• 제목/요약/키워드: Nonlinear Dynamics

검색결과 1,261건 처리시간 0.035초

Variable Structure Control for Discrete-time Nonlinear Systems

  • Han, So-Hee;Cho, Byung-Sun;Park, Kang-Bak
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1414-1417
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    • 2003
  • In this paper, sliding mode controller for discrete-time nonlinear systems with uncertainties and disturbances are proposed. The concept of time-delay control (TDC) which consists of estimating the uncertain dynamics of the system through past observations of the system response is used. The proposed controller guarantees that the closed-loop system states are globally uniformly ultimately bounded (GUUB). It is also shown that the closed-loop system states are globally uniformly asymptotically stable (GUAS) if uncertainties are constant.

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유한요소와 4원법을 이용한 비선형 유연체동역학의 해석기법 (The Dynamics Analysis for Nonlinear Flexible Mechanisms using Finite Elements and Algebraic Quaternions)

  • 이동현;윤성호
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 봄 학술발표회 논문집
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    • pp.9-16
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    • 2004
  • This paper deals with the development of computational schemes for the dynamic analysis of flexible and nonlinear multibody systems. Different from the existing method, this paper introduces the quaternion algebra to develop the equation of the conservation of energy. Simultaneously, Rodrigues parameters are used to express the finite rotation for the proposed scheme. The proposed energy scheme is derived such that it provides unconditionally stable conditions for the nonlinear problems. Several examples of dynamic systems are presented which illustrate the efficiency and accuracy of the developed energy schemes.

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Structural control of a steel jacket platform

  • Abdel-Rohman, Mohamed
    • Structural Engineering and Mechanics
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    • 제4권2호
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    • pp.125-138
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    • 1996
  • This paper deals with the application of certain active and passive control mechanisms to control the dynamic response of a steel jacket platform due to wave-induced forces. The forces are estimated using the nonlinear Morison equation which provides nonlinear self-excited hydrodynamic forces. The influence of these forces on the response of a structure without and with vibration control mechanisms is demonstrated using a steel jacket platform as a simple example.

Modularized Gain Scheduled Fuzzy Logic Control with Application to Nonlinear Magnetic Bearings

  • Hong, Sung-Kyung
    • 한국지능시스템학회논문지
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    • 제9권4호
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    • pp.384-388
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    • 1999
  • This paper describes an approach for synthesizing a modularized gain scheduled PD type fuzzy logic controller(FLC) of nonlinear magnetic bearing system where the gains of FLC are on-line adapted according to the operating point. Specifically the systematic procedure via root locus technique is carried out for the selection of the gains of FLC. Simulation results demonstrate that the proposed gain scheduled fuzzy logic controller yields not only maximization of stability boundary but also better control performance than a single operating point (without gain scheduling)fuzzy controller.

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로보트 매니플레이터의 비선형 강건 제어 (Robust nonlinear control of robotic manipulators)

  • 박현우;배준경;박종국
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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    • pp.32-36
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    • 1988
  • Generally, for nonlinear control of robotic system, the method of computed torque or inverse dynamics is frequently used. In this case, exact knowledge of the system parameters is required, however. This paper addresses the problem of nonlinear control when the parameter of system is varied. The approach is based upon decoupled model following. As an example, control of a three degree of freedom manipulator arm under mass variation is simulated.

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연소 불안정 현상의 비선형적 특성 고찰 (Note on Nonlinearity of Combustion Instability)

  • 서성현
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2003년도 제20회 춘계학술대회 논문집
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    • pp.240-243
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    • 2003
  • Combustion instability phenomena have been observed in various different combustion systems. For each specific combustion system, pressure fluctuations measured during high frequency combustion instability presented many different characteristics. High frequency instability occurring in a lean premixed gas turbine combustor mar be dominantly affected by a nonlinear relation between pressure oscillations and heat release rate fluctuations, and gas dynamics plays a crucial role in determining an amplitude of a limit cycle for a liquid rocket thrust chamber. Combustion instability phenomena manifest their inherent nonlinear characteristics. One is a limit cycle and the other bifurcation described by nonlinear time series analysis.

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Constructing Nonlinear Sliding Surface for Spacecraft Attitude Control Problems

  • Cheon, Yee-Jin
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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    • pp.41-44
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    • 1999
  • Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters(MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.

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비선형 공기압시스템 특성연구 (A Study on Nonlinear Pneumatic System Characteristics)

  • 박재범;김동수;김형의;염만오
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.826-830
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    • 1996
  • The pneumaic systems are widely applied to chemical factory of fire dangry and factory automation. by using compressed air, it is difficult to dynamics action analysis that the pneumatics system acts to nonlinear motion through orifices and valve flow. This paper was studied to a nonlinear chararistics of pneumaic spring, damper and absorber of pneumaic cushion cylinder.

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