• Title/Summary/Keyword: Ship control

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The Design Optimization of a Flow Control Fin Using CFD (CFD를 이용한 유동제어 핀의 최적설계)

  • Wie, Da-Eol;Kim, Dong-Joon
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.2
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    • pp.174-181
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    • 2012
  • In this paper, the Flow Control Fin(FCF) optimization has been carried out using computational fluid dynamics(CFD) techniques. This study focused on evaluation for the performance of the FCF attached in the stern part of the ship. The main advantage of FCF is to enhance the resistance performance through the lift generation with a forward force component on the foil section, and the propulsive performance by the uniformity of velocity distribution on the propeller plane. This study intended to evaluate these functions and to find optimized FCF form for minimizing viscous resistance and equalizing wake distribution. Four parameters of FCF are used in the study, which were angle and position of FCF, longitudinal location, transverse location, and span length in the optimization process. KRISO 300K VLCC2(KVLCC2) was chosen for an example ship to demonstrate FCF for optimization. The optimization procedure utilized genetic algorithms (GAs), a gradient-based optimizer for the refinement of the solution, and Non-dominated Sorting GA-II(NSGA-II) for Multiobjective Optimization. The results showed that the optimized FCF could enhance the uniformity of wake distribution at the expense of viscous resistance.

Practical Application of the Active Vibration Control System to Ship Superstructure (선체 상부구조 진동의 능동제어시스템 실용화 연구)

  • T.Y. Chung;S.J. Moon;H.C. Park;Y.C. Huh;S.Y. Han
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.2
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    • pp.119-126
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    • 1996
  • A hydraulic type active control system has been developed for the purpose of vibration suppression of ship superstructrures. The active mass of the developed system weighs about three tons and is designed to have ${\pm}5mm$ stroke below 10Hz. Thus maximum control force of the system is about 60kN. Performance test of the developed system has been carried out on a 4,400TEU contrainer carrier built in Samsung Heavy Industry Co., LTD. Through the exciter tests, it has been confirmed that the vibration levels of the superstructure can be reduced to about 20% of the uncontrolled levels near resonant frequency.

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A study on the development of ballast water management-related familiarization training pursuant to the STCW convention

  • Lee, Young-Chan;Ha, Weon-Jae
    • Journal of Advanced Marine Engineering and Technology
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    • v.41 no.2
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    • pp.163-170
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    • 2017
  • The International Convention for the Control and Management of Ships' Ballast Water and Sediments (hereafter "BWM Convention") will be enforced beginning on September 8, 2017. Even though the STCW Convention (International Convention on Standards of Training, Certification and Watchkeeping for Seafarers) and other international instruments require all ship personnel be qualified under certain competencies and standards, the International Maritime Organization (hereafter "IMO") has no unified requirements for training ship personnel on ballast water management. When the BWM Convention enters into force, all officers and crew on board ships should be intimately familiar with the guidelines and procedures outlined by the BWM Convention, regarding, among other topics, proper record keeping techniques and measures, the layout of the ballast control system, methods of ballast water exchange, and inspections by the port state control. To ensure that officers and crew members are adequately familiar, this paper proposes new competency requirements for ballast water management training and education to be added to the STCW Code. To support the introduction of these new competency requirements, this paper explores the evolution of the BWM Convention and examines how international regulations will be used to implement it.

A Study on the Automatic Control for Collision Avoidance of the Ships (선박의 충돌회피를 위한 자동제어에 관한 기초적 연구)

  • Lee, Seung-Keon;Kwon, Bae-Jun
    • Journal of Navigation and Port Research
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    • v.26 no.1
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    • pp.8-14
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    • 2002
  • The collisions of vessel at sea show high among the whole marine accidents. Especially, the accidents of fishing vessels take the largest portion of the collisions. Therefore, a technique to reduce these accidents should be developed. The automatic control for avoiding collision suggested in this study consists of two steps. The first is recognizing collision risk with fuzzy Theory and the other is maneuvering the model ship on the basis of collision risk calculated from the first step. The information form the position and estimated time of collision point(DCPA and TCPA) is used to assess the collision risk. To verify this system, a fishing vessel was simulated according to MMG mathematical model. The simulations result shows quite good application in avoiding the collision of ship.

Development of Creating Continuous and Common Cutting NC Data Program (소부재 연속/공용 절단 데이터 생성 프로그램 개발)

  • Hyun, Sung-Yeol;Oh, Sung-Kwon;Huh, Ok-Jae;Shim, Hyun-Sang
    • Special Issue of the Society of Naval Architects of Korea
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    • 2011.09a
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    • pp.101-105
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    • 2011
  • In most shipbuilding company, cutting procedure is proceed by cutting machine which run by CNC(Computer Numerical Code) data. In our cutting process, all CNC data is created by our nesting post processor system automatically. Among them, in case that cutting piece in the remnant plate, our system creates only one piece CNC data. Because remnant plate is not typical shape, and ship designers don't know remnant plate shape and quantity. In can happen some merit and good point if we modify 1:1 piece NC data by shorten cutting path, reducing cutting time or re-arrangement piece. For modifying cutting data, outside workers have to call to ship designer or have to go to NC control room where control the CNC system and cutting machine. It makes stop work process, and it waste time. In this paper, we introduce a program that can modify and replace 1:1 NC data with continuous or common NC data automatically.

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A Study on the Remote Monitoring and Control of Ship's Emergency Lighting System (선박 비상조명 원격 모니터링 제어)

  • Yang, Hyun-Suk;Kim, Kun-Woo;Lim, Hyun-Jung;Moon, Jung-Pil;Lee, Sung-Geun;Kim, Yoon-Sik
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.207-210
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    • 2005
  • This paper describes a design of several ship's emergency lighting system(SELS) that power factor is improved and power is controlled extensively, and techniques to control and monitor this system in remote distance by PC serial communication. The remote monitoring control system is composed of emergency power supply system (EPSS), half bridge(HB)inverter, fluorescent lamp(FL), microprocessor, multi communication interface. EPSS checks the voltage of the emergency backup battery in real time. In case that the voltage of 13[V] or less has been detected for 5[msec] or longer for 3 times in a row, charger circuit is connected for battery charging. Experimental works using proposed system confirm that speedy and stable power to be supplied when main power source cut-off, compared with conventional analog type, and input power up to 35.0[%] by adjusting of pulse frequency of the HB inverter.

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A Study on the Damage Control System and Flooding Simulation of Naval Vessels Using M&S (M&S를 통한 함정의 침수상황 가시화 및 손상통제기법 연구)

  • Ahn, Byoung-Kwon;Lew, Jae-Moon
    • Journal of the Society of Naval Architects of Korea
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    • v.44 no.5
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    • pp.526-533
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    • 2007
  • It should be primarily aimed to increase survivability consisting of susceptibility, vulnerability and recoverability of naval vessels including ship hull, armament system as well as crews from the design stage to practical operations. With this in mind, swift and efficient actions should be executed on the basis of accurate calculations for the recoverability of damaged vessels. In this paper, it is established how the damage control system of naval vessels is embodied through step-by-step processes intending to cope with various damaged situations that may possibly occur during real operations. It is validated that this system has the applicability to naval vessels through the case study of the battle ship which has been damaged during the operation.

A Study on the Action to Cope with the Recent Port State Control Trend (항만국통제(PSC) 동향에 따른 대응방안에 관한 조사연구)

  • Yoo, Young-Jong;Lee, Hee-Joon;Lee, Sok-Hee
    • Journal of Korea Ship Safrty Technology Authority
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    • s.28
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    • pp.78-89
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    • 2010
  • 항만국통제는(Port State Control)은 자국 항만 또는 수역 내에서 기준미달선을 제거하기 위하여 선박이 외국항에 기항하였을 때 해당 항만국의 검사관(Port State Control Officer)이 승선하여 그 선박이 국제협약 또는 항만국의 규정에 적합하게 건조, 정비 및 운용되고 있는지를 확인하고 결함사항이 발견된 선박에 대하여 억류 등의 제제조치를 가하는 제도이다. 최근의 항만국통제는 기항 선박에 대한 Target Matrix를 활용한 점검대상 선박 선정, 집중점검프로그램 운용 및 목표 점검율 상향조정 등으로 항만국통제 활동은 점점 더 강화되고 있다. 우리공단 검사선박의 경우 PSC에 의한 출항정지 척수가 2006년 1척, 2007년 2척 그리고 2008년 4척으로 점차 증가하는 경향을 보이고 있다. 따라서 공단 검사선박의 출항정지율 저감을 위한 방안을 개발하기 위하여 Paris MOU, Tokyo MOU 그리고 USCG의 최근 PSC 점검동향과 우리 공단의 검사선박중 출항정지 선박 및 지적된 결함사항에 대하여 조사 분석한 결과 최근 7년간 출항정지 당한 선박 10척중 6척이 도입선과 2척이 탈급선이고 그리고 주요 지적사항으로는 만재흘수선 관련 결함사항이 가장 많이 지적되었음으로 분석되었다. 따라서 그러한 분석 결과를 바탕으로 공단 검사선박의 출항정지율 저감을 위한 대책을 검토하고 새로 도입되거나 개선되어야 할 점 등에 대한 안을 제시하였다.

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Performance Estimation for Shipboard Directional Pedestal by Using M&S Methodologies (M&S기법을 활용한 선박용 지향성 요동보상장치 성능 분석)

  • Lee, Sungkyun;Go, Jinyong;Han, Yongsu;Kim, Changhwan
    • IEMEK Journal of Embedded Systems and Applications
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    • v.13 no.6
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    • pp.297-303
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    • 2018
  • Recently, the tasks assigned to surface ship are becoming diverse and important. In this trend, shipboard directional pedestals are widely used for surveillance and electronic warfare because ships are always under angular motion such as rolling, pitching and yawing. To estimate the performance of pedestal, the motion responses of vessel as well as mechanical characteristics of pedestal should be considered. In this study, both the motion responses of vessel which the pedestal will be mounted and the behavior of 3-axis pedestal are considered. Numerical analysis based on potential theory is used to obtained motion characteristics of vessel and then 6-DOF motions of vessel are simulated under operational condition. 1st-order time delay model and LQR control algorithm are used for modeling of pedestal drive model and control model, respectively. By using coordinate transform, the angular motions which the pedestal should compensate are calculated from the vessel's angular motion. Through these M&S methodologies, time history of pedestal behavior and maximum angular error of each pedestal axis are obtained. Overall M&S results show that 3-axis pedestal compensate the angular motion induced by vessel, efficiently.

Hull Form and Layouts of 740-ton Replacement Vessel for R/V Eardo of KIOST: Ship Design and SMRs (740톤급 종합해양연구선 이어도호 대체선 선형 및 설계 특성)

  • Park, Cheong Kee;Park, Dong-Won;Lee, Gun Chang;Kim, Young Jun;Min, Young Ki
    • Ocean and Polar Research
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    • v.42 no.2
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    • pp.171-178
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    • 2020
  • R/V EARDO, commissioned in 1992, has successfully carried out ocean research campaigns in Korean jurisdictional and adjacent waters, including continental margins and coastal zones within the Korean Exclusive Economic Zone (EEZ), for 29 years. However, it will soon be reaching the end of its useful service life. A replacement for R/V EARDO is urgently needed to ensure the safety of vessel itself and its crews, and efficient ship operation and maintenance, as well as to meet modern scientific mission requirements (SMRs). Basic specifications for a replacement ship have been devised and reviewed over the past nine months. A test of the proposed hull form was also performed. The total tonnage of the proposed vessel is approximately 740 tons, and the overall length and width are 62.0 and 11.6 m, respectively. The new ship will thus be 73% larger than the current R/V EARDO; in particular, the research workspace will be 4.4 times larger. The major design priorities are the propulsion system, efficiency of radiated noise and vibration control, and the dynamic positioning system. An environmentally friendly emission system, meeting International Maritime Organization (IMO) Tier III regulations, will be installed in the third exhaust pipe. Various wet and dry lab spaces as well as 32 different scientific instruments have also been considered in the ship design.