• Journal of Advanced Marine Engineering and Technology
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• 제38권10호
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• pp.1318-1326
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• 2014

The purpose of a tracking control system is to track a moving target and to find the exact information of the target. If the platform of the tracking control system is equipped on a moving vehicle such as a ship, the tracking control system will treat even the additional platform motion. In order to avoid the complexity comprising the tracking control system, a process to treat the platform motion, named stabilizing system, must be separated from the tracking control system. In this paper, a method to comprise an attitude control system for the platform stabilization is proposed using an adaptive fuzzy control which is applicable to the system with structural and parametric uncertainty. The suggested adaptive fuzzy control algorithm is the 2nd/1st-type indirect adaptive fuzzy control algorithm using the advantages of 1st-type and 2nd-type indirect adaptive fuzzy control algorithm. Several experiments using the implemented stabilizing system are executed for verifying the effectiveness of the suggested method.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2011년도 추계학술대회
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• pp.3-4
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• 2011

본 연구에서는 Manta type UUV의 비선형 수학모델과 유체력 미계수를 소개하고, 자유항주실험용으로 제작된 Manta type UUV의 슬라이딩 모드 제어기 설계를 다루고 있다. 비선형운동에 대해 강인한 제어기를 설계하기 위해서 슬라이딩 모드 제어 기법을 사용하였고, 조류의 영향을 고려한 6자유도 운동 수학모델을 기반으로 하는 심도 및 방위제어기를 설계하였다. 또한, 설계된 심도 및 방위제어기의 성능을 컴퓨터 시뮬레이션으로 확인하였다.

• Journal of Power Electronics
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• 제16권6호
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• pp.2099-2108
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• 2016

The cascaded multilevel converter is widely adopted to medium/high voltage and high power electronic applications due to the small harmonic components of the output voltage and the facilitation of modularity. In this paper, the operation principle of a T-type H-bridge topology is investigated in detail, and a carrier phase shifted pulse width modulation (CPS-PWM) based control method is proposed for this topology. Taking a virtual five-level waveform achieved by a unipolar double frequency CPS-PWM as the output object, PWM signals of the T-type H-bridge can be obtained by reverse derivation according to its switching modes. In addition, a control method for the T-type H-bridge based cascaded multilevel converter is introduced. Then a single-phase T-type H-bridge cascaded multilevel static var generator (SVG) prototype is built, and a repetitive controller based compound current control strategy is designed with the DC-link voltage balancing control scheme analyzed. Finally, simulation and experimental results validate the correctness and feasibility of the proposed modulation method and control strategy for T-type H-bridge based cascaded multilevel converters.

• 한국정밀공학회지
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• 제14권8호
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• pp.146-154
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• 1997

Solenoid-folw control type ABS is used with a 'dump and reapply' pressure control arrangement instead of using 2/2 (normal open/close) solenoid valves in convensional systems(sol. -sol. control type), a flow control valve is used which replaces the (no) inlet valve. The flow control valve controls fluid flow providing a nearly constant reapply rate( .theta. ) after the dump plase of ABS operation. In this study, to investigate a characteristics of brake pressure by PWM control, test rig was consisted of ABS hydraulic modulator, digital controller, pneumatic power supply and brake master cylinder. For comparison with experi- mental results, system modelling and computer simulation were performed. As a result, experiment results showed fairly agreement with the simulation. Also, it is shown that the pressure gradient (tan .theta. ) is affected by pressure, frequency, duty ratio and expressed with an exponential funtion.

• 조명전기설비학회논문지
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• 제28권2호
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• pp.100-108
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• 2014

In this paper, an idea of a network type distributed control of a system with inner loop control structure will be considered. Generally, in case of a control system with inner loop control structure, it is not easy to implement circuits and programming. Using network type distributed control structure, it will show how it is better than before. CAN(Controller Area Network) protocol which has been known that it has a high reliability on the signal in the various network protocols is used. Also, Arago's Disk System which has a inner loop control stucture is made to validate effectiveness of the proposed method.

• 설비공학논문집
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• 제15권5호
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• pp.382-388
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• 2003

Refrigerant flow rates of the multi-type air-conditioning system can be regulated by electronic expansion valves (EEV). The performance of the multi-type air-conditioning system may be improved by lowering the superheat at the compressor suction side. In this study, a superheat temperature setpoint reset algorithm was developed by using fuzzy logics, and a PI algorithm was applied to control the superheat temperature near setpoints. Experimental results showed energy savings and stable operations at a multi-type air-conditioning system. Therefore, the developed setpoint reset algorithm may be effectively used for the EEV superheat temperature control of the multi-type air-conditioning system.

• 한국지능시스템학회논문지
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• 제25권2호
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• pp.168-173
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• 2015

비행 시 외부 조건에 따라 비선형시변 동적특성을 갖는 항공기의 비행제어는 종 제어(longitudinal control)와 횡 제어(lateral control)로 나눌 수 있으며, 종 제어는 승강키(elevator)에 의한 피치(pitch)값, 횡 제어는 에일러론(aileron)에 의한 롤(roll)값과 방향키(rudder)에 의한 요(yaw)값들을 제어대상으로 삼는다. 현재까지 항공기의 안정성, 조종성 그리고 기동성을 보장하기 위한 제어시스템 개발에 많은 연구들이 활발히 진행되어 왔으나, 최근에는 다양하고 복잡한 풍동실험과 환경실험들을 필요로 하는 기존연구들과는 다른 항공기의 지능제어시스템 개발에 관련된 연구들이 이루어지고 있다. 본 논문은 대표적인 지능제어방식인 Interval Type-2 퍼지논리기법에 의한 항공기 종 제어시스템을 제시하고 F-4 제트전투기의 컴퓨터 모의실험을 통해 그 효용성을 입증한다.

• 대한수학회지
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• 제37권4호
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• pp.625-643
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• 2000

In this paper we formulate an optimal control problem governed by time-delay Volterra integral equations; the problem includes control constraints as well as terminal equality and inequality constraints on the terminal state variables. First, using a special type of state and control variations, we represent a relatively simple and self-contained method for deriving new necessary conditions in the form of Pontryagin minimum principle. We show that these results immediately yield classical Pontryagin necessary conditions for control processes governed by ordinary differential equations (with or without delay). Next, imposing suitable convexity conditions on the functions involved, we derive Mangasarian-type and Arrow-type sufficient optimality conditions.

• 전기의세계
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• 제29권7호
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• pp.460-470
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• 1980

The design of a control unit for a playback-type industrial robot is studied. Implemented for the cylindrical-coordinate type industrial robot with 5 degrees of freedom, the control unit constructed for the study consists of (i) z-80 .mu.p-based .mu.-computer control system (ii) Teach-Box for work command, and (iii) various softwares for generating signals for servo driving unit and operating the robot as playback-type. Softwares are developed by using high level Basic Language and low level z-80 Assembly Language for ease of programming and speed of program execution. To show the effectiveness, and example is included.

• Journal of Power Electronics
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• 제11권1호
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• pp.59-63
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• 2011

This paper presents the modeling of the sampling effect in the p-type average current mode control. The prediction of the high frequency components near half of the switching frequency in the current loop gain is given for the p-type average current mode control. By the proposed model, the prediction accuracy is improved when compared to that of conventional models. The proposed method is applied to a buck converter, and then the measurement results are analyzed.