• 전자공학회논문지SC
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• 제49권2호
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• pp.1-9
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• 2012

본 논문에서는 이원화된 필드버스 기반의 선박 엔진용 분산 제어시스템을 설계 및 구현한다. 구현된 시스템은 엔진의 상태 값을 감시하기 위해서 CAN과 MODBUS 프로토콜을 혼합 형태로 이용하여 서로 다른 영역의 통신 구조로 구성한다. 첫 번째 층은 CAN프로토콜을 이용하여 엔진의 상태 값을 공유하게 된다. 두 번째 층은 MODBUS를 이용하여 엔진룸에서 기관실의 AMS로 모니터링 데이터 전송을 위한 통신을 지원한다. 테스트 베드 환경을 구축하여 구현된 시스템을 선급기술규칙의 요구사항에 의거하여 테스트 및 성능 검증하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제21권4호
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• pp.414-420
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• 1997

An intelligent speed control system for marine diesel engines is presented. The approach adopt¬ed is to use a conventional PID controller for normal operation and a feedforward controller for adaptive control. The feedforward controller is a neural network. The neural network is the inverse dynamics model of the plant, which is being trained on line. The parametric model of the diesel engine is represented in a linear second-order system, with a first-order combustion part and a revolution part each at a normal operating point. The time delay in the control of the com¬bustion part is approximated to the first-order system. The tuned PID parameters are set based on the model for normal operating point. To obtain the inverse dynamics of the diesel engine system, two neural networks are used, one for inverse, the other for forward dynamics. The former is posi¬tioned across the plant to learn its inverse dynamics during operation, and the latter is placed in series with the controlled plant. Simulation results are presented to illustrate the applicability of the proposed scheme to intelligent adaptive control of diesel engines.

• 한국기계가공학회지
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• 제11권2호
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• pp.27-33
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• 2012

A marine propeller is designed for preventing cavitation priority. Cavitation is a phenomenon which is defined as the vibration or noise by dropping the pressure on the high-speed rotation of the propeller. There has to be a enough thrust on the low-speed rotation for preventing cavitation. Thus, it has to be considered in the increasing of the number of blade and the angle of wing to design the propeller. In addition, flow resistance will be increasing by narrowing the width between blades. So high quality surface roughness of the hub to minimize flow resistance is required. Interference problems with tool and neighboring surfaces often take place from this kind of characteristics of the propeller. During 5-Axis machining of these propellers, the excessive local interference avoidance, necessary to avoid interference, leads to inconsistency of cutter posture, low quality of machined surface. Therefore, in order to increase the surface quality, it is necessary to minimize the cutter posture changes and create a continuous tool path while avoiding interference. This study, by using a MC-space algorithm for interference avoidance and a MB-spline algorithm for continuous control, is intended to create a 5-Axis machining tool path with excellent surface quality. Also, an effectiveness is confirmed through a verification manufacturing.

• 대한조선학회논문집
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• 제41권4호
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• pp.77-84
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• 2004

Active control is regarded as one of the most efficient and economic countermeasures to reduce excessive vibration of ship superstructure. However, it is difficult to find its practical application in real ships in spite that many studies on such systems have been done. In this study, for the practical use of an active control system to reduce ship superstructure vibration, we have developed an active vibration compensator consisting of a mechanical actuator having compact size and expected lifetime over 20 years, its control panel including exclusive signal processing and computing board, sensors to detect phase and vibration, and its operation software providing various user-interface functions. From the performance verification test of the system at a 5,500 TEU container carrier, we have confirmed the system could reduce ship superstructure vibration of a harmonic component of main engine rotating frequency up to 0.1 mm/s.

• 대한조선학회논문집
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• 제29권4호
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• pp.27-35
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• 1992

컴퓨터 그래픽스와 빠른 하드웨어의 발달에 힘입어, WYSIWYG(What You See Is What You Get)로 특징지워지는 GUI(Graphical User Interface)는 기존의 사용자 인터페이스 개념을 컴맨드를 이용한 언어모델에서 풀다운 메뉴, 스크롤바, 아이콘 등을 이용한 공간모델로 바꾸어 놓았다. 여기서 개발된 선박개념설계를 위한 그래픽 사용자 인터페이스 모델(MBASWIN)은 Event-driven 프로그래밍 기법과 객체지향 개념을 도입하였다. 또한 기존의 설계 프로그램이 인터페이스 부분을 포함하여 프로그램 전체를 제어했던 방식에서 벗어나, 설계 프로그램과 사용자 인터페이스 부분을 완전 분리하여, 사용자 인터페이스 루틴이 설계 루틴들을 제어하는 방식을 도입하였다. 이를 이용하여 설계자는 유연성있는 설계를 수행할 수 있게 된다.

• 드라이브 ㆍ 컨트롤
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• 제11권3호
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• pp.7-13
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• 2014

Everyday about 90% of cargos are delivered by ships, and thousands of vessels enter and depart the international container harbors such as Shanghai, Singapore, Hong Kong, Busan, Rotterdam, etc. Maneuvering at harbor is known as the most sophisticated and difficult procedure, because the effectiveness of actuators during low speed berthing is reduced. In this paper, a new berthing method is discussed. Tugboats are combined with damper systems to ensure safe berthing. A mathematical model describing the interaction between unactuated ship, tugboats and damper systems is presented. An optimal controller is designed to maneuver the ship without oscillation and overshoot. MCL (Marine Cybernetics Lab) model ship is used to evaluate the efficiency of the proposed approach through MatLab simulation.

• 대한기계학회논문집A
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• 제26권2호
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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.

• 대한기계학회논문집
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• 제17권8호
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• pp.2023-2032
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• 1993

This study suggests a new type shaft generating system driven by hydrostatic transmission suitable for small size vessels. Since the shaft generating system is affected ceaselessly by disturbances such as speed variation in pump driving speed and variation in external load, a robust servo control must be implemented to obtain stable electric power with constant frequency. Thus, in this study, a digital robust servo control algorithm is applied to the controller design. By the experiment and the numerical computation, the frequency variation characteristics of the generating system under various disturbances are investigated. Conclusively, it is said that the shaft generating system proposed in this study shows excellent control performances.

• 제어로봇시스템학회논문지
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• 제17권9호
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• pp.869-874
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• 2011

This paper addresses the trajectory tracking problem for ship berthing by using sliding mode technique. With significant potential advantages: insensitivity to plant nonlinearities, parameter variations, remarkable stability and robust performance with environmental disturbances, the multivariable sliding modes controller is proposed for solving trajectory tracking of ship in harbor area. In this study, the ship position and heading angle are simultaneously tracked to guarantees that the ship follows a given path (geometric task) with desired velocities (dynamic task). The stability of the proposed control law is proved based on Lyapunov theory. The proposed approach has been simulated on a computer model of a supply vessel with good results.

• 대한기계학회논문집
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• 제18권6호
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• pp.1374-1381
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• 1994

This study suggests a new type shaft generating system driven by hydrostatic transmission suitable for small size vessels. In this system, the hydraulic motor speed is controlled by displacement adjustment using a 3-way high speed on/off valve. The 3-way high speed valve is operated by PWM control signal. In this study, a digital robust servo control algorithm is applied to the controller design of the system. By experiments and numerical computations, the frequency variation characteristics of the generating system under various disturbances are investigated. Conclusively, it is said that the shaft generating system proposed in this study shows excellent control performances.