes é investir em inovação. Diante deste cenário, o presente trabalho visa contribuir para evolução do processo de obtenção do furo quadrado em máquina CNC. O processo para obtenção de furo quadrado em máquina CNC é recente, porém limitado, atualmente é possível produzir furos quadrados com cantos arredondados e apenas com ferramenta de medida igual à medida do furo que se quer produzir. Os testes feitos com uma nova modelagem matemática, mostraram ser possível obter mais pontos de programação e consequentemente obter uma melhor geometria do furo, com cantos afiados, e também aumentar a flexibilidade do processo, já que com uma ferramenta é possível fazer vários furos de medidas distintas à medida da ferramenta. Através dos experimentos, também foi possível mostrar uma aplicação prática do processo, tornando-o ainda mais vantajoso e produtivo / Abstract: For industries to increase productivity it is necessary to keep seeking for improvements and often radical improvements in their manufacturing processes. One of the ways to succeed and improve the existing processes it is to invest in innovation. In this scenario, the present work aims to contribute to the evolution of obtaining the square hole in CNC machine process. The process for obtaining the square hole CNC machine new, but limited. Currently it is possible to produce square holes with rounded corners and with only the same extent as the hole tool which it is willing to produce. The tests made with a new mathematical modeling showed that it is possible to obtain more points programming therefore get a better geometry of the hole with sharp corners also increase the flexibility of the process, as with a tool it is possible to make several holes measures as distinct from the tool. Through the experiments it was also possible to show a practical application of the process, making it even more beneficial and productive / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica