• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.5
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• pp.35-41
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• 1998

This paper presents a decoupling controller of the missile seeker scan loop with a spin-stabilized platform. A precise seeker motion with respect to the scan command is essential for the higher acquisition probability of the target. As the seeker scan loop is a deeply cross-coupled two input two output system, an accurate pointing or scanning for each axis to the target is very difficult, even though provided with the help of a high performance controller. When a decoupling control is applied to the seeker scan loop, the cross-coupling between two axes can be reduced to a remarkable amount. As a low order of controller is required for the real time operation, a PI controller with decoupling filter is suggested and compared with other controllers. A linearized dynamic model of seeker scan loop is used and validated through the comparison of experimental results of step responses.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.3
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• pp.670-684
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• 2014

Ship Information Systems (SISs) have been one of the main research focuses in ship design and become a multidisciplinary area. With these growing research trends, it is important to consolidate the latest knowledge and information to keep up with the research needs. In this paper, the SIS and its different forms are introduced and discussed. The beginning of this paper discusses the history and evolution of SIS. The next part of this paper focuses on different fields and research areas such as networking technology, information fusion, information decision, message display, ship control in real-time SISs. A Semi-Physical Simulation Platform (SPSIM) designed for SIS research and its running effect through a new Fuzzy-PID fusion algorithm are introduced in this paper then. A brief literature survey and possible future direction concerning each topic is included.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.3 s.96
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• pp.109-115
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• 1999

This paper presents a stabilization control designed to improve position stabilization performance of a position servo-system(turret) mounted on a manuvering platform(vehicle). In the consideration of the motion of the platform, a dynamic model of the stabilization system is derived and shows the viscous and stick-slip friction torques are the major source of stabilization errors. An extended generalized minimum variance control which consists of a feedforward disturbance compensation as well as a pole placement feedback control is suggested to reduce the stabilization errors caused from the friction disturbances. This modeling and control are applied to a small experimental set-up and the experimental results confirm the accuracy of the model and the effectiveness of the suggested control.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.1
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• pp.1-13
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• 2014

A new 5-MW floating offshore wind turbine moored by a spring-tensioned-leg was proposed for installation in about 50m water depth. Its substructure is a platform of the inverted conical cylinder type with massive ballast weight plate at the bottom. A 1:128 scale model was built for the preliminary engineering development. The model tests in waves and wind were carried out to estimate motion characteristics of this platform in the Ocean Engineering Wide Tank of the University of Ulsan. Its motions were measured and the RAOs were compared. The proposed floating offshore wind turbine showed a good stability and decent responses in waves, wind and operation of the wind turbine.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.2
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• pp.93-99
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• 2011

In this paper, an ATSC(Advanced Television Standard Committee)-M/H(Mobile/Handheld) multiplexer is designed and implemented using an embedded Linux based hardware platform. The ATSC-M/H multiplexer is composed of a CPU(Central Processor Unit), an FPGA(Field-Programmable Gate Array), ASI(Asynchronous Serial Interface)/SMPTE310(Society of Motion Picture and Television Engineers310) interface board, and a GPS(Global Position System) clock processing block. The main functions of the ATSC-M/H multiplexer executed in the CPU and FPGA are described. The operation of the ATSC-M/H multiplexer is verified by processing its broadcast signal on a commercial receiver analyzer.

• Korean Journal of Applied Biomechanics
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• v.31 no.2
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• pp.119-125
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• 2021

Objective: The purpose of this study was to identify the effect of dynamic postural balance control against tilting platform between golfers and non-golfers. Method: 24 golfers and 26 non-golfers were participated. Eight motion capture cameras, two force plates, and one dynamic balance control platform were used for sensory perception test. It was performed two-way repeated ANOVA with a Bonferroni adjustment at a significant level of a 0.05. Results: Golfers' perception ability was higher than non-golfer according to slope. the CoP, time, angle variables were indicated main effect and interaction effect between golfer and non-golfer. Conclusion: It was known that golfer's proprioception perception ability was higher than non-golfers. Repeated practice such as shots and putting on the uneven ground might improve their balance control.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.4_1
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• pp.513-519
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• 2022

In this paper, we describe performances of P-PD controllers in the quadrotor system with steady-state error compensation by adding a corrective term to the system input. A decentralized control system using P-PD controllers was successfully implemented on a quadrotor platform. We also presented the results of a mathematical modeling analysis for control the quadrotor and experimental results for each response performance according to the heading reference value in accordance with the mathematical modeling and P-PD controller design. A control experiment with the real system was implemented for the test platform, and the results were evaluated and compared.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.495-495
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• 2000

The Stewart platform manipulator is a closed-kinematis chain robot manipulator that is capable of providing high st겨ctural rigidity and positional accuracy. However, this is a complex structure, so controllability of the system is not so good. In this paper, it introduces a new robust motion control algorithm using partial state feedback for a class of nonlinear systems in the presence of modelling uncertainties and external disturbances. The major contribution of this work introduces the development and design of robust observer for the slate and the perturbation w.hich is integrated into a variable structure controller(VSC) structure. The combination of controller/observer gives rise to the robust routine called sliding mode control with sliding perturbation observer(SMCSPO). The optimal gains of SMCSPO are easily obtained by genetic algorithm. Simulation and experiment are presented in order to apply to the stewart platform manipulator. There results show highly' accuracy and performance.

• Progress in Medical Physics
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• v.25 no.4
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• pp.242-247
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• 2014

To see the discrepancies between the calculated and the delivered dose distribution of IMRT fields for respiratory-induced moving target according to the motion ranges. Four IMRT plans in which there are five fields, for lung and liver patients were selected. The gantry angles were set to $0^{\circ}$ for every field and recalculated using TPS (Eclipse Ver 8.1, Varian Medical Systems, Inc., USA). The ion-chamber array detector (MatriXX, IBA Dosimetry, Germany) was placed on the respiratory simulating platform and made it to move with ranges of 1, 2, and 3 cm, respectively. The IMRT fields were delivered to the detector with 30~70% gating windows. The comparison was performed by gamma index with tolerance of 3 mm and 3%. The average pass rate was 98.63% when there's no motion. When 1.0, 2.0, 3.0 cm motion ranges were simulated, the average pass rate were 98.59%, 97.82%, and 95.84%, respectively. Therefore, ITV margin should be increased or gating windows should be decreased for targets with large motion ranges.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.7
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• pp.560-570
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• 2017

Recently, well-known SAR imaging algorithms have been developed to form the focused SAR images for stationary targets. In general, the conventional methods exploit the range variation only defined by the motion of radar platform and SAR geometry. However, for SAR imaging of ground moving targets, the motion of the targets induces an additional range shift, yielding the blurred SAR images. To overcome the problem, in this paper we propose an effective motion compensation algorithm operated under a multi-channel SAR, named along-track interferometry(ATI) and phase unwrapping to directly estimate the motion parameters of the targets. In simulations, 50 Monte-Carlo simulation results show the effectiveness of the algorithm in the presence of noise.