116 research outputs found

    Improvement of Low Traffic Volume Gravel Roads in Nebraska

    Get PDF
    In the state of Nebraska, over one-third of roadways are unpaved, and consequently require a significant amount of financial and operational resources to maintain their operation. Undesired behavior of surface gravel aggregates and the road surfaces can include rutting, corrugation, and ponding that may lead to reduced driving safety, speed or network efficiency, and fuel economy. This study evaluates the parameters that characterize the performance and condition of gravel roads overtime period related to various aggregate mix designs. The parameters, including width, slope, and crown profiles, are examples of performance criteria. As remote sensing technologies have advanced in the recent decade, various techniques have been introduced to collect high quality, accurate, and dense data efficiently that can be used for roadway performance assessments. Within this study, two remote sensing platforms, including an unpiloted aerial system (UAS) and ground-based lidar scanner, were used to collect point cloud data of selected roadway sites with various mix design constituents and further processed for digital assessments. Within the assessment process, statistical parameters such as standard deviation, mean value, and coefficient of variance are calculated for the extracted crown profiles. In addition, the study demonstrated that the point clouds obtained from both lidar scanners and UAS derived SfM can be used to characterize the roadway geometry accurately and extract critical information accurately

    QUANTIFYING GULLY EROSION IN WEST TENNESSEE USING HIGH RESOLUTION LIDAR DATA

    Get PDF
    This research demonstrates the use of Light Detection and Ranging (LIDAR) for detailed measurement of volume change and erosional and depositional processes within a small gully and assessing the impact of digital elevation model (DEM) resolution on these measurements. The study site is an active gully in Meeman-Shelby Forest State Park in Tennessee, USA. DEMs were derived from an airborne LIDAR survey and multiple terrestrial LIDAR scans. DEM differences were used to quantify gross volumes of erosion and deposition within the gully over a three year period and a 49 day period. Analysis of the airborne LIDAR point cloud indicated that approximately 10,000 m3 of material eroded from the bluff since the gully was formed between 1969 and 1973. A total volume of 615.8 m3 of material was discharged from the gully between January 2012 (the airborne LIDAR survey) and December 2014 (the first terrestrial LIDAR survey). The surveys using the terrestrial laser scanner generated two 2 cm DEMs representing the gully terrain change during a short period of 49 days between December 2014 and February 2015. The comparison of these two DEMs indicates an estimated 2.1 m3 of material was imported into the gully with 11.5 m3 of gross erosion and 13.6 m3 of gross deposition. The DEM scale analysis indicates that turning points exist in the trends of erosion and deposition estimates at 0.18 m and 0.28 m resolutions, respectively. These turning points represent the resolutions at which the accuracy of erosion and deposition measurements begin to deteriorate and are revealed by examining the strength of linear fits to data points on either side of the turning point. The analyses described in this thesis offer insight into the benefits and challenges of using LIDAR to study gully morphology and serve as a starting point for continuously monitoring of gully development processes taking place within the pool gully at very fine scales

    A new WebGIS approach to support ground penetrating radar deployment

    Get PDF
    En raison de l’agglomĂ©ration complexe des infrastructures souterraines dans les grandes zones urbaines et des prĂ©occupations accrues des municipalitĂ©s ou des gouvernements qui dĂ©ploient des systĂšmes d’information fonciĂšre ou des industries qui souhaitent construire ou creuser, il devient de plus en plus impĂ©ratif de localiser et de cartographier avec prĂ©cision les pipelines, les cĂąbles d’énergie hydroĂ©lectrique, les rĂ©seaux de communication ou les conduites d’eau potable et d’égout. Le gĂ©oradar (Ground Penetrating Radar ou GPR) est un outil en gĂ©ophysique qui permet de produire des images en coupe du sous-sol desquelles de l’information utile sur les infrastructures souterraines peut ĂȘtre tirĂ©e. Des expĂ©riences antĂ©rieures et une analyse documentaire approfondie ont rĂ©vĂ©lĂ© que les logiciels disponibles pour rĂ©aliser des levĂ©s GPR qui sont utilisĂ©s directement sur le terrain et hors site ne reposent pas ou trĂšs peu sur des fonctionnalitĂ©s gĂ©ospatiales. En outre, l’intĂ©gration de donnĂ©es telles que la visualisation de donnĂ©es GPR dans des espaces gĂ©orĂ©fĂ©rencĂ©s avec des orthophotos, des cartes, des points d’intĂ©rĂȘt, des plans CAO, etc., est impossible. Lorsque disponible, l’ajout d’annotations ou l’interrogation d’objets gĂ©ospatiaux susceptibles d’amĂ©liorer ou d’accĂ©lĂ©rer les investigations ne proposent pas des interfaces conviviales. Dans ce projet de recherche, une nouvelle approche est proposĂ©e pour dĂ©ployer le GPR et elle est basĂ©e sur quatre fonctionnalitĂ©s issues du Web et des systĂšmes d’information gĂ©ographique (WebGIS) jugĂ©es essentielles pour faciliter la rĂ©alisation de levĂ©s GPR sur le terrain. Pour dĂ©montrer la faisabilitĂ© de cette nouvelle approche, une extension de la plate-forme logicielle existante GVX (conçue et vendue par Geovoxel) appelĂ©e GVX-GPR a Ă©tĂ© dĂ©veloppĂ©e. GVX-GPR propose aux utilisateurs d’instruments GPR quatre fonctionnalitĂ©s soit 1) intĂ©gration de cartes, 2) gĂ©o-annotations et points d’intĂ©rĂȘt, 3) gĂ©orĂ©fĂ©rencement et visualisation de radargrammes et 4) visualisation de sections GPR gĂ©orĂ©fĂ©rencĂ©es. Afin de tester l’approche WebGIS et GPXGPR, deux sites d’étude ont Ă©tĂ© relevĂ©s par deux professionnels diffĂ©rents, un expert et un non-expert en gĂ©ophysique, ont Ă©tĂ© sĂ©lectionnĂ©s. Une premiĂšre expĂ©rimentation rĂ©alisĂ©e sur le campus de l’UniversitĂ© Laval Ă  QuĂ©bec prĂ©voyait l’identification de trois objets enterrĂ©s soit un cĂąble Ă©lectrique, une fibre optique et un tunnel dont leur position XYZ Ă©tait connue. Le deuxiĂšme essai s’est passĂ© Ă  l’Universidade Federal do Rio de Janeiro (Rio de Janeiro, BrĂ©sil), avec un professionnel expert en gĂ©ophysique. Ce 2e site cherchait Ă  reproduire un environnent plus rĂ©aliste avec une quantitĂ© inconnue d’objets enterrĂ©s. Les quatre fonctionnalitĂ©s proposĂ©es par GVX-GPR ont donc Ă©tĂ© testĂ©es et leur intĂ©rĂȘt discutĂ© par les deux utilisateurs GPR. Les deux utilisateurs GPR se sont dits trĂšs intĂ©ressĂ©s par l’outil GVX-GPR et ses nouvelles fonctionnalitĂ©s et ils aimeraient pouvoir l’intĂ©grer Ă  leur travail quotidien car ils y voient des avantages. En particulier, l’approche et GVX-GPR les a aidĂ©s Ă  dĂ©couvrir de nouvelles cibles, Ă  dĂ©limiter le territoire Ă  couvrir, Ă  interprĂ©ter les donnĂ©es GPR brutes en permettant l’interaction entre les donnĂ©es gĂ©ospatiales (en ligne) et les profils de donnĂ©es GPR, et finalement pour la cartographie Ă  produire tout en respectant la norme CityGML (donc utile au partage Ă©ventuel des donnĂ©es). De mĂȘme, une fois le systĂšme maitrisĂ©, GVX-GPR a permis d’optimiser la durĂ©e du levĂ©. Ce projet de maitrise a donc permis d’élaborer une nouvelle approche pour effectuer des levĂ©s GPR et proposer un outil logiciel pour tester la faisabilitĂ© de celle-ci. Une premiĂšre Ă©tape de validation de la faisabilitĂ© et de l’utilitĂ© a Ă©tĂ© rĂ©alisĂ©e grĂące aux deux tests effectuĂ©s. Évidemment, ces deux tests sont des premiers pas dans une phase plus large de validation qui pourrait s’effectuer, et ils ont ouvert la porte Ă  des ajustements ou l’ajout d’autres fonctionnalitĂ©s, comme la manipulation des outils de visualisation 3D et l’ajout de filtres et traitement de signal. Nous estimons nĂ©anmoins ces premiers tests concluant pour ce projet de maĂźtrise, et surtout ils dĂ©montrent que les instruments GPR gagneraient Ă  davantage intĂ©grer les donnĂ©es et fonctionnalitĂ©s gĂ©ospatiales. Nous pensons Ă©galement que nos travaux vont permettre Ă  des communautĂ©s de non spĂ©cialistes en gĂ©ophysique de s’intĂ©resser aux instruments de type GPR pour les levĂ©s d’objets enfouis. Notre approche pourra les aider Ă  prĂ©parer les donnĂ©es gĂ©ospatiales utiles Ă  la planification, Ă  effectuer le levĂ© terrain et Ă  produire les cartes associĂ©esDue to the complex agglomeration of underground infrastructures in large urban areas and accordingly increased concerns by municipalities or government who deploy land information systems or industries who want to construct or excavate, it is imperative to accurately locate and suitability map existing underground utility networks (UUN) such as pipelines, hydroelectric power cables, communication networks, or drinking water and sewage conduits. One emerging category of instrument in geophysics for collecting and extracting data from the underground is the ground penetrating radar (GPR). Previous experiments and a thorough literature review revealed that GPR software used in and off the field do not take advantage of geospatial features and data integration such as visualization of GPR data in a georeferenced space with orthophotographies, map, point of interest, CAD plans, etc. Also missing is the capability to add annotation or querying geospatial objects that may improve or expedite the investigations. These functions are long-lived in the geospatial domain, such as in geographic information system (GIS). In this research project, a new approach is proposed to deploy GPR based on four core WebGIS-enabled features, used to support field investigations with GPR. This WebGIS is based on an existing platform called GVX, designed and sold by Geovoxel as a risk management tool for civil engineering projects. In this proposed approach, a generic guideline based on GVX-GPR was developed which users can follow when deploying GPR. This approach is based on four core features which are missing on most GPR software, (1) map integration, (2) geo-annotations and points of interest, (3) radargram georeferencing and visualization, and (4) georeferenced slice visualization. In order to test the designed WebGIS-based approach, two different professionals, an expert in geophysics and a person without any background in geophysics, used the proposed approach in their day-to-day professional practice. The first experiment was conducted at UniversitĂ© Laval (QuĂ©bec – Canada) when the subject undertook an area to a survey in order to identify 3 possible targets premapped. The second, with a Geophysics-specialist, took place in Rio de Janeiro, at Universidade Federal do Rio de Janeiro’s campus. This study covered an area counting on an unknown number of buried objects, aiming at reproducing a realistic survey scenario. Four new feature were added and discussed with GPR practitioners. Both GPR user declared to be very interested by the proposed by the tool GVX-GPR and its features, being willing to apply this software on their daily basis due to the added advantages. Particularly, this approach has aided these professionals to find new buried objects, delimit the survey area, interpret raw GPR data by allowing geospatial data interaction and GPR profiles, and, finally, to produce new maps compliant with standards such as CityGML. Also, once mastered, the technology allowed the optimization of survey time. This project enabled the development of a new approach to leverage GPR surveys and proposed a new tool in order to test the approach’s feasibility. A first step into the validation of this proposal has been taken towards a feasibility and utility evaluation with two tests accomplished. Unmistakably, these are the first steps of a likely larger validation process, opening up new possibilities for the continuity of the project such as the addition of signal processing techniques and 3D data handling. We nevertheless consider these conclusive for this master’s project, above all demonstrating the value add by geospatial data integration and functions to GPR instruments. This work is also intended to the community of newcomers, or interested in GPR, to further explore this technology, since this approach shall facilitate the preparation, execution, and post-processing phases of a GPR survey

    Autonomous Scene Understanding, Motion Planning, and Task Execution for Geometrically Adaptive Robotized Construction Work

    Full text link
    The construction industry suffers from such problems as high cost, poor quality, prolonged duration, and substandard safety. Robots have the potential to help alleviate such problems by becoming construction co-workers, yet they are seldom found operating on today’s construction sites. This is primarily due to the industry’s unstructured nature, substantial scale, and loose tolerances, which present additional challenges for robot operation. To help construction robots overcome such challenges and begin functioning as useful partners in human-robot construction teams, this research focuses on advancing two fundamental capabilities: enabling a robot to determine where it is located as it moves about a construction site, and enabling it to determine the actual pose and geometry of its workpieces so it can adapt its work plan and perform work. Specifically, this research first explores the use of a camera-marker sensor system for construction robot localization. To provide a mobile construction robot with the ability to estimate its own pose, a camera-marker sensor system was developed that is affordable, reconfigurable, and functional in GNSS-denied locations, such as urban areas and indoors. Excavation was used as a case study construction activity, where bucket tooth pose served as the key point of interest. The sensor system underwent several iterations of design and testing, and was found capable of estimating bucket tooth position with centimeter-level accuracy. This research also explores a framework to enable a construction robot to leverage its sensors and Building Information Model (BIM) to perceive and autonomously model the actual pose and geometry of its workpieces. Autonomous motion planning and execution methods were also developed and incorporated into the adaptive framework to enable a robot to adapt its work plan to the circumstances it encounters and perform work. The adaptive framework was implemented on a real robot and evaluated using joint filling as a case study construction task. The robot was found capable of identifying the true pose and geometry of a construction joint with an accuracy of 0.11 millimeters and 1.1 degrees. The robot also demonstrated the ability to autonomously adapt its work plan and successfully fill the joint. In all, this research is expected to serve as a basis for enabling robots to function more effectively in challenging construction environments. In particular, this work focuses on enabling robots to operate with greater functionality and versatility using methods that are generalizable to a range of construction activities. This research establishes the foundational blocks needed for humans and robots to leverage their respective strengths and function together as effective construction partners, which will lead to ubiquitous collaborative human-robot teams operating on actual construction sites, and ultimately bring the industry closer to realizing the extensive benefits of robotics.PHDCivil EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/149785/1/klundeen_1.pd

    Imaging Sensors and Applications

    Get PDF
    In past decades, various sensor technologies have been used in all areas of our lives, thus improving our quality of life. In particular, imaging sensors have been widely applied in the development of various imaging approaches such as optical imaging, ultrasound imaging, X-ray imaging, and nuclear imaging, and contributed to achieve high sensitivity, miniaturization, and real-time imaging. These advanced image sensing technologies play an important role not only in the medical field but also in the industrial field. This Special Issue covers broad topics on imaging sensors and applications. The scope range of imaging sensors can be extended to novel imaging sensors and diverse imaging systems, including hardware and software advancements. Additionally, biomedical and nondestructive sensing applications are welcome

    Urban Informatics

    Get PDF
    This open access book is the first to systematically introduce the principles of urban informatics and its application to every aspect of the city that involves its functioning, control, management, and future planning. It introduces new models and tools being developed to understand and implement these technologies that enable cities to function more efficiently – to become ‘smart’ and ‘sustainable’. The smart city has quickly emerged as computers have become ever smaller to the point where they can be embedded into the very fabric of the city, as well as being central to new ways in which the population can communicate and act. When cities are wired in this way, they have the potential to become sentient and responsive, generating massive streams of ‘big’ data in real time as well as providing immense opportunities for extracting new forms of urban data through crowdsourcing. This book offers a comprehensive review of the methods that form the core of urban informatics from various kinds of urban remote sensing to new approaches to machine learning and statistical modelling. It provides a detailed technical introduction to the wide array of tools information scientists need to develop the key urban analytics that are fundamental to learning about the smart city, and it outlines ways in which these tools can be used to inform design and policy so that cities can become more efficient with a greater concern for environment and equity

    Urban Informatics

    Get PDF
    This open access book is the first to systematically introduce the principles of urban informatics and its application to every aspect of the city that involves its functioning, control, management, and future planning. It introduces new models and tools being developed to understand and implement these technologies that enable cities to function more efficiently – to become ‘smart’ and ‘sustainable’. The smart city has quickly emerged as computers have become ever smaller to the point where they can be embedded into the very fabric of the city, as well as being central to new ways in which the population can communicate and act. When cities are wired in this way, they have the potential to become sentient and responsive, generating massive streams of ‘big’ data in real time as well as providing immense opportunities for extracting new forms of urban data through crowdsourcing. This book offers a comprehensive review of the methods that form the core of urban informatics from various kinds of urban remote sensing to new approaches to machine learning and statistical modelling. It provides a detailed technical introduction to the wide array of tools information scientists need to develop the key urban analytics that are fundamental to learning about the smart city, and it outlines ways in which these tools can be used to inform design and policy so that cities can become more efficient with a greater concern for environment and equity
    • 

    corecore