• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.5
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• pp.10-16
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• 1996

In this paper, we consider a generalized mixed H_2/H_{\infty}$ output feedback problem. It is finding an internally stabilizing controller that minimizes a mixed $H_{2}$/ $H_{performance}$ measure. We show that a generalized mixed H_2/H_{\infty}$ system with two exogenous inputs and two controlled signals is transformed into auxiliary system with two exogenous inputs and one controlled signal. The two systems have equivalent performance. Therefore, a complete solution of generalized mixed H_2/H_{\infty}$ output feedback problem is achieved by existing results of mixed H_2/H_{\infty}$ control theory.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1178-1183
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• 2008

The variable structure control(VSC) with sliding mode is an important and interesting topic in modern control of nonlinear systems. However, the discontinuous control law in VSC leads to undesirable chattering in practice. As a method solving this problem, in this paper, we propose a scheme of the VSC with neural network sliding surface. A neural network sliding surface with boundary layer is employed to solve discontinuous control law. The proposed controller can eliminate the chattering problem of the conventional VSC. The effectiveness of the proposed control scheme is verified by simulation results.

• Journal of applied mathematics & informatics
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• v.9 no.1
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• pp.61-76
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• 2002

The robust non-fragile guaranteed cost control problem is studied in this paper for class of uncertain linear large-scale systems with time-varying delays in subsystem interconnections and given quadratic cost functions. The uncertainty in the system is assumed to be norm-hounded arid time-varying. Also, the state-feedback gains for subsystems of the large-scale system are assumed to have norm-bounded controller gain variations. The problem is to design state feedback control laws such that the closed-loop system is asymptotically stable and the closed-loop cost function value is not more than a specified upper bound far all admissible uncertainties. Sufficient conditions for the existence of such controllers are derived based on the linear matrix inequality (LMI) approach combined with the Lyapunov method. A parameterized characterization of the robust non-fragile guaranteed cost contrellers is 7iven in terms of the feasible solution to a certain LMI. Finally, in order to show the application of the proposed method, a numerical example is included.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2120-2122
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• 2001

This paper describes a PID controller for an attraction type magnetic levitation system considering $H^{\infty}$ performance. PID controllers are a kind of fixed structure reduced order controllers. Using change of variables a reduced order control problem can be recast into a static output feedback control problem and can be solved efficiently by LMI(Linear Matrix Inequality) method. In this paper, cone complementarity method is adopted and the simulation shows good results.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.87.1-87
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• 2001

For a plant subject to several kinds of disturbances in the plant input side, we consider a problem of designing a controller based on the disturbance cancellation. The conventional loop transfer recovery (LTR) technique can not be used since the extended system consisting of the plant and the disturbance model is not necessarily stabilizable. We propose a new LTR technique that can be applied for our problem. As a target of the LTR, we choose a state feedback controller using a disturbance estimator. We find an LTR procedure based on the Riccati equation formalism where the stochastic model contains the filter gain matrix of the disturbance estimator in the target. The procedure recovers the target feedback ...

• Journal of the Korean Society for Precision Engineering
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• v.12 no.4
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• pp.88-99
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• 1995

The demand for automatic manufacturing systems is increasing. Flexible Manufacturing System(FMS) is usually considered as a soluting for the shop floor automation. One of the difficulties in FMS is the communications problem. Since various machineries with different communications protocoles are included, applying a unified scheme is almost impossible. Therefore, a systematic approach is a key point to solve the communication problem. A cell is difined as an automation unit where closely related for a job reside together. A cell is a messenger between upper level computers and lower level machine equipment. In this research, the fonctions of the cell are defined to have more capabilities than conventional cells since a cell can be often a total manufacturing system is a small to medium sized factory. The cell conducts communications with different machines through the communications schemes established here. A set of software system has been developed according to the defined communication. The software has been tested for a simulation and real experiments for proof.

• Journal of the Korean Mathematical Society
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• v.51 no.1
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• pp.99-111
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• 2014

In this paper, we deal with the problem of practical observer design and the practical stabilization for a class of perturbed impulsive systems. We show that, under the classical conditions of uniform complete controllability and uniform complete observability of the nominal system without impulsive effects, it is possible to design an observer controller for a class of perturbed linear impulsive system when the origin is not an equilibrium point.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.68.5-68
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• 2001

This paper investigates the problem of linear parameter-dependent output feedback controllers design for interconnected linear parameter-varying(LPV) plant. By using a parameter-independent common Lyapunov function, sucient conditions for solving the problems are established, which allow us to design linear parameter dependent decentralized controllers in terms of scaled H-infinite control problems for related linear systems without interconnections. The solvability conditions are expressed in terms of finite-dimensional linear matrix inequalities(LMI´s) evaluated at the extreme points of the admissible parameter set.

• Journal of Korea Multimedia Society
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• v.16 no.2
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• pp.213-225
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• 2013

This paper proposes a design method of ball-plate robot controller using single camera and two motors to balance the ball on plate and reduce steady state control error. To design the ball-plate system, it is necessary to observe state of the ball and maintain balance of the plate. The state of the ball is tracked by using the CAMShift algorithm and position error of the ball is compensated by the Kalman filter. Balance of the plate is controlled by driving two motors and we used DC motors which has smaller measurement error. Due to surface condition of the plate or tracking error of ball's position, there are small errors remained. These errors are accumulated and disturb maintaining balance of the ball. To handle the problem, we propose a controller supplemented with an integrator.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.5
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• pp.19-27
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• 2004

A delay dependent fuzzy $H_2/H_{\infty}$ controller design method for delayed fuzzy dynamic systems is considered. Using delay-dependent Lyapunov function, the asymptotical stability and $H_2/H_{\infty}$ performance problem are discussed. A sufficient condition for the existence of fuzzy controller is presented in terms of linear matrix inequalities(LMIs). A simulation example is given to illustrate the design procedures and performances of the proposed methods.