• Title/Summary/Keyword: dynamic variable

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Aerodynamics and Flight Control of Air Vehicle with Variable Span Morphing Wing (가변스팬 모핑날개를 가진 비행체의 공력특성 및 비행 제어)

  • Bae, Jae-Sung;Hwang, Jai-Hyuk;Park, Sang-Hyuk;Kim, Jong-Hyuk
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.18 no.4
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    • pp.1-8
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    • 2010
  • In the aerospace field, the study on a morphing-wing is in progress to improve flight performance and perform multi flight mission. There are many concepts of morphing-wing such as camber-change, wing-twist, variable-span, and so on. In this study, the aerodynamic characteristics and flight control of an air vehicle with a variable-span morphing wing (VSMW) have been investigated. VSMW with symmetric span control(SSC) can increase cruising range of aircraft by reducing drag in various flight condition. VSMW with anti-symmetric span control(ASSC) can be used in the roll control of an aircraft. The flight control about pure rolling dynamic system and full dynamic system have been performed about the cruise missile.

Contact Mechanics of Variable-Gauge Wheeles With Flexible Body (탄성체를 이용한 궤간가변 대차용 윤축시스템의 접촉력 해석)

  • Lee Young-Joo;Bae Dae-Sung;Kim Wan-Goo;Jang Seung-Ho;Han Jun-Suk
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.379-384
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    • 2005
  • Research interest on flexible body dynamics, has been increased recently. The major application areas are the auto-mobile, train, and heavy machinery. This paper attempted the dynamic analysis for the variable-gauge wheelset with a flexible body, to better understand the dynamic characteristics of the variable-gauge wheelset. In order to achieve this goal, a 3D-Virtual Mock-up model was built. The tendency of the stress and deformation for the flexible lever was investigated through component mode synthesis, contact mechanics and flexible body dynamics. This study is a pioneering work for the development of Korean type variable-gauge wheelset.

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An Euler Parameter Updating Method for Multibody Kinematics and Dynamics (다물체의 기구해석 및 동적거동해석을 위한 오일러 매개변수의 교정방법)

  • 김성주;배대성;최창곤;양성모
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.4
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    • pp.9-17
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    • 1996
  • This paper develops a sequential updating method of the Euler parameter generalized coordinates for the machine kinematics and dynamics, The Newton's method is slightly modified so as to utilize the Jacobian matrix with respect to the virtual rotation instead of this with repect to the Euler parameters. An intermediate variable is introduced and the modified Newton's method solves for the variable first. Relational equation of the intermediate variable is then solved for the Euler parameters. The solution process is carried out efficiently by symoblic inversion of the relational equation of the intermediate variable and the iteration equation of the Euler parameter normalization constraint. The proposed method is applied to a kinematic and dynamic analysis with the Generalized Coordinate Partitioning method. Covergence analysis is performed to guarantee the local convergence of the proposed method. To demonstrate the validity and practicalism of the proposed method, kinematic analysis of a motion base system and dynamic analysis of a vehicle are carried out.

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Multi-Body Dynamics Characteristics of Variable Nozzle (가변노즐의 다물체동력학적 특성)

  • Park, Dong-Chang;Lee, Sang-Youn;Yun, Su-Jin;Yoon, Hyun-Gull
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.711-712
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    • 2010
  • In the present work, the dynamic characteristics of variable nozzles are described. Variable nozzles are used to enhance the effectiveness of aircraft engines at various altitudes. The dynamic characteristics of variable nozzle mechanism including flaps are analyzed by a multi-body dynamics analysis software, RecurDyn.

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Optimal Design of a Variable-Speed Cam for Power Circuit Breaker (고압 회로차단기의 비등속 회전 캠의 최적설계)

  • Kim, Jun-Hyeong;An, Gil-Yeong;Kim, Su-Hyeon;Gwak, Yun-Geun
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.12
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    • pp.47-53
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    • 2001
  • Power Circuit Breaker uses a variable-speed cam mechanism actuated by pre-loaded spring force. This paper presents the optimal design procedure for a variable-speed cam mechanism based on the dynamic model of a complete spring-actuated cam system. The optimal cam is compared with an original cam. Simulation results show that the dynamic behaviors of the designed cam are superior to those of the original cam.

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An Application of Variable Structure Model Following Adaptive Control Using Time-Varying Sliding Regime to Robot Manipulator with Vertical 3 links (수직3관절 로보트 매니풀레이터에 대하여 시변슬라이딩레짐을 사용한 가변구조 모델추종 적응제어의 응용)

  • Kim, Joong-Wan;Kang, Dae-Gi;Kim, Byoung-Oh;Oh, Hyun-Seong;Jung, Hee-Kyun
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.6
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    • pp.158-167
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    • 1994
  • The design concept of varaiable structure control is useful not only to stochasic systems but also to adaptive control systems. The Dynamic equation of vertical three linkage robot was derived. And it was simplyfied according to the scheme of control strategy. And we specify the form of model. Thereafter the error dynamic equation was derived between the real state of the plant and state of the model. Some simulations were performed to control robot manipulator applying the methodology of the variable structure model following adaptive control.

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A Dynamic Variable Window-based Topographical Classification Method Using Aerial LiDAR Data (항공 라이다 데이터를 이용한 동적 가변 윈도우 기반 지형 분류 기법)

  • Sung, Chul-Woong;Lee, Sung-Gyu;Park, Chang-Hoo;Lee, Ho-Jun;Kim, Yoo-Sung
    • Spatial Information Research
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    • v.18 no.5
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    • pp.13-26
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    • 2010
  • In this paper, a dynamic variable window-based topographical classification method is proposed which has the changeable classification units depending on topographical properties. In the proposed scheme, to im prove the classification efficiency, the unit of topographical classification can be changeable dynamically according to the topographical properties and repeated patterns. Also, in this paper, the classification efficiency and accuracy of the proposed method are analyzed in order to find an optimal maximum decision window-size through the experiment. According to the experiment results, the proposed dynamic variable window-based topographical classification method maintains similar accuracy but remarkably reduce computing time than that of a fixed window-size based one, respectively.

Optimum Design of Vehicle Powertrain Mounting System (자동차용 파워트레인 마운팅 시스템의 최적설계)

  • Kim, J.H.;Lee, S.J.;Lee, W.H.;Kim, J.R.
    • Journal of Power System Engineering
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    • v.14 no.3
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    • pp.33-38
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    • 2010
  • Technology of vehicle industry has been developing and it is required a better vehicle performance than before. Therefore, the consumers are asking not only an economic efficiency, functionality, polished design, ride comfort and silence but also a driving stability. The ride comfort, silence and driving stability are influenced by the size of vehicle and various facilities. But the principal factor is a room noise and vibration sensed by a driver and passenger. Thus, the NVH of vehicle has been raised and used as a principal factor for evaluation of vehicle performance. The primary objective of this study is an optimized design of powertrain mounting system. To optimized design was applied MSC.Nastran optimization modules. Results of dynamic analysis for powertrain mounting system was investigated. By theses results, design variables was applied 12 dynamic spring constant. And the weighting factor according to translational displacement and rotational displacement applied 3 cases. The objective function was applied to minimize displacement of powertrain. And the design variable constraint was imposed dynamic spring constant ratio. The constraint of design variable for objective function was imposed bounce displacement for powertrain.

A Study on the Combined Use of Exact Dynamic Elements and Finite Elements (엄밀한 동적 요소와 유한 요소 통합 해석 방법에 관한 연구)

  • 홍성욱;조용주;김종선
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.2
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    • pp.141-149
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    • 2002
  • Although the finite element method has become an indispensible tool for the dynamic analysis of structures, difficulty remains to quantify the errors associated with discretization. To improve the modeling accuracy, this paper proposes a method to make a combined use of finite elements and exact dynamic elements. Exact interpolation functions for the Timoshenko beam element are derived using the exact dynamic element modeling (EDEM) and compared with interpolation functions of the finite element method (FEM). The exact interpolation functions are tested with the Laplace variable varied. A combined use of finite element method and exact interpolation functions is presented to gain more accurate mode shape functions. This paper also presents a combined use of finite elements and exact dynamic elements in design/reanalysis problems. Timoshenko flames with tapered sections are tested to demonstrate the design procedure with the proposed method. The numerical study shows that the combined use of finite element model and exact dynamic element model is very useful.

Dynamic Properties of Squeeze Type Mount Using MR Fluid (MR유체를 이용한 스퀴즈모드 타입 마운트의 동특성)

  • Ahn, Young-Kong;Yang, Bo-Suk;Ha, Jong-Yong;Kim, Dong-Jo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.349.1-349
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    • 2002
  • This paper presents investigation of damping characteristics of squeeze mode type MR mount experimently. The MR mount proposed in the study has variable damping characteristics according to the applied magnetic field strength. Impact and force excitation tests were performed. The dynamic property of the mount using MR fluid was compared with that of the mount using conventional oil. (omitted)

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