• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.4
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• pp.136-144
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• 1983

In this paper, a new scheme of implicit MRAC is presented for single input single output discrete system. The MRAC can be applied to the nonminimum phase system, too. They have simple structure because the parameters of the controller are estimated directly by changing the plant output equation properly. In this scheme, the observation process is well seperated from the adaptation process, so the adaptation algorithm is derived from the exponentially weighted least square method which has fast convergence characteristics and can deal with the time varying plant. The consistency of the estimated parameter is proved. And it is also proved the whole system has the stabilizing property. The effectiveness of the algorithm and the structure is illustrated by the computer simulation of the model reference adaptive control for a third order plant. It is proposed how to select the selectable parameters in the adaptive control system from the simulation results.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2630-2632
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• 2000

In this paper, a control technique of Takagi-Sugeno (TS) fuzzy systems with parametric uncertainties is developed. The uncertain TS fuzzy system is represented as an uncertain multiple linear system. The control problem of TS fuzzy system is converted into the stabilization problem of a uncertain multiple linear system. A sufficient condition for robust stabilization is obtained in terms of linear matrix inequalities (LMI). A Design example is illustrated to show the effectiveness of the proposed method.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2602-2604
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• 2000

In this paper, we study robust linear optimal model following servo system in the presence of disturbances and parameter perturbations. A technique to directly design the generalized differential operator based unified control system that covers both differential operator based continuous time and delta operator based discrete time case is presented. The quadratic criterion function for a linear system is used to design the robust unified servo control system. This servo control system is designed by applying a simple genetic algorithm to follow the output of the reference model optimally. The characteristics of the proposed servo system are analysed and simulated to verify the robustness.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.12
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• pp.1009-1014
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• 2001

The ladder diagram (LD) for programmable logic controllers (PLCs) ar responsible for much important roles in advance industrial automation. As automated systems become more complex the design procedures of the system become more difficult as well. Hence. the design automation issues based on discrete event models(DEMs) are receiving more attention. One of the popular ways of tackling these problems is employing Petri nets. In this paper, we use the modified automation Petri net(MAPN) to model the manufacturing system and the modified token passing logic (MTPL) method conversion (ECC) algorithm based on the MAPN and the MTPL Finally, an example of the manufacturing system is provided to illustrate the proposed ECC algorithm.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.7
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• pp.529-536
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• 2000

A robust controller to attenuate the various disturbances of tandem cold mills (TCM) is synthesized by measurement-feedback $H_{\infty}$ control techniques which can reflect the input direction of disturbances and the knowledge of entry thickness variation (disturbance) is synthesized by discrete-time measurement-feedback $H_{\infty}$ control theory. It is demonstrated that the $H_{\infty}$ preview control gain can be easily obtained by the seperation principle of the control and estimation problems in $H_{\infty}$ control. Finally the effectiveness of the proposed control method for TCM is evaluated by the computer simulation and compared to the other control methods which have been previously studied.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.183-186
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• 2002

In this paper, a predictive control method using wavelet neural network for chaotic nonlinear systems is presented. In our method, we use the adjusting method of the parameter for the training a wavelet neural network. The control signals are directly obtained by minimizing the difference between a reference signal and the output of a wavelet neural network. To verify the efficiency of our method, we apply it to the Duffing and the Henon system, which are a representative continuous and discrete time chaotic nonlinear system respectively.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.1
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• pp.45-51
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• 2001

본 논문은 이산 시간 Takagi-Sugeno (TS) 퍼지 시스템에 대한 출력 추종 제어기 설계에 관하여 연구한다. 출력 추종 제어기의 설계를 위하여 이산 시간 TS 퍼지 시스템을 불확실성을 포함한 선형 시스템의 집합으로서 표현하는 기법을 제시한다. 시스템의 상태에 대하여 어파인 변환을 하여 출력 추종 제어문제를 안정화 문제로 변환한다. 점근적 추종성능을 보장하는 제어기 설계를 위한 충분조건은 선형 행렬 부등식의 형태로 표현되면 주어진 제어기 설계의 해는 여러 가지 수치적 기법을 이용하여 효율적으로 구해질 수 있다. 트레일러 트럭의 임의의 위치에 후진 주차시키기 위한 제어기 설계의 예를 통하여 본 논문에서 제안한 추종 제어 기법의 효용성을 검증한다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.7
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• pp.257-266
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• 1985

A new method for the artificial beta cell which can be used to control the hyperglycemia in diabetic patients was represented. The relationship between the insulin infusion rate and the blood glucose concentration was described by the second order ARMA model, and the time varying parameters were identified by exponentially weighted least squares estimator. The design of controller was based on the pole assignment self tuning altorithm with discrete blood sampling and the constraints of input and output responsse rate were considered. The results of animal experiments show that this method may be a fruitful approach for regulating the blood glucose level. We expect that this device can be used as both therapeutic and research tools providing that its stability and reliability are improved a little more.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.3
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• pp.228-236
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• 1989

The theroy of variable structure control system (VSS) is applied to the position control for DC servo-motors. In order to use the microcomputer as a control device, the principles of VSS for the continuous-time system are extended to the discrete-time system. A new switching law is proposed to achieve the reduction of chattering. It adds a new switching structure to the conventional switching sturctures. This switching region is set near and including the conventional switching curve. The new algorithm is obtained for single-input second order system, and applied to the position control of a DC servo-motor. Experimental results show that the transient behavior is improved due to the reduction of chattering and good robustness properties are demonstrated.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.11
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• pp.913-921
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• 1989

This paper deals with a pole placement indirect adaptive control algorithm for discrete-time linear plants with arbitrary zeros. The resulting closed-loop control system is shown to be globally stable subject to the assumptions that an external input is persistently exciting and a lower bound on the magnitude of the Sylvester resultant of the plant numerator and denominator polynomials is known. The problem of controllability of the plant estimate in indirect adaptive control is handled by using an extended parameter correction. The validity of the proposed control algorithm is assured through simulation for a second-order plant.