• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.70-74
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• 1998

In this paper, by means of Lyapunov second method, we analyze the stability of IP control servo systems in the time domain for the first time. Based on the results on the stability analysis, the design rule to select the gain of IP control is suggested such that the maximum error of output to the nominal system is guaranteed for all uncertainty and load variations. An example of a speed control of brushless dc motor given to prove the unusefulness of the gain design rule.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.620-624
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• 2011

This paper propose a new delay-dependent stability criterion of neutral time-delay systems. By employing double-integral terms in augmented states and constructing a new Lyapunov-Krasovskii's functional, a delay-dependent stability criterion is established in terms of Linear Matrix Inequality. Through numerical examples, the validity and improvement results obtained by applying the proposed stability criterion will be shown.

• Earthquakes and Structures
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• v.21 no.6
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• pp.577-585
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• 2021

In this research, a neural network (NN) method was developed, which combines H-infinity and fuzzy control for the purpose of stabilization and stability analysis of nonlinear systems. The H-infinity criterion is derived from the Lyapunov fuzzy method, and it is defined as a fuzzy combination of quadratic Lyapunov functions. Based on the stability criterion, the nonlinear system is guaranteed to be stable, so it is transformed to be a linear matrix inequality (LMI) problem. Since the demo active vibration control system to the tuning of the algorithm sequence developed a controller in a manner, it could effectively improve the control performance, by reducing the wind's excitation configuration in response to increase in the cost efficiency, and the control actuator.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.24-24
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• 2000

This paper proposes a design method of sliding mode observer for SISO linear systems with a disturbance input. We first construct an observer with a constant gain matrix, a feedforward injection map and an external feedforward compensation signal input. Using the second Lyapunov method, we present a sufficient condition for the existence of sliding mode observer. The proposed observer guarantees that the state error trajectories enter a certain region in finite time and remain inside thereafter.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.2023-2026
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• 2007

In this letter, the problem for a class of neutral differential equation is considered. Based on the Lyapunov method, a stability criterion, which is delay-dependent on both ${\tau}\;and\;{\sigma}$, is derived in terms of linear matrix inequality (LMI). Two numerical examples are carried out to support the effectiveness of the proposed method.

• Journal of applied mathematics & informatics
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• v.32 no.5_6
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• pp.807-816
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• 2014

The asymptotic behavior of solutions of Lyapunov type matrix Volterra integro differential equation, in which the coefficient matrices are not stable, is studied by the method of reduction.

• Journal of the Korean Data and Information Science Society
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• v.21 no.3
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• pp.597-603
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• 2010

We obtain, in using generalized norms, some stability results for a very general system of di erential equations using the method of cone-valued Lyapunov funtions and we obtain necessary and/or sufficient conditions for the uniformly asymptotic stability of the nonlinear differential system.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.901-906
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• 1989

A robust stability problem for time delay systems is discussed by using a property of Lyapunov type operator equation. We propose a method to check the robust stability against the parameter perturbations occurring in both lumped parameter part and distributed delay element.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.150-160
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• 1999

본 논문은 ‘파트 1’에 그 기초를 두었으며, 실제 실험 상황에의 응용예를 들었다. 보편적인 ‘이중-우물 위치 진동기(double-well potential vibrator)'를 외부 공기압 감쇠기를 장치할 수 있도록 수정하였다. 감쇠는 높음 또는 낮음 으로 조정할 수 있도록 하였다. 이 실험계는 주기운동부터 카오스 운동까지 다양한 동적 특성을 보여준다. 힘-위상(Force-Stare Mapping) 방법이 선형상태 및 카오스상태에 응용되었으며, 특히 감쇠의 높고 낮음의 파악에 그 중점을 두었다. 그리고 , 부분발산지수들(Short term averaged Lyapunov exponents)의 합이 또한 감쇠를 파악함과 동시에 높은 감쇠에서 낮은 감쇠로의 변화를 감시할 수 있음을 보였다. 이 두가지 방법들을 비교하였으며 논하였다.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.20-22
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• 2005

In this paper, we propose a novel stability criterion for switched linear systems. The proposed method employs the results on the upper bound of the solution of LME(Lyapunov Matrix Equation) and on the stability of hybrid system. The former guarantees the existence of Lyapunov-like energy functions and the latter shows that the stability of switched linear systems by using these energy functions. The proposed criterion releases the restriction on the stability of switched linear systems comparing with the existing methods and provides us with easy implementation way for pole assignment.