• 한국정밀공학회지
• /
• 제21권3호
• /
• pp.59-65
• /
• 2004

The paper presents a small unmanned probing ship that can be used for acquiring information on marine and coastal environments. For communication system, we adopt direct and indirect methods based on the wireless modem of a commercial cellular telephone. The former is a direct communication between the modems of the ship and the server, and the latter is an indirect communication via internet between the ship and the server. The system is equipped with a digital compass and a GPS for position estimation, and extended Kalman filter is used for Navigation. The performance of the ship is demonstrated with the results produced by sets of experiments.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2019년도 춘계학술대회
• /
• pp.25-28
• /
• 2019

정보통신기술의 발전과 더불어 해상통신 시스템 또한 안전성, 효율성, 정확성 그리고 보안을 목적으로 하는 항해 및 통신 장비 관련 연구가 활발히 진행되고 있다. 그러나 100km 초과 원거리 조업 어선에 대해서 위치파악 및 선박상태 등 어선관리에 어려움을 겪고 있다. 그리하여 본 연구에서는 Digital-HF 통신 시스템을 통한 원거리 선박 안전을 위하여 최적주파수를 선택하고 이 주파수를 이용하여 선박 위치 확인이 가능하도록 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제18권4호
• /
• pp.1122-1140
• /
• 2024

The importance of indoor positioning has grown in numerous application areas such as emergency response, logistics, and industrial automation. In ships, indoor positioning is also needed to provide services to passengers on board. Due to the complex structure and dynamic nature of ship environments, conventional positioning techniques have limitations in providing accurate positions. Compared to other indoor positioning technologies, Bluetooth 5.1-based indoor positioning technology is highly suitable for ship environments. Bluetooth 5.1 attains centimeter-level positioning accuracy by collecting In-phase and Quadrature (IQ) samples from wireless signals. However, distorted IQ samples can lead to significant errors in the final estimated position. Therefore, we propose an indoor positioning method for ships that utilizes a Deep Neural Network (DNN) combined with IQ fingerprint maps to overcome the challenges associated with accurate location detection within the ship. The results indicate that the accuracy of our proposed method can reach up to 97.76%.

• 수산해양기술연구
• /
• 제22권4호
• /
• pp.41-48
• /
• 1986

To investigate the midwater trawl gear available for the Korean near sea trawlers, the authors carried out a field experiment on the attitude and the opening efficiency of the otter board with the Pusan 404 (160GT, 750ps), a training ship of National Fisheries University of Pusan. The experimental trawl gear was designed to be operable by the ship and the otter board was made of single iron plate with 12% camber ratio. The special-prepared potentiometric angle detector was used for determining the attitude, and the 50 KHz fish finder for the opening between the otter boards. The results obtained can be summarized as follows: 1. The angle of attack varied by moving the towing point on the towing plate of the otter board. It showed 33 to 36 degrees when the point was set at the outmost position, 25 to 31 degrees at the middle position and 19 to 30 degrees at the inmost position, with a decreasing tendency according to the increase of towing speed in each cases. 2. The heel of the otter board always occured inwards, increasing slightly according to the increase of towing speed. 3. The tilt of the otter board always occured outwards, increasing slightly according to the move of the towing point inwards, and decreasing slightly according to the increase of towing speed. 4. The opening between otter boards showed the largest value when the towing point was set at the outmost position.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 춘계학술대회 논문집
• /
• pp.719-723
• /
• 1997

The welding automation in ship manufacturing process,especially in the sub-assembly line is considered to be a difficult job because the welding part is too huge, various, unstructured for a welding robot to weld fully automatically. The weld orocess at the sub-assembly line for ship manufacturing is to joint the various stiffener on the base panel. In order to realize automatic robot weld in sub-assembly line, robot have to equip with the sensing system to recognize the position of the parts. In this research,we developed a vision system to detect the position of base panle for sub-assembly line is shipbuilding process. The vision system is composed of one CCD camera attached on the base of robot, 2-500W halogen lamps for active illumination. In the image processing algorithm,the base panel is represented by two set of lines located at its two corner through hough transform. However, the various noise line caused by highlight,scratches and stiffener,roller in conveyor, and so on is contained in the captured image, this nosie can be eliminated by region segmentation and threshold in hough transform domain. The matching process to recognize the position of weld panel is executed by finding patterns in the Hough transformed domain. The sets of experiments performed in the sub-assembly line show the effectiveness of the proposed algorithm.

• 수산해양기술연구
• /
• 제39권4호
• /
• pp.337-346
• /
• 2003

레이더 정보의 수록 및 정량적 해석을 위한 시도로써 타선의 위치정보를 자선의 전자해도 및 radar 화변상에 모니터링하여 두 선박의 간격을 측정할 수 있는 양선거리측정시스템과 ARPA radar가 탐지한 표적의 추적정보를 자선의 전자해도 화면상에 실시간으로 모니터링하기 위한 시스템을 구축함과 동시에 이들 레이더 정보를 필요에 따라 수록 및 재생할 수 있는 레이더 정보수록 및 해석 시스템을 개발하고, 실용화 실험을 행한 결과를 요약하면 다음과 같다. (1) 목포 인근해역에서 레이더 신호를 수록하고, 이 레이더 영상에 위치발생시뮬레이터에 의해 생성한 타선 위치를 RS232C interface를 통해 전송 및 중첩시켜 타선의 위치를 추적하면서 실시간으로 본선과 타선의 양선 간격을 산출한 결과, 양선 거리 및 방위의 실시간 측정이 가능하여 이 시스템을 양선 거리계로써 활용할 수 있음이 입증되었다. (2) 타선의 레이더 신호를 수신한 후, $\alpha$-$\beta$ tracker를 이용하여 타선 영상의 중심 위치를 실시간으로 추적하면서 침로, 속력, 방위, 거리 등을 예측한 결과, 매우 안정된 평활화 추정치를 얻을 수 있었다. (3) ARPA 시뮬레이터를 이용하여 표적의 추적정보를 TTM sentence 등으로써 생성한 후, 이 코드를 전자해도상에 전송 및 중첩 표시시킨 결과, 추적표적의 위치, 속력, 침로, 방위, 거리 등의 추적정보의 실시간 모니터링이 안정적으로 실현된 바, 선내의 여러 장소에서 ARPA 정보를 공유하기 위한 멀티 모니터링 장치의 개발이 기대된다.

• 한국항해항만학회지
• /
• 제34권2호
• /
• pp.105-110
• /
• 2010

The studies on automatic ship collision avoidance system, which have been carried out in the last 10 years, are facing on new situation due to newly developed high technology such as computer and other information system. It was almost impossible to make it used in real navigation field 3-4 years ago because of the absence of any tool to give other ship's information, however recently developed technology suggests new possibility. This study is carried out to develop the automatic ship collision avoidance support system which considers ship's manoeuvrability into it's collision avoidance algorithm. One of the important part in ship collision avoidance system is collision decision module which can calculate collision risk with other ships and act properly to avoid the situation. Many of previous researches are using present ship's dynamic data such as present speed, position and course to calculate collision risk. However when a ship commences avoidance action, the real situation is quite different with one that has been estimated by the ship's initial data due to the ship's manoeuvring characteristic. Therefore it is better to take into account ship's manoeuvring characteristic from the stage of collision decision in ship collision avoidance system. In this study, these effects are included in the developed system. The proposed system are verified its usefulness in numerical simulation environments.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
• /
• pp.281-284
• /
• 2006

After building a ship in a shipyard, there are so many repeated inspection of welding seam defects and painting status before delivering to the ship's owner. An inspection on the bottom part of a ship in commercial service should be done in every two years for the purpose of safety and for the prevention of ship speed deterioration. conventional welding seam inspection systems are rely on the visual inspection by human or the ultrasonic inspection for the selective part of a ship. This paper suggests a remote controlled inspection system for the examination of large ships or steel structures. The proposed system moves in contact with the ship under inspection and have a CCD camera to provide visual-guidance information to a remotely located human worker. Additionally this system utilizes a weld line tracking algorithm for an optimal position control. We verified the effectiveness of the inspection system by experimental data.

• 대한임베디드공학회논문지
• /
• 제15권2호
• /
• pp.71-78
• /
• 2020

This paper proposes vision sensors and deep learning-based around view monitoring system for ship berthing. Ship berthing to the port requires precise relative position and relative speed information between the mooring facility and the ship. For ships of Handysize or higher, the vesselships must be docked with the help of pilots and tugboats. In the case of ships handling dangerous cargo, tug boats push the ship and dock it in the port, using the distance and velocity information receiving from the berthing aid system (BAS). However, the existing BAS is very expensive and there is a limit on the size of the vessel that can be measured. Also, there is a limitation that it is difficult to measure distance and speed when there are obstacles near the port. This paper proposes a relative distance and speed estimation system that can be used as a ship berthing assist system. The proposed system is verified by comparing the performance with the existing laser-based distance and speed measurement system through the field tests at the actual port.

• 한국항해학회지
• /
• 제7권2호
• /
• pp.65-113
• /
• 1983

A lot of studies of ship's economy are on the traditional fields such asreducing propulsion resistance, raising cargo handling rates and lessening building consts, but there are few researches on the merchant ship's economy concerning their deadweights and speeds according to shipping companies managerial cercumstances. Contrary to the contemporary trend that "the bigger, the better, if the cargo handling rate could increased sufficiently to hold down port time to that rate of smmaler vessels", this paper demonstrates the existence of certain limits in ship's size and speed according to the coditions of the freight rates, voyage distances, cargo handing rates, prices of fuel oil, interst rates etc. Fom the curves of criteria contour for various ship's deadweights and speeds which are depicted from the gird search method, one can get the costs and the yearly profit rates under the conditiions of large volume with long term contracts for the transportation of bulk cargoes. In estimating ship's transportation economy, the auther takes the position that the profit rate method is properer than the cost method, and introduces the calculation table of the voyage profit rate index. The use of the criteria contours will be of help to ship owners in determining the size and speed of the ship which will be built or purchased and serve in a certain trade route.