• Journal of the Korean Society of Marine Environment & Safety
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• v.11 no.1 s.22
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• pp.23-28
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• 2005

We have investigated the usefulness cf active stabilizing system to reduce ship rolling under disturbances, using varying reaction cf the flaps. In the proposed anti-rolling system for a ship, the flaps as the actuator are installed on the stem to reject rolling motion induced by disturbances like wave. The action induced by flaps which depends on power of disturbances am take the ship balance. Especially, in this study we identify the controlled system under the undefined system structure using spectral analysis and experimental studies. Based on these informations, we design the controller to evaluate the usefulness of the proposed system.

• 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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.33-39
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• 2004

A ship runs with various modes of motion due to waves. Among the modes, roll mainly influences on the safety of cargos and crew's fatigue. Therefore a ship equipped with anti-rolling devices are on an increasing trend. In this research, we developed a free running model ship to evaluate the performances of fin stabilizer and moving weight stabilizer. Also those performance tests were carried out through the proposed test procedure.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.10a
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• pp.83-86
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• 2003

선박은 근본적으로 파랑이 향상 존재하는 해상에서 운항하게 되므로 파랑 중에서의 선체운동 여객, 승무원, 화물 및 선박 자체의 안전과 밀접한 관계를 가지게 된다. 뿐만 아니라 선박의 운동은 해상에서의 각종 활동과 임무수행의 정도를 결정하는 주요한 인자가 되고 있다. 횡동요(Rolling)는 6 자유도 운동 가운데에서 가장 중요한 운동이며, 선박들이 근본적으로 횡동요에 대하여 낮은 감쇠특성을 갖고 있기 때문에 안정성 측면에서 볼 때에 가장 많이 제어되어 왔다. (중략)

• 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.

• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.725-731
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• 2003

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-.oiling system (MD-ARS) might be one candidate of several systems against the ship's rolling. As the movable range of the mass on the ship is finite, the control system must include restriction on the mass position to protect the device and the ship. This restriction usually causes windup phenomenon and control performance is deteriorated seriously. We adopt anti-windup technique to improve the control performance and demonstrate its efficiency by simulation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1244-1251
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• 2022

Marine accidents due to a loss of stability, have been gradually increasing over the last decade. Measures must be taken on the roll reduction of a ship. Amongst the measures, building an anti-roll tank in a ship is recognized as the most simple and effective way to reduce the roll motion. Therefore, this study aims to develop a computational model for a U-tube type anti-roll tank and to validate it by experiment. In particular, to validate the developed computational model, the height of the free surface in the tank was measured in the experiment. To develop a computational model, the mesh dependency test was carried out. Further, the effects of a turbulence model, time step size, and the number of iterations on the numerical solution were analyzed. In summary, a U-tube type anti-roll tank simulation had to be performed accurately with conditions of a realizable k-𝜖 turbulence model, 10^-2s time step size, and 15 iterations. In validation, the two cases of measured data from the experiment were compared with the numerical results. In the present study, STAR-CCM+ (ver. 17.02), a RANS-based commercial solver was used.

• 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.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.566-574
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• 2005

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-rolling system (MO-ARS) might be one candidate of several systems against the ship's rolling. As the movable range of the mass on the ship is finite, the control system must include restriction on the mass position to protect the device and the ship. This restriction usually causes windup phenomenon and control performance is deteriorated seriously. Two control algorithms, anti-windup control and saturated sliding mode control, are studied in this paper. Control performance and robustness problem are checked out by numerical simulations.