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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.
351

Μεταφορά εξομοιωμένου συστήματος ελέγχου σε μικροεπεξεργαστή για τροφοδότηση φορτίου από φωτοβολταϊκή γεννήτρια

Κωστούλας, Στέφανος 08 January 2013 (has links)
Στόχος της παρούσας διπλωματικής εργασίας είναι η τροφοδοσία ενός μεταβαλλόμενου RL φορτίου από μια φωτοβολταϊκή γεννήτρια, επιδιώκοντας η τάση σε αυτό να είναι σταθερή κατά μέτρο και συχνότητα. Η επίτευξη του στόχου προϋποθέτει την χρήση μιας σειράς διατάξεων, προκειμένου να δημιουργήσουμε ένα πειραματικό σύστημα πάνω στο οποίο θα αναπτύξουμε την εφαρμογή μας. Έτσι η πειραματική μας διάταξη εκτός από την πηγή (φωτοβολταϊκή γεννήτρια) και το φορτίο αποτελείται και απο έναν τριφασικό αντιστροφέα πηγής τάσης, έναν τριφασικό μετασχηματιστή, ένα βαθυπερατό φίλτρο LC, μια συσκευή βηματικής μεταβολής του φορτίου και έναν μικροεπεξεργαστή με την βοήθεια του οποίου θα υλοποιήσουμε τους απαραίτητους ελέγχους. Το πρώτο επίπεδο ελέγχου αφορά τον τριφασικό αντιστροφέα και συγκεκριμένα την παλμοδότηση την διακοπτικών του στοιχείων. Με την βοήθεια του μικροεπεξεργαστή πετυχαίνουμε την υλοποίηση του κυκλώματος παλμοδότησης εφαρμόζοντας την μέθοδο της ημιτονοειδούς διαμόρφωσης εύρους παλμών (Sinusoidal Pulse Width Modulation, SPWM). Σε δεύτερο επίπεδο ελέγχου υλοποιούμε έναν PI ελεγκτή ο οποίος σε συνεργασία με το κύκλωμα παλμοδότησης εξασφαλίζει την σταθεροποίηση της τάσης στο φορτίο, συνεπώς και την αδιάλειπτη τροφοδοσία του. Πραγματοποιώντας βηματικές αλλαγές στο φορτίο, καταγράφουμε τις μεταβολές στα μεγέθη εκείνα που επιβεβαιώνουν την λειτουργία και αποδοτικότητα του συνολικού συστήματος ελέγχου. Ιδιαίτερη αξία έχει ο τρόπος με τον οποίο παράγουμε τον κώδικα που υλοποιεί, μέσω του μικροεπεξεργαστή, το κύκλωμα ελέγχου. Η διαδικασία περιλαμβάνει αρχικά την μοντελοποίηση του κυκλώματος στο Simulink και στην συνέχεια την χρήση των κατάλληλων εργαλείων, οπότε μέσω μιας αυτόματης διαδικασίας παράγεται ο επιθυμητός κώδικας. Η διπλωματική εργασία διαρθρώνεται με τον εξής τρόπο: Στο κεφάλαιο 1 γίνεται μια σύντομη αναφορά στον σημαντικό ρόλο που καλούνται να διαδραματίσουν οι ανανεώσιμες πηγές ενέργειας, στις σημερινές και μελλοντικές ανάγκες του τομέα της ηλεκτρικής ενέργειας. Ακολουθεί μια συνοπτική παρουσίαση της φωτοβολταϊκής τεχνολογίας και του τρόπου αξιοποίησής της. Στο κεφάλαιο 2 γίνεται η πλήρης ανάπτυξη της μεθόδου ημιτονοειδούς διαμόρφωσης εύρους παλμών για την αξιοποίησή της σε μετατροπέα DC/AC (αντιστροφέα), ενός σκέλους και τριφασικού. Παρουσιάζονται αναλυτικά τα χαρακτηριστικά της μεθόδου και ο τρόπος εφαρμογής της σε ψηφιακά συστήματα. Στο κεφάλαιο 3 γίνεται η περιγραφή και ανάλυση της πειραματικής μας διάταξης. Διαχωρίζοντας το συνολικό σύστημα στα επιμέρους κυκλώματα ισχύος και ελέγχου, περιγράφουμε την κάθε διάταξη ξεχωριστά, αναλύοντας το αντίστοιχο θεωρητικό υπόβαθρο. Ιδιαίτερα, όσον αφορά το κύκλωμα ελέγχου, αναπτύσσουμε συνοπτικά την θεωρία του PI ελέγχου, στον βαθμό που κρίνεται απαραίτητο για την εφαρμογή μας. Στο κεφάλαιο 4 παρουσιάζεται το σύστημα eZdspTM F28335. Το σύστημα αυτό περιλαμβάνει τον επεξεργαστή ψηφιακού σήματος F28335, με την βοήθεια του οποίου υλοποιούμε το κύκλωμα ελέγχου. Γίνεται αναφορά στις δυνατότητες του συστήματος και περιγράφονται τα περιφερειακά του που χρησιμοποιούνται στην παρούσα εφαρμογή. Στο κεφάλαιο 5 γίνεται η ανάλυση του μοντέλου Simulink που υλοποιεί το κύκλωμα ελέγχου. Αρχικά, παρουσιάζεται συνοπτικά η διαδικασία ταχείας προτυποποίησης και ο τρόπος με τον οποίο επιτυγχάνουμε την αυτόματη παραγωγή κώδικα μέσω των μοντέλων του Simulink. Στη συνέχεια περιγράφουμε αναλυτικά τα μπλόκ που συνιστούν το μοντέλο της εφαρμογής μας. Στο κεφάλαιο 6 γίνεται η παρουσίαση των πειραματικών αποτελεσμάτων που προέκυψαν κατά την διάρκεια των μετρήσεων. Συγκεκριμένα παρατίθενται μετρήσεις και γραφήματα που έχουν στόχο να αναδείξουν την λειτουργία του ελέγχου και τον τρόπο με τον οποίο επιδρά στο σύστημά μας. Στο κεφάλαιο 7 παρουσιάζονται τα τελικά συμπεράσματα και οι πιθανές μελλοντικές προοπτικές της εφαρμογής. / The objective of this thesis is the power supply of a variable RL load, by the use of a photovoltaic generator as our energy source, aiming to a load voltage with constant rms value and frequency. To achieve this objective, involves the use of several devices, in order to create an experimental system on which we will develop our application. Thus, our total system, other than the source (photovoltaic generator) and the load, is composed of a three-phase voltage source inverter (VSI), a three-phase transformer, a low pass LC filter, a device that electronically chooses the value of the load and a microprocessor which implements the necessary control system. The first part of the control system refers to the generation of the signals that control the switching elements of the three-phase voltage source inverter. With the help of the microprocessor we achieve the implementation of the appropriate pulse generator circuit using a method called sinusoidal pulse width modulation (SPWM). In the second part of the control system we implement a PI controller which, in collaboration with the above circuit, ensures the stabilization of the voltage on the load, therefore the uninterrupted power supply. Making step load changes, we record the variation of those parameters that confirm the operation and efficiency of the entire control system. Of great importance is the way we produce the code that implements the control circuit, when executed by the microprocessor. The procedure begins with the modeling of the circuit in Simulink, followed by the use of the appropriate development tools that result in an automatic process of production of the desired code. The thesis is organized in the following way: In Chapter 1 we give a brief reference to the importance of the renewable energy sources, regarding the present and future needs of the electricity sector. We continue with a summary of the photovoltaic technology and it’s means of exploitation. In Chapter 2 we make a thorough description of the method called sinusoidal pulse width modulation and we discuss it’s use for the DC/AC converter (inverter), both single-leg and three-phase. We give a full presentation on the characteristics of the method and the manner to be implemented in digital systems. In Chapter 3 we make the description and analysis of our experimental system. By separating the overall system to two individual parts, the power circuit and the control circuit, we describe each device separately and analyze the relevant theory. In particular, with respect to the control circuit, we summarize the theory of PI controller, to the necessary extent for our application. In Chapter 4 we introduce the system eZdspTM F28335. This system includes the digital signal processor F28335, which undertakes the implementation of the control circuit. Reference is made to the overall capabilities of the system and especially to the peripherals used in this application. In Chapter 5 we give the analysis of the Simulink model which implements the control circuit. Initially, we outline the procedure of rapid prototyping and describe the way in which we achieve the automatic production of our executable code through the Simulink models. Then we describe in detail the blocks that form the model of our application. In Chapter 6 we present the results obtained during the experimental phase. In particular there are listed measurements and graphs that aim to highlight the function of the control system and the manner in which it influences our system. In Chapter 7 we present our final conclusions and possible future prospects of the application.
352

Die ontwikkeling van 'n pasklaar-vervaardigde kunsmatige intervertebrale skyf-implantaat

Odendaal, Adriaan Izak 12 1900 (has links)
Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Current technology enables researchers to identify a broad spectrum of opportunities in the biomedical industry to develop new and innovative products. Imaging technology, such as Computerised Tomography (CT) scanners or Magnetic Resonance Imaging (MRI) scanners, allow doctors to visualise a patient’s internal organs and bone structure in high quality three-dimensional images. Rapid Prototyping Technology (RPT) can already produce high quality complex parts, such as concept parts for the automobile industry and medical models for preoperative planning. These parts are divided into thin layers and manufactured layer by layer. At the same time the layers are joined together to produce the desired part. Generic artificial intervertebral disc implants already exist. However, these discs are only available in standard geometrical dimensions. The possibility of using imaging technology and RPT to design and manufacture a customized, patient specific implant will be investigated. A simple design (ball and socket) is used to illustrate the design process of a customized disc. It should be noted that this project does not attempt to design a new artificial intervertebral disc implant, but rather describes the design process. The research question is: How accurate can the customised disc implant’s inverse geometry represent the geometry of the vertebrae’s endplates? A preliminary research was done and the results were used to calculate the sample size for this study. A cadaver, provided by Stellenbosch University’s Faculty of Health Sciences’ Anatomy and Histology Department, was CT scanned. The L4- and L5-vertebrae were dissected, cleaned and measured using a photogrammetry measuring machine. Meanwhile, the data gathered from the CT scan is used to design the customised disc implant. The disc is manufactured from Ti6Al4V using a RPT technique called Direct Metal Laser Sintering. After the part is manufactured it is also measured using a photogrammetry measuring machine. The photogrammetry data from the vertebrae and the manufactured customised disc implant are compared, analysed and a hypothesis is formed. It can now be determined, with a certain degree of confidence, how accurate the customised disc implant’s geometry can represent the geometry of the vertebrae’s endplates. The design of a customised disc implant demands many work hours from a qualified engineer or designer, which in turn increases the production costs. This study describes a user-friendly program which will semi-automate the design process. Only limited input from the physician will be required. This program will decrease design time, which will have a direct effect on the production costs. The manufacturing costs are investigated as well. The results from this study indicates that it is possible to design a customized prosthetic, with the help of a custom disc generator, within 27 minutes. The customized disc can then be manufactured with an accuracy of 0.37 mm using rapid prototyping. / AFRIKAANSE OPSOMMING: Huidige tegnologie maak dit vir navorsers moontlik om ʼn breë spektrum geleenthede in die biomediese bedryf te identifiseer en nuwe produkte te ontwikkel. ʼn Pasiënt kan met ʼn Gerekenariseerde Tomografie (GT) -flikkergram of ʼn Magnetiese Resonansiebeelding (MRB) - masjien geskandeer word om sodoende ʼn drie-dimensionele beeld van sy of haar interne organe en beenstrukture te verkry. Deur gebruik te maak van snelle prototiperingstegnologie (SPT) kan daar alreeds enige komplekse geometriese vorm vervaardig word. Hierdie tegnologie word ingespan om parte, ontwerp met die hulp van RGO (Rekenaargesteunde Ontwerp), te vervaardig. Die spesifieke part word in dun lae opgedeel en daarna laag vir laag vervaardig. Terselfdertyd word die lae aan mekaar geheg, totdat die gewenste vorm gegenereer is. Die moontlikheid om ʼn GT-flikkergram én SPT te gebruik, met die doel om ʼn pasklaar-vervaardigde, persoon-spesifieke implantaat te ontwerp en te vervaardig, word in hierdie projek ondersoek. Daar bestaan alreeds generiese kunsmatige intervertebrale skyf-implantate (KISI’s). Hierdie skywe word egter beperk deurdat dit slegs in standaard geometriese dimensies vervaardig word. Met dié projek word die moontlikheid van ʼn pasklaar-vervaardigde intervertebrale skyf-implantate (PVKISI) vir ʼn bepaalde pasiënt, ondersoek. ʼn Eenvoudige meganiese ontwerp (bal-en-pootjie) word gebruik om die ontwerpproses van ʼn pasklaar-skyf in hierdie projek te beskryf. Let daarop dat die projek nie poog om ʼn nuwe kunsmatige intervertebrale skyf te ontwerp nie, maar om die ontwerpproses te beskryf. Die vraag wat ondersoek word, is: Hoe akkuraat kan ʼn PVKISI die inverse geometrie van die pasiënt se intervertebrale kontakoppervlaktes voorstel? ʼn Voorafgaande ondersoek is gedoen en die resultate is gebruik om die steekproef-grootte vir hierdie studie te bepaal. ʼn Kadawer, voorsien deur die Universiteit van Stellenbosch se Fakulteit Gesondheidwetenskappe se Departement Anatomie en Histologie, is met ʼn GT-flikkergram geskandeer. Die L4- en L5-werwels is gedissekteer, skoon gemaak en met ʼn fotogrammetriemeetmasjien gemeet. Intussen is die data, verkry van die GT-flikkergram, gebruik om die PVKISI te ontwerp. Die PVKISI is van Ti6Al4V vervaardig deur Direkte Metaal Laser-Sintering (DMLS). Die part is ook met ʼn fotogrammetrie-meetmasjien gemeet. Die fotogrammetrie-data van die werwels en die PVKISI is vergelyk, geanaliseer en ʼn hipotese is daar gestel. Daar kan dus met statistiese sekerheid bepaal word hoe akkuraat die PVKISI die inverse geometrie van die intervertebrale kontakoppervlaktes kan voorstel. Die ontwerp van ʼn PVKISI vereis baie werksure van ʼn gekwalifiseerde ingenieur of ontwerper, wat veroorsaak dat die vervaardigingskoste van so ʼn implantaat kan verhoog. In dié projek word ʼn gebruikersvriendelike koppelprogram beskryf wat die ontwerpproses semi-outomatiseer. Daar sal slegs beperkte bystand van die betrokke medici vereis word. Dié koppelprogram behoort heelwat te bespaar aan die hoeveelheid werksure bestee aan die ontwerp van die PVKISI, wat direk die koste van ʼn implantaat sal verlaag. Die kostes vir die vervaardiging van die PVKISI met DMLS is ook ondersoek om te bepaal hoe kostes bespaar kan word. Daar is getoon dat ʼn pasklaar-prostese se kontakoppervlaktes met ʼn akkuraatheid van 0.37 mm, deur snelle prototipering, vervaardig kan word. Deur van die koppelprogram, wat in die studie beskryf word, gebruik te maak, sal dit moontlik wees om ʼn pasklaar-protese binne 27 minute te ontwerp.
353

Do modelo geom?trico ao modelo f?sico: o tridimensional na educa??o do arquiteto e urbanista

Costa, Fernando Jos? de Medeiros 02 March 2013 (has links)
Made available in DSpace on 2014-12-17T13:56:53Z (GMT). No. of bitstreams: 1 FernandoJMC_TESE.pdf: 4090837 bytes, checksum: c86bb775317f1faa46b14511be554257 (MD5) Previous issue date: 2013-03-02 / In the teaching practice of architecture and urbanism in Brazil, educational legislation views modeling laboratories and workshops as an indispensable component of the infrastructure required for the good functioning of any architectural course of study. Although the development of information technology at the international level has created new possibilities for digital production of architectural models, research in this field being underway since the early 1990s, it is only from 2007 onwards that such technologies started to be incorporated into the teaching activity of architecture and urbanism in Brazil, through the pioneering experience at LAPAC/FEC/UNICAMP. It is therefore a recent experiment whose challenges can be highlighted through the following examples: (i) The implementation of digital prototyping laboratories in undergraduate courses of architecture and urbanism is still rare in Brazil; (ii) As a new developing field with few references and application to undergraduate programs, it is hard to define methodological procedures suitable for the pedagogical curricula already implemented or which have already been consolidated over the years; (iii) The new digital ways for producing tridimensional models are marked with specificities which make it difficult to fit them within the existing structures of model laboratories and workshops. Considering the above, the present thesis discusses the tridimensional model as a tool which may contribute to the development of students skills in perceiving, understanding and representing tridimensional space. Analysis is made of the relation between different forms of models and the teaching of architectural project, with emphasis on the design process. Starting from the conceptualization of the word model as it is used in architecture and urbanism, an attempt is made to identify types of tridimensional models used in the process of project conception, both through the traditional, manual way of model construction as well as through the digital ones. There is also an explanation on how new technologies for digital production of models through prototyping are being introduced in undergraduate academic programs of architecture and urbanism in Brazil, as well as a review of recent academic publications in this area. Based on the paradigm of reflective practice in teaching as designed by Sch?n (2000), the experiment applied in the research was undertaken in the integrated workshop courses of architectural project in the undergraduate program of architecture and urbanism at Universidade Federal do Rio Grande do Norte. Along the experiment, physical modeling, geometric modeling and digital prototyping are used in distinct moments of the design process with the purpose of observing the suitability of each model to the project s phases. The procedures used in the experiments are very close to the Action Research methodology in which the main purpose is the production of theoretical knowledge by improving the practice. The process was repeated during three consecutive semesters and reflection on the results which were achieved in each cycle helped enhancing the next one. As a result, a methodological procedure is proposed which consists of the definition of the Tridimensional Model as the integrating element for the contents studied in a specific academic period or semester. The teaching of Architectural Project as it is developed along the fifth academic period of the Architecture and Urbanism undergraduate program of UFRN is taken as a reference / Na pr?tica do ensino de Arquitetura e Urbanismo no Brasil, verifica-se a exist?ncia de laborat?rios e oficinas de maquetes, reconhecidas pela legisla??o educacional como parte da infraestrutura necess?ria para o funcionamento de um curso. Embora a evolu??o da tecnologia da informa??o no ?mbito internacional disponibilize novas possibilidades para a produ??o digital de maquetes e modelos de Arquitetura com pesquisas produzidas desde o in?cio da d?cada de 1990, no Brasil essas tecnologias s? come?aram a ser apropriadas pelo ensino de Arquitetura e Urbanismo a partir de 2007 com a experi?ncia pioneira do LAPAC/FEC/UNICAMP. Trata-se, portanto de uma experi?ncia recente e que evidencia a desafios. Por exemplo: (i) s?o raros os casos de implanta??o de laborat?rios de prototipagem digital em cursos de Arquitetura e Urbanismo no Pa?s; (ii) por ser um campo em desenvolvimento com poucas refer?ncias de aplica??es na gradua??o, h? dificuldades na defini??o de procedimentos metodol?gicos que sejam adequados aos projetos pedag?gicos j? implantados e consolidados; (iii) as novas formas digitais de produ??o de modelos tridimensionais cont?m especificidades que dificultam a compatibiliza??o com as estruturas de laborat?rios e oficinas de maquetes j? existentes. Considerando o exposto, na presente tese se discute o modelo tridimensional como instrumento auxiliar no desenvolvimento da capacidade do estudante de perceber, compreender e representar o espa?o tridimensional. Analisa-se a rela??o entre diferentes formas de modelos e o ensino de projeto de Arquitetura e Urbanismo com interesse no processo projetual. Partindo da conceitua??o do modelo em Arquitetura e Urbanismo, busca-se identificar os tipos de modelos tridimensionais utilizados no processo de elabora??o do projeto, tanto nas formas tradicionais de constru??o manual de maquetes e modelos quanto nos meios digitais. Procura-se conhecer como as novas tecnologias para a produ??o digital de modelos por meio da prototipagem digital est?o sendo introduzidas nos cursos de gradua??o de Arquitetura e Urbanismo no Brasil, assim como a produ??o acad?mica recente na ?rea. Considerando o paradigma do ensino pr?tico reflexivo concebido por Sch?n (2000), o experimento realizado na pesquisa tem como ambiente de estudo o ateli? integrado de projeto do Curso de Arquitetura e Urbanismo da Universidade Federal do Rio Grande do Norte. No experimento a Modelagem f?sica, a Modelagem Geom?trica e a Prototipagem Digital s?o inseridas em momentos do processo do projeto com o objetivo de se observar a adequa??o do modelo ?s fases do projeto. A metodologia empregada nos experimentos muito se aproxima da Pesquisa A??o na qual o alvo principal ? a cria??o de conhecimento te?rico com o aprimoramento da pr?tica. O processo se repetiu por tr?s semestres consecutivos e a reflex?o sobre os resultados alcan?ados em cada ciclo forneceram subs?dios para aprimoramento no seguinte. Como resultado prop?e-se um procedimento metodol?gico no qual o Modelo Tridimensional constitui elemento integrador de conte?dos desenvolvidos em um per?odo curricular, tendo como refer?ncia o ensino de Projeto Arquitet?nico e Urban?stico no quinto per?odo do Curso de Arquitetura e Urbanismo da UFRN
354

CAD e engenharia reversa como ferramentas de aux?lio na fabrica??o de cartuchos para pr?teses ortop?dicas

Pereira, Edson Jorge Alc?ntara 10 August 2007 (has links)
Made available in DSpace on 2014-12-17T14:57:43Z (GMT). No. of bitstreams: 1 EdsonJAP.pdf: 1427766 bytes, checksum: 2d062c892b501f8f46093e7d7c17a9b2 (MD5) Previous issue date: 2007-08-10 / The manufacturing of above and below-knee prosthesis starts by taking surfac measurements of the patient s residual limb. This demands the making of a cartridg with appropriate fitting and customized to the profile of each patient. The traditiona process in public hospitals in Brazil begins with the completion of a record file (according to law n?388, of July 28, 1999 by the ministry of the health) for obtaining o the prosthesis, where it is identified the amputation level, equipment type, fitting type material, measures etc. Nowadays, that work is covered by the Brazilian Nationa Health Service (SUS) and is accomplished in a manual way being used commo measuring tapes characterizing a quite rudimentary, handmade work and without an accuracy.In this dissertation it is presented the development of a computer integrate tool that it include CAD theory, for visualization of both above and below-knee prosthesis in 3D (i.e. OrtoCAD), as well as, the design and the construction a low cos electro-mechanic 3D scanner (EMS). This apparatus is capable to automatically obtain geometric information of the stump or of the healthy leg while ensuring smalle uncertainty degree for all measurements. The methodology is based on reverse engineering concepts so that the EMS output is fed into the above mentioned academi CAD software in charge of the 3D computer graphics reconstruction of the residualimb s negative plaster cast or even the healthy leg s mirror image. The obtained results demonstrate that the proposed model is valid, because it allows the structura analysis to be performed based on the requested loads, boundary conditions, material chosen and wall thickness. Furthermore it allows the manufacturing of a prosthesis cartridge meeting high accuracy engineering patterns with consequent improvement in the quality of the overall production process / A fabrica??o de pr?teses para amputados de membros inferiores (transfemural e transtibial) exige a confec??o de um cartucho com encaixe adequado e personalizado ao perfil de cada paciente. O processo tradicional de atendimento a pacientes em hospitais p?blicos no Brasil inicia-se com o preenchimento de uma ficha conforme portaria n?388, de 28 de Julho de 1999 do minist?rio da sa?de para obten??o da pr?tese, onde ? identificado o n?vel de amputa??o, tipo de equipamento, tipo de encaixe, material, medidas etc. Atualmente, esses cartuchos s?o fabricados de forma manual atrav?s de instrumentos de baixa precis?o, caracterizando um trabalho bastante rudimentar, artesanal e sem nenhuma acuracidade. Nesta disserta??o prop?e-se o desenvolvimento de uma ferramenta integrada que envolva o CAD, para visualiza??o das pr?teses dos tipos transfemural/transtibial em 3D (OrtoCAD), bem como, o projeto e a constru??o um leitor eletromec?nico (esp?cie de scanner tridimensional), capaz de obter automaticamente e qualitativamente, com menor grau de incerteza as informa??es geom?tricas do coto ou da perna sadia. A metodologia inclui a aplica??o de conceitos de engenharia reversa para gerar computacionalmente a representa??o do coto e/ou a imagem reversa do membro sadio. Os resultados obtidos demonstram que o modelo posposto ? v?lido, pois permite a an?lise estrutural em fun??o do carregamento solicitado e a confec??o de um cartucho de pr?tese atendendo elevados padr?es de acuracidade da engenharia com conseq?ente melhoria na qualidade do processo de fabrica??o
355

Solução de tecnologia para planejamento e tratamento ortodôntico de dentes inclusos / Technology solution for treatment and planning of teeth included orthodontic treatment

Lima, Jefferson Felipe Silva de 22 December 2016 (has links)
Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2018-05-24T12:40:53Z No. of bitstreams: 1 PDF - Jefferson Felipe Silva de Lima.pdf: 26931863 bytes, checksum: b52e9a3ab1c58df593cae907b9fc936d (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2018-06-05T11:33:36Z (GMT) No. of bitstreams: 1 PDF - Jefferson Felipe Silva de Lima.pdf: 26931863 bytes, checksum: b52e9a3ab1c58df593cae907b9fc936d (MD5) / Made available in DSpace on 2018-06-05T11:33:36Z (GMT). No. of bitstreams: 1 PDF - Jefferson Felipe Silva de Lima.pdf: 26931863 bytes, checksum: b52e9a3ab1c58df593cae907b9fc936d (MD5) Previous issue date: 2016-12-22 / The Additive Manufacturing (MA), actually is used aiming the production of small proto- types, until a recent application in the field of dentistry, intended for the planning, simulation, testing and surgeries auditions and other dental procedures. Some orthodontic surgeries are endowed with levels of difficulty and require dexterity of the highest quality, due mainly to the lack of predictability in the treatment, not allowing a precise and direct plan for the case addressed. Among the most recurrent surgical procedures in this scenario, it is the canine tooth traction surgery included. A situation that occurs frequently during adolescence, requi r- ing a great deal of inference from the responsible professional, that if isn’t treated in time, may compromise the reorganization of other teeth and bring irremediable sequelae in long term. In this context, this research aimed at the development of a technology solution for o r- thodontic planning and treatment of included teeth, where clinical cases were used in which it was indicated the surgery of traction and subsequent alignment of canine teeth included. Free and recent software were analyzed that offered the potential to improve the planning process and subsequent treatment through the creation of a biomodel to serve as the basis of the deci- sions of the surgeon and orthodontists acting in the correction of the problem. In this way the present master's work presents a process of software use, which allows the end user to have a free manipulation on the images in the pre-prototyping phase, thus generating a biomodel that carries beyond the visual load obtained through the treatment of DICOM images, the traject o- ry traversed by the tooth during the surgery, allowing also a virtual simulation of the surgery. / A Manufatura Aditiva (MA), atualmente estende a sua utilização desde a fabricação de pe- quenos protótipos diversos, até a recente aplicação no âmbito da odontologia, destinada ao planejamento, simulação, teste e ensaio de cirurgias e outros procedimentos odontológicos. Algumas cirurgias ortodônticas são dotadas de níveis de dificuldade e requerem destreza altís- sima, devido principalmente à falta de previsibilidade no tratamento, não permitindo um pla- nejamento preciso e direto para o caso abordado. Dentre os procedimentos cirúrgicos mais recorrentes nesse cenário está a cirurgia de tracionamento de dentes caninos inclusos. Situa- ção que ocorre com grande frequência durante a adolescência, exigindo grande poder de infe- rência por parte do profissional responsável, que se não tratada a tempo pode vir a comprome- ter a reorganização dos demais dentes e trazer sequelas irremediáveis a longo prazo. Nesse contexto, esta pesquisa objetivou o desenvolvimento de uma solução de tecnologia para pla- nejamento e tratamento ortodôntico de dentes inclusos, onde foram utilizados casos clínicos nos quais estava indicada a cirurgia de tracionamento e posterior alinhamento de dentes cani- nos inclusos. Foram analisados softwares livres e recentes que oferecessem potencial de apri- morar o processo de planejamento e posterior tratamento através da confecção de biomodelo a servir como base das decisões do cirurgião e ortodontistas atuantes na correção do problema. Dessa forma o presente trabalho de mestrado apresenta um processo de utilização de software, que permite que o usuário final tenha uma livre manipulação sobre as imagens na fase de pré- prototipagem, gerando assim um biomodelo que carregue além da carga visual obtida através do tratamento de imagens DICOM, a trajetória percorrida pelo dente durante a cirurgia, permitindo também uma simulação virtual da cirurgia.
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Projeto e fabricação de moldes para prensagem isostática utilizando tecnologias CAD/CAE e prototipagem rápida. / Design and manufacturing of moulds in isostatic pressing using CAD/CAE technology and rapid prototyping.

Rodrigo Bresciani Canto 08 November 2002 (has links)
Apresenta uma metodologia para o projeto e fabricação de moldes para prensagem isostática de pó cerâmico (alumina) utilizando ferramentas computacionais CAD/CAE associadas à tecnologia de Prototipagem Rápida. O processo de prensagem isostática é simulado utilizando o método dos elementos finitos. Para a representação da compactação do pó cerâmico é utilizado o modelo de Drucker-Prager/cap e para a representação do comportamento do material elastomérico é utilizado o modelo hiperelástico de Mooney-Rivlin, ambos disponíveis no programa ABAQUS. Tal simulação visa obter o projeto do molde de forma mais rápida e precisa, ajustando-o até que se alcance um molde adequado para produzir um compacto com uma quantidade de sobrematerial ideal para o processo de usinagem a verde. Para isso utilizou-se como estudo de caso uma esfera cerâmica para implante de quadril. Um protótipo virtual do molde adequado obtido das simulações é então modelado e reproduzido em plástico ABS (Acrylonitrile Butadiene Styrene) pela tecnologia de Prototipagem Rápida FDM (Fused Deposition Modeling). Esse protótipo físico é a base para o desenvolvimento de matrizes rígidas e em silicone, que são utilizadas para a confecção da parte flexível do molde (matriz elastomérica) e de partes rígidas como a gaiola suporte obtidas por vazamento dos polímeros. Constatou-se a viabilidade da utilização da metodologia de projeto e fabricação do molde para prensagem isostática, considerando que as simulações mostraram-se bastante coerentes com os resultados experimentais obtidos de componentes prensados. / This work presents a methodology for the design and fabrication of ceramic powder isostatic pressing moulds using CAD and CAE tools and Rapid Prototyping. The isostatic pressing process was simulated using the finite element method. The compaction behavior of ceramic powder is described by the Drucker-Prager/cap constitutive model and the behavior of elastomeric material is described by the Mooney-Rivlin constitutive model within the commercial finite element software ABAQUS®. These simulations are required to adjust the mould design in order to suit the geometry of the compact and green machining allowance. For this study, it is used a case study consisting of pressing a ceramic sphere for hip implant stem. A virtual prototype was designed from the geometry obtained from the simulations and reproduced in Acrylonitrile Butadiene Styrene (ABS) polymer, using the Rapid Prototyping technology - Fused Deposition Modeling (FDM). Silicone moulds were obtained from the polymer prototype and used to aid in the making of the elastomeric bag and mould support cage. The methodology used in this investigation was validate considering that the simulations yield to a good agreement with measured manufactured components.
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Obtenção de modelos CAD tridimensionais a partir de imagens tomográficas para auxílio em cirurgias corretivas / Reconstruction of 3D CAD models from computed tomography images to surgery aid

Alexandre Zanni Hubinger 28 November 2002 (has links)
No início da década de 90 a tecnologia de prototipagem rápida foi utilizada na simulação e planejamento de cirurgias de correções de deformidades da face. Os modelos eram construídos a partir de imagens do exame de tomografia computadorizada. Seu custo era elevado e os modelos podiam ser utilizados uma única vez. Considerando-se estas desvantagens, este trabalho desenvolve uma nova alternativa: a simulação da cirurgia em um modelo CAD através de operações matemáticas equivalentes às técnicas utilizadas nas cirurgias. Para obter o modelo CAD, utilizaram-se programas de uso educacional para o processamento das imagens da tomografia de uma mandíbula. Através do desenvolvimento de um programa que detecta os dados das bordas das imagens, reduz estes dados, e, utilizando um conversor IGES, introduz estes dados no sistema CAD onde é construído o modelo matemático. A partir do modelo CAD gera-se, utilizando a prototipagem rápida, o protótipo físico da mandíbula. Compara-se este protótipo ao outro obtido, a partir das mesmas imagens tomográficas, pelo uso de programas comerciais, e também, à mandíbula original. Os resultados obtidos são relatados discutindo-se as suas principais fontes de erro para validação do procedimento. / In the beginning of the nineties the technology of rapid protyping was first used in simulation and planning of surgeries of face injuries. The models were built starting from images from computerized tomography (CT). Its cost was elevated and the models could be used only one time. Considering these difficulties, this work develops a new procedure: the simulation of the surgery in a CAD model through equivalent mathematical operations to the techniques used in the surgeries. To obtain the CAD model, educational programs were used for the processing of the CT images of a jaw. Through the development of a program that detects and reduces the edges of the images and introduces these data in the CAD system by using the IGES interface, the mathematical model is built. From the CAD system, using the rapid prototyping technology the prototype is generated. This prototype is compared to the one produced by using commercial packages and also to the original jaw. The results are presented and the main sources of erros are discussed in order to validate the procedure.
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Interactive Virtual Machining : A Voxel Based Approach

Mahesh, N 12 1900 (has links) (PDF)
No description available.
359

Návrh 3D tiskárny s dvojicí tiskových hlav / Design of 3D printers with a pair of printheads

Halamíček, Lukáš January 2017 (has links)
The master thesis deals with design of multi material FDM 3D printer. In the first part, current market situation and possible principles of multi material printing are described. Possible variants of individual construction nodes are described in the next part and then the selected variant is processed into a design solution. The benefit of this thesis is a proposal of solution for the automatic printing head exchange, which is practically not concerned by printer manufacturers.
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Použití modelů zhotovených technologii 3D tisku při výrobě odlitků do bentonitových forem na formovací lince / Using of 3D printed patterns for mass production of castings on "green sand" moulding lines

Vašek, Vojtěch January 2017 (has links)
Shortening of the time required to make first product after demand is a crucial factor in every field of industry, not excluding the foundry. To lower this delay, there are rapid prototyping methods. The aim of this thesis is to execute an experiment and then evaluate possibilities of using patterns made by 3D FDM printer on an automatic molding line.

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