• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.97-100
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• 2005

This paper proposes a linearization method that is to control the operating point of a class AB amplifier according to its output power. The proposed linearization method is presented in this paper and the performance test results using two-tone signal are presented also.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1221-1224
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• 1996

As in most industrial processes, the dynamic characteristics of an electric power system are subject to changes. Amongst those effects which cause the system to be uncertain, faults on transmission lines are considered. For the stabilization of the power system, we present an indirect adaptive control method, which is capable of tracking a sudden change in the effective reactance of a transmission line. As the plant dynamics are nonlinear, an input-output feedback linearization method is combined with an identification algorithm which estimates the effect of a fault.

• Honam Mathematical Journal
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• v.30 no.4
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• pp.631-635
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• 2008

In this paper we discuss on the formal linearization and exact solution of Klein-Gordon's equation (1) $u_{tt}-au_{xx}+bu-cu^3=0 a,b,c{\in}R^+$ So that we know an efficient method for constructing of particular solutions of some nonlinear partial differential equations is introduced.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.578-585
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• 2015

Electromagnetic levitation system(EMLS) is one of the well known nonlinear systems. Often, it is not easy to control an EMLS due to its high nonlinearity. In this paper, we first apply two linearization method(jacobian and input-output feedback linearization) to design two feedback controllers for an EMLS. Then, by observing the advantages of each controller, we design a switching control algorithm which engage two controllers depending on the position of the steel ball in order to achieve the improved performance over each controller. The validity of our switching control approach is verified via both simulation and actual experimental results.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.12
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• pp.1176-1181
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• 2010

This paper proposes three positioning algorithms using TOA measurements: 1) The well-known linearization method using Taylor series, 2) a modified Savarese method considering measurement noise, which does not need linearization, and 3) a modified Bancroft method where TOA measurements instead of pseudorange measurements are considered. Furthermore, through an error analysis, for Savarese method, divergence of altitude is anticipated if the transmitters are located at the same height. To prevent height divergence, the Savarese method is modified again for receivers which assumed moving on the even plane. Error analysis also shows the relationship between Bancroft and Savarese method. From the analysis it is expected that the performance of Savarese method is worse than Bancroft method because of error amplification during difference operation. Experiments using real TOA measurement from the time difference of ultra sound and RF validate the proposed methods and show that analysis is correct.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.644-647
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• 1997

Asymmetric cylinders are usually used as an actuator of active suspensions. The conventional optimal controller design does not include actuator dynamics as a state and force controller is needed to track the desired force. But the actuator is not ideal, so performance of an active suspension system is degraded. In this paper, we take account nonlinear actuator dynamics and obtain a linear model using a feedback linearization technique then apply optimal control method. Effectiveness of proposed method is demonstrated by numerical simulation of 1/4 car model.

• Korean Journal of Optics and Photonics
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• v.22 no.2
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• pp.72-76
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• 2011

We demonstrate a k-domain linearization using a fiber Bragg grating (FBG) array for Fourier domain optical coherence tomography based on a wavelength swept laser. The k-domain linearization is carried out with an interpolation method using a FBG array with five FBGs. The measured signal-to-noise ratio from the point spread function after k-domain linearization is 12 dB improved over that of without k-domain linearization at the 1 mm depth of the sample. Clear OCT imaging of the slide glass with k-domain linearization could be obtained.

• 전기의세계
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• v.22 no.1
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• pp.28-34
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• 1973

This paper treats with the sub-optimal control problem of noninear systems by approximation method. This method involves the approximation by linearization which provides the sub-optimal solution of non-linear control problems. The result of this work shows that, in the problem in which the controlled plant is characterized by an ordinary differential equation of first order, the solution obtained by this method coincides with the exact solution of problem. In of case of the second or higher order systems, it is proved analytically that this method of linearization produces the sub-optimal solution of the given problem. It is also shown that the sub-optimality of solution by the method can be evaluated by introducing the upper and lower bounded performance indices. Discussion is made on the procedure with some illustrative examples whose performance indices are given in the quadratic forms.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.33-34
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• 2003

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.7
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• pp.729-739
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• 1990

This paper deals with the fault detection problem in uncertain linear/non-linear systems having both undermodelling and noise. A robust fault detection method is presented which accounts for the effects of noise, model mismatch and nonlinearities. The basic idea is to embed the unmodelled dynamics in a stochastic process and to use the nominal model with a predetermined fixed denominator. This allows the input /output relationship to be represented as a linear function of the system parameters and also facilitate the quatification of the effect of noise, model mismatch and linearization errors on parameter estimation by the Bayesian method. Comparisons are made via simulations with traditional fault detection methods which do not account for model mismatch or linearization errors. The new method suggested in this paper is shown to have a marked improvement over traditional methods on a number of simulations, which is a consequence of the fact that the new method explicitly for the effects of undermodelling and linearization errors.