Tripping the Light Fantastic: Using Light-Based Techniques to Digitally Document Megalithic Architecture

This paper presents and discusses the preliminary results of a small scale visualisation project as part of which the low-cost LiDAR scanner that now comes as standard with the iPad Pro was used in conjunction with both the Arctec Leo structured light scanner and photogrammetric survey methods to record, analyse and present the recently excavated remains of a Neolithic passage tomb at Dowth Hall, Co, Meath, Ireland. It considers the ease and speed with which the small to medium scale structural components found here can be scanned or photographed, meshed, and textured using each approach and further explores whether the outputs produced in each case might be used to support and enhance each other

Application of TLS method in digitization of bridge infrastructures : a path to BrIM development

Over the past years, bridge inspection practices and condition assessments were predi-cated upon long-established manual and paper-based data collection methods which were generally unsafe, time-consuming, imprecise, and labor-intensive, influenced by the experience of the trained inspectors involved. In recent years, the ability to turn an actual civil infrastructure asset into a detailed and precise digital model using state-of-the-art emerging technologies such as laser scanners has become in demand among structural engineers and managers, especially bridge asset managers. Although advanced remote technologies such as Terrestrial Laser Scanning (TLS) are recently established to overcome these challenges, the research on this subject is still lacking a comprehensive methodology for a reliable TLS-based bridge inspection and a well-detailed Bridge Information Model (BrIM) development. In this regard, the application of BrIM as a shared platform including a geometrical 3D CAD model connected to non-geometrical data can benefit asset managers, and significantly improve bridge management systems. Therefore, this research aims not only to provide a practical methodology for TLS-derived BrIM but also to serve a novel sliced-based approach for bridge geometric Computer-Aided Design (CAD) model extraction. This methodology was further verified and demonstrated via a case study on a cable-stayed bridge called Werrington Bridge, located in New South Wales (NSW), Australia. In this case, the process of extracting a precise 3D CAD model from TLS data using the sliced-based method and a workflow to connect non-geomet-rical information and develop a BrIM are elaborated. The findings of this research confirm the reliability of using TLS and the sliced-based method, as approaches with millimeter-level geometric accuracy, for bridge inspection subjected to precise 3D model extraction, as well as bridge asset management and BrIM development

Statistical Language Models for Graphical Object Recognition

This paper explores automatic recognition and semantic capture in vector graphics for graphical information systems. The low-level graphical content of graphical documents, such as a map or architectural drawing, are often captured manually and the encoding of the semantic content seen as an extension of this. The large quantity of new and archived graphical data available on paper makes automatic structuring of such graphical data desirable. A successful method for recognising text data uses statistical language models. This work will investigate and evaluate similar and adapted statistical models (Statistical Graphical Langauge Models, SGLM) to graphical languages based on the associations between different classes of object in a drawing to automate the structuring and recognition of graphical data

Statistical Language Models for Graphical Object Recognition

This paper explores automatic recognition and semantic capture in vector graphics for graphical information systems. The low-level graphical content of graphical documents, such as a map or architectural drawing, are often captured manually and the encoding of the semantic content seen as an extension of this. The large quantity of new and archived graphical data available on paper makes automatic structuring of such graphical data desirable. A successful method for recognising text data uses statistical language models. This work will investigate and evaluate similar and adapted statistical models (Statistical Graphical Langauge Models, SGLM) to graphical languages based on the associations between different classes of object in a drawing to automate the structuring and recognition of graphical data

An Investigation of Quantifying and Monitoring Stone Surface Deterioration Using Three Dimensional Laser Scanning

Three dimensional laser scanning is considered to be the next generation of documentation methods, however the cost of these technologies remains extremely high and there are both known and unknown limitations of their application. This thesis, therefore, investigates the strengths and weaknesses of 3D laser scanning, identifies potential sources of error, investigates potential uses for the data while focusing on its use for quantifying and monitoring stone surface deterioration, and determines the success of resulting 3D models for communicating conditions information. Additionally, the ambiguity in existing literature regarding success of applications of 3D laser scanning for meeting project objectives, including cost - benefit analyses, indicates this topic warrants exploration. In order to perform this analysis four topics of investigation are followed: 1) Identification of tools for recording and monitoring surface deterioration of stone, which will provided a basis for comparing laser scanning techniques. 2) Identification of recording standards and objectives for heritage sites, which laser scanning methods must satisfy. 3) Identification of stone deterioration types and surface appearance, specifically marble, which laser scanning data will need to represent for conditions analysis. 4) Undertaking a test case study: three dimensional laser scanning of the stone lions at the Merchants’ Exchange Building, Philadelphia, PA, to determine whether the data can be used for conditions surveying and monitoring of surface deterioration on the lions. The coalescence of these topics will provide a datum on which to begin investigating whether or not 3D laser scanning is an appropriate and practicable tool for enabling informed decision making for conservation and heritage management

Advanced approaches for bridge deck assessment using ground penetrating radar

Ground penetrating radar (GPR) data were acquired across four bridge decks with the objective of developing an advanced workflow for GPR operation that would allow the bridge owners to estimate repair quantities for certain bridge decks, based on GPR data. The primary contributions from this research are as follows: 1. It was demonstrated that the conditions of bridge decks can be cost-effectively and efficiently assessed using the GPR tool. 2. The GPR tool\u27s ability to provide rapid and reliable results in comparison with conventional bridge deck condition assessment techniques was established. 3. The qualitative and quantitative relationships between the GPR reflection amplitude and depth of concrete degradation were analyzed to develop an effective technique to estimate the amount of deteriorated concrete present in a particular bridge deck; this technique could enable bridge owners to use the GPR tool (only) to estimate the thickness of concrete that would be removed by processes such as hydro demolition. 4. The air-launched and ground-coupled GPR systems were compared in terms of accuracy of data acquisition and reliability of results. It was determined that air-launched GPR is a reliable tool for the fast and cost-effective assessment of bridge decks. This work is new and important because it extends the traditional use of the GPR technique and presents the advanced approach for data interpretation and concrete material removal estimation, especially in areas where deterioration was not visually exposed --Abstract, page iii

Brownfield Factory Layout Planning using Realistic Virtual Models

To stay competitive in an increasingly digitalised and global context, manufacturing companies need to increase productivity and decrease waste. This means their production systems must improve; something they can achieve in a multitude of ways. For example, increasing the level of automation, improving scheduling and improving product and process flows. Often, these production system improvements entail redesigning the system to incorporate these ensuing changes; a unique and temporary endeavour that is often structured as a project. One part of the production system design process is layout planning, in which the positions of operators, workstations, machines and other parts of the system are decided. This planning process can have a major impact on the overall efficiency of operations.In industrial settings, factory layout planning is often conducted in brownfield settings. In other words, in operational facilities. Since every production system and facility is unique, so is every factory layout planning project. Each such project has different preconditions, existing knowledge, availability and quality of data, lead-times, expectations and driving forces, to name just a few. If factory layout planning were treated as a design problem (more subjective than mathematical in nature), it would be hard to produce a mathematical solution for an optimal layout that would also work in reality. Instead, if a layout is developed and adapted to all real constraints and factors while it is being developed, the result would more likely be installable and work as expected.The long-term vision of this thesis is of a future in which sustainable manufacturing industry continues playing a vital role in society, because its contribution is more than just economic. A future in which the manufacturing industry is appreciated and engaged with by the local community; in which high performance is connected to the successful adoption and efficient use of digital tools in developing and improving existing brownfield production systems. This thesis aims to ensure that manufacturing industry adopts realistic virtual models in its brownfield factory layout planning processes. It does this by identifying and describing common challenges and how they may be reduced by developing and using realistic virtual models. This leads to improvements in the planning, installation and operational phases of production systems.The findings of this thesis show that brownfield factory layout planning represents a significant proportion of industrial layout planning. Its challenges lie mainly in the areas of data accuracy and richness. There are difficulties in grasping scale and perspective, communicating ideas and gathering input in the layout planning phase. By applying 3D laser scanning to provide accurate data and virtual reality to provide immersion and scale, realistic virtual models have been created. These reduce or eliminate the challenges stated above and allow more employees to be involved in the layout planning process. This, in turn, results in the identification of flaws in the layout and improvements in the early stages, rather than during or after installation. There is also an overall improvement to brownfield factory change processes, with costs that pale by comparison to the total cost of layout changes

Geometric tolerances of tubular T-joint test-specimens

The objective of present work is estimation of geometric tolerances of fabricated laboratory test-models from 3D CAD models. A set of 7 welded S355 steel specimens with T-joint design have been investigated. The specimens, with nominal dimensions ø114 mm for the brace and ø219 mm for the chord imitate a typical welded T-connection widely met in offshore structures like oil rigs and is to be used for fatigue testing at the UiS lab facilities. As a result of the study 3D CAD models of the test-specimens were acquired with the use of laser scanning tool “HandyScan 3D” combined with the Creaform CAD software. This study investigates weld geometry requirements covered in standard AWSD1.1 On the basis of the standard requirements 3D models of reference weld geometry were modelled in Autodesk Inventor CAD application. One model for least material condition (LMC) and another for maximum material condition (MMC) weld profile. Later on the scanned meshes of specimens is compared with reference models resulting in virtual validation reports made in VXelements environment. Geometric tolerances of weld and the assembly are estimated and compared with the values measured during virtual validation. General conclusion is that the scanned weld geometry of real specimens in every case exceeds the upper limits of allowable weld shape deviation. It is a safe approach from manufacturing side, however it does not provide an optimal fatigue resistant weld profile delivered by the AWSD1.1 standard