• Journal of Institute of Control, Robotics and Systems
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• v.16 no.6
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• pp.592-600
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• 2010

The problem of motion control for AUV (Autonomous Underwater Vehicles) is addressed. The utilization of such robotic vehicles has gained an increasing importance in many marine activities. In this paper the objective is to describe how to design and apply FGS (Fuzzy Gain Scheduling) PD (Proportional Derivative) controller for an AUV (Autonomous Underwater Vehicle) to control the yaw and depth of the vehicle by keeping the path of the navigation to a desired point, and/or changing the path according to a set point.

• International Journal of Ocean System Engineering
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• v.3 no.4
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• pp.218-224
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• 2013

This paper describes the design and control of a hovering AUV test-bed and analyzes the dynamic performance of the vehicle using simulation programs. The main purpose of this vehicle is to carry out fundamental tests of its station keeping, attitude control, and desired position tracking. Its configuration is similar to the general appearance of an ROV for underwater operations, and its dimensions are $0.75m{\times}0.5m{\times}0.5m$. It has four 450-W thrusters for longitudinal/lateral/vertical propulsion and is equipped with a pressure sensor for measuring the water depth and a magnetic compass for measuring its heading angle. The navigation of the vehicle is controlled by an onboard Pentium III-class computer, which runs with the help of the Windows XP operating system. This provides an appropriate environment for developing the various algorithms needed for developing and advancing a hovering AUV.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.38-46
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• 2000

In this paper, robust depth and course controllers of AUV(autonomous underwater vehicles) using LMI-based H$_{\infty}$ servo control are proposed. The $H_{\infty}$ servo problem is modified to an $H_{\infty}$ control problem for the generalized plant that includes a reference input mode, and then a sub-optimal solution that satisfies a given performance criteria is calculated by LMI(Linear Matrix Inequality) approach. The robust depth and course controllers are designed to be satisfied the robust stability about the modeling error generated from the perturbation of the hydrodynamic coefficients and the robust tracking property under sea wave and tide disturbances. The performances of the designed controllers are evaluated by computer simulations, and these simulation results show the applicability of the proposed robust depth and course controller.

• Journal of Ocean Engineering and Technology
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• v.29 no.5
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• pp.392-397
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• 2015

An autonomous underwater vehicle (AUV) can perform flexible operations even in complex underwater environments because of its autonomy. Localization is one of the key components of this autonomous navigation. Because the inertial navigation system of an AUV suffers from drift, observing fixed objects in an inertial reference system can enhance the localization performance. In this paper, we propose a method of AUV localization using visual measurements of underwater structures. A camera measurement model that emulates the camera’s observations of underwater structures is designed in a particle filtering framework. Then, the particle weight is updated based on the extracted visual information of the underwater structures. The proposed method is validated based on the results of experiments performed in a structured basin environment.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.12
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• pp.1266-1272
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• 2011

For way-point tracking of an autonomous underwater vehicle, a state feedback controller was designed by using pole placement scheme in discrete time domain. In the controller, 4 state variables were used for regulating the depth of the vehicle in z direction, and 3 state variables, for steering the vehicle in xy plane. Assuming constant speed of AUV, we simplified the design of the way-point tracking system. The proposed controller was simulated by MATLAB/Simulink using 6 degree-of-freedom nonlinear model and its performance of way point tracking was shown to be fulfilled within 1 m, nevertheless the proposed controller is quite simple and easy to implement compared to sliding mode controller.

• Journal of Ocean Engineering and Technology
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• v.21 no.3 s.76
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• pp.33-39
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• 2007

The more deeply the researches make progress in ocean researches including the seabed resource investigation or the oceanic ecosystem investigation, the more important the role of UUV gets. In case of study on the deep sea, there are difficulties in telecommunications between AUV and ships, and in data communication and recharging. Therefore, docking is required. In AUV docking system, the AUV should identify the position of docking device and make contact with a certain point of docking device. MOERI (Maritime & Ocean Engineering Research Institute), KORDI has conducted the docking testing on AUV ISIMI in KORDI ocean engineering water tank. As AUV ISIMI approachs the docking device, there is some cases of showing an unstable attitude, because the lights which is on Image Frame are disappeared. So we propose the docking algorithm that is fixing the rudder and stem, if the lights on image frame are reaching the specific area in the Image Frame. Also we propose the new docking device, which has a variety of position and light number. In this paper, we intend to solve the some cases of showing an unstable attitude that were found in the testing, which, first, will be identified the validity via simulation.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.335-338
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• 2006

The more deeply the researches make progress in ocean researches including the seabed resource investigation or the oceanic ecosystem investigation, the more important the role of UUV gets. In case of study on the deep sea, there are difficulties in telecommunications between AUV and ships, and in data communication and recharging. Therefore, docking is required. In AUV docking system, the AUV should identify the position of docking and make contact with a certain point of docking device. MOERI (Maritime & Ocean Engineering Research Institute), KORDI has conducted the docking testing on AUV ISIMI in KORDI Ocean Engineering Water Tank. As AUV ISIMI approachs the docking device, it is presented that attitude is unstable, because the lights Which is on Image Frame are disappeared. So we fix the rudder and stem, if the lights on Image Frame are reaching the specific area in the Image Frame. In this paper, we intend to solve the problems that were found in the testing, which, first, will be identified via simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.213-216
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• 2007

The paper deals with a approach to underwater acoustic based Ad-hoc communication, which allows major design strategies for Media Access Control (MAC) within a group of the autonomous underwater vehicles(AUV). The proposed MAC aims at deploying AUV-centric star topology, which minimizes overhead of sensor nodes and improves energy-efficiency. Furthermore, that is also well under long and unknown propagation delays of the underwater acoustic medium. The implemented MAC protocol makes it easier to achieve frame synchronization than TDMA due to deploying localized schedule time, in addition to saving energy consumption by letting nodes sleep. It is also superior to MACA and MACAW in terms of propagation delay. This scalable centralized protocol has the potential to serve as a primer for development of MAC protocol for future underwater acoustic based ad-hoc networks.

• Journal of Advanced Navigation Technology
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• v.23 no.2
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• pp.125-133
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• 2019

In this paper, a new study was performed on the docking of AUV to docking station using light and light sensor system under the water. For this, a guiding system for AUV loading sensor system composed of lense, light sensor, signal processor, and processor and docking system with LED are proposed. An analysis on light sensor system and light-collecting lense to obtain accurate relative angle and measurement accuracy was performed. To prove this, the system was built and a basic experiment was performed. Finally, the feasibility of the developed docking system was verified the test in the water tank.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1027-1028
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• 2010