• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1987-1992
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• 2004

A Variable Structure Model Reference Adaptive Controller (VS-MRAC) using state Variables is proposed for single input multi output systems. . The structure of the switching functions is designed based on stability requirements, and global exponential stability is proved. Transient behavior is analyzed using sliding mode control and shows perfect model following at a finite time. The effect of input disturbances on stability and transients is investigated and shows preference to the conventional MRAC schemes with integral adaptation law. Sliding surfaces are independent of system parameters and therefore VS-MRAC is insensitive to system parameter variations. Simulation is presented to clear the theoretical results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.125.4-125
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• 2001

The problem of recongurable ight control is investigated, focusing on model reference adaptive control(MRAC) through imprecise fault diagnosis. The method integrates the fault detection and isolation(FDI) scheme with the model reference adaptive control, and can be implemented on-line and in real-time. The algorithm can cope with the fast varying parameters. The Simulation results demonstrate the ability of reconguration to maintain the stability and acceptable performance after a failure.

• Journal of Mechanical Science and Technology
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• 제18권3호
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• pp.337-346
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• 2004

The control scheme using fuzzy modeling and Parallel Distributed Compensation (PDC) concept is proposed to provide asymptotic tracking of a reference signal for the flexible joint manipulators with uncertain parameters. From Lyapunov stability analysis and simulation results, the developed control law and adaptive law guarantee the boundedness of all signals in the closed-loop multi-input/multi-output system. In addition, the plant state tracks the state of the reference model asymptotically with time for any bounded reference input signal.

• 한국지능시스템학회논문지
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• 제4권1호
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• pp.24-34
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• 1994

A RMFSOC(Reference Model Following Self-Organizing Fuzzy Logic Controller) is propose in this paper. In the RMFSOC, the refernce model is introduced, where the desired control performance can be specified by an operator of the controlled process. The self-organizing level of the RMFSOC organizes the control rules of FLC which make the process output follow the reference model output. In addition, for the use of preventing improper modifications of control rules, a complementary decission rule is induced from the possible relations between the process output and reference model output. Through a simulation study, it is shown that the robustness of the control system using the proposed RMFSOC to the set-point changes and distur bances can be greatly improved being conpared with that of the control system using the Procyk and Mamdani's SOC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1872-1875
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• 1998

In the industrial motor drive system, a shaft torsional vibration is often generated when a motor and a load are connected with a flexible shaft. This paper treats the vibration suppression control of such a system. Recently, there are new methods which estimate unknown state variables by using a reduced order observer and feedback these state variables by using a pole placement design method. But there is a trade-off between the fast command following property and the attenuation of disturbances and vibrations in these design methods. In this paper, the vibration suppression control of a two-mass system using a reference model is proposed. Because of using a reference model, the proposed control satisfy the fast command following property and the attenuation of disturbances and vibrations. Control parameter can be changed to maintain high system performance in control using a reference model. Experimental results show the validity of the proposed state feedback control using a reference model, and this controller is compared with the state feedback controller.

• 제어로봇시스템학회논문지
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• 제8권11호
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• pp.928-934
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• 2002

A natural way to cope with fault tolerant control (FTC) problems is to modify the control parameters according to an online identification of the system parameters when a fault occurs. However. due to not only difficulties Inherent to the online multivariable identification in closed-loop systems, such as modeling errors, noise or the lack of excitation signals, but also long time requirement to identify the post-fault system and implemeutation of control problems during the identification process, we propose an alternative approach based on the observer-based fault detection and isolation (FDI) and model reference adaptive control (MRAC). The proposed robust fault diagnosis method is based on a bank of observers. We also propose a model reference adaptive control with changeable reference models according to the occurred faults. Simulation results of a flight control example show the validity and applicability of the proposed algorithms.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.763-766
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• 1996

A model helicopter is an unstable, multi-input multi-output nonlinear system exposed to strong disturbances and its system parameters change continually. In this paper, Time Delay Control(TDC) is adopted for these reasons. TDC uses past observation of the system's response and the control input to directly modify the control action rather than adjusting the controller gains leading to a model independent robust controller. TDC can force the plant to follow an appropriate reference model, but the reference model cannot be chosen arbitrarily. In this paper the procedure of choosing a reference model and the performance of the controller are presented.

• 대한기계학회논문집A
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• 제26권6호
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• pp.1135-1142
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• 2002

In this study, a methodology of synchronous control which can be applied to position synchronization of a multi-axes driving system has been developed. The synchronous error is caused by model uncertainties and disturbance at each axis. To overcome these problems, the synchronous control system of each axis has been composed of reference model, speed and synchronous controllers. The speed control system has been designed to follow speed reference. And the synchronous controller has been designed to keep minimizing the position synchronous error by reference model and H$\sub$ / approach. By the proposed method, position synchronous control system can be easily extended to two or more axes driving system. The effectiveness of the proposed method has been demonstrated by experiment.

• 전력전자학회논문지
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• 제7권3호
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• pp.215-223
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• 2002

본 논문은 벡터로 제어되는 유도전동기 드라이브를 위하여 퍼지논리에 기초한 속도 및 자속제어기의 적응제어를 제시한다. 적응 메카니즘에서 제시된 모델기준 적응방법은 전동기의 속도와 기준모델의 출력 사이에서 측정한 오차와 오차의 변화에 의하여 퍼지논리를 수행한다. MIRAC(Model Reference Adaptive Control) 퍼지제어기는 다양한 동작조건을 위하여 시뮬레이션에 의해 평가한다. 제시한 MIRAC 퍼지제어기의 타당성은 유도전동기 드라이브 시스템에 적용하여 성능 결과로 입증한다.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.405-415
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• 2016

This paper presents a model predictive control for shunt active power filters in synchronous reference frame using space vector pulse-width modulation (SVPWM). The three phase load currents are transformed into synchronous rotating reference frame in order to reduce the order of the control system. The proposed current controller calculates reference current command for harmonic current components in synchronous frame. The fundamental load current components are transformed into dc components revealing only the harmonics. The predictive current controller will add robustness and fast compensation to generate commands to the SVPWM which minimizes switching frequency while maintaining fast harmonic compensation. By using the model predictive control, the optimal switching state to be applied to the next sampling time is selected. The filter current contains only the harmonic components, which are the reference compensating currents. In this method the supply current will be equal to the fundamental component of load current and a part of the current at fundamental frequency for losses of the inverter. Mathematical analysis and the feasibility of the suggested approach are verified through simulation results under steady state and transient conditions for non-linear load. The effectiveness of the proposed controller is confirmed through experimental validation.