• Journal of Navigation and Port Research
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• v.29 no.10 s.106
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• pp.827-832
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• 2005

In this paper, as a fundamental study of ship collision avoidance supporting system in close quarters situation, we propose ship collision avoidance support model for decreasing ship collision accidents those have occurred due to navigator's unsuitable maneuvering in close encounter. This model will effectively support maneuvering for collision avoidance through displaying the feasible area and the method of collision avoidance using own ship's turning characteristic about action of target ship's keeping course and velocity.

• Journal of Navigation and Port Research
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• v.44 no.2
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• pp.53-64
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• 2020

This paper discusses the hydrodynamic characteristics of a catamaran at low speed. In this study, the Delft 372 catamaran model was selected as the target hull to analyze the hydrodynamic characteristics by using the RANS (Reynold-Averaged Navier-Stokes) numerical method. First, the turbulence study and mesh independent study were conducted to select the appropriate method for numerical calculation. The numerical method for the CFD (Computational Fluid Dynamic) calculation was verified by comparing the hydrodynamic force with that obtained experimentally at high speed condition and it rendered a good agreement. Second, the virtual captive model test for a catamaran at low speed was conducted using the verified method. The drift test with drift angle 0-180 degrees was performed and the resulting hydrodynamic forces were compared with the trends of other ship types. Also, the pure rotating test and yaw rotating test proposed by Takashina, (1986) were conducted. The Fourier coefficients obtained from the measured hydrodynamic force were compared with those of other ship types. Conversely, pure sway test and pure yaw test also were simulated to obtain added mass coefficients. By analyzing these results, the hydrodynamic coefficients of the catamaran at low speed were estimated. Finally, the maneuvering simulation in low speed conditions was performed by using the estimated hydrodynamic coefficients.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.5
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• pp.287-293
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• 2017

The naval unmanned surface vehicle (USV) conducts the surveillance operations, based on the mission plan set by the user. For setting the mission planning, the user needs to analyze the suitability of the operation for the mission planning. In this paper, we proposed a simulation program that estimates the probability of detecting targets of the mission planning in the analysis. In the simulation analysis, we design the USV's maneuvering characteristics, radar detection operational performance equipped on the USV, and targets infiltrating into surveillance area in the simulation experiment scenario. Based on the simulation results, we evaluated the mission planning suitability and find a mission planning solution recursively.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.1
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• pp.39-44
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• 2010

A method is presented of dynamic determination of mode transition probability for IMM in order to improve the accuracy performance of maneuvering target tracking for air traffic control surveillance processing system under multiple radar environment. It is shown that dynamic determination of mode transition probability based on the time intervals between the data input from multiple radars gives the optimized performance in terms of position estimation accuracy.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.697-708
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• 2017

The complex battlefield environment makes it difficult to intercept maneuvering targets for guided missiles. In this paper, a finite-time convergent (FTC) guidance law based on the second-order sliding mode (SOSM) control theory is proposed to achieve the requirements of stability, accuracy and robustness. More specifically, a second-order sliding mode observer (SMOB) is used to estimate and compensate for the total disturbance of the controlled system, while the target acceleration is extracted from the line-of-sight (LOS) angle measurement. The proposed guidance law can drive the LOS angular rate converge to zero in a finite time, which means that the missile will accurately intercept the target. Numerical simulations with some comparisons are performed to demonstrate the superiority of the proposed guidance law.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.1
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• pp.170-182
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• 1999

In this paper, we present a tracking accuracy enhancement method by compensating the time delay of the video tracker in an EOTS. The proposed method has two functional parts, which can cope with the time delay of LOS and maneuvering target informations by Smith predictor and Kalman filter. So it can dramatically reduce the tracking error over conventional PI control or Smith predictor control. To verify the proposed method, various and extensive simulation and experimental results are given.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.145-147
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• 2017

Tracking filter plays a key role in accurate estimation and prediction of maneuvering vessel's dynamics. The third-order ${\alpha}-{\beta}-{\gamma}$ filter is one of the special cases of the general solution provided by the Kalman filter. Fading memory algorithm performs a better performance in numerous of ${\alpha}-{\beta}-{\gamma}$ filter algorithms. This study aims to optimize the fourth-order fading memory algorithm ${\alpha}-{\beta}-{\gamma}-{\eta}$ filter, which is extended form ${\alpha}-{\beta}-{\gamma}$ filter, to get much more accurate position of high dynamic target on the condition that the own ship is also high dynamic.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.156.5-156
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• 2001

Stabilized tracking platform in a missile consisting of a flat planar antenna, pitch/yaw gimbals, gear trains, and current controlled DC drive motors for pitch and yaw gimbal must have a capability to track a target as an inertial sensor in the presence of missile body motion such as maneuvering and vibration. Because of this reason, tracking a target from dynamic platform requires a servo architecture that includes a outer tracking loop(position loop) and inner rate loop that stabilizes the line of sight(LOS). This paper presents a gimbaled platform model including nonlinear phenomena due to viscous and Coulomb friction based on experimental data and torque equilibrium equation, the design concept for the inner tacholoop having P controller structure ...

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.222-224
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• 1995

This paper deals with 3-dimensional missile guidance law. This presents the general optimal solution of the state equation which includes the target maneuvering as the Gauss-Markov processing. The main results ore about the transformation between the Cartesian coordinates on which both the guidance law and the filter are bused and the polar coordinates system in real missile guidance and measurement information. And the extended Kalman filter and adjustment of the estimated target acceleration by triangular functions is proposed solution to this transformation problem. It is shown that this proposed transformation is valid in real 3-dimensional guidance problem by the computer simulation.

• Journal of Advanced Navigation Technology
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• v.2 no.1
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• pp.34-42
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• 1998

An adaptive state and input estimator for the tracking of a target with unknown randomly switching input is developed. In modeling the unknown inputs, it is assumed that the input sequence is governed by semi-Markov process. By incorporating the semi-Markov probability concepts into the Bayesian estimation theory, an effective adaptive state and input estimator which consists of parallel Kalman-type filters is obtained. Computer simulation results reveal that the proposed adaptive estimator have improved tracking performance in spite of the unknown randomly switching input.