• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.153-163
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• 1999

본 연구에서는 격자패널을 통한 소음전달을 감소시키기 위하여 외부 구조적 가진으로부터 유발된 경량 패널의 진동을 능동 제어하는 기법을 기술한다. 최적 되먹임제어기와 적응 앞먹임제어기가 결합된 혼합형 제어기가 진동제어기로 사용된다. 되먹임제어기는 주파수 영역의 모델규명법에 의해 추출된 다중 입/출력 패널진동계 모델에 대하여 LQG 최적기법을 이용하여 감쇠능을 향상시키도록 설계된다. 앞먹임제어기는 되먹임 궤환의 결합효과를 자동적으로 보정할 수 있는 제안된 학습법칙에 기초하여 패널의 잔류진동이 최소가 되도록 적응된다. 45.7${\times}$45.7${\times}$2.54 ${cm^3}$ 벌집형상의 고강도 패널, 4개의 관성형 구동기 및 이산신호처리장치에 의해 구현된 패널 진동계에 대한 능동제어 실험을 수행해 본 결과 600Hz 주파수대역에 대한 12dB 진동저감이 이루어 질 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.377-382
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• 1989

암모니아 합성을 위한 다단식급냉반응기를 대상으로 물질 및 에너지보존법칙을 적용하여 수식모델을 전개하였다. 실제 4단 반응기의 설계 및 운전자료를 기준으로 하여 정상상태의 다중성을 해석하고 각 촉매층의 체적비와 반응물의 공급유량비에 대한 최적화 연구를 수행한 결과 실제 조업조건하에서 3개의 서로 다른 정상상태가 존재하며 실제 설계 및 조업조건은 최적조건을 다소 완화한 조건에 상당한 것임을 확인하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.27 no.1
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• pp.109-116
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• 2023

In this paper, we study the containment control problem for second-order multi-agent systems, which consists of multiple leaders and followers. The goal is to drive the followers toward the convex hull spanned by the leaders. Thus, the swarm behavior can be obtained by controlling the entire group by the leaders. This paper considers the leaders move at a constant speed and the followers have input saturations. Moreover, we assume that the followers can exchange information with neighbors, and only relative state information is available. Under these assumptions, we propose the Proportional-Integral based distributed control algorithm to solve the containment control problem with moving leaders. Moreover, based on Lasalle's invariance principle, the conditions for the control gains that guarantee the convergence of the followers to the convex hull spanned by the leaders are investigated, and it was shown that it can be designed only using the system parameter. Finally, the simulations are conducted to validate the theoretical result.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.341-347
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• 2015

Since the advent of Apple's iPhone, the smartphone industry has been producing new technologies and concepts at an accelerated pace. The speed of progress in this sector is exponentially increasing in accordance with Moore's Law, and smartphones are rapidly changing various aspects of human life. Especially, object control technologies using smartphones are being utilized in various sectors, including robots, home automation, and smart objects. However, the current smartphone object control technology is limited in terms of multicontrol. This study proposes the combined usage of the Bluetooth and Zigbee Modules for multiple object control using smartphones, and presents the necessary application design properties and the methodology for Zigbee communication. The study is an attempt at a territorial expansion of design, as a proposal of new methods for utilizing smartphones in the age of smart objects.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1663-1669
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• 2021

This paper considers the cooperative control problem for multiple leaders and a single follower with interactions. The leaders are controllable, and the follower has interactions with all leaders and is controlled by the interactions. Then, we study the cooperative control problem that achieves the consensus by controlling the leaders. The leaders and the follower are modeled by the single-integrator and the double-integrator, respectively, and it is assumed that the interactions have the nonlinearities. The leaders can estimate the interaction between the follower and exchange the estimated information with neighbors. Then, this paper proposes the consensus-based cooperative control algorithm using the information exchange of the estimated interactions and the virtual velocity variables to achieve the velocity consensus. We analyze the convergence of the agents to the common state based on the Lasalle's Invaraince Principle. Finally, we provide the numerical example to validate the theoretical results.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.2
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• pp.76-83
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• 1996

We have developed the unconventional robot arm which is composed of the two main parts, one is a ball screw and the other is a robot arm. The dynamic systems of the robot arm and ball screw are unstable systems coupled with each other. The ball screw mechanism is unstable system but controllable system. The robot arm's dynamics is quasi stable system when ball screw's angular position is zero, else, unstable system. Our system has the duality between stability and controllability at the view point of control. This duality causes difficulty to control of the robot arm using normal control law. We have investigated the location of the characteristic roots of the dynamic equation. And we have found out that the best condition for the control of the arm is quasi stable state. In this paper, we have proposed multiple control laws which are consist of three components to guarantee the stability and controllability simultaneously. The computer simulations were carried out based on VSC about the angular position control of the robot arm, and it is confirmed that the good performances could be obtained by using new controller.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.4
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• pp.284-291
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• 2021

In this paper, we study the consensus problem for multi-agent systems with input saturations. The goal of consensus is to achieve a swarming behavior of multi-agent systems by reaching the agreement through information exchange. This paper considers agents modeled by first-order dynamics with input saturations. In order to guarantee the global convergence of the agents, it is assumed that the agents are stable. Moreover, considering the disturbances, we propose the PI based duplex control method to achieve the consensus. The proposed P controller and I controller are composed of different information network. Then, we investigate the conditions of the information networks and the control gains of P, I controllers to achieve the consensus applying the Lyapunov stability theorem and the Lasalle's Invariance Principle. Finally, we conduct the simulations to validate the theoretical results.

• Electronics and Telecommunications Trends
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• v.13 no.4 s.52
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• pp.43-58
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• 1998

애니메이션이나 멀티미디어에서 사용될 물체들을 모두 처음부터 만들어 나간다는 것은 굉장히 시간이 많이 들고 힘든 일이다. 따라서, 물체를 처음부터 디자인하는 것이 아니라 단순한 모양의 물체로부터 복잡한 모양의 물체를 쉽게 만드는 방법에 대한 연구가 많이 진행되었다. 본 논문에서는 그래픽스 분야의 물체 변형기법에 대한 연구 결과들을 살펴본다. 대표적인 변형기법으로 Barr의 음함수 변형법, 자유형태 변형기법과 그 확장, skeleton warping 등을 살펴본다. 물체의 보다 사실적인 변형을 얻기 위해서 물리 법칙을 이용하는 방법과, 구조가 복잡한 물체를 여러 상세 단계로 나누어 처리하는 다중해상 방법도 살펴본다. 그리고, 매개변수 함수로 표현된 물체를 편집할 경우에 곡선/곡면의 제어점 대신 물체상의 임의의 위치를 직접 움직이는 직접제어 기법의 연구동향을 살펴본다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.11
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• pp.990-998
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• 2007

Adaptive output feedback control technique using Neural Networks(NN) is proposed for uncertain nonlinear Multi-Input Multi-Output(MIMO) systems. Modified Dynamic Inversion Model(MDIM) is introduced to decouple uncertain nonlinearities from inversion-based control input. MDIM consists of approximated dynamic inversion model and inversion model error. One NN is applied to compensate the MDIM of the system. The output of the NN augments the tracking controller which is based upon a filtered error approximation with online weight adaptation laws which are derived from Lyapunov's direct method to guarantee tracking performance and ultimate boundedness. Several numerical results are illustrated in the simulation of Van der Pol system and unmanned helicopter with model uncertainties.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.81-86
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• 2006

This paper deals with a driving current fault monitor design methodology for a DDV actuation system which has a dual hydraulic power supply system, and triplex electric control capability. A fault existing among these redundant channels should be detected accurately and removed timely, and the remaining channels are to be reconfigured in order to compensate the role of a removed faulty channel. An integrated analysis on the aerodynamics, flight control laws, and DDV actuation system is essential for the design of an actuation system fault monitor. A method to define a fault transient boundary which specifies a maximum travel of an actuation system caused by the first faulty operation is proposed based on the top level requirement on the fault effect specified in MIL-F-8785C.