• 제목/요약/키워드: underwater positioning system

검색결과 47건 처리시간 0.023초

어군행동 원격감시 시스템의 개발에 관한 연구 ( 1 ) - 하드웨어와 소프트웨어 - ( Development of the Underwater Telemetry System to Monitor the Behavior of Fish ( 1 ) - Hardware and Software - )

  • 신형일
    • 수산해양기술연구
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    • 제30권4호
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    • pp.263-272
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    • 1994
  • The hardware and the software of the prototype telemtry system to monitor the behavior of the fish are designed. This system consistes of five parts I. e. three omni-directional hydrophones, three ultrasonic receivers, a single board computer for the signal processing, two RF transceivers for the data communication, and a personnel computer. The sensitivty of the hydrophones is -170dB(re 1V/$\mu$Pa), the gain and the 3dB receiving bandwidth of the ultrasonic receivers are 115dB and 1500Hz respectively, and the sampling period is 33.3$\mu$sec in the signal processing part. The positioning error of the system using hyperbolic method is estimated to be less than 0.2m in case that the pinger locates inside of the baselines. The perfomance of the system considering a practical use was examined by numerical simulation and a water tank test of a pinger tracking experiment. In results, the system developed in prototype was confirmed that it could be useful for monitoring the behavior of fish in the limited water area.

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An In-situ Correction Method of Position Error for an Autonomous Underwater Vehicle Surveying the Sea Floor

  • Lee, Pan-Mook;Jun, Bong-Huan;Park, Jin-Yeong;Shim, Hyung-Won;Kim, Jae-Soo;Jung, Hun-Sang;Yoon, Ji-Young
    • International Journal of Ocean System Engineering
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    • 제1권2호
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    • pp.60-67
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    • 2011
  • This paper presents an in-situ correction method to compensate for the position error of an autonomous underwater vehicle (AUV) near the sea floor. AUVs generally have an inertial navigation system assisted with auxiliary navigational sensors. Since the inertial navigation system shows drift in position without the bottom reflection of a Doppler velocity log, external acoustic positioning systems, such as an ultra short baseline (USBL), are needed to set the position without surfacing the AUV. The main concept of the correction method is as follows: when the AUV arrives near the sea floor, the vehicle moves around horizontally in a circular mode, while the USBL transceiver installed on a surface vessel measures the AUV's position. After acquiring one data set, a least-square curve fitting method is adopted to find the center of the AUV's circular motion, which is transferred to the AUV via an acoustic telemetry modem (ATM). The proposed method is robust for the outlier of USBL, and it is independent of the time delay for the data transfer of the USBL position with the ATM. The proposed method also reduces the intrinsic position error of the USBL, and is applicable to the in-situ calibration as well as the initialization of the AUVs' position. Monte Carlo simulation was conducted to verify the effectiveness of the method.

해저 지형 정보를 이용한 다중 상태 소나의 표적 위치 측정 (Target Localization Using Underwater Objects in Multistatic Sonar)

  • 이광희;서익수;한동석
    • 전자공학회논문지
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    • 제51권2호
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    • pp.141-147
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    • 2014
  • 본 논문에서는 사전에 알고 있는 해저 지형정보를 이용하여 송수신기의 위치와 해저 음속의 정확성을 향상시켜 탐지 범위에 따른 오차에 강인한 위치 측정 알고리듬과 최적의 수신기 개수를 제안하고자 한다. 송수신기 위치, 음속정보의 정확도는 표적 위치 측정의 성능에 영향을 미치며, 송수신기는 GPS를 통해 위치 정보를 얻는다. 그러나 GPS 오차에 의해 여전히 오차를 가지고 있으며, 음속 정보는 수온을 포함한 다양한 요인들에 의해 영향을 받는다. 먼저 송수신기 위치 오차, 음속 오차의 영향을 수학적으로 분석하고 해저 지형 정보를 이용하여 오차를 줄일 수 있는 방법을 확인한다. 컴퓨터 모의실험을 통하여 기존의 알고리듬과 제안된 기법의 성능을 비교 평가하고, 탐지 범위에 따른 최적의 수신기 개수를 확인한다.

Low energy ultrasonic single beacon localization for testing of scaled model vehicle

  • Dubey, Awanish C.;Subramanian, V. Anantha;Kumar, V. Jagadeesh
    • Ocean Systems Engineering
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    • 제9권4호
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    • pp.391-407
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    • 2019
  • Tracking the location (position) of a surface or underwater marine vehicle is important as part of guidance and navigation. While the Global Positioning System (GPS) works well in an open sea environment but its use is limited whenever testing scaled-down models of such vehicles in the laboratory environment. This paper presents the design, development and implementation of a low energy ultrasonic augmented single beacon-based localization technique suitable for such requirements. The strategy consists of applying Extended Kalman Filter (EKF) to achieve location tracking from basic dynamic distance measurements of the moving model from a fixed beacon, while on-board motion sensor measures heading angle and velocity. Iterative application of the Extended Kalman Filter yields x and y co-ordinate positions of the moving model. Tests performed on a free-running ship model in a wave basin facility of dimension 30 m by 30 m by 3 m water depth validate the proposed model. The test results show quick convergence with an error of few centimeters in the estimated position of the ship model. The proposed technique has application in the real field scenario by replacing the ultrasonic sensor with industrial grade long range acoustic modem. As compared with the existing systems such as LBL, SBL, USBL and others localization techniques, the proposed technique can save deployment cost and also cut the cost on number of acoustic modems involved.

A New Approach to the Design of An Adaptive Fuzzy Sliding Mode Controller

  • Lakhekar, Girish Vithalrao
    • International Journal of Ocean System Engineering
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    • 제3권2호
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    • pp.50-60
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    • 2013
  • This paper presents a novel approach to the design of an adaptive fuzzy sliding mode controller for depth control of an autonomous underwater vehicle (AUV). So far, AUV's dynamics are highly nonlinear and the hydrodynamic coefficients of the vehicles are difficult to estimate, because of the variations of these coefficients with different operating conditions. These kinds of difficulties cause modeling inaccuracies of AUV's dynamics. Hence, we propose an adaptive fuzzy sliding mode control with novel fuzzy adaptation technique for regulating vertical positioning in presence of parametric uncertainty and disturbances. In this approach, two fuzzy approximator are employed in such a way that slope of the linear sliding surface is updated by first fuzzy approximator, to shape tracking error dynamics in the sliding regime, while second fuzzy approximator change the supports of the output fuzzy membership function in the defuzzification inference module of fuzzy sliding mode control (FSMC) algorithm. Simulation results shows that, the reaching time and tracking error in the approaching phase can be significantly reduced with chattering problem can also be eliminated. The effectiveness of proposed control strategy and its advantages are indicated in comparison with conventional sliding mode control FSMC technique.

심해무인잠수정 해미래의 고도정보 추정을 위한 다중센서융합 알고리즘 (Multiple Sensor Fusion Algorithm for the Altitude Estimation of Deep-Sea UUV, HEMIRE)

  • 김덕진;김기훈;이판묵;조성권;박연식
    • 한국정보통신학회논문지
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    • 제12권7호
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    • pp.1202-1208
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    • 2008
  • 본 논문에서는 유삭식 심해무인잠수정인 해미래와 진수장치인 해누비로 이루어지는 심해무인잠수정 시스템의 항법 알고리즘에 사용되는 다중 센서 융합 기법에 대하여 소개하고 있다. 수중 위치 추적 시스템의 성능은 초단기선, 장기선, 고도계와 같은 수중 음향 센서의 성능에 의해 결정되는데 수중음향 신호는 다양한 형태의 노이즈를 가지고 있어 특별한 주의가 요망된다. 본 논문에서는 이동 관측창 개념을 이용한 실용적인 다중 센서 융합 알고리즘을 제안하였다. 해미래의 동해 실해역 시험을 통해 획득된 계측치에 본 알고리즘을 적용하여 그 성능을 고찰한 결과 우수한 성능을 보임을 알 수 있었다.

Study for Operation Method of Underwater Cable and Pipeline Burying ROV Trencher using Barge and Its Application in Real Construction

  • Kim, Min-Gyu;Kang, Hyungjoo;Lee, Mun-Jik;Cho, Gun Rae;Li, Ji-Hong;Yoon, Tae-Sagm;Ju, Jaeheung;Kwak, Han-Wan
    • 한국해양공학회지
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    • 제34권5호
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    • pp.361-370
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    • 2020
  • We developed a heavy-duty work class ROV trencher named URI-T (Underwater robot it's trencher) that can conduct burial and maintenance tasks for underwater cables and small diameter pipelines. It requires various supporting systems, including a dynamic positioning (DP) vessel, launch and recovery system (LARS), A-frame, and winch in order to perform burial tasks because of its dimensions (6.5 m × 5.0 m × 4.5 m, 20 t) and the tough working environment. However, operating a DP vessel has disadvantages as it is expensive to rent and operate and it is difficult to adjust the working schedule for some domestic coast construction cases. In this paper, we propose a method using a barge instead of a DP vessel to avoid the above disadvantages. Although burying the cable and pipeline using a barge has lower working efficiency than a DP vessel, it can save construction expenses and does not require a large crew. The proposed method was applied over two months at the construction of the water supply in Yokji-do, and the results were verified.

Interactive Navigational Structures

  • Czaplewski, Krzysztof;Wisniewski, Zbigniew
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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    • pp.495-500
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    • 2006
  • Satellite systems for objects positioning appeared indispensable for performing basic tasks of maritime navigation. Navigation, understood as safe and effective conducting a vehicle from one point to another, within a specific physical-geographical environment. [Kopacz, $Urba{\acute{n}}ski$, 1998]. However, the systems have not solved the problem of accessibility to reliable and highly accurate information about a position of an object, especially if surveyed toward on-shore navigational signs or in sea depth. And it's of considerable significance for many navigational tasks, carried out within the frameworks of special works performance and submarine navigation. In addition, positioning precisely the objects other than vessels, while executing hydrographical works, is not always possible with a use of any satellite system. Difficulties with GPS application show up also while positioning such off-lying dangers as wrecks, underwater and aquatic rocks also other naturaland artificial obstacles. It is caused by impossibility of surveyors approaching directly any such object while its positioning. Moreover, determination of vessels positions mutually (mutual geometrical relations) by teams carrying out one common tasks at sea, demands applying the navigational techniques other than the satellite ones. Vessels'staying precisely on specified positions is of special importance in, among the others, the cases as follows: - surveying vessels while carrying out bathymetric works, wire dragging; - special tasks watercraft in course of carrying out scientific research, sea bottom exploration etc. The problems are essential for maritime economy and the Country defence readiness. Resolving them requires applying not only the satellite navigation methods, but also the terrestrial ones. The condition for implementation of the geo-navigation methods is at present the methods development both: in aspects of their techniques and technologies as well as survey data evaluation. Now, the classical geo-navigation comprises procedures, which meet out-of-date accuracy standards. To enable meeting the present-day requirements, the methods should refer to well-recognised and still developed methods of contemporary geodesy. Moreover, in a time of computerization and automation of calculating, it is feasible to create also such software, which could be applied in the integrated navigational systems, allowing carrying out navigation, provided with combinatory systems as well as with the new positioning methods. Whereas, as regards data evaluation, there should be applied the most advanced achievements in that subject; first of all the newest, although theoretically well-recognised estimation methods, including estimation [Hampel et al. 1986; $Wi{\acute{s}}niewski$ 2005; Yang 1997; Yang et al. 1999]. Such approach to the problem consisting in positioning a vehicle in motion and solid objects under observation enables an opportunity of creating dynamic and interactive navigational structures. The main subject of the theoretical suggested in this paper is the Interactive Navigational Structure. In this paper, the Structure will stand for the existing navigational signs systems, any observed solid objects and also vehicles, carrying out navigation (submarines inclusive), which, owing to mutual dependencies, (geometrical and physical) allow to determine coordinates of this new Structure's elements and to correct the already known coordinates of other elements.

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실해역 환경에서 무인 잠수정의 초기 상태 정렬을 위한 GPS와 관성 항법 센서 기반 항법 정렬 알고리즘 (GPS and Inertial Sensor-based Navigation Alignment Algorithm for Initial State Alignment of AUV in Real Sea)

  • 김규현;이지홍;이필엽;김호성;이한솔
    • 로봇학회논문지
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    • 제15권1호
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    • pp.16-23
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    • 2020
  • This paper describes an alignment algorithm that estimates the initial heading angle of AUVs (Autonomous Underwater Vehicle) for starting navigation in a sea area. In the basic dead reckoning system, the initial orientation of the vehicle is very important. In particular, the initial heading value is an essential factor in determining the performance of the entire navigation system. However, the heading angle of AUVs cannot be measured accurately because the DCS (Digital Compass) corrupted by surrounding magnetic field in pointing true north direction of the absolute global coordinate system (not the same to magnetic north direction). Therefore, we constructed an experimental constraint and designed an algorithm based on extended Kalman filter using only inertial navigation sensors and a GPS (Global Positioning System) receiver basically. The value of sensor covariance was selected by comparing the navigation results with the reference data. The proposed filter estimates the initial heading angle of AUVs for navigation in a sea area and reflects sampling characteristics of each sensor. Finally, we verify the performance of the filter through experiments.

다물체 연성효과를 고려한 부유체의 동적거동 안전성 해석 (Dynamic Analysis of Floating Bodies Considering Multi-body Interaction Effect)

  • 김영복;김무현;김용욱
    • 대한조선학회논문집
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    • 제46권6호
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    • pp.659-666
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    • 2009
  • Recently, there are several problems in space, contiguity and facility of the existing harbors issued due to the trend of enlarging the container capacity of the large container vessel, the Mobile Harbor has been proposed conceptually as an effective solution for those problems. This concept is a kind of transfer loader of the containers from the large container ship, which is a floating barge with a catamaran type in the underwater part, and so prompt maneuverability and work effectiveness. For the safe mooring of two floating bodies, a container and the mobile harbor, in the near sea apart from the quay, a robot arm mooring facility specially devised would be designed and verified through comparison study under various environmental sea condition in the inner and outer harbor. DP system (Dynamic Positioning System) using the azimuth thruster and a pneumatic fender, etc, will be considered as a next research topic for the mooring security of multi-body floaters.