• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1103-1104
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• 2011

This paper presents 1kW BLDC motor drive system and magnetic coupler for water thrust in ROV. In order to get a high performance and reliability, some design flow is proposed in this paper. The proposed system is verified by the experimental tests.

• Journal of Energy Engineering
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• v.3 no.1
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• pp.77-83
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• 1994

아연-산화은 2차전지는 높은 에너지 밀도의 이점을 가진 반면, 짧은 사이클수명(설계 및 사용방법에 따라 10∼200 사이클)을 가진 단점이 있다. 산화은 전극의 비싼 가격 때문에 높은 에너지 밀도가 요구되는 분야에서 제한적으로 사용되고 있다. 본 논문은 수중운동체계의 추진용으로 사용하기 위한 신뢰성이 높은 아연-산화은 전지의 개발을 다루었다. 고율방전에서 양극 활물질의 양에 따른 전압 특성과 음극활물질의 첨가제에 따른 사이클 수명 비교 시험을 실시하였다. 본 연구결과 우수한 전압 특성과 고율방전에서10회 이상의 사이클 수명을 갖는 아연-산화은 2차전지를 개발하였다.

• IE interfaces
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• v.11 no.2
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• pp.25-37
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• 1998

In this paper, a simulation model is proposed to evaluate the system effectiveness of underwater battery propulsion systems which consist of motors, main switchboard, generators and batteries. The various operating environments such as emergency situations, equipment's failure and repair, and system performance degradation due to equipment's failures affect the system effectiveness and the environment elements are considered as the input parameters in the simulation model. Some simulation results with estimated data are studied.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.66-70
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• 2018

낙동강 하구 유역은 상류에서 퇴적되는 모래로 인해 수심의 변화가 매우 심한 지역으로써, 부산청에서는 인근 항해 선박의 안전을 위해 저수심 표시용 등주를 설치하여 운영하고 있다. '04년 첫 설치 이후, 지역적 특성과 구조물 자체의 한계로 선박추돌 및 기상(태풍, 홍수 등)으로 인한 등주 분실사고가 매년 발생(총 305기)하였으며, 이렇게 유실된 등주는 낙동강 하구 유역을 통항하는 선박의 항행 안전에 큰 위협이 되었다. 부산청은 침몰된 등주와 통항선박과의 충돌 등 안전사고 예방을 위해 '17년 낙동강 하구 분실 등주에 대한 수색 및 인양 사업을 실시하였다. 본 논문은 동 사업의 준비단계부터 최종준공까지의 추진방안 및 결과 등 주요사항들을 고찰하고 공유하여 향후 해저 항행위험물 제거 사업 추진에 있어 참고가 되고자 한다.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.4
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• pp.256-265
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• 2023

This paper describes the results of the development of the submarine Free Running Model (FRM). First, the goal of development was set based on the test conditions and the test environment, and the system was obtained accordingly. The target submarine, Joubert BB2 submarine, was selected with a scale of 18.35 in accordance with the development goal. In order to conduct a submarine FRM test underwater, where communication is impossible, the FRM must operate at least semi-autonomously. For this purpose, an Extended Kalman Filter (EKF) based underwater integrated navigation system and control system using a sailplane and an X-shaped sternplane were designed respectively. In addition, a ballast system was designed to enable the model to float to the water surface in case of an emergency. To verify its propulsion, navigation, and control performance, the FRM tests were conducted in both indoor and outdoor basins. As a result, the relationship between propeller RPM and vehicle speed was derived, and it was confirmed that the navigation and control performance met the target value.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.27-40
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• 2013

This study is about development of technology system for an advanced deep-sea unmanned underwater robot of S. Korea analysed by the application of scenario planning. It was developed a 6000m class next-generation deep-sea unmanned underwater vehicle(or robot, UUV) system, soonly ROV 'Hemire' and Depressor 'Henuvy' in 2006 at S. Korea and motion control, adaptive control algolithm, a work-space manipulator control algolithm, especially the underwater inertial-acoustic navigation system robust to initial errors and sensor failures. But there are remained matters on position tracking of the USBL, inertial-acoustic navigation system, attitude sensor, designed sonar sensors. So this study suggest the new idea for settle the matters and then this idea help the development of the underwater inertial-acoustic navigation system robust to initial errors and sensor failures, such as acoustic signal drop-out, by modifying the error covariance of the failed sonar signal when drop-out occurs. As a result, the future policy for deep-sea unmanned underwater robot of S. Korea is to further spur the development of new technology and more improvement of the technology level for deep-sea unmanned underwater robot system with indicator and imaginary wall as external device.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.447-455
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• 2006

Together with the trend of enhancement in domestic industrial development and economic progress due to import and export, the demand for construction of the roads, bridges, especially port facilities, and several coastal protection and ocean structures is increasing rapidly. MOMAF of Korean Government is driving construction cf 9 new ports and renovation cf the existing fishery ports. Among these structures most of bridge base, wharves, dolphins, quays, and jetties are being newly built cf steel or concrete pile. As the base, supporting bulkheads, and piles are underwater after construction, it is difficult to figure out the status of structures and not enough to get maintenance and strengthen the structures. Every year, moreover, these works suck the government budget due to higher incomplete maintenance expense for protection from corrosions cf structures and increased underwater construction period. For the purpose cf cutting down the expense cf government budget, it is necessary to extend the life cycle of the existing structures. Therefore, we developed a new method for maintenance of submerged structures near the waterline by allowing dry work environment with the floating caisson. The method shows easy to move around the working area and handle. It also showed not only a significant reduction of maintenance expenses and time for anti-corrosion work but also better protection This will be a milestone to reduce the maintenance and construction expenses for the shore and water structures.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.163-170
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• 2006

Together with the trend of enhancement in domestic industrial development and economic progress due to import and export, the demand for construction of the roads, bridges, especially port facilities, and several coastal protection and ocean structures is increasing rapidly. MOMAF of Korean Government is driving construction of 9 new ports and renovation of the existing fishery ports. Among these structures most of bridge base, wharves, dolphins, quays, and jetties are being newly built of steel or concrete pile. As the base, supporting bulkheads, and piles are underwater after construction, it is difficult to figure out the status of structures and not enough to get maintenance and strengthen the structures. Every year, moreover, these works suck the government budget due to higher incomplete maintenance expense for protection from corrosions of structures and increased underwater construction period. For the purpose of cutting down the expense of government budget, it is necessary to extend the life cycle of the existing structures. Therefore, we developed a new method for maintenance of submerged structures near the waterline by allowing dry work environment with the floating caisson. The method shows easy to move around the working area and handle. It also showed not only a significant reduction maintenance expenses and time for anti-corrosion work but also better protection. This will be a milestone to reduce the maintenance and construction expenses for the shore and water structures.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.25-28
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• 2006

수소는 청정에너지로서 미래에너지의 대안으로 여겨지고 있기 때문에 수소에너지 관련 기술은 미래 국가 경쟁력을 좌우할 것으로 예상되며 이러한 수소에너지의 핵심인 수소스테이션 관련 기술은 국가연료전지 시장을 비롯한 수소자동차 사업 전반에 커다란 영향을 미칠 것으로 예상되고 있다. 이에 따라 전 세계적으로 수소에너지를 차세대 에너지원으로 개발하기 위하여 전력을 다하고 있으며, 수소연료전지자동차 개발과 아울러 수소스테이션 개발에 대한 인프라 구축 및 실증연구가 본격적으로 이루어지고 있다. 국내에서도 가스공사를 비롯한 에너지 관련 기업에서 수소스테이션 건설이 추진되고 있으며, 본 연구에서도 수소인프라 구축의 일환으로 추진되고 있는 수소스테이션 개발 현황에 대하여 논의하고자 한다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.377-384
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• 2022

Vortex-induced vibration (VIV) occurs owing to the vortex generated from the back side of the appendages of ships and submarines during operation. Recently, the importance of high-order modes (HOMs) vibration and fatigue failure has become increasingly emphasized by increasing the speed of ships and the size of structures. In addition, predicting the vibration of HOMs is significantly necessary as the VIV becomes stronger in the fast flow speed condition than in the low flow speed condition. This study introduces a methodology according to HOMs hybrid Fluid Structure Interaction (FSI) for predicting the HOMs VIV on the hydrofoils. The HOMs FSI system is verified by comparing the VIV results from the FSI simulation with the experimental results. Finally, the effectiveness of the HOMs FSI is determined by applying the maximum von-Mises stress obtained from the VIV on the hydrofoil to the S-N curve released from Det Norske Veritas (DNV). VIV results from the HOMs FSI include the lock-in characteristics as well as a significant increase of more than 10 times compared with that of low-order modes (LOMs) FSI. In the future works, advanced studies will be required for improving cantilever boundary conditions and the shape of hydrofoils.