• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1176-1178
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• 1998

This paper presents a model reduction procedure of the high order MIMO (multi input multi output) controller designed for the steam turbine in the generating plant. The application limit to reduction of the order is reviewed by variation in Hankel singular value as well as by variation in singular value Bode diagrams of transfer function matrices. Dynamic performances in the time domain are also compared for each reduced order model.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.12
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• pp.1833-1844
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• 2004

A controller is proposed for the robust backstepping control of a class of nonlinear multiple-input multiple-output (MIMO) systems which can be converted to a strict feedback form. The proposed robust backstepping control scheme follows a systematic procedure for the design of control laws and uses time delay estimation (TDE) to estimate the uncertainties such as parameter variations, unknown disturbances, and unmodeled dynamics, etc. The proposed controller can be also applied to nonlinear MIMO systems with unmatched uncertainties. Stability analysis of the closed-loop system which contains the plant and the proposed controller is also studied and hereby a sufficient stability condition for the closed-loop system is proposed. The simulation results show that the control scheme works well with uncertainties and the proposed stability condition is valid. The controller is experimentally verified on a single-link flexible arm to show the effectiveness of the proposed scheme in the complicated systems with uncertainties.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.728-731
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• 2015

Nowadays, the majority of the manufacturing plant equipment tend to be transformed with automation system than traditional manual equipment. Production manager to make the process decision-making, not accustomed to manage and take advantage of professional decision-making technique. So rather than using the system proposed, it is common to undergo sporadic measures through the external intermediary. In this paper, whether possible delivery to match the delivery through the issue and decision-making system of the data input to be generated in the manufacturing process, review the supply information of the material used in the process, a plurality of input / output device We have proposed an input module that utilizes the Android Application and ATmega2560. As a result, easily cope with the improvement and change of process information of the work efficiency of the production business of the manufacturing process, and reduced plant data missing tasks, and management improvement to the improvement of the delivery compliance and product satisfaction by improving productivity we try to contribute to.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.7
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• pp.556-562
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• 2002

This paper studies the identification of a combustion model, which is used to design a linear controller of a steam generation quantity and harmful exhaust gases of a Refuse Incineration Plant(RIP). Even though the RIP has strong nonlinearities and complexities, it is identified as a MIMO parametric ARX model from experimental input-output data sets. Unknown model parameters are decided from experimental input-output data sets, using system identification algorithm based on Instrumental Variables(IV) method. It is shown that the identified model well approximates the input-output combustion characteristics.

• Transactions on Control, Automation and Systems Engineering
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• v.3 no.4
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• pp.250-256
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• 2001

This paper deals with a design problem of a decentralized controller with a strongly connected two-input two-output multivariable system. To this end, we present a classical design approach which consists of two main steps: one is to decompose the multivariable plant into two single-input single-output systems by means of the Individual Channel Design (ICD) concept, the other is to design controller of each channel by the Coefficient Diagram Method (CDM) so that it satisfies, especially, time domain specifications such as settling time, overshoot etc.. A design procedure was proposed and then was applied to a 2$\times$2 hot rolling mill plant. Simulation results showed that the proposed method has excellent control performances.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2616-2628
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• 1994

Recently the Time Delay Control(TDC) method has been proposed as a promising technique in the robust control area, where the plant has unknown dynamics with parameter variations and substantial disturbances are present. When TDC is applied to the plant with saturation nonlinearity, however, the so called windup phenomena are observed to arise, causing excessive overshoot and instability. In order to solve this problem, we have proposed an anti-windup method for TDC. The stability of the overall system has been analyzed for a class of LTI MIMO system. The effectiveness for the proposed method has been shown with simulation and experiment results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.11
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• pp.106-111
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• 2014

Currently, the commonly used method for PWM(Pulse Width Modulation) Inverter of the Solar Power Plant. However, the limit of the developing performance to the non-linear and switch devices of the Inverter. Therefore, we propose a model predictive control techniques applied to Laguerre functions. LMPC(Laguerre functions model predictive control) reduces the number of computations made and so online implementation becomes possible where traditional MPC would have fail. In this paper, we comment on the appropriate scope and functions degree of the LMPC inverter control. The simulation results from MATLAB are also provided.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.6
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• pp.142-155
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• 2000

A MIMO model reference control scheme incorporating the variable structure theory for a vehicle four wheel steering system(4WS) is proposed and evaluated for a class of continuous-time nonlinear dynamics with known or unknown uncertainties. The scheme employs an neural network to identify the plant systems, where the neural network estimates the nonlinear dynamics of the plant. By the Lyapunov direct method, the algorithm is proven to be globally stable, with tracking errors converging to the neighborhood of zero. The merits of this scheme is that the global system stability is guaranteed and it is not necessary to know the exact structure of the system. With the resulting identification model which contains the neural networks, it does not need higher degrees of freedom vehicle model than 3 degree of freedom model. Th proposed scheme is applied to the active four wheel system and shows the validity is used to investigate vehicle handing performances. In simulation of the J-turn maneuver, the reduction of yaw rate overshoot of a typical mid-size car improved by 30% compared to a two wheel steering system(2WS) case, resulting that the proposed scheme gives faster yaw rate response and smaller side angle than the 2WS case.

• Journal of Power System Engineering
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• v.15 no.1
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• pp.78-85
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• 2011

In order to design the control system of the magnetic bearing for the high speed 3 phase induction motor, the mathematical modeling was conducted and LQ regulator system was designed. When the plant is controllable and detectable, the nominal stability of LQ regulator could be guaranteed. However, LQ regulator doesn't ensure the robustness of stability and performance for the real system because LQ control is the mathematical optimal theory. In this paper to ensure the robustness of stability and performance for the real system, the control systems are designed by the simulation to the variation system parameters and this method was confirmed as an effective means.

• Journal of Power System Engineering
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• v.5 no.4
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• pp.44-52
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• 2001

This paper considers a modeling and identification for the MIMO magnetic bearing system. To obtain the nominal plant transfer functions, we have experimented on the frequency response by a closed-loop identification method because the system is unstable essentially. We suggest a method of curve-fitting for obtaining the transfer function from the frequency responses by using the system's modeling structure and two controllers which are different from each other. From the frequency response results, we found the effects of coupling by opposing controllers. And using this effects and the system's modeling structure, we could obtain the transfer functions of which have the same modularized denominators.