• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.10 s.253
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• pp.1249-1254
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• 2006

Existing adaptive observers may cause the parameter drifts due to disturbances even if state estimation errors remain small. To avoid the drift phenomena in the presence of bounded disturbances, several robust adaptive observers have been introduced addressing bounds in state and parameter estimates. However, it is not easy for these observers to manipulate the size of the bounds with the selection of the observer gain. In order to reduce estimation errors, this paper introduces the (equation omitted) gain minimization problem in the adaptive observer structure, which minimizes the (equation omitted) gain between disturbances and estimation errors. The stability condition of the adaptive observer is reformulated as a linear matrix inequality, and the observer gain is optimally chosen by solving the convex optimization problem. The estimation performance is demonstrated through a numerical example.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.920-925
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• 1993

For a multi-input, multi-output system, it is widely known that feedback control gain presents extra freedom pole placement problem. An eigenstructure assignment utilizes this freedom for assignment of all or some elements of the closed-loop eigenvectors. In this paper, a nonlinear optimization technique is adopted to obtain a small gain controller that assigns closed-loop eigenvalues and elements of eigenvectors simultaneously. To illustrate the approach, a numerical example of the Airplane mode decoupling using an advanced fighter is shown.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.1140-1145
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• 1989

A general dynamic iterative learning control scheme is proposed for a class of nonlinear systems. Relying on stabilizing high-gain feedback loop, it is possible to show the existence of Cauchy sequence of feedforward control input error with iteration numbers, which results in a uniform convergance of system state trajectory to the desired one.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1137-1139
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• 1996

Feedback Linearization technique needs the exact cancellation of nonlinearity which restricts its application to real environment. To overcome these shortcomings, High-pin feedback is good remedy to this problem. In this paper, we briefly survey the high-gain feedback control technique and show some conditions for applying this method to nonlinear systems. In order to use this technique in real situation, some properties of ${\varepsilon}$-bound and semi-global stabilization are discussed.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.5
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• pp.18-26
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• 1994

We express fundamental second-order and third- order harmonic distortions and intermodulation distortions in terms of the laser parameters. Compared to the Darcie `s result only limited to the high frequency (f >1GHz), these expression are quite valid in the entire modulation frequency region. It is found that the fundamental nonlinear distortions are strongly effected by the spontaneous emission to lasing mode as well as the gain compresion damping in the low frequency region.

• Journal of IKEEE
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• v.11 no.4
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• pp.213-218
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• 2007

We consider a web transport system. The objective of this paper is to design the output feedback controller such that the controller can track a desired tension and processing speed on web transport system. We propose the new design method using observer and feedback linearization technique. The proposed method use a nonlinear feedback to transform to linear system and high gain observer to estimate the state value. We show that the proposed controller can achieve the control object using only output. We show a performance of controller via the simulation.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.135-137
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• 1995

A new design method is proposed for a fuzzy PD controller. By analyzing phase plane characteristics we can build and optimize the rule base of fuzzy logic controller. Also, a new gain tuning method is used to improve performance in the transient and steady state. The improved performance of the new methodology is shown by an application to the design of control system with a highly nonlinear actuator.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.12
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• pp.1086-1089
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• 2012

We propose a near optimal controller design method for ramp metering based on SDRE (State Dependent Riccati Equation) approach. We parameterize the optimal nonlinear controller in terms of the solution matrices of an SDRE. We also give a simple algorithm to obtain the controller gain. Finally we give numerical results to show the effectiveness of the proposed near optimal traffic controller design method.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.1
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• pp.18-21
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• 2014

We propose a nonlinear observer design method for traffic control systems based on T-S fuzzy approach. We parameterize the observer gains in terms of the solution matrices of LMIs. We also give a simple algorithm to compute the observer gain matrices. Finally we give simulation results to show the effectiveness of the proposed fuzzy observer design method.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.521-524
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• 1999

In spite of advances in image resolution and film contrast, check screen/film mammography remains one of diagnostic imaging modality where the image interpretation is very difficult. For the enhancement of film mammography, in this paper, dyadic wavelet transform is introduced. An unsharp masking technique is proposed and performed in wavelet domain. In addition, simple nonlinear enhancement and a denosing stage that preserves edges using wavelet shrinkage are computed into this technique. In this paper. we propose a new method for the gain setting of nonlinear enhancement and show result and comparison.