• Title/Summary/Keyword: Dynamic Model

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Analysis of the Dynamic Characteristics of A Passenger Car Automatic Transmission (승용차용 자동변속기의 동특성 해석)

  • 김영흡;박찬일
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.3
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    • pp.172-181
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    • 1997
  • The dynamic characteristics during gear ratio change including the disturbance of output torque has been one of the most important issues in the study of automatic transmissions of passenger cars. In this paper, to investigate the dynamic characteristics of a passenger car automatic transmission during gear ratio change, a dynamic model of the driveline of a passenger car focused on the automatic transmission is proposed and the dynamic simulation program is developed. The results of the simulation show good agreements with the experimental data, which process the use fullness of the dynamic model and the simulation of the driveline.

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A Study of Human Model Based on Dynamics (동력학기반 인체 모델 연구)

  • 김창희;김승호;오병주
    • Journal of Biomedical Engineering Research
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    • v.20 no.4
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    • pp.485-493
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    • 1999
  • Human can generate various posture and motion with nearly 350 muscle pairs. From the viewpoint of mechanisms, the human skeleton mechanism represents great kinematic and dynamical complexity. Physical and behavioral fidelity of human motion requires dynamically accurate modeling and controling. This paper describes a mathematical modeling, and dynamic simulation of human body. The human dynamic model is simplified as a rigid body consisting of 18 actuated degrees of freedom for the real time computation. Complex kinematic chain of human body is partitioned as 6 serial kinematic chains that is, left arm, right arm, support leg, free leg, body, and head. Modeling is developed based on Newton-Euler formulation. The validity of proposed dynamic model, which represents mathematically high order differential equation, is verified through the dynamic simulation.

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Dynamic Modeling of a Railway Vehicle under Braking (제동시의 철도차량을 위한 동적모델)

  • Park, Joon-Hyuk;Goo, Byeong-Choon
    • Journal of the Korean Society for Railway
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    • v.10 no.4
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    • pp.431-437
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    • 2007
  • This paper describes the dynamic modeling of a railway vehicle when it is under braking force. It is important for the enhancement of braking performance to establish a proper dynamic model of a railway vehicle because the braking performance is affected by some dynamic forces generated by a railway vehicle when it undergoes braking. In this paper, a dynamic model for one vehicle is suggested to compute the dynamic behavior of a railway vehicle in the HILS(Hardware In-the-loop Simulation) system for the railway vehicle braking devices. To simplify the dynamic model, friction between a wheel and a rail is assumed that there exist only the static and the dynamic friction forces. Static friction coefficient is also assumed to be a function of the running speed. Some simulations are carried out with various braking forces, and the braking characteristics according to the change of the braking force are discussed. This study can provide some fundamental results to construct the HILS system for braking devices of a railway vehicle.

Dynamic Model of a Vertical Tube Absorber for Ammonia/water Absorption Refrigerators (암모니아/물 흡수식 냉동기의 수직원관형 흡수기의 동적 모델)

  • 문현석;정은수;김병주
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.10
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    • pp.844-853
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    • 2002
  • A dynamic model which simulates the coupled heat and mass transfer within a vertical tube absorber was developed. The liquid film is a binary mixture of two components, and both of these components are present in the vapor phase. The pressure, concentration, temperature and mass flow rate of the vapor are obtained by assuming that the pressure is uniform within an absorber. The model was applied to an absorber for an ammonia/water absorption refrigerator. The transient behaviors of the pressure, the outlet temperature and the concentration of the solution and the cooling water outlet temperature on a step change at the absorber inlet of the cooling water temperature, the vapor mass flow rate and the concentration of the solution were shown.

Flexible Multibody Dynamic Model of a Maglev Vehicle Bogie (자기부상열차 대차 유연 다물체 모델)

  • Kim, Ki-Jung;Han, Hyung-Suk;Lee, Nam-Jin;Kim, Bong-Sub
    • Proceedings of the KSR Conference
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    • pp.1207-1212
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    • 2009
  • The flexible multibody dynamic model of an EMS-type Maglev vehicle is necessary in design stage to predict its behavior, load history and levitation performance. Especially in EMS-type Maglev vehicle, the body flexibility of its bogie with electromagnets affects the levitation performance because its feedback control system is more sensitive to vibration of bogie structure. The flexible multibody dynamic model of a 1/2 Maglev vehicle under test is presented. The basic modeling procedure is almost the same as in other applications. However, the feedback control system model unique in EMS-type maglev vehicle must be included in the model. With the model proposed in this study, the dynamic behavior, load history and levitation performance are more precisely predicted. This model could realize the virtual prototyping in EMS-type Maglev vehicle area.

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Ultrasonic Distance Measurement Method by Using the Envelope Model of Received Signal Based on System Dynamic Model of Ultrasonic Transducers

  • Choe, Jin-Hee;Lee, Kook-Sun;Choy, Ick;Cho, Whang
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.981-988
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    • 2018
  • In order to acquire an accurate TOF, this paper proposes a method that produces TOF by using a mathematical model for the envelope of the received signal obtained from a system dynamic model of ultrasonic transducer. The proposed method estimates the arrival time of the received signal retrospectively by comparing its wave form obtained after triggering point with its mathematical envelope model. Experimental result shows that the error due to variation of triggering point can be dramatically decreased by implementing the proposed method.

Optimal Velocity Profile for Minimum Power Consumption of Korean Total Artificial Heat

  • Chang, Jun-Keun;Min, Byoung-Goo
    • Journal of Biomedical Engineering Research
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    • v.18 no.1
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    • pp.51-64
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    • 1997
  • A dynamic model of the Korean total artificial heart(TAH) which contains a brushless DC motor, all of mechanical components, the pump system with integrated variable volume space(WS) and the circulatory system model including the bronchial circulation were established Two different sets of seven differential equations were separately derived for the left and right systolic period of the Korean TAH operation. Throughout the computer simulation, a full-state fEedback optimal controller that minimizes the power consumption of the Korean TAH and drives the end stage velocity of the energy converter to zero was developed based upon the optimal control theory. Robustness of the controller were also analyzed with the dynamic model of the Korean TAH.

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Modeling and Countermeasure for Positioning Stage Base Vibration (위치결정 스테이지 베이스 진동 모델링 및 저감기법 개발)

  • Park, Ah-Yeong;Lim, Jae-Gon;Hong, Seong-Wook
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.4
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    • pp.476-484
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    • 2010
  • Precise positioning stages are often employed for precise machinery. For the purpose of vibration isolation, these precise positioning stages are mounted on a heavy base structure which is supported by compliant springs. Then the base structure is subjected to residual vibration due to the reactive force and vertical moving load induced by the stage motion. This paper investigates the vibration behavior of a positioning stage base and the associated vibration suppression technique. A dynamic model is developed to investigate the base vibration due to the reactive force and moving load effects by the moving stage. An input shaping technique is also developed to suppress the residual vibrations in base structures. Simulations and experiments show that the developed dynamic model adequately represents the base vibration and that the proposed input shaping technique effectively removes the residual vibrations from the positioning stage base.

Nuclides Transport Analysis and Dose Calculation Using Dynamic Model for Rice Ingestion Pathway (쌀 섭취경로에서 동적모델을 사용한 장반감기핵종의 거동해석 및 내부피폭 선량계산)

  • Lee, Chang-Woo;Choi, Yong-Ho;Hwang, Won-Tae;Lee, Jeong-Ho
    • Journal of Radiation Protection and Research
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    • v.17 no.2
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    • pp.15-23
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    • 1992
  • Transport behaviors of Cs-137 and Sr-90 were analyzed and ingestion doses were calculated using dynamic model for rice field-rice-man pathway. Cs-137 binding strongly to soil remain longer in rice field than Sr-90. Foliar deposition on rice plant during growing period is the main contamination mechanism.

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Three-Dimensional Dynamic Model of Full Vehicle (전차량의 3차원 동역학 모델)

  • Min, Kyung-Deuk;Kim, Young Chol
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.1
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    • pp.162-172
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    • 2014
  • A three-dimensional dynamic model for simulating various motions of full vehicle is presented. The model has 16 independent degrees of freedom (DOF) consisting of three kinds of components; a vehicle body of 6 DOF, 4 independent suspensions equipped at every corner of the body, and 4 tire models linked with each suspension. The dynamic equations are represented in six coordinate frames such as world fixed coordinate, vehicle fixed coordinate, and four wheel fixed coordinate frames. Then these lead to the approximated prediction model of vehicle posture. Both lateral and longitudinal dynamics can be computed simultaneously under the conditions of which various inputs including steering command, driving torque, gravity, rolling resistance of tire, aerodynamic resistance, etc. are considered. It is shown through simulations that the proposed 3D model can be useful for precise design and performance analysis of any full vehicle control systems.