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[IEEE 2019 IEEE Intelligent Transportation Systems Conference - ITSC - Auckland, New Zealand (2019.10.27-2019.10.30)] 2019 IEEE Intelligent Transportation Systems Conference (ITSC) - Graph-based Map-Aided Localization using Cadastral Maps as Virtual Laser Scans
摘要： Environment-based localization algorithms, such as laser odometry, can achieve a remarkable accuracy on the local scale. For autonomous driving, however, it is mandatory to combine these estimates with global information to overcome large scale drift. Our approach uses freely accessible cadastral plans (building footprints) together with 2D laser information and odometry in a graph-based approach to realize real-time global localization. The main contributions of our work reside in the way we create a virtual laser scan from cadastral plans, and that we consider the observation integrity by identifying corridor-like environment configurations (ambiguous positioning along the longitudinal axis). Besides, we evaluate our approach on a vehicle in two urban scenarios. We present a comparison of the obtained precision using different relevant combinations of the proposed contributions and show that we can reach an average positioning accuracy of 55cm at best without requiring a first passage of an equipped vehicle to build a map.
关键词： laser scan,autonomous driving,localization,cadastral maps,graph-based
更新于2025-09-16 10:30:52
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Hydraulic Engineering Topographic Mapping and Modeling Based on Three Dimensional Laser Scanning Technology
摘要： Topographic mapping and modeling is one of the most basic and important work in hydraulic engineering construction. This paper present a work flow which contains data measurement, pre-process and post-process with three dimensional laser scan technology. By adopting B-tree and its expansion structure, a multi-level point cloud management and storage method has been established. Then propose a contour generation method based on scan data and the equivalent point interpolation data. A self-adaptive mesh Delaunay algorithm is introduced with point cloud data in order to generate triangular irregular network digital elevation model. Finally, the modeling accuracy and error has been analysis, the results proves this method is with high efficient and accuracy and can be provide assistance for the project construction.
关键词： topography,contour,hydraulic engineering,3D laser scan,3D model
更新于2025-09-16 10:30:52
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Evaluation of digital staining for ex vivo confocal laser scanning microscopy
摘要： Background: Ex vivo confocal laser scanning microscopy (CLSM) is a novel diagnostic tool for the fast examination of native tissue. However, CLSM produces black/white/green images, depending on the refraction indices of the tissue structures, complemented by nuclear fluorescence staining, which the vast majority of Mohs surgeons and dermatopathologists are not trained to interpret. Digital staining is applicable to ex vivo CLSM investigations to simulate the images of conventional slides stained with haematoxylin & eosin (H&E). Objectives: The aim of our study was to evaluate in detail the appearance of human skin structures using digitally stained ex vivo CLSM images and compare the results to that of conventional H&E slides of the same specimen. Methods: After providing informed consent, 26 patients donated their Burow’s triangles (healthy skin) that resulted from plastic reconstruction after the R0- excision of skin tumours. After being investigated by ex vivo CLSM, including automated digital staining (VivaScope 2500M-4G, MAVIG GmbH), the specimens were fixed in formalin, embedded in paraffin and stained with H&E. Results: Almost all skin structures in the digitally stained ex vivo CLSM images morphologically resembled the structures in the histopathological images acquired from H&E slides. Due to the high refraction index of melanin, the hair shafts appeared bright pink, and the melanocytes and melanophages were poorly imaged, resulting in a strong pink appearance that vastly differed from the appearance of conventional H&E-stained histopathology. Conclusions: Digital staining of ex vivo CLSM images is an easy and highly useful tool to facilitate the interpretation of black-field images generated by confocal laser scanning microscopy for dermatopathologists and Mohs surgeons who are familiar with H&E staining. Unlike the pigmented structures, the cutaneous and subcutaneous structures had excellent visualization with only minimal differences from their appearance on H&E slides.
关键词： digital staining,ex vivo confocal laser scan microscopy,dermatopathology
更新于2025-09-16 10:30:52
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Investigation on Ti6Al4V laser metal deposition using Taguchi based grey approach
摘要： An optimization of laser metal deposition process considering tensile strength, clad hardness, clad grain size and clad porosity as performance characteristics were investigated. The influence of laser power and laser scan speed on the thermal gradient and cooling rate with regard Ti6Al4V powder coating on Ti6Al4V substrate was focused. Taguchi’s experimental design approach is employed for planning the experiments and analyzing the dependency of input variables on desired performance measures such as micro hardness, tensile strength, porosity and grain size. The laser scan speed is found as the dominant factor on the clad hardness while laser power has the influencing effect on grain size of the substrate. GRA is opted for determining the multi performance machining characteristics of laser metal deposition process. The experimental outcomes reveal that the proposed method of multi objective optimization considerably enhances the multi performance machining characteristics.
关键词： Laser metal deposition,Ti6Al4V,Grain size,Thermal gradient,Grey relational approach,Laser scan speed
更新于2025-09-12 10:27:22
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Laser scanned patterns of machined surfaces
摘要： In this contribution, machined surfaces are analyzed corresponding to the dynamic aspects of cutting operation. Productivity is limited due to harmful vibrations that deteriorate the quality of the machined surface. The related surface pattern carries the history of the resultant relative vibrations, thus the dynamical properties of the machining system could be extracted. To describe the surface of a machined workpiece, a laser displacement sensor is applied for scanning purposes. The measurement procedure of the surface scanning is described, its applicability and limitations are also discussed. In turning processes, the static displacement error and the arising chatter frequency are analyzed along a shaft by means of the measured diameter offset and gradient of the chatter marks, respectively.
关键词： Machining,Surface analysis,Chatter,Laser scan
更新于2025-09-12 10:27:22
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A study on microhardness and microstructural evolution of titanium/zirconium diboride cermet coatings with varying scan speeds during laser cladding on Ti6Al4V substrate
摘要： Titanium/zirconium diboride cermet coatings were deposited at different laser scan speeds on Ti–6Al–4V alloy using laser cladding technique. Microhardness of the coatings was compared with the microhardness of the substrate, while the microstructural morphologies of coatings were evaluated via scanning electron microscope with energy dispersive spectroscopy. In addition, resultant grain sizes of the coatings were observed and phases formed within the coatings were also examined. The microhardness of the coatings was seen to be four times harder than the substrate. Scanning electron microscopic images exhibited a refinement in grain size and the development of distinct microstructural features. X-ray diffraction patterns showed significant hard phases such as Al2Zr and Ti3B4 which may be responsible for the sky-rocketed microhardness values of the coatings. This study proffers profound insight on the influence of laser scan speed, during deposition, on the microhardness and microstructural morphology of titanium/zirconium diboride cermet coatings.
关键词： titanium/zirconium diboride cermet coatings,laser cladding technique,Ti6Al4V substrate,laser scan speed
更新于2025-09-11 14:15:04
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[IEEE 2018 IEEE Symposium on Product Compliance Engineering - Asia (ISPCE-CN) - Shenzhen, China (2018.12.5-2018.12.7)] 2018 IEEE Symposium on Product Compliance Engineering - Asia (ISPCE-CN) - Segmentation of Precast Concrete Elements in Outdoor Laser Scan Data via Image Processing
摘要： Image processing technology has many applications, such as medical image processing, face detection and vehicle detection. At present, in the field of civil engineering, there are many difficulties in the intelligent manufacturing process of precast concrete elements (PCEs), such as non-contact measurement of PCEs using 3D laser scanners. In order to solve the data acquisition problem of PCE data in outdoor laser scan data, this paper is the first attempt to map a 3D laser scan data into 2D images, and then use image processing technology to realize the segmentation of outdoor laser scan data which contains the PCE data. We convert the processed objects from laser scan data to images, and computation time is reduced effectively as a result. This segmentation technique includes four steps, data preprocessing, 3D laser scan data mapping into 2D images, image processing for segmentation and laser scan data processing. Finally, the results obtained by experiments prove the effectiveness of this segmentation technique.
关键词： Image processing,Segmentation technique,Outdoor laser scan data,Precast concrete element
更新于2025-09-11 14:15:04