• Journal of the Society of Naval Architects of Korea
• /
• v.36 no.2
• /
• pp.61-71
• /
• 1999

This paper resents a novel cargo system adapted for a sea port subjected to severe time-varying tide. The proposed system can perform loading or unloading by using a sort of hydraulic elevator associated with real-tim position control. As a preliminary phase, a small-sized model of the cargo system is designed and constructed. The model consists of three principal components ; container palette transfer(CPT) car, platform with lifting columns and cargo ship. The platform activated by the electro-rheological(ER) valve-cylinder is actively controlled to track the position of the cargo ship subjected to be varied due to the time-varying tide and wave motion. Following the derivation of the dynamic model for the platform and cargo ship motions, an appropriate control scheme incorporating time sequence and PID(proportional-integral-derivative) controller is formulated and implemented. Both the simulated and the measured control results are presented to demonstrate the effectiveness of the proposed cargo system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2018.11a
• /
• pp.7-8
• /
• 2018

파 중 선박 조종운동시험을 위하여 선박해양플랜트연구소 공학수조 내 자유항주시험 시스템을 구성하였다. 모형선 내에 제어계측 장비와 PC를 탑재하고 육상 관제 PC에서 원격 통제, 모니터링하며, 레이저 추적 방식으로 모형선 실시간 위치를 계측하였다. 준비된 시스템으로 KVLCC2 1/100 축소모형선의 규칙파 중 선회시험을 수행하였다. 파 중 선회성능은 초반의 전진거리, 전술직경, 정상선회 시의 궤적밀림 거리, 각도 등으로 지수화할 수 있다. 각 지수를 추출하여 분석하였고, 동일한 파장 조건에 대한 궤적밀림 경향은 유사함을 보였다.

• Journal of Navigation and Port Research
• /
• v.29 no.1 s.97
• /
• pp.29-34
• /
• 2005

A mis-handling of the ship operators, treated as one qf the main causes of a ship accidents, normally has caused a ship to collide with obstacles like a reef, a rock and other ships etc. since their ability has been declining little by little even though the port conditions have been getting worse. The ship needs a highly sophisticated technology as her size and speed increase as the ship have been demanded. For example, Auto Avoidance Control System gradually has been receiving a growing interest to control the entire ship safely. From that purpose, this research has been done. The research was based on the MMG mathematical model, used Surge-Sway-Yaw-Roll motion equation and Fuzzy theory for calculating the collision-risk Also the research successively was done when the ship encountered continual multitude ships.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.10
• /
• pp.1171-1179
• /
• 2012

In this study, we consider a dynamic positioning system (DPS) design problem that can be extended to many application fields. Toward this end, tracking and positioning control problems are discussed. In particular, we design a tracking control system that incorporates an observer based on the 2-DOF servo system design approach in order to obtain the desired state information. In the case of observer design, a weighted $H_{\infty}$ error bound approach for a state estimator is considered. Based on an algebraic Riccati equation (inequality) approach, a necessary and sufficient condition for the existence of a full-order estimator that satisfies the weighted $H_{\infty}$ error bound is introduced. The condition for the existence of the estimator is denoted by a linear matrix inequality (LMI) that yields an optimized solution and the observer gain.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2003.05a
• /
• pp.279-282
• /
• 2003

본 연구에서 구현하고자 하는 선박의 회두각 제어의 경우 파도, 바람, 조류 등의 외란의 영향을 많이 받고 있을 뿐만 아니라 그 운동 특성 역시 비선형이므로 적절한 파라미터의 선정과 제어기 구성에 어려움이 따른다. 이의 해결을 위해 K. M Passino 등에 의해 비선형 특성을 지닌 기준 모델 적응 퍼지 알고리즘을 적용하여 제어기 구성을 시도한바 있고, 국내에서도 김종화 등에 의해 유사한 방법이 시도되어졌다. 본 연구에서는 이상의 시도에서 기준 모델에 의한 제어기 파라미터의 동정의 방법으로 사용한 M.I.T 룰 대신 일반적인 유전 알고리즘에 의해 퍼지 제어기의 파라미터를 동정하고자 한다. 유전 알고리즘에 기반한 기준 모델 적응 퍼지 제어기(MRGAFC: Model Reference Genetic Adaptive Fuzzy Controller) 알고리즘을 제안하며, 이의 검증을 위하여 화물선 회두각의 조향문제에 이를 적용하여 종래의 방법들과 비교를 수행할 것이다.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.2
• /
• pp.192-198
• /
• 2013

This paper presents the stabilization and design of a pan-tilt control part for the directional pan-tilt system for shipboard directional equipment. In order to control each control axis with compensation for ship motion, the 2 degree of freedom(2DOF) PID controller is designed and its parameters are tuned using a real-coded genetic algorithm(RCGA). Simulation demonstrates the effectiveness of the 2 DOF PID controller tuning.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.538-539
• /
• 2013

수평 자세제어에 관한 연구는 플랜트 외부에서 발생하는 미지의 진동이나 불특정 외란이 인가되었을 때 이러한 외란을 적절히 제거하여 플랜트의 안전성을 확보할 수 있는 중요한 기술이다. 특히 수평 자세제어에 대한 문제는 선박이나 항공기 등 진동이나 미지의 외란이 발생하는 비선형시스템에 대하여 플랜트의 안전성을 확보하기 위하여 다양한 제어 알고리즘을 적용하여 진동 및 외란을 제거하고 있다. 본 논문에서 활용하고자하는 수평 자세제어용 액추에이터는 전자기적 에너지를 직선운동을 하는 기계적 운동 에너지로 변환하는 장치로서 산업현장에서 많이 활용하고 있는 액추에이터이다. 이러한 리니어 액추에이터(linear actuator) 3개로 구성된 3축을 활용하여 리니어 액추에이터 상부에 놓여진 플랜트의 수평을 제어하고자 한다. 또한 플랜트의 수평 상태를 계측하기 위한 센서로는 플랜트에 인가되는 외란을 계측하기 위한 가속도 센서 및 정확한 플랜트의 자세를 계측하기 위한 자이로 센서를 활용하여 플랜트의 수평 상태를 계측하도록 하며, 3개의 리니어 액추에이터를 제어하기 위한 마이크로프로세서를 기반으로 PID 제어기를 설계하여 리니어 액추에이터를 활용한 수평제어 성능을 제시하고 한다.

• Journal of the Society of Naval Architects of Korea
• /
• v.38 no.2
• /
• pp.33-43
• /
• 2001

The design and construction of special purpose vessels such as drillship and shuttle tankers have been increased. These vessels install the DPS(dynamic positioning systems) to maintain the position and heading for long-time operation. This paper deals with the experimental method for model-based DP system and the control theory and filter algorithms. In this experiment, the length of model ship is 4 meters and it has three thrusters to maintain the position. The ability of tracking along the given course and keeping of heading in waves are confirmed. For the calculation of thruster input the PID control theory are adopted and the effects of PID gain were investigated. To estimate the low frequency motions Kalman filter and digital filter were used and their effects were investigated.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.10
• /
• pp.1089-1097
• /
• 2002

In this paper, the novel shipboard Active Phased Array Antenna(APAA) system for maritime mobile satellite communications is introduced. The antenna uses novel technologies like wide range hybrid tracking, single antenna elements with both of Rx and Tx, asymmetrical array structure, interference isolation between Rx and Tx, and error correction method from frequency scan effect. The antenna has single aperture for both of Rx and Tx with 32 $\times$ 4 two-dimensional array. The antenna has two beams. Its frequencies are 7.25 ~ 7.75 GHz for Rx and 7.9 ~ 8.4 GHz for Tx. The antenna gains are 35.4 dBi for Rx and 35.7 dBi for Tx, those are 54 % of efficiency. The electrically steering ranges are $\pm$35$^{\circ}$ of elevation direction and $\pm$4$^{\circ}$ of azimuth direction. The mechanical control ranges at hybrid tracking capability are continuous 360$^{\circ}$ of azimuth direction and $\pm$10$^{\circ}$ of elevation direction. The antenna has 2.2$^{\circ}$ of 3 dB beamwidth, -14 dB of sidelobe level, and 21 dB of cross-pol suppression. The antenna performance was measured by near field measurement set. Its system performance was tested on the ship motion simulator and with the satellite transponder simulator. The test result showed that its tracking error was within -3 dB from its peak gain under motion condition. The antenna system was tested by real modulated Direct Broadcasting Satellite(DBS) signals to check its communication processing function.

• Journal of Navigation and Port Research
• /
• v.32 no.8
• /
• pp.589-596
• /
• 2008

In this paper, Artificial Neural Network(ANN) is applied to automatic berthing control for a ship. ANN is suitable for a maneuvering such as ship's berthing, because it can describe non-linearity of the system. Multi-layer perceptron which has more than one hidden layer between input layer and output layer is applied to ANN. Using a back-propagation algorithm with teaching data, we trained ANN to get a minimal error between output value and desired one. For the automatic berthing control of a containership, we introduced low speed maneuvering mathematical models. The berthing control with the structure of 8 input layer units in ANN is compared to 6 input layer units. From the simulation results, the berthing conditions are satisfied, even though the berthing paths are different.