• Journal of Advanced Marine Engineering and Technology
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• v.31 no.6
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• pp.784-790
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• 2007

This paper is mainly concerned with the development of the semi-autonomous underwater vehicle (SAUV). Underwater vehicles are affected by external disturbances due to the sea conditions such as currents and waves when it is performing various missions In this paper we present a design scheme of the SAUV system with mathematical models. Also. we present a control system including motion control of motors and main controller and a communication based on CAN method for interrelated control between the controllers and actuators.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.57-62
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• 2003

This paper describes the design and simulation of a multivariable optimal control system for the combined speed, heading and depth control of a Semi-Autonomous Underwater Vehicle (SAUV) developed in Korea Ocean Research and Development Institute (KRODI). The SAUV is a test-bed for the evaluation of the navigation and manipulator technologies developed for a mine disposal vehicle (MDV) in military use and for a light working underwater vehicle in scientific use. The vehicle was designed to control its cruising speed, heading and depth with 4 horizontal thrusters installed at the rear of the hull. Therefore, the decoupled control methods are limited to apply to the SAUV because the thrust forces are highly coupled with the surging, yawing, and pitching motion of the vehicle. The multivariable Linear Quadratic (LQ) control method is chosen to control steering and diving in variable speed motion automatically. A series of simulation is carried out with fully nonlinear six degree of freedom dynamic model to validate the controller.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.34-39
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• 2002

A Semi-Autonomous Underwater Vehicle (SAUV) capable of simple work at sea bed is under development in KRISO-KORDI. A pressure vessel of SAUV which is composed of FRP was manufactured to load electronic equipments. The objective of this paper is to verify the safety of the pressure vessel through conducting the structural analysis and test in pressure tank. Strain and stress under unit load were obtained by using ANSYS in the linear structural analysis. And local buckling analysis was performed with NASTRAN for the middle cylindrical hull. For the pressure test, strains were measured at three point. We found that the results by linear structural analysis and experiment are coincide well at the points where buckling does not occur. Maximum depth was estimated to be 250m by the local buckling analysis.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2685-2688
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• 2003

A PC-based system for both monitoring and controlling SAUV is developed. The developed system is located on a ship and communicate with the SAUV through optical link through which the system sends motion command and receives video data, SSBL and Digital I/O data. The motion command includes velocity data and direction data. The overall system is developed with the intention of easy operation for operator and safe motion of SAUV. The easy operation is realized by GUI-based interface and the safe motion is realized by fault tolerant capability.

• Journal of Ocean Engineering and Technology
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• v.18 no.4 s.59
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• pp.52-58
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• 2004

A Semi-Autonomous Underwater Vehicle (SAUV), capable of simple work on the seabed, is under development in KRISO-KORDI. This SAUV pressure vessel is composed of fiberglass reinforced plastic (FRP), and is also manufactured to carry electronic equipment. The objective of this paper is to describe the safety check for the pressure vessel. This is achieved fly conducting structural analysis and testing in a pressure tank. Strain and stress test results, under unit load, are obtained fly using ANSYS in linear structural analysis. Local buckling analysis are performed with NASTRAN at the middle oj the cylindrical hull. The first test, using linear structural analysis, is unsuccessful, as buckling occurred. During the second test, linear structural analysis, combined with local buckling analysis, is conducted. There is no buckling up to 250 m when both ANSYS and NASTRAN are used.

• The Magazine of the IEIE
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• v.38 no.7
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• pp.20-29
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• 2011

무인잠수정(Unmanned Underwater Vehicle, UUV)은 하드웨어 구성과 관련하여 ROV (Remotely Operated Vehicle), SAUV (Semi-Autonomous Underwater Vehicle), AUV (Autonomous Underwater Vehicle) 등으로 구분할 수 있으며, 그 중에서 자율무인잠수정(AUV)은 주어진 임무의 난이도, 작업 환경의 정보, 그리고 운용자의 간섭 정도에 따라 다양한 수준으로 자율 정도를 분류한다. 무인잠수정은 미국을 중심으로 1952년부터 개발되기 시작하였으며 최초는 전적으로 운용자에 의해서 직접 운용되는 ROV가 주를 이루었다. 자율무인잠수정은 1980년대부터 다양한 수중관련 기술 및 컴퓨터 발전과, 민군의 사용분야가 증가되면서 급속한 발전을 이루어 왔으며 이에 따라 AUV 자율수준 정의와 기술개발도 급속한 진전이 이루어져 왔다. 본 기고에서는 무인잠수정의 개발현황, 자율개념 및 자율수준(Autonomy Levels for Underwater Vehicle, ALFUV)의 정의, 자율을 정립함에 필요한 방법 또는 기술 등을 알아보고 마지막으로 자율 알고리즘으로 개발된 구조의 표준화를 중심으로 현황을 파악하였으며 또한 미래의 자율수준 개발 동향을 살펴보았다.

• Journal of Ocean Engineering and Technology
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• v.17 no.6
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• pp.83-90
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• 2003

This paper presents an underwater hybrid navigation system for a semi-autonomous underwater vehicle (SAUV). The navigation system consists of an inertial measurement unit (IMU), and a Doppler velocity log (DVL), accompanied by a magnetic compass. The errors of inertial measurement units increase with time, due to the bias errors of gyros and accelerometers. A navigational system model is derived, to include the scale effect and bias errors of the DVL, of which the state equation composed of the navigation states and sensor parameters is 20. The conventional extended Kalman filter was used to propagate the error covariance, update the measurement errors, and correct the state equation when the measurements are available. Simulation was performed with the 6-d.o,f equations of motion of SAUV, using a lawn-mowing survey mode. The hybrid underwater navigation system shows good tracking performance, by updating the error covariance and correcting the system's states with the measurement errors from a DVL, a magnetic compass, and a depth sensor. The error of the estimated position still slowly drifts in the horizontal plane, about 3.5m for 500 seconds, which could be eliminated with the help of additional USBL information.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.149-156
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• 2003

This paper presents an underwater hybrid navigation system for a semi-autonomous underwater vehicle (SAUV). The navigation system consists of an inertial measurement unit (IMU), an ultra-short baseline (USBL) acoustic navigation sensor and a doppler velocity log (DVL) accompanying a magnetic compass. The errors of inertial measurement units increase with time due to the bias errors of gyros and accelerometers. A navigational system model is derived to include the error model of the USBL acoustic navigation sensor and the scale effect and bias errors of the DVL, of which the state equation composed of the navigation states and sensor parameters is 25 in the order. The conventional extended Kalman filter was used to propagate the error covariance, update the measurement errors and correct the state equation when the measurements are available. Simulation was performed with the 6-d.o.f. equations of motion of SAUV in a lawn-mowing survey mode. The hybrid underwater navigation system shows good tracking performance by updating the error covariance and correcting the system's states with the measurement errors from a DVL, a magnetic compass and a depth senor. The error of the estimated position still slowly drifts in horizontal plane about 3.5m for 500 seconds, which could be eliminated with the help of additional USBL information.