• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.60.4-60
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• 2002

Nonlinear adaptive control for the laboratory pressure-flow model. Control valves are installed on both sides. The pressure and the outlet flow rate are measured. The pressure and outlet flow rate are controlled variables and the control valve stem positions on both sides are the manipulated variables. The variation in both inputs will influence both controlled variables. The control performance is good, in spite of varying valve coefficients of inlet and outlet.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.185-189
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• 1987

The controller with robustness described in this paper is designed for processes with variable time-delays. This adaptive mechanism includes servo and stabilizing compensators. In the proposed multivariable controller. knowledge of the system time-delay is not required.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.670-677
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• 1991

All models of dynamical systems invariably have some measure of uncertainties associated with some of their dynamics. The recent approaches to establish robustness of stabilizing feedback control against the possible uncertainties have a serious limitation, that is, their applicability only to the systems that satisfy the matching conditions. Such conditions are rarely met in general applications. If a particular system satisfies the matching conditions, the addition of an actuator will destroy the satisfaction of such conditions. In this paper, we develop robust control algorithm for uncertain multivariable systems in which the matching conditions are not necessarily met. In order to eliminate an influence over partial state variables due to unknown constant disturbances we perform the appropriate block-decomposition for a given system. Functional observers are introduced to estimate the unknown constant disturbances. The sliding mode controller is designed in such a way that the partial state variables in the state-space are directed towards switching surfaces and regulated to the origin asymptotically. Numerical examples are discussed as illustrations.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.10
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• pp.65-73
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• 2009

For mass production of printed electronics in roll-to-roll fashion, precision tension control is important to reduce register errors. Register error should be minimized within several to tens of microns for many electronic devices to be manufactured through printing technology. In order to achieve this goal, tension disturbance must be attenuated before printing process within a certain range. In this paper, a certain tension range which allows maintaining register error within 10 micron was defined with specific operating conditions. A LQG controller was proposed instead of the conventional PI controller for precision tension control using a multivariable feedback. A guideline to determine design parameters for calculating LQ gain was proposed. The proposed LQG controller was compared to both PI controller and LQ regulator with white noise by numerical simulations. Results showed that the proposed LQG controller was effective for attenuating tension disturbance with white noise.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.8
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• pp.805-815
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• 1992

In this paper, robust decoupling control scheme of miftivarlable systems Is studied. Design methods for Input-Output decoupling systems with robustness against signal failure In arbitrary feedback loop or actuator loop Is suggested based on the Riccati type matrix equation and state feedback, and is simulated In Turbo-Generator systems with B-Input, 2 output. The results of simulation represents the decoupled and stable response against the failure of signal In sensor or actuator loop. However, the system designed by conventional ,it ate feedback shows the unstable response. This method Is applied for robust decoupling control of the complicated multivariable systems.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.337-340
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• 1997

In this paper we propose direct and indirect adaptive controllers for a nonlinear multivariable steam generating unit(200MW). In the direct adaptive scheme the estimation of the controller parameter are achieved from tracking error, while in the indirect approach the unknown parameter of the boiler system is estimated by the Hopfield network-based identifier. The performance of two proposed adaptive controllers is shown through simulations.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.1040-1044
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• 1992

This paper presents an algebraic approach for finding a dynamic state feedback controller when the linear multi-input system with delays in both state and input is controllable. In the time-delay case, controllability of the system does not always imply that system is cyclizable. Therefore, reduced order augmentation systems which is cyclizable as the time-varying case are considered. It is possible to construct feedback contorl systems by using single-input methods.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.55-60
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• 1986

Conditions for achieving noninteraction in nonlinear multivariable systems via the decomposition of state space are well established. The main contribution of this paper is to present a Standard Decomposed System (SDS). The SDS is similar to the decomposed system of Isidorl, Krener, Gori-Giorgi, and Monaco but has a finer structure. The finer structure parallels the one used by Gilbert for linear systems. A weaker form of noninteraction, based on input-output behaviour, is decoupling. Some connections between decomposition and decoupling are also established.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.373-376
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• 1986

This paper proposes a robust model following control system which realizes good properties such as asymptotic stability, disturbance rejection and model following with reduced sensitivity for plant parameter variation. This algorithm can be easily applied to the multivariable control systems and the control structure is simple. As an example the aircraft control system of a convair C-131B is designed and its characteristics are examined by simulation.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.9
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• pp.60-66
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• 1997

WE consider the stabilization of a class of multivariable nonlinear system using variable structure output feedback control. A high-gain observer is used to estimate state variable while rejecting the effect of the disturbances. We design a globally bounded output feedback variable structure controller that semi-globally stabilize the closed-loop system, while state variables do not exhibit a peaking.