• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.626-630
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• 2005

This paper presents a novel Intelligent-Welding-Carriage (IWC) for automation of curved block in shipbuilding. The curved block is usually used in both front and back side of the ship. In curved block root gap is big, $1{\sim}7$ [mm] and inclination, $0{\sim}30$ [deg]. Since available conventional carriage type is limited to use below root gap of 3 [mm], only manual welding is employed in curved block. To adopt an IWC in curved block, it requires control of the welding conditions, i.e., voltage, current and travel speed, with respect to root gap and inclination to achieve good welding quality. In this paper, an IWC is developed for automization of welding operation to accommodate gap and inclination. Kinematics model and dynamics using Lagrangian formulation of the manipulator is introduced. IWC utilizes a database to perform accurate welding. The database is programmed based on numerous experimental test results with respect to gap, inclination, material, travel speed, weaving condition, voltage, and current. Finally, experimental result using PID control is addressed for verify the trajectory tracking accuracy of end-effector.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.171-176
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• 2005

This paper presents a novel Intelligent-Welding-Carriage (IWC) for automation of curved block in shipbuilding. The curved block is usually used in both front and back side of the ship. In curved block root gap is big, 1-7 (mm) and inclination, 0-30 (deg). Since available conventional carriage type is limited to use below root gap of 3 (mm), only manual welding is employed in curved block. To adopt an IWC in curved block, it requires control of the welding conditions, i.e., voltage. current, weaving speed, dwell time and travel speed, with respect to root gap and inclination to achieve good welding qualify. In this paper, an IWC is developed for automization of welding operation to accommodate gap and inclination. Kinematics model and dynamics using Lagrangian formulation of the manipulator is introduced. IWC utilizes a database to perform accurate welding. The database is programmed based on numerous experimental test results with respect to gap, inclination, material, travel speed, weaving condition, voltage, and current. Finally, experimental result using PID control is addressed for verifying the trajectory tracking accuracy of end-effector.

• 한국지반공학회지:지반
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• 제14권3호
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• pp.109-122
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• 1998

Geogrid를 보강재로 사용하는 Keystone block 보강토 옹벽의 설계와 시공에 있어서 기존의 연구와 설계기준들은 전부 직선 구간에 관한 것들로서 곡선구간의 설계 및 시공에 관한 연구는 부족한 실정때 있다. 따라서, 본 연구에서는 돌출형 곡선 부분의 시공성 및 구조적인 안정성을 검토하기 위하여 직선구간의 NCMA 해석법과 이를 이용한 곡선구간의 해석 및 시공상의 문제점 및 그 원인을 분석하여, 이에 따른 설계 및 시공시의 문제점과 대책을 강구하는데 그 목적이 있다. 곡선구간을 Shell 해석에 의해 직선구간과의 변위 및 응력들의 차이점을 규명하고 이를 이용하여 돌출형 곡선구간의 Keystone block wall의 문제점 분석 및 대책강구를 위한 기초자료 연구에 목적을 두고 있다.

• 한국지반신소재학회논문집
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• 제18권2호
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• pp.23-36
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• 2019

본 논문에서는 블록식 보강토옹벽의 현장계측을 통해 곡선부 보강영역의 변형특성을 분석하였다. 보강토공법은 설계 및 시공이 증가하여 실생활에서 쉽게 접할 수 있게 되었으나, 곡선부의 균열 및 붕괴사례가 빈번히 발생하여 안전에 대한 중요성이 대두되고 있다. 이러한 붕괴원인은 곡선부에 대한 연구 부족과 설계기준의 미흡, 경제성과 공기단축에 의한 시공성 결여, 충분하지 못한 다짐 공간 등에 있다고 할 수 있다. 이에 본 연구에서는 기존 설계 및 시공 기준을 검토하고 블록형 보강토옹벽 곡선부 사고사례를 통해 원인을 분석하였으며, 실제 시공된 블록형 보강토옹벽의 현장계측을 통해 직선부와 곡선부의 거동을 비교 분석하고 곡선부 보강영역의 변형특성을 확인하였다. 그 결과, 먼저 곡선부의 수평변위가 직선부와 비교하여 볼록형에서 최대 90%, 오목형에서 최대 60% 높게 나타났으며, 다음으로 곡선부 보강영역에서 볼록형의 경우 보강토옹벽 중심에서 수평방향으로 H/2구간에서 최대변위를 보이며 H까지의 영향범위를 나타내었으며, 오목형의 경우 중심에서 최대변위를 보이며 수평방향으로 H/4구간에서 최소변위를 확인하였다. 이러한 결과로 형태에 따른 곡선부의 영향범위와 현장적용을 위한 보강영역의 재정립이 필요하다고 판단되며, 본 연구결과가 이를 위한 기초 자료로서 활용 가능할 것으로 판단된다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년도 춘계 학술대회 개요집
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• pp.77-79
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• 2006

To achieve high productivity of assembly hull blocks, it is important to predict welding deformations accurately and to apply these data to the production planning. In the deformation analysis of hull block, simplified methods (elastic analysis) such as inherent method, equivalent loading method and local & global approach are usually used instead of thermal-elastic-plastic analysis because of calculating time and cost. To be much more practical, these simplified methods should consider gravity effect of plate and contact condition between the plate and the positioning jig. In this research, using finite element method, practical predicting method for the welding deformation of the curved hull blocks with considering welding sequence, gravity effect and contact condition is proposed.

• 제어로봇시스템학회논문지
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• 제22권12호
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• pp.1002-1010
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• 2016

This paper describes the design of a cellphone curved glass measuring device using by camera. The measuring device was composed of two camera, two backlight system, a body and so on, and the program was made for a camera calibration and noise removal, and also the program was made for height measurement of a cellphone curved glass using by subpixel algorism. And then a new technique for measuring the height of the cell phone curved glass was proposed. The characteristics test of height measurement of gage blocks and cell phone curved glasses was carried out, the error of the height measurement of gage block is less than ${\pm}0.005$ and the error of the height measurement of the cell phone curved glasses is less than ${\pm}0.005$. Thus it thought that the designed cellphone curved glass measuring device and the new technique for measuring the height was used to measure the height of the cellphone curved glass.

• 한국정보통신학회논문지
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• 제23권3호
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• pp.267-275
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• 2019

현재 스마트 폰의 대중적인 보급으로 QR코드는 다양한 부가 서비스를 가능하게 하고 있다. 그러나 곡면에 부착된 QR코드는 불균일한 조도로 인해 인식률 저하를 초래한다. 그래서 본 논문에서는 QR 코드와 같은 응용에 적합하도록 블록 적응적 이진화 방법을 도입하여 최적의 이진화 임계치를 구하는 방법을 도입한다. 즉, 큰 블록에 대해 히스토그램을 구하여 초기의 임계치를 구하고, 그 블록을 분할하여 히스토그램에 따른 블록의 특성이 반영된 세분화된 임계치를 구하는 방법으로 이진화를 수행한다. 또한, 모폴로지 연산을 도입하여 QR코드와 같은 이웃 화소들의 특징이 반영되도록 하는 방법으로 적용된다. 주어진 정품 칼라코드와 입력 코드를 다수의 방법으로 비교하여 정품을 구별하는 판별 방법을 제안한다. 다양한 실험을 통하여 QR코드를 검출함에 있어 제안한 방법은 기존의 방법보다 우수한 성능을 보임을 확인하며, 또한, 기존의 방식에 비해 40도까지의 높은 곡률에서도 우수한 인식률을 유지함을 보인다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1999년도 특별강연 및 추계학술발표대회 개요집
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• pp.87-90
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• 1999

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.122-125
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• 2008

Generally, in shipbuilding, large curved block components which have large curvature radius along various directions are used for huge ships such as LPG-vessel and oil tanker ships. Lots of the blocks are manufactured by line heating method which uses a heat source to bend the thick plate materials. The conventional forming process is entirely dependent on the experience of experts because it is done by manual method thus the curvatures and qualities are not uniform even for same part. However, it is hard to adopt the press forming process using die tool sets fur the manufacturing because of the characteristics of the industry that based on the small quantity and variety in the products. In this study, flexible forming technology using numbers of punches is investigated based on the simulation to substitute for the conventional forming method. Thick plate material model was applied to the proposed process to verify the feasibility for hull structure block forming process. The press forming processes were simulated by adopting the explicit-to-implicit sequential solution. Moreover, experiment of the flexible forming process was also conducted and its results were compared with that of simulation.

• 한국기계가공학회지
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• 제19권6호
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• pp.36-42
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• 2020

Nowadays, the touch screen panel (TSP) cover glass for mobile smart devices is being developed with a curved glass shape due to different design requirements. Because the sizes of mobile smart devices continue to increase, there has also been a great increase in the demand for large-area curved glass greater than 20 inches. In this study, heat and fluid flow analysis using CFD was performed to optimize the heating surface temperature distribution of the large curved glass formation system. Five cooling water flow paths in the cooling block were designed and analyzed for each case. A function that can quantitatively calculate the temperature uniformity of the heating surface was proposed and these values were obtained for the five models. The temperature distributions of the heating surface and the energy consumption of the heating system were also compared and comprehensively analyzed. Based on the analysis results of the five different cooling channel path models, the optimal path design could be presented.