• International Journal of Precision Engineering and Manufacturing
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• 제3권4호
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• pp.15-23
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• 2002

With the development of a laser scanner of high precision and increased speed, reverse engineering becomes a key approach to reduce the time for the development of new products. But the modeling process is not so automated enough until now. Modeling in real workshops is usually performed by the experienced operators and it requires a skillful technique to get the resultant surface of high quality and precision. In this paper, a systematic solution is proposed to automate the free-form surface generation from the measured point data. Compatibility is imposed to the measured point data during input curve generation. And the compatibility of cross-sectional curve is also considered for the loft surface generation. The data in each step is produced in IGES file format to make an easy interface to other CAD/CAM software without any further data manipulation.

• 한국정밀공학회지
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• 제20권9호
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• pp.197-204
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• 2003

This study proposes a method to reduce errors in scanning object and registration using a laser scanner. The method consists of 3 stages. First, there is an error induced by the difference of the distance between the probe and the object. It is possible to reduce the error by planning a scanning strategy: object setting, scan path. Second, the scan data of the tooling ball affects calculating the tooling ball center. A z-direction compensation is given to calculate more accurate registration points. Third, three points are used to determine a coordinate transformation on each frame. The maximum error usually lies on the third tooling ball in the conventional merging method. LSM (Least Square Method) is applied to a coordinate transformation to reduce the registration error.

• 제어로봇시스템학회논문지
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• 제18권12호
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• pp.1115-1121
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• 2012

This paper proposes a method to extract accurate plane of an object in unstructured environment for a humanoid robot by using a laser scanner. By panning and tilting 2D laser scanner installed on the head of a humanoid robot, 3D depth map of unstructured environment is generated. After generating the 3D depth map around a robot, the proposed plane extraction method is applied to the 3D depth map. By using the hierarchical clustering method, points on the same plane are extracted from the point cloud in the 3D depth map. After segmenting the plane from the point cloud, dimensions of the planes are calculated. The accuracy of the extracted plane is evaluated with experimental results, which show the effectiveness of the proposed method to extract planes around a humanoid robot in unstructured environment.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2010년 춘계학술발표회 논문집
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• pp.245-247
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• 2010

This research presents both system structure analysis to improve performance of 3D laser scanner, which has time of flight method, and scheme to minimize distance measurement errors during signal process. With the help of reference source, we minimized the instability of electronic signal processing time and possibility of distance measurement errors. Furthermore, it helps easy alignment and accuracy of system by using fiber delay line and coupler.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.339-340
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• 2007

This paper proposes a object avoidance algorithm that enables a mobile robot with laser scanner. Object detecting system has a function to detect object in front of the mobile robot by using a laser scanner. The proposed method based on probability distribution and finds local-paths to avoid collisions. Simulation results show the feasibility of the proposed method.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.859-861
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• 2003

In order to present a space in details, it is indispensable to acquire 3D shape and texture simultaneously from the same platform. 3D shape is acquired by Laser Scanner as point cloud data, and texture is acquired by CCD sensor. Positioning data is acquired by IMU (Inertial Measurement Unit). All the sensors and equipments are assembled on a hand-trolley. In this research, a method of integrating the 3D shape and texture for automated construction of Digital Surface Model is developed. This Digital Surface Model is applied for efficient feature extraction. More detailed extraction is possible , because 3D Digital Surface Model has both 3D shape and texture information.

• 대한전자공학회논문지
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• 제23권2호
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• pp.257-263
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• 1986

A laser scanner utilizing a computer-generated hologram(CGH) as beam deflector is reported. The CGH optical element has been used mainly for under-filled scanning. Here, a CGH optical element for overfilled scanning is proposed. It can achieve, under the same limitation of fabrication accuracy, better resolution and longer scan length than those for under-filled scanning. Measured scanning characteristics of the laser scanner show the scan length of 40 cm and the beam diameter of 100\ulcorner, where the designed minimum distance between the lines of CGH is 8\ulcorner.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.638-643
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• 2017

3D 레이저 스캐너는 센서로부터 목표물까지 거리를 측정하는 방식으로 작동되며, 광파거리 측정기와 동일한 원리로 작동된다. 최근 3차원 데이터의 수요 및 활용이 급격히 증가함에 따라 레이저 스캔 관련 기술이 빠르게 발달하고 있으며, 이로 인해 과거에 비해 공간상의 대상물에 대한 위치 정보를 쉽게 취득할 수 있게 되었다. 본 연구에서는 3D 레이저 스캐너와 토털스테이션을 통합한 새로운 장비를 활용하여 공간정보를 구축하고, 기존 작업방법과 비교 분석을 통해 공간정보 구축을 위한 새로운 기술의 활용 가능성을 제시하고자 하였다. 연구결과, 3D 레이저 스캐너와 토털스테이션 통합에 의한 공간정보 구축의 효율성을 제시할 수 있었다. 제안한 방법은 기존의 토털스테이션을 이용하는 방법보다 데이터 취득에 소요되는 시간을 단축시킬 수 있을 것으로 기대되며, 취득된 데이터를 이용한 단면도 생성, 체적산출 등 다양한 활용이 가능하였다. 향후 3D 레이저 스캐너와 토털스테이션 통합에 의한 공간정보 구축 방법은 관련분야의 작업 효율성 향상에 크게 기여할 것이다.

• 한국산업융합학회 논문집
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• 제23권5호
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• pp.735-746
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• 2020

Recently, in Korea, various technology developments have been made to utilize 3D space and facility data such as unmanned aerial vehicles (UAV) and laser scanners with the goal of improving productivity at construction sites. However, the lack of related regulations for 3D laser scanner surveying has been a barrier to using the technology across the surveying industry. As a result, owners, contractors, and construction supervisors are reluctant to introduce and apply technology to the site. In this study, the guidelines (drafting and inspection work to be supervised by construction supervisors when constructing earthworks using laser scanners) was developed and presented so that the earth surveying and quantity calculation technology using a laser scanner could be applied and diffused in a construction site. Through the development of this guideline (proposal), it is judged that the supervision and inspection of earthworks quantity using a laser scanner will be activated in the field.

• 한국기계가공학회지
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• 제19권6호
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• pp.96-101
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• 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.