• 제목/요약/키워드: Dynamic Method

검색결과 13,151건 처리시간 0.05초

H$\infty$ Fuzzy Dynamic Output Feedback Controller Design with Pole Placement Constraints

  • Kim, Jongcheol;Sangchul Won
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.176.5-176
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    • 2001
  • This paper presents a fuzzy dynamic output feedback controller design method for Parallel Distributed Compensation (PDC)-type Takagi-Sugeno (T-S) model based fuzzy dynamic system with H$\infty$ performance and additional constraints on the closed pole placement. Design condition for these controller is obtained in terms of the linear matrix inequalities (LMIs). The proposed fuzzy controller satisfies the disturbance rejection performance and the desired transient response. The design method is verified by this method for an inverted pendulum with a cart using the proposed method.

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Dynamic bending response of SWCNT reinforced composite plates subjected to hygro-thermo-mechanical loading

  • Chavan, Shivaji G.;Lal, Achchhe
    • Computers and Concrete
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    • 제20권2호
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    • pp.229-246
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    • 2017
  • The dynamic bending response of single walled carbon nanotube reinforced composite (SWCNTRC) plates subjected to hygro-thermo-mechanical loading are investigated in this paper. The mechanical load is considered as wind pressure for dynamic bending responses of SWCNTRC plate. The dynamic version of the High Order shear deformation Theory (HSDT) for a composite plate with Matrix and SWCNTRC plate is first formulated. Distribution of fibers through the thickness of the SWCNTRC plate could be uniform or functionally graded (FG). The dynamic displacement response is predicted by using Nemarck integration method. The effective material properties of SWCNTRC are estimated by using micromechanics based modeling approach. The effect of different environmental condition, volume fraction of SWCNT, Width-to-thickness ratio, wind pressure, different SWCNTRC-FG plates, boundary condition, E1/E2 ratio, different temperature on dynamic displacement response is investigated. The dynamic displacement response is compared with the available literature and it shows good agreement.

A study on the Adaptive Controller with Chaotic Dynamic Neural Networks

  • Kim, Sang-Hee;Ahn, Hee-Wook;Wang, Hua O.
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제7권4호
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    • pp.236-241
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    • 2007
  • This paper presents an adaptive controller using chaotic dynamic neural networks(CDNN) for nonlinear dynamic system. A new dynamic backpropagation learning method of the proposed chaotic dynamic neural networks is developed for efficient learning, and this learning method includes the convergence for improving the stability of chaotic neural networks. The proposed CDNN is applied to the system identification of chaotic system and the adaptive controller. The simulation results show good performances in the identification of Lorenz equation and the adaptive control of nonlinear system, since the CDNN has the fast learning characteristics and the robust adaptability to nonlinear dynamic system.

Nonlinear dynamic analysis by Dynamic Relaxation method

  • Rezaiee-Pajand, M.;Alamatian, J.
    • Structural Engineering and Mechanics
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    • 제28권5호
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    • pp.549-570
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    • 2008
  • Numerical integration is an efficient approach for nonlinear dynamic analysis. In this paper, general category of the implicit integration errors will be discussed. In order to decrease the errors, Dynamic Relaxation method with modified time step (MFT) will be used. This procedure leads to an alternative algorithm which is very general and can be utilized with any implicit integration scheme. For numerical verification of the proposed technique, some single and multi degrees of freedom nonlinear dynamic systems will be analyzed. Moreover, results are compared with both exact and other available solutions. Suitable accuracy, high efficiency, simplicity, vector operations and automatic procedures are the main merits of the new algorithm in solving nonlinear dynamic problems.

압축하중을 받는 방진고무의 동특성 해석 및 실험 (Analysis and Experiment of the Dynamic Characteristics of Rubber Materials for Anti-Vibration under Compression)

  • 김국원;임종락;한용희;손희기;안태길
    • 소음진동
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    • 제8권5호
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    • pp.900-907
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    • 1998
  • Rubber materials are extensively used in various machine design application, mainly for vibration/shock/noise control devices. Over the years an enormous effort has been put into developing procedures to provide properties of rubber material for design function. However, there are still a lot of difficulties in the understanding of dynamic characteristics of the rubber components in compression. In this paper, the dynamic characteristics of rubber materials for anti-vibration under compression were investigated. Dynamic and static tests for rubber material with 3 different hardness were performed. In dynamic tests, non-resonance method, impedance method, was used to obtain the complex modulus(storage modulus and loss factor) and the effects of static pre-strain on the dynamic characteristics were investigated. Also, a relation equation between linear dynamic and nonlinear static behavior of rubber material was discussed and its usefulness to predict their combined effects was investigated.

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전기체 동적 유한요소 모델을 이용한 소형항공기 플러터 해석 (Flutter Analysis of Small Aircraft using Full Airframe Dynamic FE Model)

  • 이상욱;백승길;김성찬;황인희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.424-429
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    • 2008
  • Aircraft flutter analysis model consists of dynamic FE model and aerodynamic model. Dynamic FE model is composed of stiffness and mass model, and is used for the prediction of normal mode characteristics of the structure. Since aircraft flutter analysis is normally performed in the modal domain, dynamic FE model shall be constructed to describe the modal characteristics of the structure with sufficient accuracy. In this study, dynamic FE modeling method was described using full airframe FE model and structural and system weight data for aircraft flutter analysis. In addition, full airframe dynamic FE model for composite small aircraft was constituted for normal mode and flutter analysis, and the mass modeling results were compared with the target weight data to validate the mass modeling method proposed. Finally, full airframe flutter analysis of composite small aircraft was performed with the dynamic FE model and the aerodynamic model composed.

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축의 굽힘효과를 고려한 회전체에 장착된 자동평형장치의 동적해석 (Dynamic Analysis of an Automatic Dynamic Balancer in a Rotor with the Bending Flexibility)

  • 방인창;정진태
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 추계학술대회논문집A
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    • pp.629-634
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    • 2000
  • Dynamic behavior of an automatic dynamic balancer is analyzed by a theoretical approach. Using Lagrange's equation, we derive the non-linear equations of motion for an automatic dynamic balancer equipped in a rotor with the bending flexibility with respect to the rectangular coordinate. Considering the rotor bending flexibility we analyze out-of-plane vibrations as well as in-plane vibrations of the automatic dynamic balaner. The time responses are computed from the non-linear equations by using a time integration method. We also investigate the effect of rotor flexibility on the behavior of the automatic dynamic balancer

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경기장 구조물의 효율적인 진동해석 (Efficient Vibration Analysis of Stadium Structure)

  • 김기철;이동근
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.475-482
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    • 2001
  • Stadium stand could be led to significant dynamic response due to rhythmical activities of spectator. The dynamic loads induced by spectators movements are considered as static loads in design standard of many countries but these loads have dynamic characteristics. So, it is desirable to apply measured dynamic loads created by spectator activities and to analyze the dynamic behavior of stadium system. The precise investigation of the dynamic loads on stadium structures and the accurate analysis of dynamic behavior of stadium systems are demanded for effective design. As the floor mesh of stadium stand is refined, the number of nodes increase in numerical analysis. So it is difficult to analyze entire stadium structures and much more computer memory are necessary for vibration analysis of stadium system. In this study, the various dynamic loads induced by spectator movements are measured and analyzed. And new modeling method that reduce the nodal points of stadium systems are introduced. Vibration analysis of stadium system is executed to inspect the accuracy and the efficiency of proposed method in this paper.

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Dynamic impedance of a 3×3 pile-group system: Soil plasticity effects

  • Gheddar, Kamal;Sbartai, Badreddine;Messioud, Salah;Dias, Daniel
    • Structural Engineering and Mechanics
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    • 제83권3호
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    • pp.377-386
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    • 2022
  • This paper considers dynamic impedance functions and presents a detailed analysis of the soil plasticity influence on the pile-group foundation dynamic response. A three-dimensional finite element model is proposed, and a calculation method considering the time domain is detailed for the nonlinear dynamic impedance functions. The soil mass is modeled as continuum elastoplastic solid using the Mohr-Coulomb shear failure criterion. The piles are modeled as continuum solids and the slab as a structural plate-type element. Quiet boundaries are implemented to avoid wave reflection on the boundaries. The model and method of analysis are validated by comparison with those published on literature. Numerical results are presented in terms of horizontal and vertical nonlinear dynamic impedances as a function of the shear soil parameters (cohesion and internal friction angle), pile spacing ratio and frequencies of the dynamic signal.