• 제어로봇시스템학회논문지
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• 제19권4호
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• pp.281-284
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• 2013

This paper describes a reduced observer design problem for one-sided Lipschitz nonlinear systems which are considered as a generalization of Lipschitz systems. The sufficient conditions to ensure the existence of reduced order observer are provided by using linear matrix inequalities. Moreover, it is shown that existence conditions of reduced order observer can be obtained from sufficient conditions on the existence of full order observer. As a result, this fact implies that the existence of full order observer for one-sided Lipschitz systems guarantees that of reduced order observer. Finally, a simulation example is given to verify the validness of the proposed design.

• 전자공학회논문지
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• 제50권7호
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• pp.253-257
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• 2013

본 논문은 지연된 출력과 미지의 외란을 갖는 비선형 시스템에 대한 강인 관측기 설계방법을 제안한다. 지연된 출력의 존재에도 불구하고 관측기의 추정오차에 대한 외란의 효과를 원하는 수준까지 줄일 수 있음을 보인다. 강인 관측기의 존재조건은 시간 지연 값에 의존적인 선형행렬 부등식을 이용하여 제시한다. 마지막으로 제안한 결과의 유효성을 증명하기 위하여 수치 예제를 제공한다.

• 제어로봇시스템학회논문지
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• 제14권1호
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• pp.42-48
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• 2008

This paper presents an observer design method for a special class of multi input multi output(MIMO) nonlinear systems. First, we characterize the class of MIMO nonlinear systems with a block triangular structure. Also, the observability matrices for SISO nonlinear systems are extended to MIMO systems. By using the generalized observability matrices, it is shown that under the boundedness conditions of system state and input, the proposed observer guarantees the local exponential stability of error dynamics. Finally, its application to induction motor is given to verify the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2236-2238
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• 2004

This paper proposes the self-recurrent wavelet neural network (SRWNN) observer based sliding mode control (SMC) method for nonlinear systems. Unlike the classical SMC, we assume that all states of nonlinear systems are not measured and design the SRWNN observer to measure the states of nonlinear systems. The SRWNN in the observer is used for approximating the observer system's gain. To generate the control input for controlling the nonlinear system, the measured states are used. The sliding surface with a boundary layer is defined to remove the chattering of the control input. Simulation result to show the effectiveness of the SRWNN observer is presented.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1828-1832
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• 1991

We study the observer design problem for nonautonomous discrete-time nonlinear systems. We investigate the structure of nonautonomous discrete-time systems which are state equivalent to the nonlinear observer form and characterize their class. Necessary and sufficient conditions for the existence of an input independent (local) diffeomorphism axe derived which transforms multi-input, multi-output nonlinear systems into the nonlinear observer form.

• 전기학회논문지
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• 제64권3호
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• pp.451-457
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• 2015

In this paper, we consider the observer design problem that truly reflects the nonlinear stiffness of the manipulators. The two key ideas of our design are that (a) estimation error dynamics of the manipulator equipped with accelerometer dose not dependent on nonlinearities at the link part, when the measured signals are the motor position and the output of the accelerometer and (b) the nonlinear stiffness is indeed a Lipschitz function. In order to effectively compensate the nonlinear stiffness, the gain of the proposed observer is carefully chosen from the ARE(algebraic Riccati equations) which depend on Lipschitz constant. Comparative simulation result verifies the effectiveness of the proposed solution.

• 한국지능시스템학회논문지
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• 제17권7호
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• pp.977-980
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• 2007

비선형 시스템의 관측기 구성은 일반적으로 어려운 문제임이 잘 알려져 있다. 본 논문에서는 가관측 시스템에 대한 피드백 GA 모델 예측 관측기를 제안한다. 관측기와 같이 매순간 GA를 반복적으로 수행하는 경우에 피드백 GA 개념을 사용하면 온라인 설계가 가능하다. 우리의 관측기의 유용성은 모의실험을 통해 보인다.

• 전자공학회논문지SC
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• 제49권3호
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• pp.26-30
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• 2012

본 논문에서는 출력에 시간지연이 존재하는 이산 시간 비선형 시스템에 대한 상태관측기 설계방법을 제안한다. 비선형항에 대한 Lipschitz 조건을 가정하고 비선형항을 하나의 상태변수처럼 고려함으로써 비선형 이산시간 오차동역학방정식의 안정도 문제가 시간지연을 갖는 선형방정식의 안정도 문제로 변환될 수 있음을 보인다. 또한, 시간 지연 값에 의존적인 충분조건을 선형행렬 부등식을 이용하여 제시한다. 마지막으로 제안한 결과의 유효성을 증명하기 위하여 모의실험 예제를 제공한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.366-370
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• 1998

Indirect vector control for induction motors requires the use of observers for estimation or observation of rotor flux magnitude and position. In this paper, authors discribe the induction motor vector control and introduce a nonlinear observer, named ELO(extended Luenberger Observer), without simulation results as a preliminary work for trial application. Normally, design of nonlinear observer need coordinate transfromation and linearization through solving the partial different equation. However, ELO requires minimal solution of nonlinear partial differential equation. Simulation was performed by under the enviroment of Matlab and Simulink without the proposed observer because we are still working. Simulation was performed with conventional flux observer, a dc-ac inverter by SVPWM technique, a vector controller armed with multiple PI controllers

• 전기학회논문지
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• 제57권7호
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• pp.1247-1253
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• 2008

A design method of a T-S fuzzy model based reduced order nonlinear unknown input observer(NUIO) is presented. The fuzzy NUIO is designed based on the parallel distributed compensation(PDC) concept. It consists of a number of the linear UIOs, each of which is designed for each local linear model in the T-S fuzzy model of a class of nonlinear systems. The fuzzy NUIO provides not only the state estimates insensitive to the unknown inputs, for example, disturbances and faults etc., but also the estimates of the unknown inputs. Therefore, It can be employed in the state feedback control and disturbance rejection control of a class of nonlinear systems with unknown disturbances. It also applied to the robust residual generation for the fault detection and isolation systems and to the design of fault tolerant control systems. As an example, the NUIO is applied to an inverted pendulum system to show the state and disturbance estimation performance and to illustrate the fuzzy reduced order NUIO design method.