• 한국산학기술학회논문지
• /
• 제14권9호
• /
• pp.4507-4513
• /
• 2013

수중사석고르기와 같은 수중공사작업을 수행하기 위하여 개발 진행 중인 무인수중장비를 수중공사현장에 투입할 경우, 작업 시 발행하는 부유물들로 인하여 탁도가 높아진다. 이러한 수중환경에서 광학카메라를 이용할 경우, 수중전방인식이 불가능할 수 있다. 이를 극복하기 위하여 무인수중장비에 소나를 탑재하고자 한다. 소나를 무인수중 장비에 적용하기에 앞서, 본 연구에서는 소나의 분해능, 탁도가 높은 물 속에서 스캐닝한 소나이미지를 확인하여 장비의 성능을 분석하였다. 그리고 수중공사현장의 경계면을 표시하기 위한 방법을 제안하였다. 이를 통하여 무인수중 장비에 적용하기 위한 소나의 기초 성능을 확인하였다.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제3권3호
• /
• pp.174-180
• /
• 2011

This paper shows added mass and inertia can be acquired from the pure heaving motion and pure pitching motion respectively. A Vertical Planar Motion Mechanism (VPMM) test for the spheroid-type Unmanned Underwater Vehicle (UUV) was compared with a theoretical calculation and Computational Fluid Dynamics (CFD) analysis in this paper. The VPMM test has been carried out at a towing tank with specially manufactured equipment. The linear equations of motion on the vertical plane were considered for theoretical calculation, and CFD results were obtained by commercial CFD package. The VPMM test results show good agreement with theoretical calculations and the CFD results, so that the applicability of the VPMM equipment for an underwater vehicle can be verified with a sufficient accuracy.

• 한국산학기술학회논문지
• /
• 제17권5호
• /
• pp.372-378
• /
• 2016

항만 구조물인 케이슨 및 블록 등을 수중에 거치하기 위해서는 기초사석을 투하하고 이 위에 구조물을 설치한다. 이때 기초 사석은 상구구조물을 지지하기 위한 기초 토대로서 사석의 규격, 비중, 중량 모양 및 치수 등이 균일하고 치밀하여야 하며 선정시험을 통과한 사석만을 사용하여 시공하야 한다. 또한 이러한 기초 사석을 고르게 만들어 주는 작업 구조물의 거치 이전에 반드시 이루어 져야 한다. 본 연구에서는 수중 고르기 작업 공정의 무인화를 위하여 수중 고르기 및 굴삭용 무인기계 뿐만 아니라 무인기계화 시공을 위한 원격제어용 운영시스템, 수중 물체 인식 및 수중위치 분석을 위한 수중 환경 모니터링 시스템이 개발되었다. 본 장비는 육상 및 수중 테스트를 통하여 검증을 완료 하여 우수한 성능을 확인하였다. 그러나 현장에 본 장비를 투입하기 위해서는 성능뿐만 아니라 건설 공정의 제안 및 분석 그리고 효율(경제성)이 분석되어야 한다. 본 연구에서는 수중고르기장비의 성능 및 기능, 건설공정절차, 기존의 공법과의 비교 분석하였다. 분석결과 기존의 잠수부를 투입하는 건설공법에 비하여 경제성, 효율성, 안전성이 향상되는 것으로 확인되었다.

• International Journal of Ocean System Engineering
• /
• 제1권4호
• /
• pp.192-197
• /
• 2011

This paper describes the mathematical modeling, control algorithm, system design, hardware implementation and experimental test of a Manta-type Unmanned Underwater Vehicle (MUUV). The vehicle has one thruster for longitudinal propulsion, one rudder for heading angle control and two elevators for depth control. It is equipped with a pressure sensor for measuring water depth and Doppler Velocity Log for measuring position and angle. The vehicle is controlled by an on-board PC, which runs with the Windows XP operating system. The dynamic model of 6DOF is derived including the hydrodynamic forces and moments acting on the vehicle, while the hydrodynamic coefficients related to the forces and moments are obtained from experiments or estimated numerically. We also utilized the values obtained from PMM (Planar Motion Mechanism) tests found in the previous publications for numerical simulations. Various controllers such as PID, Sliding mode, Fuzzy and $H{\infty}$ are designed for depth and heading angle control in order to compare the performance of each controller based on simulation. In addition, experimental tests are carried out in a towing tank for depth keeping and heading angle tracking.

• 한국해양공학회지
• /
• 제20권3호
• /
• pp.7-14
• /
• 2006

This paper discusses the structural design and analysis of a 6,000 meters depth-rated capable deep-sea unmanned underwater vehicle (UUV) system. The UUV system is currently under development by Maritime and Ocean Engineering Research Institute(MOERI), Korea Ocean Research and Development Institute (KORDI). The UUV system is composed of three vehicles - a Remotely Operated Vehicle (ROV), an Autonomous Underwater Vehicle (AUV) and a Launcher - which include underwater equipment. The dry weight of the system exceeds 3 tons hence it is necessary to carry out the optimal design of structural system to ensure the minimum weight and sufficient space within the frame for the convenient use of the embedded equipments. In this paper, therefore, the structural design and analysis of the ROV and launcher frame system were carried out, using the optimizing process. The cylindrical pressure vessels for the ROV were designed to resist the extreme pressure of 600 bars, based on the finite element analysis. The collapse pressure for the cylindrical pressure vessels was also checked through a theoretical analysis.

• 한국산업융합학회 논문집
• /
• 제26권4_2호
• /
• pp.697-703
• /
• 2023

Intertidal zones, akin to tidal flats, are among the potential areas where underwater cultural heritage might be submerged. However, the shallow depths in these regions present challenges for conventional vessel-based survey methods. Moreover, during low tides, intertidal zones transform into tidal flats, limiting the efficiency of survey efforts due to restricted access and potential risks. As a result, proper underwater cultural heritage surveys encounter difficulties in these environments. In recent times, extensive research is underway to address these issues by investigating underwater cultural heritage surveys in intertidal zones, encompassing diverse fields, including equipment-based investigations. This study aimed to explore the feasibility of utilizing unmanned aerial vehicles (UAVs) to conduct intertidal cultural heritage surveys, employing aerial photography and 3D mapping to create detailed orthoimages and 3D models. The study focused on assessing the potential application of these techniques for cultural heritage surveying within intertidal zones. Notably, the survey conducted in Jindo's Naesan-ri demonstrated high-resolution capabilities, enabling the distinction of actual pottery fragments mixed within gravel fields. Similarly, in the survey of Jindo's Byeokpa-hang, it was found that a wooden pillar structure existed in a section about 200m long. The integration of various sensors, including LiDAR, with UAVs allows for diverse investigation possibilities, including bathymetric measurements, and is expected to facilitate the acquisition of varied datasets for further research and assessment.

• International Journal of Ocean System Engineering
• /
• 제2권4호
• /
• pp.223-232
• /
• 2012

For the accurate estimation of the position and orientation of a UUV (unmanned underwater vehicle), a low-cost AHRS (attitude heading reference system) was developed using a low-cost IMU (inertial measurement unit) sensor which provides information on the 3D acceleration, 3D turning rate and 3D earth-magnetic field data in the object coordinate system. The main hardware system is composed of an IMU sensor (ADIS16405) and TMS320F28335, which is coded with an extended kalman filter algorithm with a 50-Hz sampling frequency. Through an experimental gimbal device, good estimation performance for the pitch, roll, and yaw angles of the developed AHRS was verified by comparing to those of a commercial AHRS called the MTi system. The experimental results are here presented and analyzed.

• 한국수산과학회지
• /
• 제23권6호
• /
• pp.451-456
• /
• 1990

Underwater acoustic navigation and position fixing systems have been extensively used not only in surface position fixing but also in underwater position fixing. Tn recently, application of these systems has been in the field of underwater inspection of offshore platforms, where it is vital to track the position of an unmanned submersible or diver carrying underwater cameras and nondestructive testing equipment. But these systems are included the fixing errors as results of a signal with additive noise, the attenuation of sound and the interference effects due to multipath reflection and forward scattering. In this paper to improve the position fixing by the supershort baseline acoustic position system, a method to apply the Kalman filter to the fix of the system is proposed and the digital simulation under noise condition is conducted. The optimal positions by the Kalman filter are compared with original positions, and it is confirmed that the results of the pro-posed method are evidently more accurate.

• 로봇학회논문지
• /
• 제18권4호
• /
• pp.472-480
• /
• 2023

This paper describes the development of a test-equipment for the pre-verification of navigation performance in cluster-based AUVs (Autonomous Underwater Vehicle). In the development of an AUV, conducting hardware and software development sequentially is not efficient due to the limited research and development period. Therefore, in order to reduce the overall development time and achieve successful development results, it is essential to pre-validate the navigation system and navigation algorithms. Accordingly, this paper explains the test-equipment for pre-verification of navigation performance, and ultimately confirms the stability of the navigation system and the performance of the navigation algorithms through the analysis of five types of navigation sensor data stored during real-sea experiments. The results demonstrate that through the development and verification of the test-equipment, it is possible to shorten the overall development period and improvement of product quality in the process of developing multiple AUVs.

• 한국항해항만학회지
• /
• 제35권5호
• /
• pp.359-363
• /
• 2011

본 연구에서는 만타 형상을 가진 무인잠수정(Manta-type unmanned underwater test vehicle)의 제어 성능 평가를 수행 하였다. 제어 방법으로서 PID제어, Fuzzy 제어가 적용되었으며, 6자유도 운동 수학모델과 Matlab Simulink을 이용하여 조종 운동 시뮬레이션을 수행하였다. 또한, 설계된 제어기로 수심제어 및 방위제어에 적용하여, 조류의 외란 하에서 제어 성능을 평가하였다.