• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.185-189
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• 1998

This paper addresses analysis and design of a fuzzy model-based-controller for the control of uncertain SISO nonlinear systems. In the design procedure, we represent the nonlinear system by using a Takagi-Sugeno fuzzy model and construct a global fuzzy logic controller via parallel distributed compensation and sliding mode control. Unlike other parallel distributed controllers, this globally stable fuzzy controller is designed without finding a common positive definite matrix for a set of Lyapunov equations, and has good tracking performance. The stability analysis is conducted not for the fuzzy model but for the real underlying nonlinear system. Furthermore, the proposed method can be applied to partially known uncertain nonlinear systems. A numerical simulation is performed for the control of an inverted pendulum, to show the effectiveness and feasibility of the proposed fuzzy control method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1449-1454
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• 2003

For many industrial processes there are good static models used for process design and steady state operation. By using system identification techniques, it is possible to obtain black-box models with reasonable complexity that describe the system well in specific operating conditions [1]. But black-box models using inductive modeling(IM) is not suitable for model based control because they are only valid for specific operating conditions. Thus we need to use deductive modeling(DM) for a wide operating range. Furthermore, deductive modeling is several merits: First, the model is possible to be modularized. Second, we can increase and decrease the model complexity. Finally, we are able to use model for plant design. Power plant must be able to operate well at dramatic load change and consider safety and efficiency. This paper proposes a simplified nonlinear model of an industrial boiler, one of component parts of a power plant, by DM method and applies optimal control to the model.

• 제어로봇시스템학회논문지
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• 제9권10호
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• pp.836-843
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• 2003

The automatic train control (ATC) system development project for the Automated Guideway Transit (AGT) system has high technical risk because the system is unmanned train control system using wireless technology which was unprecedented in train control industry of Korea. To overcome the technical risk during concept design phase of the ATC system development project, the integrated product team(IPT) carried out a reverse and reengineering process using a systems engineering design model. The generic systems engineering process is incorporated in the both reverse and reengineering process. As a result of the systems engineering effort, the IPT has built top layer systems engineering design model of the ATC subsystem. The purpose of this paper is to deliver the reverse and reengineering process which was used to develop the systems engineering design model of ATC system using a computer aided systems engineering tool. This study also shows that the model based reverse and reengineering process can reduce the technical risk by identifying the differences of requirement, functional and physical architecture between a reference system and a target system.

• 제어로봇시스템학회논문지
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• 제10권5호
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• pp.385-394
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• 2004

This paper proposes the generalized structure of a model-based disturbance rejection controller called a Robust Internal-loop Compensator (RIC). The framework consists of the RIC in the internal-loop to eliminate disturbances and a feedback controller in the external-loop to achieve nominal control performance. As the main contribution of this paper, we redefine the design problem of the RIC as a regulation control problem, then show that this new definition with the RIC structure provides more design flexibility and less implementation constraints. This is verified through a comparative structural analysis with Disturbance Observer (DOB) and Adaptive Robust Control (ARC). Two design examples of the RIC are given, along with practical issues that should be considered in the design procedure. The proposed framework is demonstrated by simulations of a rotary-type motor and experiments with a linear-type motor system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.381-385
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• 1992

In this paper, dynamic modeling and adaptive control problems for a space robot system are discussed. The space robot consist of a robot manipulator mounted on a free-floating base where no attitude control is applied. Using an extended robot model, the entire space robot can be viewed as an under-actuated robot system. Based on nonlinear control theory, the extended space robot model can then be decomposed into two subsystems: one is input-output exactly linearizable, and the other is unlinearizable and represents an internal dynamics. With this decomposition, a normal form-augmentation approach and an augmented state-feedback control are proposed to facilitate the design of adaptive control for the space robot system against parameter uncertainty, unknown dynamics and unmodeled payload in space applications. We demonstrate that under certain conditions, the entire space robot can be represented as a full-actuated robot system to avoid the inclusion of internal dynamics. Based on the dynamic model, we propose an adaptive control scheme using Cartesian space representation and demonstrate its validity and design procedure by a simulation study.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1516-1520
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• 2005

We proposed the indirect adaptive fuzzy model based sliding mode controller to control a nonaffine nonlinear systems. Takagi-Sugano fuzzy system is used to represent the nonaffine nonlinear system and then inverted to design the controller at each sampling time. Also sliding mode component is employed to eliminate the effects of disturbances, while a fuzzy model component equipped with an adaptation mechanism reduces modeling uncertainties by approximating model uncertainties. The proposed controller and adaptive laws guarantee that the closed-loop system is stable in the sense of Lyapunov and the output tracks a desired trajectory asymptotically.

• 한국항공우주학회지
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• 제41권6호
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• pp.488-494
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• 2013

전자식 비행제어시스템(Fly-By-Wire Flight Control System)에 적용되는 헬리콥터의 제어법칙 설계 및 해석은 모델기반 설계기법(Model Based Design)을 사용하여 개발되고 있다. 모델기반 설계기법은 회전익뿐만 아니라 고정익, 무인항공기, 자동차 산업에서도 널리 사용되고 있다. 모델기반 설계기법은 핵심기술인 시뮬레이션과 자동생성코드를 이용하여 개발기간 단축 및 개발리스크 감소라는 장점을 제공한다. 본 논문에서는 FBW 헬리콥터 비행제어법칙의 자동생성코드에 대해서 체계적인 기능검증을 위한 프로세스를 개발하였다. 그리고 지식경제부 과제로 진행하고 있는 FBW 헬리콥터 개발에 적용하여 비행제어법칙 자동생성코드의 기능 검증을 수행 결과, 요구 조건을 충족하는 것으로 확인할 수 있었다.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1901-1910
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• 2023

The safety-class (1E) digital control system (DCS) of nuclear power plant characterized structural multiple redundancies, therefore, it is important to quantitatively evaluate the reliability of DCS in different degree of backup loss. In this paper, a reliability evaluation model based on T-S fuzzy fault tree (FT) is proposed for 1E DCS of nuclear power plant, in which the connection relationship between components is described by T-S fuzzy gates. Specifically, an output rejection control system is chosen as an example, based on the T-S fuzzy FT model, the key indicators such as probabilistic importance are calculated, and for a further discussion, the T-S fuzzy FT model is transformed into Bayesian Network(BN) equivalently, and the fault diagnosis based on probabilistic analysis is accomplished. Combined with the analysis of actual objects, the effectiveness of proposed method is proved.

• Journal of Mechanical Science and Technology
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• 제18권11호
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• pp.1961-1968
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• 2004

The design of a reliable and failsafe control system requires that sensor failures be detected and identified within acceptable time limit so that system malfunction can be prevented. This paper presents a model-based approach to sensor fault detection with applications to vehicle stability control systems. The effectiveness of the proposed method is illustrated through test data-based evaluation. Vehicle test data-based evaluation results show that the proposed fault management scheme can be used for the design of a failsafe VSCs.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.165-168
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• 1996

In this paper, we propose a design method of PID adaptive controller based on frequency domain analysis. The method is based on the estimation of a nonparametric process model in the frequency domain and the determination of the PID controller parameters by achieving partial model matching so as to minimize a performance function concerning to relative model error between the loop transfer function of the control system and the desired system. In the design method the process is represented only by a discrete set of points on the Nyquist curve of the process. Therefore it is not necessary to estimate a full order parameterized process model.