Laser Scanning Method Research Articles

Thermal and structural changes of pasteurized milk fat globules during storage

Pasteurization, homogenization and storage are essential steps in the processing of commercial milk. However, their effects on thermal and structural properties of milk fat globules (MFG) remain poorly understood. MFG were extracted from raw bovine milk (RM), pasteurized milk (PM), and homogenized-pasteurized milk (HPM) that were stored at 4 °C for 24, 48 and 72 h. Crystallization and melting properties of the MFG were studied using differential scanning calorimetry, and the size distributions were analyzed using laser light scattering. Structural characteristics were observed using confocal laser scanning method and polarized light microscopy, and characterization of crystal polymorphism was done using X-ray diffraction (XRD). Briefly, the bovine milk fat contained about 65% saturated fatty acids. The fat globules from fresh RM and PM had a significantly higher mean diameter than the fresh HPM (2.9, 3.0 and 2.1 µm, respectively). Notably, the crystallization and melting temperatures of the PM fat globules increased by about 4 °C after 72 h storage. Furthermore, the milk fat globule membrane (MFGM) of PM was pierced by fat crystals after 48 h storage. With HPM, the integrity of the membrane was more easily maintained due to finer crystals and thicker MFGM after high pressure treatment. XRD patterns showed a transformation trend of α → β' → β polymorphs in MFG from both processed milks. Thermal and morphology properties of MFG were altered during low temperature storage as a result of the formation of more thermodynamically stable and larger-sized β crystals.

Acquisition method of asphalt pavement texture information based on the CPR Technology

In order to obtain the asphalt pavement texture information in real time and accurately monitor the anti-skid performance of the road pavement, an automatic close range photogrammetry system (ACPR system) was proposed and built based on the circle arranged three cameras close range photogrammetry (CPR) technology to obtain the asphalt pavement surface texture. Automatic image acquisition and 3D reconstruction were achieved by the ACPR system. Sand patch method and laser scanning method (ZGScan) were used to collect the on-site comparison test of the asphalt pavement texture. Mean texture depth (MTD) and root mean square roughness (RSMR) were chosen as the statistical indicators of road surface texture. The results show that the texture data obtained by ACPR system has relatively high accuracy and efficiency, and the recognition accuracy is close to 0.02mm. The ACPR system improves the efficiency and accuracy of traditional close range photogrammetry and provides real-time and effective road surface anti-skid information for subsequent safety braking of autonomous vehicle.

A review of climatic and vegetation surveys in urban environment with laser scanning: A literature-based analysis

Laser scanning is a promising relatively new technology of land surveying and has different contributions to research areas and practical applications. We performed a review based on query terms in the Scopus database. We determined the number of papers where the laser scanning was the technique of the survey and refined the results with the aerial (ALS) and terrestrial (TLS) laser scanning methods, and the urban and vegetation searching terms. Results showed that geosciences had a 30-40% ratio within the scientific papers using LiDAR. TLS had larger relevance related to ALS considering the total number of research papers, urban application and vegetation analysis in urban environment. We analysed the current status of the technology and discussed the underlying possible causes.

Сравнение методов фотограмметрии и лазерного сканирования для создания трехмерных моделей объектов и территорий археологических ГИС (на примере археологического раскопа Увекского городища)

Сравнение методов фотограмметрии и лазерного сканирования для создания трехмерных моделей объектов и территорий археологических ГИС (на примере археологического раскопа Увекского городища)

Инвестиции в сохранение и развитие культурного наследия региона: библиотека BIM-элементов памятников национальной архитектуры и градостроительства

Introduction: The paper presents a methodology for reduction of expenses within investment projects aimed at the preservation and development of cultural heritage sites, based on the combined use of methods of scientific restoration, laser scanning and information modeling, as well as creation of a library of unique BIM elements of ancient city buildings, identified at protected sites of the urban environment, using restoration of a building in the Old Tatar Quarter (Staro-Tatarskaya Sloboda) in Kazan as an example. Methods: The authors performed standard (traditional) scientific restoration activities and innovative field studies using laser scanning and built a parametric information model of the cultural heritage site for further development of a restoration plan with account for site adaptation to modern functions. Results and discussion: Point cloud processing is carried out to create an information model and a library of unique BIM elements, which can be used repeatedly in restoration and reconstruction, thus reducing costs for BIM-model development in future investment projects. The practical significance of the study lies in the creation of a public good — a library (encyclopedia) of ancient architectural elements in the form of a library of BIM elements for BIM models of architectural and urban-planning landmarks in the region, as well as in the development of recommendations (by individuals, regional and local regulatory authorities) for an efficient policy in urban planning and restoration with regard to similar historical and cultural, architectural and urban-planning landmarks.

Examining a scallop shell-shaped plate from the Late Roman Period discovered in Osie (site no.: Osie 28, AZP 27-41/26), northern Poland

Research conducted using Airborne Laser Scanning methods in northern Poland allowed traces of a settlement from almost 2,000 years ago to be registered. The most valuable item found is a copper-alloy scallop shell-shaped plate which is still an unk-nown object in the cultural realities of the Roman Period in northern Poland. The results of pollen analysis of the material obta-ined during the cleaning of the found scallop shell-shaped plate indicate the dominance of herbaceous plants over the represen-tation of trees in the vicinity of the archaeological site discussed. The advantage of synanthropic plants among herbaceous plants informs us about the open habitat communities formed as a result of human activity (fields, meadows, roads or ruderal areas).

Localized Swelling Inhomogeneity Detection in Lithium Ion Cells Using Multi-Dimensional Laser Scanning

The safety, performance and lifetime of lithium-ion cells are critical for the acceptance of electric vehicles (EVs) but the detection of cell quality issues non-destructively is difficult. In this work, we demonstrate the use of a multi-dimensional laser scanning method to detect local inhomogeneities. Commercially available cells with Nickel Cobalt Manganese (NMC) cathode are cycled at various charge and discharge rates, while 2D battery displacement measurements are taken using the laser scanning system. Significant local swelling points are found on the cell during the discharge phase, the magnitude of swelling can be up to 2% of the cell thickness. The results show that the swelling can be aggravated by a combination of slow charge rate and fast discharge rate. Disassembly of the cells shows that the swelling points are matched with the location of ‘adhesive-like’ material found on the electrode surfaces. Scanning Electron Microscope (SEM) images show that the material is potentially blocking the electrodes and separators at these locations. We therefore present laser-scanning displacement as a valuable tool for defect/inhomogeneity detection.

Visualization of Spatio-Temporal Building Changes Using 3D Web GIS

Modern laser scanning methods and photogrammetric techniques provide tools for rapid data acquisition and semi-automated 3D scene construction. The common access to measuring sensors allow building digital representation of scanned objects relatively easy. This enables the construction of photorealistic building models and complex GIS/BIM models.Recently, increasing number of government departments and local councils trying to use 3D models as part of their planning, development, promotion strategy can be observed. To date, there is no universal, low-cost methodology that will allow visualizing changes of building facades using the Internet. The article presents a study which explored the possibilities of building a web application to visualize the changes in the buildings with the use of 3D models. It allows to integrate current three-dimensional models with those based on historical data. An interactive web application presenting the spatio-temporal changes of buildings in two study areas was presented (campus of the University of Warmia and Mazury and the Old Town of Olsztyn). The proposed architecture is low-cost and easy to implement. The content displayed on the map is determined by the timeline slider, which allows presenting changes in the building facades over time. Each building has its own attributes, some of which also have one or more 3D models. In the end, the potential stages of the system’s development were presented, including the possibility of participating volunteers in the process of obtaining historical data and using the Augmented Reality to present 3D models of the buildings directly in the field.

Экспериментальное исследование деформативности предварительно напряженных многослойных деревоплит методом сплошного лазерного сканирования

Экспериментальное исследование деформативности предварительно напряженных многослойных деревоплит методом сплошного лазерного сканирования

Possibilities of use of remote sensing technology in survey process in the territory of Pils island in Jelgava

In the study, creation of 3D surface relief model in Jelgava, for southern part of the Castle Island is depicted. Information about remote sensing, its historical development, as well as directions of remote sensing, development of photogrammetry and laser scanning is summarized and analysed. Principles of work and methods of photogrammetry and laser scanning. Information about creation of surface relief model from planning of unmanned aircraft, data capture and alignment to the end product – surface relief model. Application of evaluation of data obtained. The purpose of the study – to create 3D surface relief model in Jelgava, for the southern part of the Castle Island. Tasks of the study – to consider development and improvement of photogrammetry and its processes, as well as development of laser scanning and principles of its work; to research, analyse and describe technological processes of laser scanning; to create 3D surface relief model in Jelgava, for the southern part of the Castle Island; to perform comparison of surface models obtained and describe application of laser scanning. Preparation of surface relief model is time-consuming process, which includes flight planning and preparation of end-product. End-products obtained in data processing of laser scanning have very broad usage in many sectors related to geodesy and construction.

A Dual-Platform Laser Scanner for 3D Reconstruction of Dental Pieces

Abstract This paper presents a dual-platform scanner for dental reconstruction based on a three-dimensional (3D) laser-scanning method. The scanner combines translation and rotation platforms to perform a holistic scanning. A hybrid calibration method for laser scanning is proposed to improve convenience and precision. This method includes an integrative method for data collection and a hybrid algorithm for data processing. The integrative method conveniently collects a substantial number of calibrating points with a stepped gauge and a pattern for both the translation and rotation scans. The hybrid algorithm, which consists of a basic model and a compensation network, achieves strong stability with a small degree of errors. The experiments verified the hybrid calibration method and the scanner application for the measurement of dental pieces. Two typical dental pieces were measured, and the experimental results demonstrated the validity of the measurement that was performed using the dual-platform scanner. This method is effective for the 3D reconstruction of dental pieces, as well as that of objects with irregular shapes in engineering fields.

Active thermographic inspection of carbon fiber reinforced plastic laminates using laser scanning heating

In this study, inspection capability of active thermographic nondestructive inspection using the laser scanning method was examined. Carbon fiber reinforced plastic (CFRP) specimens were heated using a CO2 laser scanning device and their inspection capability was investigated. The experimental results indicate that the temperature and phase behavior after laser scanning heating were similar to those after conventional instantaneous flash heating. We also investigated the effect of the relationship between the scanning direction and fiber direction of the tested CFRPs on defect detection. The numerical and experimental results showed that the observed temperature contrast appearing on the defective surface varied depending on the scanning direction, and the temperature contrast increased when the scanning direction was the same as the fiber direction of the laminates. In addition, it was found that defects in a CFRP specimen located 10 m from the heat source could be detected using the laser scanning heating. These results suggest that using the laser scanning heating method is effective to inspect large objects located at far distances.

Investigation of micron-sized fish-scale surface structures on tool steel surfaces using laser galvanometer scanning

Micronized structured surface exhibits excellent surface functions for surface science applications. However, the cost is high for fabricating, especially specialized structure surfaces. The work prepared the micron-sized fish-scale surface structures on rough DC 53 tool steel surfaces. CW (continuous wave) laser beam irradiation method was used from a scanning galvanometer in the filling scan mode. The surface morphology and structure before and after laser irradiation were analyzed by optical microscopy, laser scanning confocal microscopy, and scanning electron microscopy. The elemental distribution of the structure was measured by energy dispersive spectroscopy (EDS) and Auger electron spectroscopy (AES), with the chemical analyses detected by the X-ray photoelectron spectroscopy (XPS). The combination of the AES with XPS analysis was also developed by the ion sputtering with the depth etching. It is found that the fish-scale surface structures can be prepared using a crossover laser scanning method, and their formation is based on superficial surface melting achieved by laser irradiation. The XPS results showed that the oxide layer of the fish-scale surface was composed of FeO, Fe2O3 and SiO2. The AES and EDS results showed the high content of Si and O in the fish-scale surface structure boundary. The combination of AES and XPS results showed that the boundary of the fish scale was composed of SiO2. Laser fluence and scanning mode were the key factors in the preparation of micron-sized fish-scale surface structure. A laser fluence of 33.16 J/mm2 induced a well-defined fish-scale corrugated structure. At the scanning speed of 140 mm/s, the flow of material on the surface of the tool steel was gradually controlled, and the shape of the fish-scale structure tended to be obvious. The scanning method has a significant effect on the spacing of the fish scales on the surface. By adjusting the appropriate scanning pitch, a regular distribution of the fish scale surface structure can be obtained. It is indicated that the precipitation of SiO2 (inclusions) has a great potential for the structuring of the fish-scale surface on DC 53 tool steel.

Применение технологии лазерного сканирования для моделирования объектов недвижимости в 3D-кадастре

The authors present the results of theoretical and experimental studies on the use of laser scanning technology for the 3D-modeling of real estate objects in the cadastre. The result of the theoretical part of the research was a set of parameters for 3D modeling of real estate objects influencing the choice of the scanning method (ground, air or mobile), which showed that when creating separate 3D models of real estate objects (buildings, structures, premises and objects of unfinished construction) the method of ground-based laser scanning should be used. Based on the theoretical part, an experiment on 3D-modeling of a typical real estate object (building) was performed on the basis of data obtained with the method of ground- based laser scanning. The model of the real estate object was built with various degrees of detail to demonstrate its accuracy characteristics, depending on the distance from the scanner stations, the use of photographic materials, etc. The results of the experimental part of the studies show that the model obtained is in full conformity with the current requirements of the legislation in the field of cadastre. The proposed solution can be used as a methodological basis for constructing three-dimensional models in the transition of the Russian Federation to a 3D-cadastre system.

A novel one-body dual laser profile based vibration compensation in 3D scanning

Recently, the 3D laser profile scanner has often been used for the precise measurement of 3D surface information (object surface) such as height, area, and slope. However, a difficulty encountered with the conventional laser scanning method is that it cannot compensate for the errors resulting from vibration, so the scanned object should be measured in a fixed (immobile) state. In this paper, we propose a novel dual laser profile method and its error compensation algorithm to compensate for vertical vibration, even with a moving object. In order to remove errors caused by vibration, the proposed system projects two laser profiles onto the surface, such that the projected position overlaps the one with the previous position. With the overlapped position, the height difference between the measured objects is used to calculate the vibration errors. To generate two laser profiles simultaneously, we present a novel approach for generating two laser profiles from one laser-emitting source (a one-body dual line laser using a triangular structured blazed grating reflector). By exploiting the one-body dual line laser and error compensation algorithm, the proposed 3D laser profile scanner system achieves an error reduction of about 96.3% in the root mean square error (RMSE), compared to the conventional approach.

Rapid mapping and analysing rock mass discontinuities with 3D terrestrial laser scanning in the underground excavation

Whilst laser scanning techniques have been shown to facilitate rapid identification and analysis of rock mass characteristics, relatively little research has been conducted for 3D laser scanning in underground spaces. In the present study, a semi-automatic laser scanning method has been presented for non-contact discontinuity identification and rock mass characterisation in a Western Australian underground gold mine. The accuracy of the 3D laser scanning technique was compared with traditional window mapping with a strong correlation being noted. The average dip/dip direction discrepancy between the two methods was found to be 1.5°/16° and attributed to the ability of 3D laser scanning to collect significant quantities of data when compared to traditional methods. Potential sources of error, together with the influence of the scale effect, were discussed with an optimum scanning resolution of 7.5 mm at 5 m being noted to provide a combination of significantly reduced collection and processing time and high levels of accuracy. Overall, the present study demonstrated the potential of 3D laser scanning techniques to replace traditional methods with increased efficiency and accuracy in underground mines.

Multimodal Volumetric Retinal Imaging by Oblique Scanning Laser Ophthalmoscopy (oSLO) and Optical Coherence Tomography (OCT).

While fluorescence imaging is widely used in ophthalmology, a large field of view (FOV) three-dimensional (3D) fluorescence retinal image is still a big challenge with the state-of-the-art retinal imaging modalities because they would require z-stacking to compile a volumetric dataset. Newer optical coherence tomography (OCT) and OCT angiography (OCTA) systems overcome these restrictions to provide three-dimensional (3D) anatomical and vascular images, but the dye-free nature of OCT cannot visualize leakage indicative of vascular dysfunction. This protocol describes a novel oblique scanning laser ophthalmoscopy (oSLO) technique that provides 3D volumetric fluorescence retinal imaging. The setup of the imaging system generates the oblique scanning by a dove tail slider and aligns the final imaging system at an angle to detect fluorescent cross-sectional images. The system uses the laser scanning method, and therefore, allows an easy incorporation of OCT as a complementary volumetric structural imaging modality. In vivo imaging on rat retina is demonstrated here. Fluorescein solution is intravenously injected to produce volumetric fluorescein angiography (vFA).

Evaluating the Erosion Process from a Single-Stripe Laser-Scanned Topography: A Laboratory Case Study

Topographies during the erosion process obtained from the single-stripe laser-scanning method may provide an accurate, but affordable, soil loss estimation based on high-precision digital elevation model (DEM) data. In this study, we used laboratory erosion experiments with a sloping flume, a rainfall simulator, and a stripe laser apparatus to evaluate topographic changes of soil surface and the erosion process. In the experiments, six slope gradients of the flume (5° to 30° with an increment of 5°) were used and the rainfall simulator generated a 30-min rainfall with the kinetic energy equivalent to 80 mm/h on average. The laser-scanned topography and sediment yield were collected every 5 min in each test. The difference between the DEMs from laser scans of different time steps was used to obtain the eroded soil volumes and the corresponding estimates of soil loss in mass. The results suggest that the collected sediment yield and eroded soil volume increased with rainfall duration and slope, and quantified equations are proposed for soil loss prediction using rainfall duration and slope. This study shows the applicability of the stripe laser-scanning method in soil loss prediction and erosion evaluation in a laboratory case study.

Novel Adaptive Laser Scanning Method for Point Clouds of Free-Form Objects.

Laser scanners are widely used to collect coordinates, also known as point-clouds, of three-dimensional free-form objects. For creating a solid model from a given point-cloud and transferring the data from the model, features-based optimization of the point-cloud to minimize the number if points in the cloud is required. To solve this problem, existing methods mainly extract significant points based on local surface variation of a predefined level. However, comprehensively describing an object’s geometric information using a predefined level is difficult since an object usually has multiple levels of details. Therefore, we propose a simplification method based on a multi-level strategy that adaptively determines the optimal level of points. For each level, significant points are extracted from the point cloud based on point importance measured by both local surface variation and the distribution of neighboring significant points. Furthermore, the degradation of perceptual quality for each level is evaluated by the adjusted mesh structural distortion measurement to select the optimal level. Experiments are performed to evaluate the effectiveness and applicability of the proposed method, demonstrating a reliable solution to optimize the adaptive laser scanning of point clouds for free-forms objects.

Evaluation of Erosion Intensity and Dynamics Using Terrestrial Laser Scanning

A new method of instrumental measurement of the intensity of rill and linear erosion on slopes by the method of terrestrial laser scanning is proposed. This method was tested on four plots in 2012–2016 with the use of Trimble™ GX, Trimble™ VX, and Trimble™ TX8 laser scanners. The terrestrial laser scanning is characterized by a high precision and rapidity, which could not be previously achieved by other devices. It has a number of advantages: registration of various types of erosion of temporary water streams; measurements from a distance without the disturbance of the studied surface and providing the safety of works; and calculations of morphometric parameters of slope using a high-precision digital model of topography. The given examples show that this approach may be applied to assess the denudation-accumulative balance of the moved soil material on slopes, to determine the dynamics of amount of deposits on different parts of a slope as a result of different kinds of surface runoff, and to identify spatial regularities of the formation of the network of rills and gullies. In addition, laser scanning makes it possible to perform an integral assessment of the combined impact of the entire combination of exogenous processes developed on slopes and affecting the soil cover. The observations on test plots showed a rather great role of autumn rains in the total soil loss from erosion. The data obtained were used as the basis for the elaboration of practical recommendations concerning the survey organization and monitoring of erosion with the use of laser scanning.