• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.135-139
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• 2009

In the line heating for the plate forming of a ship's hull, an in line assessment of completion is necessary for an automated production system. In the current curved plate forming process, a fabricated plate is compared to a template that is made in the mold loft and is used for the determination of the heating line for the next step. In this paper, a new method is presented for the in line assessment of completion for curved plate forming. This method uses a 3-D scanner. For the registration of the scanned data for a surface and the target surface, the ICP (Iterative Closest Points) method was adopted. A computer program was developed to carry out the registration, check for similarities, visualize the surface, and control the results. This program was applied to a sample curved plate forming process.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.6
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• pp.586-595
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• 2022

In this paper, we propose a formation control algorithm for multi-USVs according to COLREGs. First, we applied the Dynamic Window Approach algorithm that can reflect the kinematic characteristics for the path movement of USVs. Then, we propose a virtual structure-based virtual leader-follower method that applies the advantages of leader-follower and virtual structure methods among conventional formation control algorithms for stability. Next, we proposed a collision avoidance algorithm according to all COLREGs when encountering an opposing ship by adding COLREGs situational conditions to the virtual leader, and finally confirmed the feasibility of the proposed method through simulation.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.1
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• pp.65-71
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• 2011

Since 2003, policies and practices related to the reduction of CO₂ gas emission from ships has been discussing by the International Maritime Organization. The representative emission index and indicator are the EEDI (Energy Efficiency Design Index) for the new ships and EEOI (Energy Efficiency Operational Indicator) during the voyage. For the CO₂ emission monitoring system, the SEEMP (Ship Energy Efficiency Management Plan) is also on the table. This global preparations to reduce theCO₂ emission is not except for the surface transportation. This research report elucidates the recent stream on the IMO CO₂ emission from ship and detail explanation on the EEDI and EEOI.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4381-4387
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• 2015

Ship hull is a compound curved shape and most of shipyards have been using gas heating method for the surface forming of steel plate. This traditional forming process have problems such as difficulties in heat input control and poor working conditions due to loud noise and air contamination. Recently, researches on automatic hull forming system have been conducted using high frequency induction heating method which have good control ability and favorable working environment. In this study, the induction heating simulation system for curved surface forming of steel plate was developed and induction heating experiments were performed. Based on the results of this study, efficient induction heating coil design and optimal heating conditions for the automatic hull forming system can be obtained.

• Journal of IKEEE
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• v.27 no.3
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• pp.225-233
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• 2023

This paper implements a system that monitors human body lifting information in the event of a marine accident. The monitoring system performs ultrasonic communication through a lifting device controller that transmits underwater environment information, and LoRa communication is performed on the water to provide GPS information within 10 km to the control center or mother ship. The underwater lifting controller transmits pneumatic sensor, gyro sensor, and temperature sensor information. In an environment where the underwater conditions increase by one atmosphere of water pressure every 10m in depth, and the amount of air in the instrument decreases by half compared to land, a model of a 60kg underwater mannequin is used. Using one 38g CO2 cartridge in the lifting appliance SMB(Surface Maker Buoy), carry out a lifting appliance discharge test based on the water level rise conditions within 10 sec. Underwater communication constitutes a data transmission environment using a 2,400-bps ultrasonic sensor from a depth of 40m to 100m. The monitoring signal aims to ensure the safety and safe human structure of the salvage worker by providing water depth, water temperature, and directional angle to rescue workers on the surface of the water.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.2
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• pp.123-130
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• 2016

With the development of fast construction mode in shipbuilding market, the demand on accuracy management of hull is becoming higher and higher in shipbuilding industry. In order to enhance production efficiency and reduce manufacturing cycle time in shipbuilding industry, it is important for shipyards to have the accuracy of ship components evaluated efficiently during the whole manufacturing cycle time. In accurate shipbuilding process, block accuracy is the key part, which has significant meaning in shortening the period of shipbuilding process, decreasing cost and improving the quality of ship. The key of block accuracy control is to create a integrate block accuracy controlling system, which makes great sense in implementing comprehensive accuracy controlling, increasing block accuracy, standardization of proceeding of accuracy controlling, realizing "zero-defect transferring" and advancing non-allowance shipbuilding. Generally, managers of accuracy control measure the vital points at section surface of block by using the heavy total station, which is inconvenient and time-consuming for measurement of vital points. In this paper, a new measurement method based on point clouds technique has been proposed. This method is to measure the 3D coordinates values of vital points at section surface of block by using 3D scanner, and then compare the measured point with design point based on ICP algorithm which has an allowable error check process that makes sure that whether or not the error between design point and measured point is within the margin of error.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.58-59
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• 2017

Through the case study, we surveyed the performance of a CNC-T BAR system on irregular-shaped building construction project. By CNC T-BAR system, we mean a surface curvature control system has been used in aircraft and ship manufacturing by controlling entire surface points on shape. For the past 10 year, the number of irregularly-shaped building design and construction project has been increased, and also the studies on irregular-shaped construction methods have been conducted. However, the previous studies did not review on the performance of the CNC T-BAR system. We collected construction-completed cases in Korea, which applied the CNC T-BAR system, and we studied its performance by comparing with a segment system in terms of construction duration and its quality. The result shows that the CNC T-BAR system can shorten the construction duration comparing with segment-assembly system while maintaining high quality. The CNC T-BAR system is expected to apply on the more number of irregularly-shape building construction project.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.671-676
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• 2001

This study are development results of solar hot water system for anchovy proceeding. The heat amounts of boiling vessel are calculated 292.66W at forward and backward direction, and surface direction are calculated 373.14W. The polyenoic rate of anchovy are measured lower as high temperature, but monoenoic and polyacid are higher. Then the others. The maximum radiation of anchovy fishing grounds are shown $350kcal/m^2h$ at pm. 13:00, Chungdo in CHINA. Distributions of Velocity and temperature in boiling vessel are calculation. Solar collector and boiling vessel for anchovy proceeding ship are developed to automatic control system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.05a
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• pp.149-152
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• 2001

선박이 해상에서 운항시, 선체는 파도에 의해 심하게 동요되기 때문에 승선감과 안전성이 저하된다. 따라서 선박의 안전항해, 쾌적한 승선감, 구조적인 안전 보장을 위한 선체제어를 위한 필요성이 증대되어 왔다. 기존의 PID 제어기법 등은 정상편차가 적어 과도응답의 문제점 및 오차누적의 문제점이 있고, 퍼지제어 기법은 최적화가 어렵다는 단점을 가진다. 본 논문에서는 퍼지추론 기법을 이용한 선체자세 제어기법으로 운동체에 관한 전문가의 지식과 경험을 바탕으로 퍼지집합과 퍼지규칙을 설정하고 설계된 퍼지 추론을 통해 현재의 운동상황을 판단함으로써 효과적인 최적화와 자세계산을 수행할 수 있다. 본 논문에서는 퍼지추론을 이용한 자세제어 알고리즘을 제안하고 실시간 시뮬레이션을 통하여 시험한다.

• Journal of the Korean Society of Visualization
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• v.19 no.2
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• pp.48-55
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• 2021

In order to design a propeller with high efficiency and excellent cavitation performance, theoretical and experimental studies on the cavitation and noise characteristics according to the blade section shape are essential. In general, sheet cavitation, bubble cavitation, and cloud cavitation are the main causes of hull vibration and propeller surface erosion. However vortex cavitation, which has the greatest influence on the noise level because the fastest CIS in ship propeller, has been researched for a long time and studies have been conducted recently to control it. In this experiment, the development process of cavitation was measured by using three dimensional wings with two different wing section and wing tip shapes, and the noise level at that time was evaluated. In addition, we evaluated the relationship between cavitation inception and hydrodynamic force using three component load cell and we measured the velocity field of wing wake using LDV.