• 한국지진공학회논문집
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• 제10권6호
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• pp.93-102
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• 2006

대형 구조물에 작용하는 큰 외력은 능동 제어 장치의 제어입력에 포화를 종종 유발한다. 그리고 구조물이 대형화될수록 질량, 강성 등의 파라미터들에 대한 정확한 값을 알기가 어려워지므로, 수학적인 모델과 실제 구조물과의 모델링 오차는 파라미터들에 대한 불확실성으로 제어기의 설계 시에 고려되어야 한다. 그러므로 건축 및 토목 구조물에 대한 능동 진동 제어 방법을 다룰 때 제어기의 안정성을 보장하기 위하여 제어입력의 포화와 계의 파라미터 불확실성을 동시에 고려한 강인 포화 제어기의 설계가 필요하다. 여기에서는 건물의 능동 진동 제어에 연구 및 적용되어진 여러 제어기들 중에서 선형 최적 제어기 LQR, 수정된 뱅뱅 제어기, 포화 슬라이딩 모드 제어기, 강인 포화 제어기의 안정성을 살펴본다. 특히 제안된 강인 포화 제어기의 필요성을 보이기 위하여 LQR, 수정된 뱅뱅 제어기, 포화 슬라이딩 모드 제어기들이 제어입력의 포화나 파라미터 불확실성이 존재하는 경우에 불안정해지는 현상들을 보인다. 2자유도 진동계에 대한 수치 예제와 능동 질량 감쇠기(AMD)를 이용한 2층 구조물에 대한 실험을 통하여 강인 포화 제어기의 강인 안정성을 보인다.

• International Journal of Aeronautical and Space Sciences
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• 제14권3호
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• pp.256-263
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• 2013

The saturation of the actuator impairs the response performance of the near space interceptor control system. A control system based on the properties of linear tracking system is designed for this problem. The properties are that the maximum value of the pseudo-Lyapunov function of the linear tracking control system do not present at the initial state but at the steady state, based on which the bounded stability problem is converted into linear tracking problem. The pseudo-Lyapunov function of the linear tracking system contain the input variables; the amplitude and frequency of the input variables affect the stability of the nonlinear control system. Designate expected closed-loop poles area for different input commands and obtain a controller which is function of input variables. The coupling between variables and linear matrices make the control system design problem non-convex. The non-convex problem is converted into a convex LMI according to the Shur complement lemma and iterative algorithm. Finally the simulation shows that the designed optimal control system is quick and accurate; the rationality of the presented design techniques is validated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.89-90
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• 2006

• International Journal of Control, Automation, and Systems
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• 제1권3호
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• pp.315-320
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• 2003

This paper presents a control augmentation system (CAS) based on the dynamic model inversion (DMI) architecture for a highly maneuverable aircraft. In the application of DMI not treating actuator dynamics, significant instabilities arise due to limitations on the aircraft inputs, such as actuator time delay based on dynamics and actuator displacement limit. Actuator input saturation usually occurs during high angles of attack maneuvering in low dynamic pressure conditions. The pseudo-control hedging (PCH) algorithm is applied to prevent or delay the instability of the CAS due to a slow actuator or occurrence of actuator saturation. The performance of the proposed CAS with PCH architecture is demonstrated through a nonlinear flight simulation.

• 한국정밀공학회지
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• 제16권5호통권98호
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• pp.169-174
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• 1999

In this paper, the CLQR(Constrained LQR) controller, which considers the actuator saturation in a cross-product term of a given performance index for an automotive active suspension control has been proposed. The effects of actuator saturations have been reflected directly in the states by using the linear relation between the control input and states. The method proposed here is more effective and intuitive compared with the conventional schemes. The CLQR has been applied to designing an automotive active suspension control system to verify its effectiveness and practical aspects.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.335-338
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• 2003

In this paper, we considered the design of gain scheduled controllers for linear systems with input constraints. The gain scheduled control is a method that uses larger control gain when the states are smaller, and smaller gain when it is larger. By doing this, we can use a full actuator capacity. Also we allow the over-saturation in control to improve the performance. First, we derive a control and a reachable set expressed as LMI form, while minimizing the $L_2$ gain from the disturbance to the measured output. Next, the reachable set is divided as nested subsets, and the control gains are obtained by minimizing the $L_2$ gain at each nested subset. Finally, the control gains are scheduled according to the status of states, i.e., the nested-subset in which the states are located. Performance of the proposed technique is illustrated through simulations of a six-story building subject to earthquake ground motion.

• 한국공작기계학회논문집
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• 제15권5호
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• pp.72-78
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• 2006

The paper proposes reference model error feedback control scheme for motion control system with hard non-linear components as like saturation and dead-zone in plant input part. Additionally, the plant has the system uncertainty effected by plant model parameter deviation and disturbance. The control algorithm uses the reference model to apply additional feedback loop with the error between reference model output and actual output effected by disturbance and non-linear components. And the stability evaluation based on Popov stability and controller design method are formulated to be performed. The effectiveness of the proposed scheme is examined by simulations. The results are proven by reasonable performances following reference model responses with good disturbance rejection performance without over-tuning of controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.41.3-41
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• 2001

In this paper, we present a decentralized adaptive neural net(NN) controller for the transient stability and voltage regulation of a multimachine power system. First, an adaptively input-output linearizing controller using NN is designed to eliminate the nonlinearities and interactions between generators. Then, a robust control term which bounds terminal voltage to a neighborhood of the operating point within the desired value is introduced using only local information. In addition, we consider input saturation which exists in the SCR amplifier and prove that the stability of the overall closed-loop system is maintained regardless of the input saturation. The design procedure is tested on a two machine infinite bus power system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2910-2912
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• 2000

Since the heavy-duty power manipulator has high ratio gear reducers at its joints, its dynamic characteristics are much slower than that of the master manipulator and it is likely to encounter the saturation in the input magnitude when it is used as the slave manipulator in telemanipulator systems. This paper proposes a force reflecting position control scheme for 2 axes heavy-duty power manipulator which compensates control input saturation. A series of experiments is shown to give an excellent tracking performance regardless of saturation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.161-164
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• 1996

The authors have recently proposed a new method for identifying Volterra kernels of nonlinear control systems by use of M-sequence and correlation technique. A specially chosen M-sequence is added to the nonlinear system to be identified, and the crosscorrelation function between the input and output is calculated. Then every crosssection of Volterra kernels up to 3rd order appears at a specified delay time point in the crosscorrelation. This method is applied to a saturation-type nonlinear feedback control system of mechanical-electrical servo system having torque saturation nonlinearity. Simulation experiments show that we can obtain Volterra kernels of saturation-type nonlinear system, and a good agreement is observed between the observed output and the calculated one from the measured Volterra kernels.