• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.2
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• pp.95-100
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• 2001

비선형 시스템의 성공적인 퍼지 모델을 구성하기 위한 최적의 퍼지 추론 시스템의 동정은 중요하고도 어려운 문제이다. 전통적으로 유전 알고리즘은 어느 정도의 전역 최적해를 찾을 수 있기 때문에 퍼지 모델의 구조와 파라미터를 동정하는데 사용되어 왔다. 그러나, 유전 알고리즘은 개체군 진화 시 우수한 개체의 출현은 지역수렴의 원인이 된다. 따라서, 본 논문에서는 바이러스 메시 유전알고리즘을 이용한 효과적인 퍼지 모델링 방법을 제안한다. 제안된 방법은 지역 정보가 개체군 내에서 교환됨으로써 지역 수렴의 대인아 될 수 있을 뿐 아니라, 가변길이 스트링을 사용함으로써 좀더 효과적이고 적응적인 구조를 가질 수 있다. 또한 본 논문에서 제안한 방법의 우수성과 일반성을 증명하기 위해 복잡한 비선형 시스템과 가스로의 퍼지모델링에 적용하였다.

• Journal of Korean Society of Transportation
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• v.19 no.1
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• pp.89-99
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• 2001

The conventional studies on equilibrium network design problem(ENDP) with fixed travel demand models assume that the future OD travel demand might not be changed even if the structure and the capacity of the network are improved. But this fixed demand assumption may loose its validity in the long-range network design because OD travel demand actually shifts with the network service level. Thus, it is desirable to involve the variable travel demand which is determined endogenously in the model in the optimal network design. In this paper a hi-level model formulation and solution procedure for ENDP with variable travel demand are presented. Firstly It is considered how to measure the net user benefits to be derived from the improved in link capacities, and the equilibrium network design problem considered here is to maximize the increase of net user benefit which results from a set of lift capacity enhancements within the budget constraints, while the OD travel demands and link travel times are obtained by solving the lower level network equilibrium problem with variable demand. And secondly sensitivity analysis is carried out to find the links to which the network equilibrium flow pattern is the most sensitive. Finally numerical example with simple network is carried out to test the validity of the model.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.285-288
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• 1997

In this paper, the dynamics of actuators for generating the input of plants is considered in a design of the variable structure systems. While the input for plants is usually implemented by means of a certain actuator, the actuator dynamics is not incorporated in most of the VSS researches until now. The control algorithm of a VSS incorporating actuator dynamics is presented, and the simulation is given to show the usefulness of the algorithms.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.12
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• pp.556-561
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• 2002

In this paper, a discrete-time variable structure controller for linear time-varying sampled-data systems with disturbances is proposed. The proposed method guarantees that the system state if globally uniformly ultimately bounded (G.U.U.B), and the ultimate bound is shown to be the order of T, O(T), where T is a sampling period.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1227-1233
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• 1993

In this paper we present the differential geometric approach for the analysis and design of sliding modes in nonlinear variable structure feedback systems. We also design the robust controller for the nonlinear system using variable structure control theory on the basis of differential geometric methods and feedback linearization applying Min-Max control based on the Lyapunov second method. The robustness against parameter uncertainties for robot manipulators with flexible joint is considered. Simulation results are presented and show the advantage of the proposed nonlinear control method.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.419-422
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• 1996

In this paper, we consider variable structure controller design of a active magnetic bearing(AMB). In particular, we design a switching hyperplane, considering coupling characteristic among each magnet. This method is designed by applying decentralized control method. Controller design consist of two factors that is, one is linear control part to drive state variables to zero asymptotically and the other is a nonlinear controller part to maintain within neighborhood of switching hyperplane. Finally, A control method designed here is checked by simulation, which shows good results.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.652-655
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• 1996

This paper develops an AC motor controller for applications. The AC motor controller is designed based on the variable structure control method and a variable structure disturbance observer is added to reduce the effects of exogenous disturbances. The designed controller is installed on the z-axis of a CNC machining center and milling experiments were performed. The results show improved performance on both position and speed tracking, when compared to the factory-designed servo controller.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1504-1508
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• 1996

In this paper, we derive dynamic equation of helicopter and design controller based on variable structure system. It is difficult to control helicopter because it has non-linear coupling between input and output of system and is MIMO system. The design of control law is considered here using variable structure methodology giving the robustness to parameter variations and invariance to some subsets of external disturbance. However we derive dynamic equations of helicopter and design stabilizing variable structure controller. Also, simulation results are given in this paper.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.852-855
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• 1996

A variable structure controller is developed for an AC servo motor used in CNC milling machines. The designed controller is implemented as an outer loop controller to a factory designed motor-servopack system. The robustness parameter is tuned for a fast response when the speed tracking error is large, while it is tuned for small oscillations when the speed tracking error is small. The designed controller is installed on a CNC machine using a PC. Cutting experiments show improved performance over the factory-designed controller.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.12-17
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• 1991

In this paper, a variable structure system control method is proposed to the trajectory control of robot arm. A proposed method uses nonlinear switching function and saturation function. Furthermore, learning control method uses to decrease of the following error. The computer simulation results show that the chattering and the following error decrease and is improved the control the performance by a proposed method.