• 전기학회논문지
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• 제63권6호
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• pp.786-796
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• 2014

This paper presents a new approach to design a robust tracking controller for linear time-invariant systems with uncertain time-delay. By introducing the model following control (MFC) structure which consists of two loops in nature, we show that the controller is capable of having a predictive control action and effectively tracking the reference output with a desired transient response as well. Three design techniques to achieve good tracking performance are suggested. It is also analytically shown that the tracking performance of the proposed scheme is more robust than that of typical single-loop feedback structure. An illustrative example is given to compare the tracking performances of the proposed methods with a single loop method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2669-2671
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• 2000

In this paper, a new model error following sliding mode control is considered with a novel sliding surface for the error. This novel sliding surface has nominal dynamics of an original state of the error system and makes it possible that the Sliding Mode Control(SMC) technique for the error of the model following is used with the various types of controllers. Its design is based on the augmented system whose dynamics have a higher order than that of the original error system. The reaching phase is removed by using an initial virtual state which makes the initial error state sliding function equal to zero.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.911-914
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• 1993

This paper makes a trial to build the model of car-following in the state of starting to stable driving on the basic of driver's knowledge that is easily characterized by linguistical cognition. There are three main steps in building the model. Firstly, each driver's rule of three testees is studied in linguistical experssion by the interview and questionary surveys that are repeated once a day for ten days. Secondly, quantification of the linguistical expression is investigated by driving experiments that includes the questionary survey to the testee in the test vehicle, and the membership functions of variables of rule are obtained. Thirdly, implicaton and composition of fuzzy inference is made by Max-Min Methods and defuzzification by gravity method. It can be said that the proposed model of car-following based on driver's knowledge is practically allpicable to the estimation of drivering of car-following on trunk roads in urban area.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.45.2-45
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• 2001

In case that the perfect model following conditions are not satisfied in the system, a perfect model-following controller is difficult to apply to the system. To deal with this problem, in this paper, a robust imperfect stable model-following controller is designed by combining time delay controller and sliding mode controller based on the concept of two degrees of freedom(2-DOF) controller design method. The experimental dynamic modeling of the commercial overhead crane with capacity of two tons is carried out. To remove the noise of the measuring signals from the swing angle measurement device and estimate the state of the swing angles of the transported object at each time instant, realtime tracker is designed using Kalman filter. The performance of the designed robust controller is tested through the commercial overhead. The experimental results show that the designed controller is robust and applicable to real systems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.548-552
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• 1994

The robust compensation controller, which has been proposed by one of the authors and is based on the fundamental principle of making the plant follow the reference model, consists of the reference model and the robust compensator. The reference model is constructed by using the nominal model of the plant and determines the input-output properties of the resultant system. The robust compensator is obtained as a solution of the mixed sensitivity problem in H infinity control theory. Therefore the resultant system is of low sensitivity and robust stability. In the case where uncertainty does not occur in the plant, the plant follows perfectly the reference model. Therefore, in the case where uncertainty occurs in the plant, we propose the system configuration which improves the following accuracy without replacing the 개bust compensator but by identifying, the plant and reconstructing the reference model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.21-23
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• 2005

NARX(Nonlinear AutoRegressive with eXogenous input) neural network was used for prediction of nuclear reactor behavior which was influenced by control rods in short-term period and also by xenon and boron in long-term period in load following operations. The developed model was designed to predict reactor power, xenon worth and axial offset with different burnup rates when control rod and boron were adjusted in load following operations. Data of UCN 3 were collected by ONED94 code. The test results presented exhibit the capability of the NARX neural network model to capture the long term and short term dynamics of the reactor core and seems to be utilized as a handy tool for the use of a plant simulation.

• 한국지능시스템학회논문지
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• 제22권4호
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• pp.476-480
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• 2012

본 논문에서는 선도 로봇을 추종하는 군집 로봇의 대형 제어를 인공 포텐셜 장을 사용하여 제안한다. 또한, 인공 포텐셜 장은 물리적으로 해석하기 쉬운 전기장을 모델링하여 구성하고, 장애물을 더욱 효과적으로 모델링하기 위해서, 장애물의 모양에 따라 전기장의식을 달리한다. 제안하는 방법은 선도 로봇의 경로를 인공 포텐셜 장을 통해 계획한 뒤, 선도 로봇을 추종 로봇이 뒤따라가는 형태로 구성된다. 마지막으로 시뮬레이션 예제를 통해 제안하는 기법의 타당성을 검증한다.

• 전자공학회논문지T
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• 제35T권1호
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• pp.82-89
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• 1998

PI제어기는 서보시스템에 널리 사용되어 왔다. 그러나 PI제어기로 설계된 시스템응답은 부하변동과 같은 외란이나 시스템 변수의 변화에 대하여 원하는 시간응답을 보존할 수가 없다. 따라서 시간응답 특성의 견실성을 확보하면서, 구현상의 어려움을 해결하기 위하여 선형요소만으로 구성되는 선형 모델추종제어(LMFC: linear model following control) 방법이 있다. 이 방법은 기준모델의 출력을 플랜트가 추종하도록 제어하는 것으로, 플랜트의 구조적 섭동에 무관한 시간응답 특성을 얻을 수 있으나 부하토크에 대한 응답속도가 느린 단점이 있다. 이러한 단점을 해결하기 위하여 모델추종제어기에 강인성향상기를 보조모델을 사용하여 도입함으로써 지주파 부하토크에 대한 응답속도를 향상시켰다. 제안된 제어기(RMFC: LMFC with robust enhancer)는 저주파 부하토크에 대하여 LMFC보다 강인한 특성을 보였으며 시뮬레이션 및 TMS320C30 DSP 시스템에 의한 실험으로 검증하였다.

• 한국정밀공학회지
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• 제17권12호
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• pp.176-184
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• 2000

TDC(Time Delay Control) deals with the time-varying system parameters, unknown dynamics and unexpected disturbances using time delay. TDC can be divided into two separate parts: an auxiliary controller and a servo controller. The two controllers can be designed independently. The auxiliary controller is used to reduce sensitivity to parameter variations, nonlinear effects, and other disturbances. The servo controller is to reduce the error between the desired command and output. We propose the model-following time delay controller with modified error feedback controller. This was applied to follow the desired reference model for the uncertain time-varying overhead crane. The model generates the damped-out swinging motion trajectory to suppress the swinging motion caused by the acceleration and the deceleration of crane transportation. The control performance was evaluated through simulations. The theoretical results indicate that this control method shows excellent performance to an overhead crane with the uncertain time-varying parameters.

• 제어로봇시스템학회논문지
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• 제15권7호
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• pp.661-666
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• 2009

The linear model following controller(LMFC) scheme controls a plant based on the output of a reference model, thereby replacing a PI controller that has better time response characteristics, which are irrelevant to the structural perturbation of a plant. However, the main weakness of the LMFC scheme is a slow response time to load changes. Thus, to solve this problem, a robust linear model following controller(RMFC) was developed that is robust in load changes. However, when compared with the LMFC scheme, the RMFC scheme has a weaker performance in the case of system parameter changes. Therefore, this paper presents a new LMFC scheme, where the controller is designed based on the output of a plant rather than the output of a model, as in the case of the conventional LMFC scheme. As a result, in the case of load changes, the response characteristics of the proposed scheme are slower than those of the RMFC scheme, yet laster than those of the conventional LMFC scheme, however, for parameter changes, the proposed scheme has a superior performance over the RMFC scheme. The usefulness of the proposed LMFC scheme is verified through a comparison using MATLAB/SIMULINK.