• 전기학회논문지
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• 제67권2호
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• pp.308-313
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• 2018

In this paper, we propose a sampled-data model predictive tracking control deign for leader-following control of multi-mobile robot system. The error dynamics of leader-following robots is modeled as a Linear Parameter Varying (LPV) model. Also, the Lyapunov function is presented to guarantee stability of the networked control system. Based on the stabilization condition using a quadratic Lyapunov function approach, model predictive sampled-data controller is designed. Finally, the leader-following control of multi mobile robots is simulated to show effectiveness of the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.226-228
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• 2006

This paper is concerned with an Adaptive Fuzzy Sliding Mode Control(AFSMC) that the fuzzy systems are used to approximate the unknown functions of nonlinear system. In the adaptive fuzzy system, we adopt the adaptive law to approximate the dynamics of the nonlinear plant and to adjust the parameters of AFSMC. The stability of the suggested control system is proved via Lyapunov stability theorem, and convergence and robustness properties are demonstrated. The simulation results demonstrate that the performance is improved and the system also exhibits stability.

• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1287-1292
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• 1999

In large-scale systems, we frequently encounter the time-delay and the uncertainty, and these should be considered in the design of controller because these are the source of the degradation of the system performance and instability of system. In this paper, we consider the robust stability of the linear large scale systems with the uncertainties and the time-delays. The considered uncertainties are both structured uncertainty and the unstructured uncertainty. Also, the considered time-delays are time-varying having finite time derivative limits. Based on the Lyapunov theorem and the linear matrix inequality(LMI) technique, we present two sufficient conditions that guarantee the robust stability of the system. The conditions are expressed as the LMI forms which can be easily checked their feasibility by using the well-known LMI control toolbox. Finally, we show by two examples that our results are less conservative than the previous results.

• 전기학회논문지
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• 제64권7호
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• pp.1096-1103
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• 2015

Electromagnetic levitation system(EMLS) is one of the well known nonlinear systems due to its high degree of nonlinearities. Moreover, when there are uncertain parameters in EMLS, it is not easy to have an accurate control of EMLS. In this paper, we first apply a standard input-output feedback linearzing controller to EMLS and investigate the possible control error caused by uncertain coil resistor. Then, as a remedy, we design and apply a robust controller using Lyapunov redesign technique to deal with this uncertain coil resistor in the system. The validity of our robust controller is verified via system analysis and experimental results.

• 한국자동차공학회논문집
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• 제10권5호
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• pp.29-34
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• 2002

This study presents the process of the continuous-time system identification for unknown nonlinear systems. The Radial Basis Function(RBF) error filtering identification model is introduced at first. This identification scheme includes RBF network to approximate unknown function of nonlinear system which is structured by affine form. The neural network is trained by the adaptive law based on Lyapunov synthesis method. The identification scheme is applied to engine and the performance of RBF error filtering Identification model is verified by the simulation with a three-state engine model. The simulation results have revealed that the values of the estimated function show favorable agreement with the real values of the engine model. The introduced identification scheme can be effectively applied to model-based nonlinear control.

• 호남수학학술지
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• 제44권3호
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• pp.402-418
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• 2022

Noise is a fundamental factor to increased validity and regularity of spike propagation and neuronal firing in the nervous system. In this paper, we examine the stochastic version of the Izhikevich-FitzHugh neuron dynamical model. This approach is based on techniques presented by Luo and Guo, which provide a general framework for the bifurcation and stability analysis of two dimensional stochastic dynamical system as an Itô averaging diffusion system. By using largest lyapunov exponent, local and global stability of the stochastic system at the equilibrium point are investigated. We focus on the two kinds of stochastic bifurcations: the P-bifurcation and the D-bifurcations. By use of polar coordinate, Taylor expansion and stochastic averaging method, it is shown that there exists choices of diffusion and drift parameters such that these bifurcations occurs. Finally, numerical simulations in various viewpoints, including phase portrait, evolution in time and probability density, are presented to show the effects of the diffusion and drift coefficients that illustrate our theoretical results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.177-178
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• 2008

An LMI-based method for robust $L_2-L_{\infty}$ filter design is proposed for poly topic uncertain time-delay systems. By using the Projection Lemma and a suitable linearizing transformation, a strict LMI condition for $L_2-L_{\infty}$ filter design is obtained, which does not involve any iterations for design-parameter search, any couplings between the Lyapunov and system matrices, nor any system-dependent filter parameterization. Therefore, the proposed condition enables one to easily adopt, with help of efficient numerical solvers, a parameter-dependent Lyapunov function approach for reducing conservatism, and to design both robust and parameter-dependent filters for uncertain and parameter-dependent time-delay systems, respectively.

• 한국산학기술학회논문지
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• 제10권10호
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• pp.2651-2659
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• 2009

본 논문에서는 구조적 불확실성을 갖는 비선형 시스템에 대한 역 최적 제어를 고려하였다. 먼저 불확실성의 구조적 범위를 논의하고, 제어 Lyapunov 함수를 기초로, 불확실성을 가지는 비선형시스템에 대한 대역적 점근적 안정도를 제안하고 증명한다. 이로부터 역 최적 제어를 위한 최저의 제약조건을 유도하고 증명한다. 이 결과를 이용하여 불확실성을 갖는 비선형시스템에 적용하였으며, 제안된 방법의 효율성을 검증하기 위하여 시뮬레이션을 하였다.

• 융합신호처리학회논문지
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• 제9권2호
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• pp.159-163
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• 2008

본 논문에서는 유연모드 부속물을 갖는 우주선의 제어를 위해서 누스범 이득을 갖는 간단한 형태의 적응제어기를 제안한다. 이 방법은 전달함수에서 고주파 이득의 정보가 필요하지 않는다. 본 논문의 방법을 사용하여 피치각도가 목표치를 추종하는 중에, 아울러 유연모드의 안정화도 이룬다. 피치각과 피치각속도 성분만 사용하여 출력궤환제어기를 설계한다. 특히 모든 시스템 파라미터 및 고주파성분은 미지로 한다. 설계의 간편성을 위해서 선형함수만을 사용하여 설계한 제어기가 전체 비선형시스템을 만족함을 시뮬레이션을 통하여 보이고, 그 근거도 설명한다. Lyapunov 함수를 구성하여 제안한 방법의 안정성을 증명하고, MATLAB을 이용한 컴퓨터 시뮬레이션 결과를 제시하여 제안한 방법의 유용성을 증명한다.

• 한국지능시스템학회논문지
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• 제21권5호
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• pp.630-636
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• 2011

본 논문은 매개변수 불확실성을 가지는 Takagi-Sugeno(T-S) 퍼지 시스템의 안정도 해석과 안정화 조건을 고려한다. T-S 퍼지 시스템의 안정도 해석 시 conservativeness를 줄이기 위해 퍼지 리아푸노프 함수를 이용한다. 매개변수 불확실성을 가지고 있는 시스템의 안정도를 해석하고 시스템을 안정화 시키는 퍼지 강인 제어기 설계 기법을 제시한다. 안정도조건과 안정화조건은 선형행렬부등식의 형태로 표현된다. 모의실험을 통해 제안된 접근 방법의 효용성을 보인다.