• Structural Engineering and Mechanics
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• 제75권6호
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• pp.785-797
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• 2020

As the growth of world trade has surged rapidly over the past years, the number is expected to continue growing over the coming years. Although the transportation costs can be reduced by using larger vessels, however, new berthing structures have to be constructed in order to cater for the larger vessels. This leads to a need for researching on designing a better berthing structure. For optimization of berthing structure design, we need to provide a better estimation of berthing energy than the previous methods in the existing guidelines. In this study, several berthing parameters were collected from previous works and researches. Moreover, the scenarios were selected efficiently by using a sampling technique. First, the berthing energy was calculated by executing 150 numerical simulations. Then, the numerical simulation results were compared with the results calculated by existing methods quantitatively to investigate the sensitivity of the berthing parameters and the accuracy of existing methods. The numerical method results have shown some deviation with respect to the existing method results in which the degree of deviation varies with the methods and the tendency of differences is dependent on certain berthing parameters. Then, one of the existing methods which has shown a small deviation was selected as a representative method and applied with several safety factors to obtain a suitable safety factor for the design.

• 한국항해항만학회지
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• 제43권3호
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• pp.186-196
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• 2019

선박의 접안과정 중 발생하는 접안에너지는 접안속도와 밀접한 관계가 있다. 접안속도가 과다할 경우 선박 및 부두에 손상이 발생하는 접안사고로 이어질 수 있으므로 적절한 접안속도를 설계하는 것이 중요하다. 선박접안속도의 경우, 일반적으로 대수정규분포를 따른다고 가정하고 있으나 국내에서는 이에 대한 검증이나 연구가 없어 해외의 사례를 바탕으로 설계접안속도를 설정하고 있는 상황이다. 이에 본 연구에서는 부두의 선박접안속도 분석을 통계학적으로 접근하여 실측데이터와 확률분포를 비교하여 가장 적합한 확률분포를 찾고자 하였다. 적합도 검정으로는 K-S(Kolmogorov-Smirnov) 검정, A-D(Anderson-Darling) 검정, Q-Q(Quantile-Quantile) 플롯 등을 이용하여 접안속도 실측치 분포에 적합한 확률분포를 확인하였다. 분석 결과, 접안속도의 빈도분포는 선박의 재화상태에 따라 만재 시, 대수정규분포, 경하 시에는 와이블분포와 적합함을 확인하였다. 또한 적합도 검정 결과를 이용하여 초과확률에 해당하는 접안속도 예측치를 산출하였다. 이 예측값과 해당 부두의 설계접안속도와 비교 해본 결과, 예측값이 설계값을 크게 초과함을 확인하였다. 이를 통해 설계 시의 접안속도가 현실과 맞지 않게 다소 낮게 설정되어 있음을 알 수 있으며, 이 결과를 바탕으로 적정 설계접안속도 산정법 개선에 기여할 수 있을 것으로 기대된다.

• 제어로봇시스템학회논문지
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• 제13권4호
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• pp.304-308
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• 2007

This paper deals with ANN(Artificial Neural Networks) and its application to automatic ship berthing. Due to the characteristic of ship's manoeuvre comparing with other moving objects on land, it has been known that the automatic control for ship's berthing cannot cope with various berthing situations such as various port shape and approaching directions. for these reasons. the study on automatic berthing using ANN usually have been carried out based on one port shape and predetermined approaching direction. In this paper, new algorithm with ANN controller was suggested to cope with these problems. Under newly suggested algorithm, the controller can select appropriate weights on the link of neural networks according to various situations. so the ship can maintain stable berthing operation even in different situations. Numerical simulations are carried out with this control system to find its improvement.

• 한국항해항만학회지
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• 제31권7호
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• pp.563-568
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• 2007

In this paper, an adaptive neural network controller and its application to automatic berthing control of ship is presented. The neural network controller is trained online using adaptive interaction technique without any teaching data and off-line training phase. Firstly, the neural networks used to control rudder and propeller during automatic berthing process are presented. Secondly, computer simulations of automatic ship berthing are carried out in Pusan bay to verify the proposed controller under the influence of wind disturbance and measurement noise. The results of simulation show good performance of the developed berthing control system.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권3호
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• pp.199-210
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• 2012

The recent researches on the automatic berthing control problems have used various kinds of tools as a control method such as expert system, fuzzy logic controllers and artificial neural network (ANN). Among them, ANN has proved to be one of the most effective and attractive options. In a marine context, the berthing maneuver is a complicated procedure in which both human experience and intensive control operations are involved. Nowadays, in most cases of berthing operation, auxiliary devices are used to make the schedule safer and faster but none of above researches has taken into account. In this study, ANN is applied to design the controllers for automatic ship berthing using assistant devices such as bow thruster and tug. Using back-propagation algorithm, we trained ANN with set of teaching data to get a minimal error between output values and desired values of four control outputs including rudder, propeller revolution, bow thruster and tug. Then, computer simulations of automatic berthing were carried out to verify the effectiveness of the system. The results of the simulations showed good performance for the proposed berthing control system.

• 대한조선학회논문집
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• 제58권6호
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• pp.358-365
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• 2021

Crabbing motion is a pure sway motion with only sway velocity. The ship's crabbing motion is essential for an ideal berthing/unberthing process. The unberthing situation proceeds in sequential order such as crabbing motion section, pivoting section, and outer port section. For the berthing situation, the sequence has a reverse order: the inner port section, pivoting section, and crabbing motion section. In this paper, the berthing/unberthing data of the reference ship, Pukyong National University research ship "NARA", was analyzed to develop a sway velocity reference model. Several constraints were defined to derive the crabbing motion section during berthing/unberthing. The sway velocity reference model for the auto-berthing/unberthing was developed using the estimated sway velocity. A reproduction simulation of the ship was performed to compare the designed reference model and the reference ship data.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2004년도 춘계학술발표회
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• pp.107-112
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• 2004

선박의 대형화 추세에 따른 항만 운영의 효율성 및 대형 선박의 접안 안전성을 향상시키기 위해서는 먼저 선체에 작용하는 접안에너지를 합리적으로 산출하여야 한다. 선박의 접안에너지는 방충재와 같은 항만시설물의 설계에 대한 허용 기준을 결정하는 변수임과 동시에 도선사 및 선박의 조선자에게는 예인선의 필요 마력이나 접안속도 둥을 결정하는데 있어 중요한 판단 요소로 활용된다. 본 연구에서는 현재 사용되고 있는 운동역학적인 방법을 토대로 한 접안에너지 산출 방법에 대해 유체역학적인 측면에서 문제를 제기하고, 부두 전면의 수심과 선박의 형상에 따라 변화하는 천수역 선체부가질량을 고려한 접안에너지의 산출 방법을 제안한다. 또한 천수역에서 선체에 작용하는 부가질량을 고려한 접안에너지 산출 방법을 사용하여 1600TEU급에서 12000TEU급까지의 컨테이너 선박을 대상으로 계통적으로 각각의 접안에너지를 계산하고, 현행의 접안에너지 산출방법과 비교 검토를 실시한다.

• 한국항해항만학회지
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• 제29권8호
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• pp.673-678
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• 2005

선박의 대형화 추세에 따른 항만 운영의 효율성 및 대형 선박의 접안 안전성을 향상시키기 위해서는 먼저 선체에 작용하는 접안에너지를 합리적으로 산출하여야 한다. 선박의 접안에너지는 방충재와 같은 항만시설물의 설계에 대한 허용 기준을 결정하는 변수임과 동시에 도선사 및 선박의 조선자에게는 예인선의 필요 마력이나 접안속도 등을 결정하는데 있어 중요한 판판 요소로 활용된다. 본 연구에서는 현재 사용되고 있는 운동역학적인 방법을 토대로 한 접안에너지 산출 방법에 대해 유체역학적인 측면에서 문제를 제기하고, 부두 전면의 수심과 선박의 형상에 따라 변화하는 천수역 선체부가질량을 고려한 접안에너지의 산출 방법을 제안한다. 또한 천수역에서 선체에 작용하는 부가질량을 고려한 접안에너지 산출 방법을 사용하여 1600TEU급에서 12000TEU급까지의 컨테이너 선박을 대상으로 계통적으로 각각의 접안에너지를 계산하고, 현행의 접안에너지 산출방법과 비교 검토를 실시한다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권2호
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• pp.347-360
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• 2014

The auto-berthing of a ship requires excellent control for safe accomplishment. Crabbing, which is the pure sway motion of a ship without surge velocity, can be used for this purpose. Crabbing is induced by a peculiar operation procedure known as the push-pull mode. When a ship is in the push-pull mode, an interacting force is induced by complex turbulent flow around the ship generated by the propellers and side thrusters. In this paper, three degrees of freedom equations of the motions of crabbing are derived. The equations are used to apply the adaptive backstepping control method to the auto-berthing controller of a cruise ship. The controller is capable of handling the system non-linearity and uncertainty of the berthing process. A control allocation algorithm for a ship equipped with two propellers and two side thrusters is also developed, the performance of which is validated by simulation of auto-berthing.

• 한국항해학회지
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• 제18권2호
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• pp.69-81
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• 1994

Studies on the ship's automatic navigation & berthing control have been continued by way of solving the ship's mathematical model, but the results of such studies have not reached to our satisfactory level due to its non-linear characteristics at low speed. In this paper, the authors propose a new berthing control system which can evaluate as closely as cap-tain's decision-making by using the FNN(Fuzzy Neural Network) controller which can simulate captain's knowledge. This berthing controller consists of the navigation subsystem FNN controller and the berthing subsystem FNN controller. The learning data are drawn from Ship Handling Simulator (NavSim NMS-90 MK Ⅲ) and represent the ship motion characteristics internally. According to learning procedure, both FNN controllers can tune membership functions and identify fuzzy control rules automatically. The verified results show the FNN controllers effective to incorporate captain's knowledge and experience of berthing.