• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.194-195
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• 2011

본 논문은 Bi-directional Inverter(BDI)에 DQ 변환을 적용한 소신호 등가 모델과 이중 루프 제어기 설계에 대해 제안한다. 일반적으로 외부루프의 경우 동적 특성이 매우 느리기 때문에 외부루프 전달함수를 고려하지 않고 설계하는 경우가 많다. 결과적으로 시스템의 안정성이나 동적 특성이 설계한 것과 다르게 나타날 수 있다. 따라서 원하는 특성을 만족하기 위해 실험적 시행착오를 거쳐 설계를 하게 된다. 본 논문에서는 정확한 소신호 등가 모델을 제시하고 제어기를 설계한다. 제안된 방식은 PSIM 시뮬레이션 및 실험을 통해 회로해석과 소신호 등가모델의 타당성 및 제어기 설계의 타당성을 증명하였다.

• Journal of Navigation and Port Research
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• v.47 no.4
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• pp.256-270
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• 2023

In this study, a sliding mode (SM) controller for dynamic positioning (DP) was specifically designed for a turret connection operation of a ship or an offshore structure in which an arbitrary point on the structure could be controlled as the motion center instead of the center of mass. The SM controller allows control of the arbitrary point and provides capability to manage uncertainties in the dynamics of ships and offshore structures, external forces caused by unknown changing marine environments, and transient performance of DP systems. The Jacobian matrix included in kinematic equations of the controlled object was modified to design the SM controller to control based on an arbitrary point of ships or offshore structures. To ensure robustness of the controller, the Lyapunov stability theory was applied in the design of the SM controller. In general, for robustness in DP control, gain scheduling based on a proportional-derivative (PD) control algorithm is employed. However, finding appropriate gains for gain scheduling complicates the application of DP systems. Therefore, in this study, the SM control algorithm was considered to mitigate the complexity of the DP controller for ships and offshore structures. To validate the proposed SM control algorithm, time-domain simulations were conducted and utilized to evaluate the performance of the control algorithm. The effectiveness of the proposed SM controller was assessed by comparing simulation results with results of a conventional PD control algorithm applied in DP control.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.749-753
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• 2003

This paper presents an output voltage regulation system using PWM Buck-Boost AC-AC converter for power qualify improvement of custom power. This paper proposes dynamic modeling of the system for control object and in addition, a controller design example. Therefore, system state equation is derived whereby the transfer function could be obtained. The paper shows a regulation controller for tracking the output voltage to the reference under specific operating point. Finally, this paper shows validity and practical applicability of the proposed modelling and system design by experimental results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.405-413
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• 2006

In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it an other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstepping control method.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.234-235
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• 2008

본 논문은 계통연계형 태양광발전 시스템의 Power Conditioning System의 성능 테스트를 위한 태양광 시뮬레이터의 제어기 최적 설계에 관한 내용이다. 태양광 시뮬레이터 기술의 핵심은 정확한 에너지원의 모델링과 빠르고 안정적인 전력증폭기 제어기술에 있다. 종래의 제어기인 비례 적분제어기를 사용하는 과정에서 비례 적분 제어기 특유의 응답지연 특성으로 시뮬레이터의 동적 특성을 완벽하게 구현할 수 없기에, 응답속도가 빠르고 안정적인 제어기법인 $H_{\infty}$제어 이론을 적용하였다. 태양광 시뮬레이터의 제어기 성능평가를 위해서 태양광 시뮬레이터의 출력을 결정 하는 DC Power Amplifier의 성능실험을 하였다. DC Power Amplifier를 정전압에서 부하의 투입/제거시 비례-적분 제어기와 $H_{\infty}$제어기의 응답속도와 변동전압의 크기를 비교하여 제어기의 성능을 비교하였다.

• Journal of KSNVE
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• v.9 no.1
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• pp.121-130
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• 1999

Generally, A Dynamic Absorber by using Active viscous Damping is highlighted for effective suspension system, such as improved ride comfort and handling in the market. Lately, this system based on the Sky-Hook damper theory is introduced by the name of "Active Dynamic Absorber" to us. This system has an excellent performance in contrast to Passive. Adaptive Dynamic Absorber, besides having low cost components of system, low energy consumption. light weight of system. In this viewpoint. most of car-maker will adopt this system in the near future. For this reason, we developed Dynamic Absorber by using Active viscous Damping which is equipped with continuously variable Dynamic Absorber and Control logic consisting Filter and Estimator. control apparatus of Dynamic Absorber operated by 16-bit microprocessor of high performance. variable device of viscous Damping. G-sensor so on. In this paper. several important points of development procedure for realizing this system will be described with results in which is obtained from experiment by simulation and Full car test in Proving ground. respectively.pectively.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1994.11a
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• pp.43-47
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• 1994

화학 열펌프 시스템의 반응기 설계를 위하여 정적 설계의 결과를 이용하여 시간에 따른 전화율, 온도, 압력, 출력 등의 변화에 대한 모사를 시도하였다. 정적 모사를 통한 설계결과는 동적 거동 모사의 결과와 유사하였으며, 이로부터 정적모사가 동적모사를 위한 적절한 초기치와 기초 설계 정보를 제공함을 알 수 있었다. 본 연구를 통하여 확립된 설계절차와 해석방법에 따른 사례연구를 통하여 향후 실용화될 화학 열펌프 시스템의 개략적인 사양과 바람직한 설계방향을 제시 할 수 있었으며, 반응기의 조작에 따른 제어변수의 영향을 평가하는 기준을 마련할 수 있었다.

• The KIPS Transactions:PartC
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• v.15C no.6
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• pp.493-506
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• 2008

In this paper we suggest dynamic access control model based on context satisfied with requirement of u-healthcare environment through researching the role based access control model. For the dynamic security domain management, we used a distributed object group framework and context information for dynamic access control used the constructed database. We defined decision rule by knowledge reduction in decision making table, and applied this rule in our model as a rough set theory. We showed the executed results of context based dynamic security service through u-healthcare application which is based on distributed object group framework. As a result, our dynamic access control model provides an appropriate security service according to security domain, more flexible access control in u-healthcare environment.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.2
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• pp.157-165
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• 2011

Base isolation system is widely used for reduction of dynamic responses of structures subjected to seismic load. Recently, research on a smart base isolation system that can effectively reduce dynamic responses of the isolated structure without accompanying increases in base drifts has been actively conducted. In this study, a smart base isolation system was applied to an arch structure subjected to seismic excitation and its control performance for reduction of seismic responses was evaluated. In order to make a smart base isolation system, 4kN MR dampers and low damping elastomeric bearings were used. Seismic response control performance of the proposed smart base isolation system was compared to that of the optimally designed lead-rubber bearing(LRB) isolation system. To this end, an artificial ground motion developed based on KBC2009 design response spectrum was used as a seismic excitation. Fuzzy control algorithm was used to control MR damper in the smart base isolation system and multi-objective genetic algorithm was employed to optimize the fuzzy controller. Based on numerical simulation results, it has been shown that the smart base isolation system can drastically reduce base drifts and seismic responses of the example arch structure in comparison with LRB isolation system.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.127-130
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• 2010

본 논문에서는 산업 안전 서비스를 위한 오류 상호 인지 및 제어 기능이 있는 IP-USN 기반의 멀티미디어 공동 작업 환경에서의 동적 오류 관리기에 대하여 기술한다. 산업 안전 서비스를 위한 동적 오류 관리를 위해서 상호 인지가 필요하다. 상호 인지란 상호 작업 이해, 참여자 관계 설정 등 결합이라는 구현 기술을 말한다. 인지의 구현 방법에는 파일 공유, 윈도우 복사, 윈도우 오버레이, 또는 윈도우 공유 등이 있다. 산업 안전 서비스를 위하여 윈도우 오버레이 기능에 세션 제어, 발언권 제어 등을 추가한 윈도우 공유 방법을 기술한다.