• Title/Summary/Keyword: Dynamic parameter

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Aircraft parameter estimation using the extended kalman filter (확장 칼만 필터를 이용한 항공기 파라미터 추정)

  • 송용규;황명신;박욱제
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1655-1658
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    • 1997
  • To obtain aircraft dynamic parameters, various estimation methods such as Maximum Likelihood, Linear Regression are applied. In this paper we adopt the extended Kalman filter(EKF) to estimate the stability and control derivatives in aircraft dynamic models from flight test data. The extended Kalman filter is applied to nonlinear augmented system assuming that unknown parameters are additional states. In this work, the results of the extended Kalman filter are compared with the results of the wind tunnel test using Chang Gong-91 aircraft flight test data.

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Robust controller for actuator plus manipulator with dynamic parameter uncertainty (동적인 매개변수 불확실성을 갖는 로보트 매니퓰레이터와 조작기에 대한 강건한 제어기)

  • 정을호;이종용;이상효
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.161-166
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    • 1990
  • In this paper, Proposed the robust controller for robot manipulator plus actuator with dynamic parameter uncertainties. In general, errors and uncertainties system parameters exist more or less between the actual system and mathematical model. To reduce these trems, used Lyapunov stability theorem. The performance of the controller is evaluated for the three degree of freedom robot manipulator plus actuator model with uncertainties of parameters and model errors.

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A method for properties evaluation of activated charcoal sorbents in iodine capture under dynamic conditions

  • Magomedbekov, Eldar P.;Obruchikov, Alexander V.
    • Nuclear Engineering and Technology
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    • v.51 no.2
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    • pp.641-645
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    • 2019
  • Experimental equipment for studying the sorption properties of iodine sorbents using radioactive methyliodide has been developed. The sorption capacity index ${\alpha}$ is proposed as a criterion parameter for assessing the quality of impregnated activated charcoals. It was found that this parameter does not depend on the dynamic conditions during the sorbent test. It was shown that values of the sorption capacity index allow to recommend iodine sorbents for industrial gas cleaning processes.

A Parameter Study for Static and Dynamic Denting

  • Jung, Dong-Won;Worswick, M.J.
    • Journal of Mechanical Science and Technology
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    • v.18 no.11
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    • pp.2009-2020
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    • 2004
  • A parametric study of the factors controlling static and dynamic denting, as well as local stiffness, has been made on simplified panels of different sizes, curvatures, thicknesses and strengths. Analyses have been performed using the finite element method to predict dent resistance and panel stiffness. A parametric approach is used with finite element models of simplified panels. Two sizes of panels with square plan dimensions and a wide range of curvatures are analysed for several combinations of material thickness and strength, all representative of auto-motive closure panels. Analysis was performed using the implicit finite element code, LS-NIKE, and the explicit dynamic code, LS-DYNA for the static and dynamic cases, respectively. Panel dent resistance and stiffness behaviour are shown to be complex phenomena and strongly interrelated. Factors favouring improved dent resistance include increased yield strength and panel thickness. Panel stiffness also increases with thickness and with higher curvatures but decreases with size and very low curvatures. Conditions for best dynamic and static dent performance are shown to be inherently in conflict ; that is, panels with low stiffness tend to perform well under impact loading but demonstrate inferior static dent performance. Stiffer panels are prone to larger dynamic dents due to higher contact forces but exhibit good static performance through increased resistance to oil canning.

Dynamic Stability of a Drum-Brake Pad Considering Rotary Inertia and Shear Deformation (회전광성과 전단변형을 고려한 드럼-브레이크 패드의 동적안정성)

  • 오부진;공용식;류봉조;이규섭;임경빈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.181-185
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    • 2001
  • This paper deals with the dynamic stability of a disc brake pad taking into account of its shear deformation and rotary inertia. A brake pad can be modeled as a beam like model subjected to distributed friction forces and having two translational springs. The study of this model is intended to provide a fundamental understanding of dynamic stability of drum brake pad. Governing equations of motion are derived from extended Hamilton's principle and their corresponding numerical solutions are obtained by applying the finite element formulation. The critical distributed friction force and the instability types are investigated bt changing two translational spring constants, rotary inertia parameter and shear deformation parameter. Also, the changes of eigen-frequencies of a beam determining instability types are investigated for various combinations of two translational spring constants.

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Comparative dynamic analysis of axially loaded beams on modified Vlasov foundation

  • Hizal, Caglayan;Catal, Hikmet Huseyin
    • Structural Engineering and Mechanics
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    • v.57 no.6
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    • pp.969-988
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    • 2016
  • Vibration analysis of the beams on elastic foundation has gained the great interest of many researchers. In the literature, there are many studies that focus on the free vibration analysis of the beams on one or two parameter elastic foundations. On the other hand, there are no sufficient studies especially focus on the comparison of dynamic response including the bending moment and shear force of the beams resting on Winkler and two parameter foundations. In this study, dynamic response of the axially loaded Timoshenko beams resting on modified Vlasov type elastic soil was investigated by using the separation of variables method. Governing equations were obtained by assuming that the material had linear elastic behaviour and mass of the beam was distributed along its length. Numerical analysis were provided and presented in figures to find out the differences between the modified Vlasov model and conventional Winkler type foundation. Furthermore, the effect of shear deformation of elastic soil on the dynamic response of the beam was investigated.

Dynamic Adjustment of Noncooperative Games Where Informations are Given at Discrete Time Intervals

  • Oh, Hyungjae
    • Journal of the Korean Operations Research and Management Science Society
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    • v.15 no.2
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    • pp.71-83
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    • 1990
  • This paper concerns the analyses of dynamic adjustments in noncooperative games where the market informations are given at discrete time intervals. During the game period, the market informations are given at discrete time intervals. During the game period, the inventories initially stored by players are to be released one day based to the completely competitive market so as to maximize each player's revenue, where players' parameters are unknown one another. Game results have shown that the continuous dynamic adjustment does not necessarily assure the better revenue, and if a player thinks that his parameter is underestimated by hig opponent, then he is better overestimate his opponent's parameter.

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A New Penalty Parameter Update Rule in the Augmented Lagrange Multiplier Method for Dynamic Response Optimization

  • Kim, Min-Soo;Choi, Dong-Hoon
    • Journal of Mechanical Science and Technology
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    • v.14 no.10
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    • pp.1122-1130
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    • 2000
  • Based on the value of the Lagrange multiplier and the degree of constraint activeness, a new update rule is proposed for penalty parameters of the ALM method. The theoretical exposition of this suggested update rule is presented by using the algorithmic interpretation and the geometric interpretation of the augmented Lagrangian. This interpretation shows that the penalty parameters can effect the performance of the ALM method. Also, it offers a lower limit on the penalty parameters that makes the augmented Lagrangian to be bounded. This lower limit forms the backbone of the proposed update rule. To investigate the numerical performance of the update rule, it is embedded in our ALM based dynamic response optimizer, and the optimizer is applied to solve six typical dynamic response optimization problems. Our optimization results are compared with those obtained by employing three conventional update rules used in the literature, which shows that the suggested update rule is more efficient and more stable than the conventional ones.

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Development of an Expert System for Nondestructive Evaluation of Tunnel Lining (터널 라이닝의 비파괴 평가를 위한 전문가시스템 개발)

  • 김문겸;허택녕;이재영;김도훈
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.10a
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    • pp.413-420
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    • 1998
  • In this study, an expert system is developed to evaluate a safety of tunnel structures. Using a dynamic finite element analysis module, this expert system predicts dynamic responses of a concrete lining surface which a transient force is applied on and estimates the condition between the concrete lining and surrounding ground. The evaluation parameter values of the module are multi-reflected wave frequency and amplitude of the dynamic responses. The multi-reflected wave frequency represents the depth of concrete lining, and the other parameter, the amplitude of the frequency, is utilized for detecting the internal flaws. A comparison of the dynamic responses between numerical and experimental model test verifies an effectiveness of this system. By this expert system, the safety of tunnel structures and the detection of internal flaws of concrete linings are estimated quantitatively.

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A Medium Access Control Protocol for rt- VBR Traffic in Wireless ATM Networks

  • Lim, In-Taek
    • Journal of information and communication convergence engineering
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    • v.5 no.1
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    • pp.29-34
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    • 2007
  • This paper proposes a MAC protocol for real-time VBR (rt-VBR) services in wireless ATM networks. The proposed protocol is characterized by a contention-based mechanism of the reservation request, a contention-free polling scheme for transferring the dynamic parameters, and a priority scheme of the slot allocation. The design objective of the proposed protocol is to guarantee the real-time constraint of rt-VBR traffic. The scheduling algorithm uses a priority scheme based on the maximum cell transfer delay parameter. The wireless terminal establishes an rt-VBR connection to the base station with a contention-based scheme. The base station scheduler allocates a dynamic parameter minislot to the wireless terminal for transferring the residual lifetime and the number of requesting slots as the dynamic parameters. Based on the received dynamic parameters, the scheduler allocates the uplink slots to the wireless terminal with the most stringent delay requirement. The simulation results show that the proposed protocol can guarantee the delay constraint of rt-VBR services along with its cell loss rate significantly reduced.