5,248 research outputs found

    An approach for real world data modelling with the 3D terrestrial laser scanner for built environment

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    Capturing and modelling 3D information of the built environment is a big challenge. A number of techniques and technologies are now in use. These include EDM, GPS, and photogrammetric application, remote sensing and traditional building surveying applications. However, use of these technologies cannot be practical and efficient in regard to time, cost and accuracy. Furthermore, a multi disciplinary knowledge base, created from the studies and research about the regeneration aspects is fundamental: historical, architectural, archeologically, environmental, social, economic, etc. In order to have an adequate diagnosis of regeneration, it is necessary to describe buildings and surroundings by means of documentation and plans. However, at this point in time the foregoing is considerably far removed from the real situation, since more often than not it is extremely difficult to obtain full documentation and cartography, of an acceptable quality, since the material, constructive pathologies and systems are often insufficient or deficient (flat that simply reflects levels, isolated photographs,..). Sometimes the information in reality exists, but this fact is not known, or it is not easily accessible, leading to the unnecessary duplication of efforts and resources. In this paper, we discussed 3D laser scanning technology, which can acquire high density point data in an accurate, fast way. Besides, the scanner can digitize all the 3D information concerned with a real world object such as buildings, trees and terrain down to millimetre detail Therefore, it can provide benefits for refurbishment process in regeneration in the Built Environment and it can be the potential solution to overcome the challenges above. The paper introduce an approach for scanning buildings, processing the point cloud raw data, and a modelling approach for CAD extraction and building objects classification by a pattern matching approach in IFC (Industry Foundation Classes) format. The approach presented in this paper from an undertaken research can lead to parametric design and Building Information Modelling (BIM) for existing structures. Two case studies are introduced to demonstrate the use of laser scanner technology in the Built Environment. These case studies are the Jactin House Building in East Manchester and the Peel building in the campus of University Salford. Through these case studies, while use of laser scanners are explained, the integration of it with various technologies and systems are also explored for professionals in Built Environmen

    A Review of State-of-the-Art Large Sized Foam Cutting Rapid Prototyping and Manufacturing Technologies.

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    Purpose – Current additive rapid prototyping (RP) technologies fail to efficiently produce objects greater than 0.5?m3 due to restrictions in build size, build time and cost. A need exists to develop RP and manufacturing technologies capable of producing large objects in a rapid manner directly from computer-aided design data. Foam cutting RP is a relatively new technology capable of producing large complex objects using inexpensive materials. The purpose of this paper is to describe nine such technologies that have been developed or are currently being developed at institutions around the world. The relative merits of each system are discussed. Recommendations are given with the aim of enhancing the performance of existing and future foam cutting RP systems. Design/methodology/approach – The review is based on an extensive literature review covering academic publications, company documents and web site information. Findings – The paper provides insights into the different machine configurations and cutting strategies. The most successful machines and cutting strategies are identified. Research limitations/implications – Most of the foam cutting RP systems described have not been developed to the commercial level, thus a benchmark study directly comparing the nine systems was not possible. Originality/value – This paper provides the first overview of foam cutting RP technology, a field which is over a decade old. The information contained in this paper will help improve future developments in foam cutting RP systems

    Evaluation of fit for 3D printed retainers as compared to thermoform retainers

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    ABSTRACT EVALUATION OF FIT FOR 3D PRINTED RETAINERS AS COMPARED TO THERMOFORM RETAINERS By David Cole, D.M.D. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University Thesis Directors: Eser Tüfekçi, D.D.S., M.S., Ph.D., M.S.H.A. Professor, Department of Orthodontics Sompop Bencharit, D.D.S., M.S., Ph.D. Associate Professor and Director of Digital Dentistry, Department of General Practice Introduction: Despite recent advances in three-dimensional (3D) printing, little information is available on 3D printed retainers Methods: Three reference models were used to fabricate traditional vacuum formed, commercially-available vacuum formed, and 3D printed retainers. For each model, three retainers were made using the three methods (a total of 27 retainers). To determine the trueness, the distances between the intaglio surface of the retainers and the occlusal surface of the reference models were measured using an engineering software. A small difference was indicative of a good fit. Results: Average differences of the traditional vacuum formed retainers ranged from 0.10 to 0.20mm. The commercially-available and 3D printed retainers had a range of 0.10 to 0.30mm and 0.10 to 0.40mm, respectively. Conclusions: The traditional vacuum formed retainers showed the least amount of deviation from the original reference models while the 3D printed retainers showed the greatest deviation

    Maintaining authenticity: transferring patina from the real world to the digital to retain narrative value

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    This research is concerned with utilizing new technologies to harvest existing narrative, symbolic and emotive value for use in a digital environment enabling "emotional durability" (Chapman, 2005) in future design. The projects discussed in this paper have been conducted as part of PhD research by Rosemary Wallin into 'Technology for Sustainable Luxury' at University of the Arts London, and visual effects technology research undertaken by Florian Stephens at University of West London. Jonathan Chapman describes vast consumer waste being "symptomatic of failed relationships" between consumers and the goods they buy, and suggests approaches for designing love, dependency, and even cherishability into products to give them a longer lifespan. 'Failed relationships' might also be observed in the transference of physical objects to their virtual cousins. Consider the throwaway nature of digital photography when compared to the carefully preserved prints in a family album. Apple often use a skeuomorphic (Hobbs, 2012) approach to user interface design, to digitally replicate the patina and 'value' of real objects. However, true transference of physical form and texture presumably occurs when an object is scanned and a virtual 3D model is created. This paper presents three practice-based approaches to storing and transferring patina from an original object, utilizing high resolution scanning, photogrammetry, mobile applications and 3D print technologies. The objective is not merely accuracy, but evocation of the emotive data connecting the digital and physical realm. As the human face holds experience in the lines and wrinkles of the skin, so the surface of an object holds its narrative. From the signs of the craftsman to the bumps and scratches that accumulate over the life of an item over time and generations, marks gather like evidence to be read by a familiar or a trained eye. According to the time and the culture these marks are read within, they will either add to or detract from its value. These marks can be captured via complex 3D modelling and scanning technologies, which allow detailed forms to be recreated as dense 3D wireframe, but the result is often unsatisfying. 3D greyscale surfaces can never fully capture the richness of patina. Authentic surfaces require other qualities such as colour, texture and depth, but there is something else - more difficult to define. Donald A. Norman expands on the idea of emotion and objects by describing three 'levels’ of design "visceral, behavioural and reflective". Visceral is based on "look, feel and sound", behavioural is focused on an object’s use, and reflective is concerned with its message. New technology is commonly seen in terms of its ability to increase efficiency, but this research has longer-term objectives: to repair or even rebuild Chapman's 'broken relationships' and enable ‘emotionally durable' design. The PhD that has formed the context for this paper examines the concept of luxury value, and how and why the value of patina has been replaced by fashion. Luxury goods are aspirational items often emulated in the bulk of mass production. If we are to alter behaviour around consumption, one approach might be to use technology to harvest patina as a way to retain emotional, symbolic and poetic value with a view to maintaining a relationship with the things we buy

    Comparative Analysis of Mobile 3D Scanning Technologies for Design, Manufacture of Interior and Exterior Tensile Material Structures and Canvasman Ltd. Case Study

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    This report aimed to investigate mobile 3D Scanning technologies to improve the 3D data capture and efficiency into Canvasman’s CAD design and manufacturing processes with focus on accurate resolution. The Santander funded Collaborative Venture Fund (CVF) project has provided research, survey data, evaluation and analysis for Canvasman Ltd. on 3D portable scanning hardware and software. The project solutions recommended in this report offers impartial product information on the current appropriate 3D scanning technology that potentially could improve efficiency of data capturing, design and manufacture of interior and exterior spaces, boats, vehicles and other similar constructions for creating and installing flexible coverings and indoor and outdoor structures

    Versatility And Customization Of Portable Cmm In Reverse Engineering A

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    Reverse engineering is the technique of gathering scientific knowledge about a part by physically examining it. In the computer aided manufacturing world this is referred to as Part to CAD conversion, where the geometry of physical objects are being captured as Digital 3-D CAD Data. This is vital not only to produce drawing of parts for which no CAD data exists, but also is frequently being used to produce better designs. The industry professionals to achieve this are frequently using Coordinate Measuring Machine [CMM] among other tools. The purpose of this thesis is to demonstrate the versatility of portable CMM as a Reverse Engineering Tool through application experiments aimed at industrial and non-industrial solutions. The thesis also researches in to the feasibility of customization options through experimentations focused on reverse engineering. Focusing further on Reverse Engineering applications, some of the interesting digitizing and CAD techniques are demonstrated and compared

    Measuring the shape. Performance evaluation of a photogrammetry improvement applied to the Neanderthal skull Saccopastore 1

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    Several digital technologies are nowadays developed and applied to the study of the human fossil record. Here, we present a low-cost hardware implementation of the digital acquisition via photogrammetry, applied to a specimen of paleoanthropological interest: the Neanderthal skull Saccopastore 1. Such implementation has the purpose to semi-automatize the procedures of digital acquisition, by the introduction of an automatically rotating platform users can easily build on their own with minimum costs. We provide all the technical specifications, mostly based on the Arduino UNO™ microcontroller technology, and evaluate the performance and the resolution of the acquisition by comparing it with the CT-scan of the same specimen through the calculation of their shape differences. In our opinion, the replication of the automatic rotating platform, described in this work, may contribute to the improvement of the digital acquisition processes and may represent, in addition, a useful and affordable tool for both research and dissemination

    Computed tomography characterisation of additive manufacturing materials

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    Additive manufacturing, covering processes frequently referred to as rapid prototyping and rapid manufacturing, provides new opportunities in the manufacture of highly complex and custom-fitting medical devices and products. Whilst many medical applications of AM have been explored and physical properties of the resulting parts have been studied, the characterisation of AM materials in computed tomography has not been explored. The aim of this study was to determine the CT number of commonly used AM materials. There are many potential applications of the information resulting from this study in the design and manufacture of wearable medical devices, implants, prostheses and medical imaging test phantoms. A selection of 19 AM material samples were CT scanned and the resultant images analysed to ascertain the materials’ CT number and appearance in the images. It was found that some AM materials have CT numbers very similar to human tissues, FDM, SLA and SLS produce samples that appear uniform on CT images and that 3D printed materials show a variation in internal structure

    Comparison of the accuracy between 3D printed and milled dental models by a digital inspection software

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    STATEMENT OF PROBLEM: The production of full arch dental models through Rapid Additive Prototyping (3D Printing) have been questioned for their accuracy in the past decade. PURPOSE: To compare the accuracy of 3D printed and milled dental models, using a digital metrology software. MATERIALS AND METHOD: A mandibular arch typodont was duplicated to produce a conventional Type IV dental stone model. This Model was scanned to create a digital model and an STL file was created which would be sent to Milling and 3D printing machines.15 models were printed using 3 different 3D printing companies and 10 models Milled with a CNC (Computerized Numeric Controlled) milling machine. Each model was scanned and a digital model was created. These scanned models were then super imposed to the scan of the master model through an inspection software (Geomagic Control X, 3D Systems) for accuracy of production. RESULTS: The mean difference in measurement in Absolute Gap, by either of the two methods of prototyping adopted, (0.075 mm for 3D Printed and 0.084 mm for milled) are well below the clinically acceptable values mentioned in previous literature. The means in absolute tooth distance discrepancy for both prototyping methods (0.0361 mm for 3DPand 0.0353 mm for Milled) were not statistically significant. CONCLUSION: 3D printed dental models were more accurate statistically than milled dental models. In general, the mean accuracy for both methods of rapid prototyping is within clinical tolerance and both are clinically acceptable

    The characteristics of the CAT to CAD to rapid prototyping system

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    ThesisComputer Aided Design (CAD), Rapid Prototyping (RP) and Computer Aided Tomography (CAT) technologies were researched. The project entails a unique combination of the abovementioned technologies, which had to be mastered by the author, on local and international terms. Nine software packages were evaluated to determine the modus operandi, required input and final output results. Fifty Rapid Prototyping systems were investigated to determine the strong and weak areas of the various systems, which showed that prototype materials, machine cost and growing time play an essential role. Thirty Reverse Engineering systems were also researched. Six different RE methods were recorded with several commercial systems available. Nineteen case studies were completed by using several different Computer Aided Tomography (CAT) and Magnetic Resonance Imaging (MRI) centers. Each scanning centre has different apparatus and is discussed in detail in the various case studies. The focus of this project is the data transfer of two dimensional CAT scanning data to threedimensional prototypes by using Reverse Engineering (RE) and Rapid Prototyping (RP). It is therefore of cardinal importance that one is familiar and understands the various fields of interest namely Reverse Engineering, Computer Aided Tomography and Rapid Prototyping. Each of these fields will be discussed in detail, with the latest developments in these fields covered as well. Case studies and research performed in the medical field should gain the medical industry's confidence. Constant marketing and publications will ensure that the technology is applied and transferred to the industry. Commercialisation of the technology is of utmost importanc
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