• Proceedings of the Acoustical Society of Korea Conference
• /
• autumn
• /
• pp.197-200
• /
• 1999

수중작업자 상호간이나 수중작업자와 수상요원간에는 수중작업의 효율 및 안전을 위한 통신 시스템이 필수적이다. 본 연구에서는 국외의 무선수중전화기 개발현황을 살펴보고 무선수중전화기 설계에서 고려해야 할 수중음향통신 환경 전기음향변환기 및 통신방식 등을 분석, 소개하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.10
• /
• pp.678-684
• /
• 2016

The detection of an underwater work space boundary is very important when an underwater construction is carried out using seabed type underwater equipment, such as underwater machines for rubble mound leveling, because it can induce industrial disasters. Therefore, divers are needed to mark the underwater work space boundary. A nylon rope is used to improve the convenience during an underwater diver's work. The results showed that the work space boundary can be detected using a sonar system. Using these results, an efficient method to detect the underwater work space boundary can be obtained when an underwater construction is carried out using seabed type underwater equipment.

• Explosives and Blasting
• /
• v.25 no.2
• /
• pp.71-78
• /
• 2007

In many cases of underwater blasting in South Korea, the special blasting is mainly used for deepening harbor, installing gas pipes, or well blasting to build a bridge. The procedure of well blasting is almost same with shaft blasting, but the difference is that water is filled in before blasting. In case of deepening blasting under water, the first step like drilling, arranging explosives, and wire connection is done on a barge, then the next step such as charging and tamping is accomplished under water by expert divers. Therefore, underwater blasting needs precise and exact plan before blasting. In this paper, authors would like to introduce a case of underwater blasting for deepening the Busan new port with emulsion explosives and non-electric detonators in order to get some of 8,500TEU out sized container vessels entered into the port and to make safe. Considering environment and vibration, the blasting was controlled to minimized the damage to the lighthouse nearby. It will be great help to many other blasting sites where emulsion explosives and non-electric detonators are used for underwater blasting through this case.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.26 no.11
• /
• pp.1697-1705
• /
• 2022

The safety of marine construction workers and marine pollution problems are occurring due to large-scale offshore construction. In particular, underwater construction work in the sea has a higher risk than other work, so it is necessary to apply an unmanned alternative system that considers the safety of the workers. In this paper, the ROV system for offshore construction has been developed for underwater unmanned work. A monitoring system was developed for position control through the control of underwater propellants, pneumatic gripper, and monitoring of underwater work. As a result of the performance evaluation, the underwater movement speed of the ROV was evaluated to be 0.89 m/s, and it was confirmed that the maximum load of the pneumatic gripper was 80 kg. In addition, the network bandwidth required for underwater ROV control and underwater video streaming was evaluated to be more than 300Mbps, wired communication at 92.7 ~ 95.0Mbit/s at 205m, and wireless communication at 78.3 ~ 84.8Mbit/s.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.12
• /
• pp.8889-8895
• /
• 2015

It is necessary to secure the underwater visibility in order to perform underwater works such as rubble mound leveling or inspection and management of underwater structures. In this study, turbidity data for typical port area in Korea were measured and analyzed according to the region. Underwater monitoring system including underwater camera and sonar system, which can be effectively attached to underwater equipment for various turbidity conditions, was also investigated.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.06a
• /
• pp.9-10
• /
• 2012

This paper presents an observer to measure the lengths of cylinders of an underwater robot for harbour construction using a pressure sensor. In harbour constructing, we place heavy armour stones weighing over 2~3 tons on the surface of the bank to protect it from storming wave. This work typically done by a diver is difficult and dangerous so that we have developed Stone Diver which is the underwater robot for harbour construction. The robot needs a position sensor to control the hydraulic cylinder. The position sensors mounted outside the cylinders cause poor durability in construction site where shock and dust usually occur. However, the pressure sensor mounted inside a waterproof box improves the durability. Based on the dynamic parameters and the pressures in the cylinder, the observer measures the cylinder's position. This paper presents the positional accuracy of the pressure based observer and the performance of the underwater robot to assemble the armour stones.

• Journal of Navigation and Port Research
• /
• v.36 no.10
• /
• pp.865-871
• /
• 2012

This paper presents an observer to estimate the displacement of hydraulic cylinders of an underwater robot for harbour construction using a pressure sensor. In harbour constructing, we place heavy armour stones weighing over 2~3 tons on the surface of the bank to protect it from storming wave. This work typically done by a diver is difficult and dangerous so that we have developed Stone Diver which is the underwater robot for harbour construction. The robot needs a displacement sensors to control the position of hydraulic cylinders. The position sensors mounted outside the cylinders cause poor durability in construction site where shock and dust usually occur. However, the pressure sensor mounted inside a waterproof box improves the durability. Based on the dynamic parameters and the pressures in the cylinder, the observer estimates the cylinder's position. This paper presents the positional accuracy of the pressure based observer and the performance of the underwater robot to assemble the armour stones.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.9
• /
• pp.4507-4513
• /
• 2013

The developing unmanned underwater equipment can be used for underwater construction site such as underwater leveling works. If a optical camera is applied to the unmanned underwater equipment, recognition in underwater can be gone to low due to high turbidity in working field. To overcome this problem, a sonar will be installed to the unmanned underwater equipment. In this study, the resolution of the sonar and the quality test of the sonar image under high turbidity environment were conducted. And the method to indicate the boundary of the underwater construction site was proposed. By these results, the basic performance of the sonar was evaluated.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2000.10a
• /
• pp.48-49
• /
• 2000

잠수기 어업 등과 같은 수중 활동에서 대부분의 경우 수중과 수상 간에는 통신수단이 없거나 있어도 효율이 낮은 유선 전화기나 밧줄 등으로 의사 전달을 하고 있는 실정이다. 이에 작업의 효율성과 안전성 향상을 위하여 우리 해양 환경에 맞는 무선수중전화기 개발의 기술 자료로 활용하고자 본 연구를 수행하였다. (중략)

• Explosives and Blasting
• /
• v.31 no.1
• /
• pp.23-32
• /
• 2013

Construction vibration such as explosive blast, hydraulic breaker, vibratory roller, pile driving noise and so on, injuries in areas around the construction sites. In particular, underwater sound caused by ground vibration is propagation such as structure borne noise. Vibration and underwater sound due to construction activities may cause injury to river, sea or land fish farms near construction sites. The purpose of present study is to measure the sound pressure level and frequency analysis of the underwater noise generated by ground vibration(Blasting, hydraulic crawler drill, hydraulic breaker, vibratory roller). Underwater noise were monitoring by a hydrophone (TC 4013) and recorded, analysis were made using a by software (Prosig).