• Title, Summary, Keyword: Inspection of the ship's bottom

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A Study on Underwater Camera Image Correction for Ship Bottom Inspection Using Underwater Drone (수중드론을 활용한 선박 선저검사용 수중 카메라 영상보정에 대한 연구)

  • Ha, Yeon-chul;Park, Junmo
    • Journal of the Institute of Convergence Signal Processing
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    • v.20 no.4
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    • pp.186-192
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    • 2019
  • In general, many marine organisms are attached to the bottom of a ship in operation or a ship in construction. Due to this phenomenon, the roughness of the ship surface increases, resulting in loss of ship speed, resulting in economic losses and environmental pollution. This study acquires / utilizes camera images attached to ship's bottom and underwater drones to check the condition of bottom. The acquired image will determine the roughness according to marine life by the administrator's visual confirmation. Therefore, by applying a filter algorithm to correct the image to the original image can help in the correct determination of whether or not attached to marine life. Various correction filters are required for the underwater image correction algorithm, and the lighting suitable for the dark underwater environment has a great influence on the judgment. The results of the research test according to the calibration algorithm and the roughness of each algorithm are considered to be applicable to many fields.

An Underwater Inspection System to Detect Hull Defects of a Ship (수중용 선체외판 길함 검사용 장치 개발)

  • Kim, Young-Jin;Cho, Young-June;Lee, Kang-Won;Shon, Woonh-Hee
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • pp.281-284
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    • 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.

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Modeling and Tracking Simulation of ROV for Bottom Inspection of a Ship using Component Drag Model (요소항력모델을 활용한 선저검사용 ROV 모델링 및 트래킹 시뮬레이션)

  • Jeon, MyungJun;Lee, DongHyun;Yoon, Hyeon Kyu;Koo, Bonguk
    • Journal of Ocean Engineering and Technology
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    • v.30 no.5
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    • pp.374-380
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    • 2016
  • The large drift and angle of attack motion of an ROV (Remotely operated vehicle) cannot be modeled using the typical hydrodynamic coefficients of conventional straight running AUVs and specific slender bodies. In this paper, the ROV hull is divided into several simple-shaped components to model the hydrodynamic force and moment. The hydrodynamic force and moment acting on each component are modeled as the components of added mass force and drag using the known values for simple shapes such as a cylinder and flat plate. Since an ROV is operated under the water, the only environmental force considered is the current effect. The target ROV dealt with in this paper has six thrusters, and it is assumed that its maneuvering motion is determined using a thrust allocation algorithm. Tracking simulations are carried out on the ship’s surface near the stern, bow, and midship sections based on the modeling of the hydrodynamic force and current effect.