• 제목/요약/키워드: Uncertain disturbances

검색결과 97건 처리시간 0.03초

Suboptimal Robust Generalized H2 Filtering using Linear Matrix Inequalities

  • Ra, Won-Sang;Jin, Seung-Hee;Yoon, Tae-Sung;Park, Jin-Bae
    • Transactions on Control, Automation and Systems Engineering
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    • 제1권2호
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    • pp.134-140
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    • 1999
  • The robust generalized H2 filtering problem for a class of discrete time uncertain linear systems satisfying the sum quadratic constraints(SQCs) is considered. The objective of this paper is to develop robust stability condition using SQCs and design a robust generalized Ha filter to take place of the existing robust Kalman filter. The robust generalized H2 filter is designed based on newly derived robust stability condition. The robust generalized Ha filter bounds the energy to peak gain from the energy bounded exogenous disturbances to the estimation errors under the given positive scalar ${\gamma}$. Unlike the robust Lalman filter, it does not require any spectral assumptions about the exogenous disturbances . Therefore the robust generalized H2 filter can be considered as a deterministic formulation of the robust Kalman filter. Moreover, the variance of the estimation error obtained by the proposed filter is lower than that by the existing robust Kalman filter. The robustness of the robust generalized H2 filter against the uncertainty and the exogenous signal is illustrated by a simple numerical example.

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비선형 마찰력이 있는 시스템의 강인한 적응제어기법 (Adaptive Robust Control of Mechanical Systems with Uncertain Nonlinear Dynamic Friction)

  • 이태봉;양현석;김병한
    • 한국산학기술학회논문지
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    • 제12권11호
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    • pp.5194-5201
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    • 2011
  • 본 논문에서는 부분적으로 알고 있는 비선형 마찰력이 있는 2차 기계시스템에 대한 강인한 적응제어 기법을 제시한다. 제시하는 적응제어 방법은 잡음이나 모델링 에러가 없는 경우에는 위치 및 속도 추적 오차는 점근적으로 영으로 수렴함을 보장하며, 잡음이나 모델링 에러가 있는 경우에는 그동안 발표된 다른 논문의 결과와 달리 디자인 변수를 적절하게 선택하면 위치 및 속도 추적 오차를 원하는 범위까지 줄일 수 있음을 보였으며 이는 시뮬레이션 결과를 통해 입증하였다.

Identification and Robust $H_\infty$ Control of the Rotational/Translational Actuator System

  • Tavakoli Mahdi;Taghirad Hamid D.;Abrishamchian Mehdi
    • International Journal of Control, Automation, and Systems
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    • 제3권3호
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    • pp.387-396
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    • 2005
  • The Rotational/Translational Actuator (RTAC) benchmark problem considers a fourth-order dynamical system involving the nonlinear interaction of a translational oscillator and an eccentric rotational proof mass. This problem has been posed to investigate the utility of a rotational actuator for stabilizing translational motion. In order to experimentally implement any of the model-based controllers proposed in the literature, the values of model parameters are required which are generally difficult to determine rigorously. In this paper, an approach to the least-squares estimation of the parameters of a system is formulated and practically applied to the RTAC system. On the other hand, this paper shows how to model a nonlinear system as a linear uncertain system via nonparametric system identification, in order to provide the information required for linear robust $H_\infty$ control design. This method is also applied to the RTAC system, which demonstrates severe nonlinearities, due to the coupling from the rotational motion to the translational motion. Experimental results confirm that this approach can effectively condense the whole nonlinearities, uncertainties, and disturbances within the system into a favorable perturbation block.

불확실한 비선형 시스템에 대한 강인 유한 시간 안정화 (Robust Finite-Time Stabilization for an Uncertain Nonlinear System)

  • 서상보;심형보;서진헌
    • 전자공학회논문지SC
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    • 제46권2호
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    • pp.7-14
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    • 2009
  • 본 논문에서는 불확실성을 가지는 비선형 시스템에 대한 강인 유한 시간 안정화 문제를 고려한다. 불확실성은 시변 외란 혹은 이미 알고 있는 옹골 집합에 포함된 파라미터들이다. 제안된 설계기법은 역진기법(backstepping)과 추가된 다이나믹스를 이용한 다이나믹 지수 보정법(dynamic exponent scaling)에 기반을 두고 있으며, 이로부터 다이나믹 스무스 궤환 제어기(dynamic smooth feedback controller)가 유도된다. 페루프 시스템의 유한 시간 안정과 제어기의 유한함은 각각 유한 시간 안정에 관한 리아푸노프 안정 이론과 새로운 개념인 '차수 지표자(degree indicator)'를 이용하여 증명된다.

불확실 이산 시스템을 위한 외란관측기와 적분 동특성형 슬라이딩 면을 갖는 새로운 둔감한 이산 적분 정적 출력 궤환 가변구조제어기 (A New Robust Discrete Integral Static Output Feedback Variable Structure Controller with Disturbance Observer and Integral Dynamic-Type Sliding Surface for Uncertain Discrete Systems)

  • 이정훈
    • 전기학회논문지
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    • 제59권7호
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    • pp.1289-1294
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    • 2010
  • In this paper, a new discrete integral static output feedback variable structure controller based on the a new integral dynamic-type sliding surface and output feedback discrete version of the disturbance observer is suggested for the control of uncertain linear systems. The reaching phase is completely removed by introducing a new proposed integral dynamic-type sliding surface. The output feedback discrete version of disturbance observer is presented for effective compensation of uncertainties and disturbance. A corresponding control with disturbance compensation is selected to guarantee the quasi sliding mode on the predetermined integral dynamic-type sliding surface for guaranteeing the designed output in the integral dynamic-type sliding surface from any initial condition for all the parameter variations and disturbances. Using discrete Lyapunov function, the closed loop stability and the existence condition of the quasi sliding mode is proved. Finally, an illustrative example is presented to show the effectiveness of the algorithm.

슬라이딩모드와 LMI를 이용한 강인 $H{\infty}$ 제어 (Robust $H{\infty}$ Control Using Sliding Mode and LMI)

  • 김수진;김민찬;박승규;안호균;곽군평;윤태성
    • 한국정보통신학회논문지
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    • 제11권2호
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    • pp.316-321
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    • 2007
  • [ $H{\infty}$ ] 제어기는 외란이나 잡음에 대해서 강인한 성능을 가지고 있지 만 파라미터 불확실성이 존재하면 제어입력을 구하기가 쉽지 않으며 불확실성의 영향에 따라서 제어 성능에 큰 차이를 보인다. 하지 만 슬라이딩 모드제어는 파라미터 불확실성에 대하여 우수한 강인성을 가지고 있는 제어 기법이다. 그러므로 본 논문에서는 슬라이딩 모드 제어기법을 도입하여 LMI를 이용한 $H{\infty}$ 제어기의 강인성을 향상시킬 수 있는 제어 기법을 제안한다.

불확실한 순궤환 비선형 계통에 대한 스위칭 미분기를 이용한 상태궤환 백스테핑 제어기 (State-Feedback Backstepping Controller for Uncertain Pure-Feedback Nonlinear Systems Using Switching Differentiator)

  • 박장현
    • 전기전자학회논문지
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    • 제23권2호
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    • pp.716-721
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    • 2019
  • 불확실한 순궤환 비선형 계통에 대한 스위칭 미분기 기반의 새로운 백스테핑 제어기를 제안한다. 제안된 제어기에서는 점근적 추종 특성을 갖는 스위칭 미분기를 사용하여 백스테핑 제어기의 매 설계 단계마다 가상 제어항이 직접 근사된다. 그 결과 제어식이 매우 단순화되고 계통에 내재된 파라미터 및 구조적 불확실성과 외란이 존재함에도 불구하고 계통의 출력이 원하는 출력을 점근적으로 추종함을 증명한다. 또한 신경망이나 퍼지시스템 같은 계통의 구조적인 불확실성에 적응적으로 실시간 보상하기 위한 범용 근사기가 불필요하다. 모의실험을 통해서 제안된 제어기의 성능과 간결함을 보인다.

Robust Stabilization of Uncertain Nonlinear Systems via Fuzzy Modeling and Numerical Optimization Programming

  • Lee Jongbae;Park Chang-Woo;Sung Ha-Gyeong;Lim Joonhong
    • International Journal of Control, Automation, and Systems
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    • 제3권2호
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    • pp.225-235
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    • 2005
  • This paper presents the robust stability analysis and design methodology of the fuzzy feedback linearization control systems. Uncertainty and disturbances with known bounds are assumed to be included in the Takagi-Sugeno (TS) fuzzy models representing the nonlinear plants. $L_2$ robust stability of the closed system is analyzed by casting the systems into the diagonal norm bounded linear differential inclusions (DNLDI) formulation. Based on the linear matrix inequality (LMI) optimization programming, a numerical method for finding the maximum stable ranges of the fuzzy feedback linearization control gains is also proposed. To verify the effectiveness of the proposed scheme, the robust stability analysis and control design examples are given.

A Global Optimal Sliding-Mode Control for the Minimum Time Trajectory Tracking with Bounded Inputs

  • Choi, Hyeung-sik
    • Journal of Mechanical Science and Technology
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    • 제15권4호
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    • pp.433-440
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    • 2001
  • A new design of the sliding mode control is proposed for the uncertain linear time-varying second order system. The proposed control drives system states to the target point in the minimum time with specified ranges of parametric uncertainties and disturbances. One of the advantages of the proposed control scheme is that the control inputs do not go beyond saturation limits of the actuators. The other advantage is that the minimum arrival time and the acceleration of the second order actuators system can be estimated with given parametric bounds and can be expressed in the closed from; conversely, the designer can select actuators based on the condition of the minimum arrival time to the target point. The superior performance of the proposed control scheme to other sliding mode controllers is validated by computer simulations.

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Model predictive control combined with iterative learning control for nonlinear batch processes

  • Lee, Kwang-Soon;Kim, Won-Cheol;Lee, Jay H.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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    • pp.299-302
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    • 1996
  • A control algorithm is proposed for nonlinear multi-input multi-output(MIMO) batch processes by combining quadratic iterative learning control(Q-ILC) with model predictive control(MPC). Both controls are designed based on output feedback and Kalman filter is incorporated for state estimation. Novelty of the proposed algorithm lies in the facts that, unlike feedback-only control, unknown sustained disturbances which are repeated over batches can be completely rejected and asymptotically perfect tracking is possible for zero random disturbance case even with uncertain process model.

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