• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.74-81
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• 2024

In the near future, autonomous ships, ships controlled by shore remote control centers, and ships operated by navigators will coexist and operate the sea together. In the advent of this situation, a method is required to evaluate the safety of the maritime traffic environment. Therefore, in this study, a plan to evaluate the safety of navigation through ship control simulation was proposed in a maritime environment, where ships directly controlled by navigators and autonomous ships coexisted, using autonomous operation technology. Own ship was designed to have autonomous operational functions by learning the MMG model based on the six-DOF motion with the PPO algorithm, an in-depth reinforcement learning technique. The target ship constructed maritime traffic modeling data based on the maritime traffic data of the sea area to be evaluated and designed autonomous operational functions to be implemented in a simulation space. A numerical model was established by collecting date on tide, wave, current, and wind from the maritime meteorological database. A maritime meteorology model was created based on this and designed to reproduce maritime meteorology on the simulator. Finally, the safety evaluation proposed a system that enabled the risk of collision through vessel traffic flow simulation in ship control simulation while maintaining the existing evaluation method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.6
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• pp.784-789
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• 2015

It was carried out a review of operating limit analysis for small high-speed boat by author. In general, a review of ship's seakeeping performance is performed in the step of ship design, but this study was carried out in the state of completion of boat. Motion performance of Pitch, Vertical and Lateral acceleration and Slamming were satisfied in some encounter angle but deck wetness was not satisfied in all it does the analysis. As a result, sea state rather than the speed and encounter angle of vessel have a greater effect on the seakeeping performance of target vessel. It seems to be due to the size of the target ship.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.958-963
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• 2023

Lately, there has been increasing research on the prediction of motion performance using artificial intelligence for the safe design and operation of ships. However, compared to conventional ships, research on small fishing boats is insufficient. In this paper, we propose a model that estimates the motion response essential for calculating the motion performance of small fishing boats using a deep neural network. Hydrodynamic analysis was conducted on 15 small fishing boats, and a database was established. Environmental conditions and main particulars were applied as input data, and the response amplitude operators were utilized as the output data. The motion response predicted by the trained deep neural network model showed similar trends to the hydrodynamic analysis results. The results showed that the high-frequency motion responses were predicted well with a low error. Based on this study, we plan to extend existing research by incorporating the hull shape characteristics of fishing boats into a deep neural network model.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.1-7
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• 2020

In recent years, cargo lashing has received much importance, to help prevent the sinking of passenger ships due to the failure of vehicle and cargo lashing during the transshipment of cargo. Consequently, the standards for lashing equipment and the structure of car ferries have been revised. According to the current standards, all vehicles loaded on a car ferry sailing in smooth sea areas must be secured if the wind speed and wave height exceed 7 m/s and 1.5 m, respectively. In this study, we measured the roll and pitch of a passenger ship sailing in smooth sea areas, and compared the measurements with the results of the New Strip Method (NSM). The vessel had a maximum pitch of 1.41° and a maximum roll of 1.37° at a wind speed of 6-8 m/s and a wave height of 0.5-1.0 m, and a maximum pitch of 1.49° and a maximum roll of 2.43° at a wind speed of 10-12 m/s and a wave height of 1.0-1.5 m. A comparison of the external forces due to the motion of the hull and the bearing capacity without lashing indicated that the bearing capacity was stronger. This suggests that vehicles without lashing will not slip or fall due to weather conditions. In future, the existing vehicle lashing standards can be revised after measuring the hull motions of various ships, and comparing the external force and bearing capacity, to establish more reasonable requirements.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.05a
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• pp.47-50
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• 2002

산업이 발달함에 따라 대량의 화물을 빠르게 운반할 수 있는 해상운송수단의 수요가 증가하게 되고 이로 인하여 해상 선박 간 충돌사고가 빈번히 발생하게 되었다 선박 충돌은 주로 조선하는 사람들의 관습, 습관의 차이, 부주의, 판단오류 등의 이유로 발생한다. 연구자들은 선박 충돌을 방지하기 위하여 조선에 관련된 많은 부분을 지능화한 지능형 충돌회피시스템 개발에 노력을 기울이고 있다. 선박을 비롯한 자율운동체의 충돌방지 기법은 비행체, 수중운동체, 자율로봇 등 영역 특성을 달리하는 다양한 분야에서 연구되어오고 있다 기존 연구들의 충돌방지는 주로 장애물의 공간적 특성에 기반하고 있다. 이에 개체의 움직임을 예측하여 시간적 요소를 가미하면 더욱 향상된 충돌방지가 가능하다. 특히, 선박은 느린 운동 특성과 조선법, 규격화된 통신수단의 발달로 인하여 상대편 선박의 이동 예측이 용이하므로 이를 적용하여 보다 향상된 충돌방지가 가능하다. 본 연구에서는 기존의 충돌회피기법의 과정에 예측을 추가한 예측기반 충돌회피모형을 제안하고 선박운항환경을 모의실험에 의하여 해당 모형 적용시 충돌회피 경로 산출의 안전성이 크게 개선됨을 보인다.

• 한국항공운항학회:학술대회논문집
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• 2016.05a
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• pp.30-34
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• 2016

TR-60 틸트로터 무인기는 전장 3m, 최대이륙중량 200kg로서 2013년 2월 자동천이비행에 성공한 비행체로서 현재 해상운용을 위한 함상이착륙기술을 개발 중에 있다. 무인기 해상운용은 육상보다 심한 염무와 바람과 선박의 운동에 의한 착륙대의 이동 등의 열악한 환경에서 이루어져야 한다. 이동이 있는 착륙대와 착륙장 주변의 장애물을 고려하면 정확한 착륙을 위한 정밀한 항법유도가 요구된다. TR-60의 정밀항법유도를 위해서 수cm 단위의 정확도를 갖는 RTK GPS 기반의 정밀상대항법과 이동 착륙장 대한 자동착륙유도를 설계하고 구현함으로 함상자동 이착륙 기술을 개발하였다. 본 논문에서는 RTK GPS 기반의 정밀상대항법과 자동착륙유도에 대한 연구와 함상접근착륙절차에 따른 자동착륙정확도 측정 비행시험 결과를 기술하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1819-1820
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• 2007

국제해사기구(IMO: International Maritime Organization)의 선박 조종성능에 관한 기준이 발효되고, 최근 환경에 대한 관심이 지속적으로 증가하는 것과 더불어 항해 안전성, 특히 해난사고에 기인한 해양오염 방지에 관한 관심이 증가함에 따라 초기 설계단계에서부터 선박의 조종성능을 정확히 추정하는 것이 매우 중요하게 되었다. 본 논문에서는 선박 조종성능을 추정할 수 있도록 선박 고유 조종 운동 특성을 선박운항에 관련한 항해센서와 함께 선박 운항에 동일한 운전 조건으로 구성하고 HILS(Hardware In the Loop Simulation)을 적용하여 선박조종 신뢰성을 향상 시킬 수 있는 방법을 제시한다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.7 no.3
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• pp.1-16
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• 2001

In view of the fact that marine casualties have more often occurred recently, there is a need for ship-handling simulator as a useful tool for maritime training, safety assessment and so on. Moreover various kinds of hull forms have appeared for the purpose of improving ship manoeuvrality. Therefore ship-handling simulator is in need of a database for various ships, and it can make diverse maneuvering simulations possible to apply respective mathematical model to ship-handling simulator. In this paper, we adopted twin-screw and twin-rudder ship and discussed mathematical model of maneuvering motions for her. It was discussed from the viewpoint of hull damping forces at low advance speed and interaction between hull, propeller and rudder. Using this model, maneuvering motion of twin-screw and twin-propeller ship was simulated numerically and her principal manoeuvrability was examined.

• Journal of Navigation and Port Research
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• v.38 no.3
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• pp.253-259
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• 2014

Traffic risks in fairway and harbour area increase lately according to be a sharpe change of ship's size and speed. It becomes hot issue to design a fairway, which's width is important to lower traffic risk and ensure navigational safety. The current design making a fairway and width do not focus on maneuvering motion of a large ship, but traffic risks are clear on reflecting the design of fairway, specially on width. To contact with these problems, this research proposes how to determine fairway' width in consideration of traffic volume. it suggests several situations of marine traffic congestion as like narrow channel and harbour area. here uses 162 simulations in MTS Ver.1 developed. Acquired simulation's results, environmental stress dates, figure in a model that relates with required fairway' width and allowable traffic volume. In added, suggested model compares current design with an width.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.4
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• pp.397-402
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• 2013

In this study, numerical hull form development of a platform supply vessel, a full scale with the overall length of 26.75m, was performed to predict a bare-hull resistance and a large scale of model tests with a 1/10 scaled model were conducted to verify the success of numerical results. Numerical analysis on heave and pitch motion as a function of encounter frequency and ship's speed for the prediction of seakeeping characteristics are also presented. The experiment results of resistance agreed well with numerical analysis. As a result in the motion response characteristics, the heave RAO indicates high values with the range of encounter frequency 1.8~2.0. The Pitch RAO indicates high motion response characteristics at Beaufort scale No. 3 and 4 in rough seas.