• Title, Summary, Keyword: 횡동요

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A Study on New Mathematical Model of Ship Manoeuvring Motion Taking Coupling Effect of Roll into Consideration (횡동요를 고려한 선박조종운동의 새로운 수학모델에 관한 연구)

  • Sohn, Kyoung-ho;Kim, Yong-min
    • Journal of Navigation and Port Research
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    • v.27 no.5
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    • pp.451-458
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    • 2003
  • A ship with small metacentric height or high speed vessel performs relatively large roll angles in her manoeuvring motion. Roll coupling effect should be taken into consideration for accurate prediction of manoeuvring motion of such a ship. This paper proposes a new mathematical model of ship manoeuvring motion taking coupling effect of roll into consideration. Some kinds of manoeuvring motion are simulated by computer, based upon the proposed model. The simualted results by proposed model here are compared with those by existing model. The proposed model is found to be practical and useful for prediction of manoeuvring motion with roll effect.

A Study on the Prediction of Ship's Roll Motion using Machine Learning-Based Surrogate Model (기계학습기반의 근사모델을 이용한 선박 횡동요 운동특성 예측에 관한 연구)

  • Kim, Young-Rong;Park, Jun-Bum;Moon, Serng-Bae
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.41-42
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    • 2018
  • This study is about the prediction of ship's roll motion characteristic which has been used for evaluating ship's seakeeping performance. In order to obtain the ship's roll RAO during voyage, this paper utilized machine learning-based surrogate model. By comparing the prediction result data of surrogate model with test data, we suggest the best approximation technique and data sampling interval of the surrogate model appropriate for predicting the ships' roll motion characteristic.

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Roll Damping Moment of a Small Fishing Vessel by Free Rolling Test in Waves (파랑중 자유 횡동요 시험에 의한 소형어선의 횡동요 감쇠모멘트에 관한 연구)

  • H.H. Chun;S.H. Chun;S.Y. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.37 no.2
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    • pp.30-37
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    • 2000
  • The roll damping characteristics of the three models of a 3ton class fishing vessel, that is the bare hull, hull with bilge keels, and hull with bilge keels and a central wing are investigated by the free roll tests in head waves in a towing tank with the variations of the forward speed, initial angle and OG. The wave length variations are also included. The experimental results are compared with the numerical results of mathematical modellings by the energy method for these three models and the energy dissipation patterns are also compared. The roll damping speed increases, the effect of the waves on the roll damping of the models with the additional devices is negligible due to the much increased damping caused by the lift increase.

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A study for roll damping performance of a platform supply vessel with or without bilge keel using CFD (전산유체역학을 이용한 해양작업지원선의 빌지킬 유무에 따른 횡동요 성능에 관한 연구)

  • Seok, Jun;Kim, Sung-Yong;Yang, Young-Jun;Jin, Song-Han;Park, Jong-Chun
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.9
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    • pp.791-798
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    • 2016
  • In this study, numerical simulations on the effects of bilge keel on roll motion were conducted. The numerical simulations were performed on a 110 m class PSV using the commercial viscous flow analysis software Star-CCM+. Before conducting the study on the 110 m class PSV, an additional simulation of DTMB 5512 was performed and compared with the experimental results to validate the feasibility of the numerical simulation. In the simulation on PSV, a nondimensional damping coefficient was calculated using a free roll decay simulation, and the response amplitude operator (RAO) for the roll motion was calculated with a nondimensional damping coefficient at two conditions (with/without bilge keel).

A Study on Rudder-Roll Stabilization System Design for Ship (방향타를 이용한 선박 횡동요 제어계 설계에 관한 연구)

  • Kim, Yeong-Bok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.2
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    • pp.329-339
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    • 2002
  • In ship operation the consequency of roll motions can seriously degrade the performance of mechanical and personnel effectiveness. So many studies for the roll stabilization control system design have been performed and very good results have been achieved. In many studies, the stabilizing fins are used. Recently rudders, which have been extensively modified, have been used to exclusively to stabilize the roll. This paper examines the two-degree-of-freedom servosystem design technique to synthesize the yaw control system which achieves the course keeping object of the ship and the H$_{\infty}$ control approach to suppress the roll motion, respectively.

On the Prediction of Inner Pressure for the Tank in Rolling Motion (동요하는 탱크의 내부 변동압력 추정에 관한 연구)

  • Lee, Seung-Keon;Sea, Young-seok
    • Journal of Navigation and Port Research
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    • v.27 no.5
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    • pp.459-464
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    • 2003
  • The inner liquid pressure of an airtight tank in rolling motions is investigated by means of forced oscillation tests, and the simple method to estimate the inner liquid pressure is proposed. A rectangular solid tank, which is fully filled with water, was used in the forced oscillation test of rolling motion. The inner pressure variations in time were measured at several points on the inner walls of tank. Measured pressures are compared with the calculated ones, and estimation methods of the inner liquid pressure of the tank in rolling motion are studied based on the considerations of the origin of pressure.

An Experimental Study on the Rolling Motion Control of a Ship Based on LMI Approach (LMI를 이용한 선박 횡동요 제어에 관한 실험적 연구)

  • 채규훈;김영복
    • Journal of Ocean Engineering and Technology
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    • v.17 no.2
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    • pp.60-66
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    • 2003
  • In this paper, an actively controlled anti-rolling system is considered, in order to reduce the rolling motion of a ship. In this control system, a small auxiliary mass is installed on the upper area of the ship, and an actuator is connected between the auxiliary mass and the ship. The actuator reacts the auxiliary mass, applying inertial control forces to the ship to reduce the rolling motion in the desired manner. In this paper, we introduce LMI based H$_{\infty}$ control approach to design the anti-rolling control system for the controlled ship. And the experimental results show that the desirable control performance can be achieved.

An Experimental Study on the Development of the Anti-Rolling Control System for a Ship (선체 횡동요 방지 장치 개발을 위한 실험적 연구)

  • 김영복;변정환;양주호
    • Journal of Ocean Engineering and Technology
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    • v.14 no.4
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    • pp.43-48
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    • 2000
  • In this paper, an actively controlled anti-rolling system is considered to reduce the rolling motion of the ship. In this control system, a small auxiliary mass is installed on the upper area of the ship, and actuator us connected between the auxiliary mass and a ship. The actuator reacts against the auxiliary mass, applying inertial control forces to the ship to reduce the rolling motion in the desired manner. In this paper, we apply the PID controller to design the anti-rolling control system for the controlled ship. And the experimental result shows that the desirable control performance is achieved.

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Swing Motion Analysis of the Container Crane Headblock (콘테이너 크레인의 헤드블록 횡동요 해석)

  • 조대승
    • Journal of KSNVE
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    • v.7 no.5
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    • pp.765-772
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    • 1997
  • This paper presents the swing motion analysis of the container crane headblock with the passive control device using hydraulic motors and anti-swing ropes. The device hauls at the headblock to opposite direction of its swing motion using the tension difference between anti-swing ropes connected to the headblock. To consider this control mechanism, the headblock is modelled as the rigid bar suspended by two hoist ropes at the overhead trolley and its non-linear equation of motion is derived using Lagrange's equation. Some numerical experiments using the equation are carried out to investigate the swing motion characteristics of the headblock under the variation of geometric relation among the cargo handling components and to evaluate the performance of the anti-swing device.

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An Experimental Study on the System Identification and Anti-Rolling System Design for a Ship with Flaps (선미측에 플랩을 갖는 선박의 동특성 규명과 횡동요 제어계 설계)

  • 김영복;강귀봉;채규훈
    • Journal of Ocean Engineering and Technology
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    • v.18 no.2
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    • pp.39-45
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    • 2004
  • We have investigated the usefulness of an active stabilizing system to reduce ship rolling under disturbances, using varying reaction of the flaps. In the proposed anti-rolling system for a ship, the flaps, as the actuator, are installed on the stern, in order to reject the rolling motion induced by disturbances, such as waves. The action induced by the flaps, which is dependent upon the power of the disturbances, can keep the ship in balance. In this study, we define the system parameters under the given system structure, using spectral analysis and experimental studies. Based on this information, we design the controller to evaluate the usefulness of the proposed system.