• The Journal of the Acoustical Society of Korea
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• v.26 no.1
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• pp.48-54
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• 2007

In this paper we have implemented a 3-D PL (Position Location) system to estimate the 3-dimensional position of a moving object in underwater environments. In this research, we let four sensors fixed in different Positions and moving sensorsto communicate with each other to find the 3-dementianal positions for both the fixed and moving objects. Using this we were also able to control the moving object remotely. When finding the position, we calculated the norm of the Jacobian matrix every iteration in the Newton algorithm. Also by using a different initial value for calculating the solution when the norm became higher than the critical value and the solution from the inverse matrix became unstable, we could find a more reliable position for the moving object. The proposed algorithm was used in implementing a DSP system capable of real-time position location. To verify the performance, experiments were done in a water tank. As a result we could see that our system could located the position of an object every 2 seconds with a error range of 5cm.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.32-44
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• 2015

In general, a series of ship steering motion is represented by the combination of translational motion and rotational motion of the ship. Especially, special-functioned ships such as large-scale cruises, ships for installing underwater optical cable, and diver ships must be able to reveal only a translational motion without the change of orientation. In this paper, a method to comprise an integrated control system based on the joystick as a command instrument for translational motion control is suggested. In order to realize the translational motion control system, several algorithms are suggested including the velocity command generation, the selection of motional variables, and the generation and tracking of reference inputs for the selected motional variables. A simulation bench is composed to execute simulations for several translational motion commands. At last, the effectiveness of the proposed method is verified by analyzing the simulation results.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.7
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• pp.1068-1079
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• 2008

Tilt and heading angles information of a remotely operated vehicle (ROV) are very important in underwater navigation. This paper presents a low.cost tilt and heading estimation system. Three single.axis rate gyros, a tri-axis accelerometer, and a tri-axis magnetometer are used. Output signals coming from these sensors are fused by two Kalman filters. The first Kalman filter is used to estimate roll and pitch angles and the other is for heading angle estimation. By using this method, we have obtained tilt (roll and pitch angles) and heading information which are reliable over long period of time. Results from experiments have shown the performance of the presented system.

• Journal of Ocean Engineering and Technology
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• v.7 no.1
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• pp.62-72
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• 1993

This paper describes the results of 3 years project on the design and development of a 500 meter class ocean survery ROV model. The design concept and the design procedure are given for each component of the ROV model. The design concept and the design procedure are given for each component of the ROV. Special emphasis is laid on the development of the position control system together with the development of the performance evaluation technique.

• Journal of Navigation and Port Research
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• v.30 no.4
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• pp.291-294
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• 2006

Corrosion is never avoided in the use rf materials with various environments. The underwater hull is normally protected against rusting by several coatings of anti-corrosive paint. The purpose of ICCP(Impressed Current Cathodic Protection) system is to eliminate the rusting or corrosion, which occurs on metal immersed in seawater. This thesis is about the ICCP control and monitoring system, which brings protection against the corrosion of the ship's hull in the sea environments. The test system for ICCP is composed of a power supply, anode, reference electrode and controller. The test system is composed power supply, anode, ref electrode, shunt and etc. The protection current is sent to the protection area though anode. Reference electrode senses whether or not the detected potential is within a range of protection of test equipment and then it is automatically controlled to increase or decrease the amount of protective current to be sent to the anode by controller. The monitoring system with LabView is also detected in order to check the normal state of the system at operation period, because an operator does not always watch over this system and thus the system cannot operate well because rf his or her negligent management. This paper was studied the variation of potential and current density with environment factors, velocity and time, and the experimental results will be explained Also, It is suggested that this system can accommodate a ship's automation for SCMS(Ship Control and Management System) and will be very useful.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.5
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• pp.277-286
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• 2017

This paper introduces mathematical modelling and control algorithm of expendable mine disposal vehicle. This vehicle has two longitudinal thrusters, one vertical thruster and internal mass moving system which can control pitch rate. Also, the vehicle has an optical camera and forward looking sonar for underwater mine detection and classification. The vehicle is controlled via an optical cable connected with operating console on the mother ship. We describe the vehicle's 6DOF dynamic model and controller which can track the desired trajectory for the way-point tracking. These simulation results shows guidance and maneuvering performance which has other sensor data or not.

• Smart Structures and Systems
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• v.20 no.4
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• pp.499-508
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• 2017

The ionic polymer-metal composite (IPMC) is an electroactive polymer material and has a promising potential as actuators for propulsion and locomotion in underwater systems. In this paper a physics based model is used to analyse the actuation dynamics of the IPMC propulsor. Moreover, proportional-integral (PI) controller is used for position control of the tip displacement of IPMC propulsor. PI parameter tuning is performed using particle swarm optimization (PSO) algorithm. Several performance indices have been used as an objective function to optimize the error of the system. Finally, the best tuning method is found out by comparing the results under various performance indices.

• 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.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.327-330
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• 2006

With the increasing requirements for the survey and development of the ocean, the demands on the of AUV(Autonomous Underwater Vehicle) technologies have been increased. Reconstruction and replay of the AUV motion on the basis of the data stored during the execution of mission, can help the development of control strategies for AUVs such as mission planning and control algorithms. While an AUV cruises for her mission, her attitude and position data are is recorded. The data can be used for visualization of the motion in off-line. However, because most of the position data gathered from acoustic sensors have long time-interval and include intermittent faulty signal, the replayed motion by the graphic simulator can not demonstrate the motion as a smooth movie. In this paper, interpolation methods are surveyed to reconstruct the AUV position data. Then, an efficient 3D visualization method for AUV motion using the interpolation method is proposed. Simulation results arc also included to verify the proposed method.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.568-570
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• 2004

This paper presents a study of a position finding system using PSD Sensor and Pan/Tilt. The position of PSD(Position Sensitive Detector) sensor is calculated by the degree of pan-tilt and the difference in height between pan-tilt and PSD. For that, the DSP which control pan-tilt is used for precise operation. The PIC microcontroller process PSD sensor data that indicate light incident position. A user using computer can acquire the conditions of pan-tilt and PSD and issue an order.