• 제목/요약/키워드: a sampled-data systems

검색결과 162건 처리시간 0.034초

Stabilization of Nonlinear Discrete-Time Systems in a Frequency Domain

  • Okuyama, Yoshifumi;Nakamori, Kenji;Takemori, Fumiaki
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.33.2-33
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    • 2001
  • The robust stability condition for sampled-data control systems with a sector nonlinearity was presented in our previous paper. Although it is applicable only to the sampled-data control system of a certain class, a usual discretetime control system can belongs to this type of class. This paper analyzes the amplitude dependent behavior of nonlinear sampled-data (i.e., discrete-time) control systems in a frequency domain. By considering restricted areas (sectors) in the nonlinear characterisitic, the existence of a sustained oscillation is estimated, and the relationship between the stable/unstable conditions and the result derived from describing function is compared. Based on these considerations, the stabilization of nonlinear discrete-time control systems is examined in the frequency domain.

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특이섭동을 포함한 타카기 - 수게노 형태의 비선형 시스템을 위한 새로운 샘플치 제어기의 설계기법 제안 (Sampled-Data Controller Design for Nonlinear Systems Including Singular Perturbation in Takagi-Sugeno Form)

  • 문지현;이재준;이호재
    • 한국지능시스템학회논문지
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    • 제26권1호
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    • pp.50-55
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    • 2016
  • 본 논문은 특이섭동을 포함한 비선형 시스템을 위한 샘플치 제어 기법을 논한다. 비선형 시스템은 타카기--수게노(Takagi--Sugeno: T--S) 퍼지모델 형태로 표현됨을 가정한다. 새로운 리아푸노프 함수와 추가적인 항등식을 이용하여 선형행렬부등식 형태의 샘플치 폐루프 T--S 퍼지시스템의 점근적 안정도 조건을 제시한다. 분석결과에 대한 몇 가지 논의점을 언급한다. 모의실험에 의하여 제안된 기법의 타당성을 보인다.

샘플치 $H_{\infty}$ 문제: 최악의 외란의 폐경로 표현을 통한 등가의 이산시간 시스템 구현 (The Sampled-Data $H_{\infty}$ Problem: Obtaining an equivalent discrete-time system via a closed-loop expression of worst-case disturbance)

  • 공민종;조창호;이상철;조도현;이상효
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.340-340
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    • 2000
  • This paper aims at deriving an equivalent finite dimensional discrete-time system for H$_{\infty}$ type problem for sampled-data control systems. A widely used ph is based on the lifting technique, but it needs somewhat complicate computation. Instead this paper derives an equivalent finite-dimensional discrete-time system directly from a description of the sampled-data system which is achieved via a closed-loop expression of the worst-case intersample disturbance.

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비선형이산치계의 최적시간제어에 관한 연구 (A Study of Time Optimal Control for Nonlinear Sampled-data Contral Systems)

  • 천희영
    • 전기의세계
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    • 제26권2호
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    • pp.84-88
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    • 1977
  • In this paper we apply the maximum principle to design of time optimal nonlinear sampled-data control systems. We introduce the general design procedures and the mathematical formalas for time optimal processes and trajectories. Then we show the application of the technique to determine the optimal control signal, control sequence, switching time and sampling period to the given 4th order process.

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시변지연을 가지는 LPV시스템의 H 샘플데이타 제어 (H Sampled-Data Control of LPV Systems with Time-varying Delay)

  • 유아연;이상문
    • 전기학회논문지
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    • 제64권1호
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    • pp.121-127
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    • 2015
  • This paper considers the problem of sampled-data control for continuous linear parameter varying (LPV) systems. It is assumed that the sampling periods are arbitrarily varying but bounded. Based on the input delay approach, the sampled-data control LPV system is transformed into a continuous time-delay LPV system. Some less conservative stabilization results represented by LMI (Linear Matrix Inequality) are obtained by using the Lyapunov-Krasovskii functional method and the reciprocally combination approach. The proposed method for the designed gain matrix should guarantee asymptotic stability and a specified level of performance on the closed-loop hybrid system. Numerical examples are presented to demonstrate the effectiveness and the improvement of the proposed method.

시간 종속적인 리아프노프 함수를 이용한 모바일 로봇의 선도-추종 샘플 데이터 제어 (Leader-Following Sampled-Data Control of Wheeled Mobile Robots using Clock Dependent Lyapunov Function)

  • 예동희;한승용;이상문
    • 대한임베디드공학회논문지
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    • 제16권4호
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    • pp.119-127
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    • 2021
  • The aim of this paper is to propose a less conservative stabilization condition for leader-following sampled-data control of wheeled mobile robot (WMR) systems by using a clock-dependent Lyapunov function (CDLF) with looped functionals. In the leader-following WMR system, the state and input of the leader robot are measured by digital devices mounted on the following robot, and they are utilized to construct the sampled-data controller of the following robot. To design the sampled-data controller, a stabilization condition is derived by using the CDLF with looped functionals, and formulated in terms of sum of squares (SOS). The considered Lyapunov function is a polynomial form with respect to the clock related to the transmitted sampling instants. As the degree of the Lyapunov function increases, the stabilization condition becomes less conservative. This ensures that the designed controller is able to stabilize the system with a larger maximum sampling interval. The simulation results are provided to demonstrate the effectiveness of the proposed method.

Stabilization for Multirate Sampled-data Control Systems in case of Open-loop Unstable Plant

  • Son, Seok-Bo;Kim, Young-Baek;Park, Chansik;Lee, Sang-Jeong
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.488-488
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    • 2000
  • This paper proposes a stabilizing controller for multirate sampled-data systems which have a periodic output The proposed controller has IMC structure, and can be decomposed into a ye-stabilizing controller, an output estimator, a filtered disturbance estimator and the inverse of the fast ye-stabilized plant model. We assume that the plant is open-loop unstable and the disturbance consists of a sum of finite number of sinusoids with different frequencies. A sufficient condition for maintaining observability in the multirate sampled-data system is derived and a design strategy for filtered disturbance rejection is proposed. In addition, we propose a design method (or the plant output estimator. The simulation results show that the proposed stabilizing controllers can stabilize the plant

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뉴트럴 타입 시간 지연을 갖는 네트워크 기반 시스템의 샘플치 퍼지 제어기 설계 (Sampled-data Fuzzy Controller for Network-based Systems with Neutral Type Delays)

  • 주영훈
    • 한국지능시스템학회논문지
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    • 제18권2호
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    • pp.151-156
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    • 2008
  • 본 논문은 뉴트럴 타입 시간 지연을 가지는 네트워크 기반 시스템의 안정도 분석 및 샘플치 퍼지 제어기 설계 방법에 관하여 논의한다. 먼저 대상이 되는 비선형 네트워크 시스템을 T-S (Takagi-Sugeno) 퍼지 모델로 표현한다. 제안하는 샘플치 퍼지 제어기를 모델링하는 퍼지 규칙과 같은 멤버쉽 함수를 가지게 설계한다. Lyapunov-Krasovskii의 안정화 이론을 도입하여 이를 바탕으로 뉴트럴 형태의 시간 지연을 갖는 T-S 퍼지 시스템의 안정도를 판별한다. T-S 퍼지 시스템의 안정도 조건을 제시하고 선형 행렬 부등식의 형태로 표현한다. 제안된 선형 행렬 부등식의 해를 통하여 샘플치 퍼지 제어기의 이득 값을 설계한다. 마지막으로, 본 논문에서 제안한 방법의 적용 가능성과 일반성을 평가하기 위하여 수치적인 예를 적용한다.

The Advanced z-Transform and Analysis of Sampled-Data Systems

  • 정태경
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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    • pp.49-51
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    • 1996
  • The z-transform method is a basic mathematical tool in analyzing and designing sampled-data control systems. However, since the z-transform method relates only the sampling-instants signals, another mathematical tool is necessary to describe the continous signals between the sampling instants. For this purpose the delayed and the modi fled z-transform methods were developed. The definition of the modi fled z-transform includes a sample in the interval [-T,0] of the original signal in its series expression, where the signal value is always zero for any physical system. From this reason one step skew of the time index always appears in its application formulas. This introduces an unnecessary operation and a gap in linking the mathematical formula and its physical interpretation. Considering the conceptual difficulty and application inconvenience, a method of using the advanced z-transform in analysis of sampled-data control systems is developed as a replacement of the modi fled z-transform. With one formulation of the advanced z-transform, now it is possible to relate both the signals of the sampling instants and those in between without any complication and conceptual difficulty.

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Sampled-Data Observer-Based Decentralized Fuzzy Control for Nonlinear Large-Scale Systems

  • Koo, Geun Bum;Park, Jin Bae;Joo, Young Hoon
    • Journal of Electrical Engineering and Technology
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    • 제11권3호
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    • pp.724-732
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    • 2016
  • In this paper, a sampled-data observer-based decentralized fuzzy control technique is proposed for a class of nonlinear large-scale systems, which can be represented to a Takagi-Sugeno fuzzy system. The premise variable is assumed to be measurable for the design of the observer-based fuzzy controller, and the closed-loop system is obtained. Based on an exact discretized model of the closed-loop system, the stability condition is derived for the closed-loop system. Also, the stability condition is converted into the linear matrix inequality (LMI) format. Finally, an example is provided to verify the effectiveness of the proposed techniques.