• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.6
• /
• pp.96-101
• /
• 2020

In this paper, we present the results of our research to perform 3D laser scanning functions by adding a focusing lens to a conventional 2D laser scanner. For the optical design, the ray-tracing technique was used along with a total of four lenses as the variable incident focusing lens, the collimating lens, and the F-Theta lens. As design variables, the curvature of the incident focusing lens (Lens #1) was assumed to be us, l mm and sumed mm, and the incident angles were set at 0cidenus, l. In addition, the distance between the focusing lens and the collimating lens was set to vary from 5 mm to 15 mm. When the incident focal length was varied from 5 mm to 15 mm, the exit focal length was calculated to vary from 67.5 mm to 56.8 mm for the lens with R = 100 mm and from 108.5 mm to 99.0 mm for the lens with R = 150 mm. When the incident angle was 0°, the focal aberration was only slightly observable at 10㎛ in both the x- and y-direction. At 7.5° was the focal aberration of approximately 20~50㎛ was measured at 20㎛. To investigate the chromatic aberration of the designed optical device, the distortion of the focus was observed when the 550 nm beam was simulated on lens designed for a 980 nm wavelength.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.38 no.1
• /
• pp.35-41
• /
• 2020

3D laser scanners are an effective way to quickly acquire a large amount of data about an object. Recently, it is used in various fields such as surveying, displacement measurement, 3D data generation of objects, construction of indoor spatial information, and BIM(Building Information Model). In order to utilize the point cloud data acquired through the 3D laser scanner, it is necessary to make the data acquired from many stations through a matching process into one data with a unified coordinate system. However, analytical researches on the accuracy of point cloud data according to the registration method are insufficient. In this study, we tried to analyze the accuracy of registration method of point cloud data acquired through 3D laser scanner. The point cloud data of the study area was acquired by 3D laser scanner, the point cloud data was registered by the ICP(Iterative Closest Point) method and the shape registration method through the data processing, and the accuracy was analyzed by comparing with the total station survey results. As a result of the accuracy evaluation, the ICP and the shape registration method showed 0.002m~0.005m and 0.002m~0.009m difference with the total station performance, respectively, and each registration method showed a deviation of less than 0.01m. Each registration method showed less than 0.01m of variation in the experimental results, which satisfies the 1: 1,000 digital accuracy and it is suggested that the registration of point cloud data using ICP and shape matching can be utilized for constructing spatial information. In the future, matching of point cloud data by shape registration method will contribute to productivity improvement by reducing target installation in the process of building spatial information using 3D laser scanner.

• Explosives and Blasting
• /
• v.33 no.4
• /
• pp.1-6
• /
• 2015

Abstract This study is to efficiently calculate and evaluate the elements of advance, overbreak and underbreak on the mine under the production using the 3D laser scanner. For this purpose, a 3D laser scanner was sued to acquire the point-cloud which records the space coordinates and modelling of the underground tunnel using the 3D modeling program. When each element was observed through the study result, the advance on the center cut was 2.6m in average while the total advance was 2.4m. If the drilling length of 3.8m is based, the advance rate was evaluated to be 67% in average in the center cut section with the total average of 64%. In addition, when the volume of overbreak was measured based on the design cross section, the average overbreak volume was found to be $4.5m^3$ on left wall, $4.5m^3$ on right wall, and $5m^3$ on roof with the total volume of $14m^3$. When the overbreak volume is measured based on the look-out cross section, it was $3m^3$ on roof with the total volume of $8.4m^3$. The rate of overbreak volume against the average excavation volume was 8% based on the design cross section and 5% based on the look-out cross section.

• Korean Journal of Optics and Photonics
• /
• v.27 no.5
• /
• pp.165-173
• /
• 2016

In this paper, we propose a three-dimensional (3D) scanning system based on two line lasers. This system uses two line lasers with different wavelengths as light sources. 532-nm and 630-nm line lasers can compensate for missing scan data generated by geometrical occlusion. It also can classify two laser planes by using the red and green channels. For automatic registration of scanning data, we control a stepping motor and divide the motor's rotational degree of freedom into micro-steps. To this end, we design a control printed circuit board for the laser and stepping motor, and use an image processing board. To compute a 3D point cloud, we obtain 200 and 400 images with laser lines and segment lines on the images at different degrees of rotation. The segmented lines are thinned for one-to-one matching of an image pixel with a 3D point.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.7
• /
• pp.7-12
• /
• 2008

• Korean Journal of Construction Engineering and Management
• /
• v.12 no.6
• /
• pp.130-141
• /
• 2011

The intelligent excavating system(IES), the development in South Korea of which has been underway since 2006, aims for the full-scale automation of the excavation process that includes a series of tasks such as movement, excavation and loading. The core elements to ensure the quality and safety of the automated excavation equipment include 3D modeling of terrain that surrounds the excavating robot and the technology for detecting objects accurately(i.e., for detecting the location of nearby loading trucks and humans as well as of obstacles positioned on the movement paths). Therefore the purpose of this research is to ensure the quality and safety of automated excavation detecting the objects surrounding the excavating robot via a 3D laser scanning system. In this paper, an algorithm for estimating the location, height, width, and shape of objects in the 3D-realized terrain that surrounds the location of the excavator was proposed. The performance of the algorithm was verified via tests in an actual earthwork field.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.12
• /
• pp.638-643
• /
• 2017

The 3D laser scanner operates by measuring the distance from the sensor to the target and operates on the same principle as Electronic Distance Measuring (EDM). Recently, 3D laser scanning technology has been rapidly developed in line with the strongly increasing demand for 3D information acquisition. Therefore, it is now possible to more easily acquire geometric information of various objects existing in real space. In this study, we constructed geospatial information by using new equipment which integrated 3D laser scanner and total station, and we suggest the possibility of using new technology for geospatial information construction by comparing and analyzing with existing methods. In the study result, we demonstrated the efficiency of the geospatial information constructed by integration of 3D laser scanner and total station. The proposed method is expected to shorten the time required for data acquisition compared to the existing method using the existing total station. Furthermore, it is possible to use various methods such as cross section analysis and volume calculation using the acquired data. In the future, spatial information construction by integration of 3D laser scanner and total station will help improve work efficiency in related fields.

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.07a
• /
• pp.351-353
• /
• 2006

• The korean journal of orthodontics
• /
• v.36 no.1 s.114
• /
• pp.1-13
• /
• 2006

Three-dimensional (3-D) laser scans can provide a 3-D image of the face and it is efficient in examining specific structures of the craniofacial soft tissues. Due to the increasing concerns with the soft tissues and expansion of the treatment range, a need for 3-D soft tissue analysis has become urgent. Therefore, the purpose of this study was to evaluate the scanning error of the Vivid 900 (Minolta, Tokyo, Japan) 3-D laser scanner and Rapidform program (Inus Technology Inc., Seoul, Korea) and to evaluate the mean error and the magnification percentage of the image obtained from 3-D laser scans. In addition, soft tissue landmarks that are easy to designate and reproduce in 3-D images of normal, Class II and Class III malocclusion patients were obtained. The conclusions are as follows; scanning errors of the Vivid 900 3-D laser scanner using a manikin were 0.16 mm in the X axis, 0.15 mm in the Y axis, and 0.15 mm in the Z axis. In the comparison of actual measurements from the manikin and the 3-D image obtained from the Rapidform program, the mean error was 0.37 mm and the magnification was 0.66%. Except for the right soft tissue gonion from the 3-D image, errors of all soft tissue landmarks were within 2.0 mm. Glabella, soft tissue nasion, endocanthion, exocanthion, pronasale, subnasale, nasal alare, upper lip point, cheilion, lower lip point, soft tissue B point, soft tissue pogonion, soft tissue menton and preaurale had especially small errors. Therefore, the Rapidform program can be considered a clinically efficient tool to produce and measure 3-D images. The soft tissue landmarks proposed above are mostly anatomically important points which are also easily reproducible. These landmarks can be beneficial in 3-D diagnosis and analysis.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.29 no.1
• /
• pp.39-46
• /
• 2011

The present study introduces a comparison between 3D R-tree and octree which are noticeable candidates to index large point clouds gathered from a 3D terrestrial laser scanner. A query method, which is to find neighboring points within given distances, was devised for the comparison, and time lapses for the query along with memory usages were checked. From tests conducted on point clouds scanned from a building and a stone pagoda, it was shown that octree has the advantage of fast generation and query while 3D R-tree is more memory-efficient. Both index and leaf capacity were revealed to be ruling factors to get the best performance of 3D R-tree, while the number of level was of oetree.