• Title/Summary/Keyword: Fluid Power Control System

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Control Performance for Semi-active Mount Featuring Magneto-Rheological Fluid (반능동형 MR유체 마운트의 성능제어)

  • Kim, O.S.;Park, W.C.;Lee, H.C.
    • Journal of Power System Engineering
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    • v.8 no.2
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    • pp.53-58
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    • 2004
  • In this paper, the semi active mount featuring Magneto rheological fluid(MR Fluid) is proposed. MR fluid is suspension of micro sized magnetizable particles in a fluid medium, and its apparent viscosity can be varied by the applied strength of magnetic field. When the controllable MR fluid is applied to mechanical devices, the devices provide simple, rapid response interfaces between electronic controls and mechanical systems. The MR fluid is applied in the conventional fluid mount for improving its performance of the mount's isolation effect. A appropriate size of the MR mount is designed and manufactured on the basis of Bingham model of MR fluid. In addition, the field dependent damping forces of MR mount are evaluated with respect to the input frequency variation.

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Trajectory Tracking Control of Injection Molding Cylinder Driven by Speed Controlled Hydraulic Pump (속도제어-유압펌프에 의하여 구동되는 사출성형 실린더의 궤적추적제어)

  • Cho, S.H.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.4 no.2
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    • pp.21-27
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    • 2007
  • This paper deals with the issue of trajectory tracking control of a clamping cylinder for injection moulding machine, which is directly driven by speed controlled hydraulic pump in combination with AC servomotor. As a fundamental step prior to tracking controller design, feedback control system is developed by implementing a position control loop parallel with a system pressure control loop. A sliding mode controller combining velocity feedforward scheme is developed for enhancing the tracking performance. Consequently a significant reduction in tracking error is achieved for both position and pressure control applications.

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A Study on the DC to DC Converter to Improve the Performance of Power LED System (파워 LED 시스템 성능개선을 위한 DC/DC 컨버터에 관한 연구)

  • Kim, Young Tae;Kim, Sei Yoon
    • Journal of Drive and Control
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    • v.19 no.4
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    • pp.85-90
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    • 2022
  • In this paper, a DC converter to improve the performance of Power LED system is discussed. The mathematical model of PWM converter power stage using 3-Terminal PWM cell is introduced for power LED system. A controller for DC converter system is used as a self-tunning regulator with a recursive least-squares algorithm. Minimum variance control method is used as a control law. Experiment results verified that proposed control system could improve the performance of Power LED system.

3D CAD Modeling of a Hydraulic Motor-Load System and Adaptive Control (유압모터-부하계의 3D CAD 모델링 및 적응제어)

  • Cho, S.H.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.8 no.2
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    • pp.23-28
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    • 2011
  • This paper investigates the motion control of a hydraulic motor-load system using the Simple Adaptive Control (SAC) method. The plant transfer function has been modelled mathematically. The open-loop responses have been obtained experimentally in order to identify the design parameters of transfer function. The hydraulic motor-load system has been modelled using the 3D CAD and imbedded in the hydraulic circuit simulation program to verify the overall performance. The experimental results confirm that the SAC method gives a good tracking performance compared to the PID control.

A Two-Dimensional Study of Transonic Flow Characteristics in Steam Control Valve for Power Plant

  • Yonezawa, Koichi;Terachi, Yoshinori;Nakajima, Toru;Tsujimoto, Yoshinobu;Tezuka, Kenichi;Mori, Michitsugu;Morita, Ryo;Inada, Fumio
    • International Journal of Fluid Machinery and Systems
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    • v.3 no.1
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    • pp.58-66
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    • 2010
  • A steam control valve is used to control the flow from the steam generator to the steam turbine in thermal and nuclear power plants. During startup and shutdown of the plant, the steam control valve is operated under a partial flow conditions. In such conditions, the valve opening is small and the pressure deference across the valve is large. As a result, the flow downstream of the valve is composed of separated unsteady transonic jets. Such flow patterns often cause undesirable large unsteady fluid force on the valve head and downstream pipe system. In the present study, various flow patterns are investigated in order to understand the characteristics of the unsteady flow around the valve. Experiments are carried out with simplified two-dimensional valve models. Two-dimensional unsteady flow simulations are conducted in order to understand the experimental results in detail. Scale effects on the flow characteristics are also examined. Results show three types of oscillating flow pattern and three types of static flow patterns.

Angular Position Control of a Rotor with Electro-Rheological Clutch (전기 유변성 클러치를 이용한 회전관성체의 위치제어)

  • 고봉춘;심현해;김창호;김권희
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.10a
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    • pp.203-211
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    • 1998
  • ER clutch is a device using electro-rheological fluid which is one of so called intelligent materials. Power transmission behavior of an ER clutch can be controlled by electrical field applied tb the fluid. In this work, a new type of servomechanism is developed with two ER clutchs, driven by two electrical motors rotating in reverse directions. The concentric cylinder type ER clutch is operated by PID control. The system shows good angular position control characteristics with respect to sinusoidal and square inputs.

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A Study on Dehumidification Characteristics of Hollow Fiber Membrane Module for Pneumatic Power Unit Using Fluid-Solid Interaction Analysis (유동-구조 연성해석을 이용한 공압용 파워 유닛에 사용되는 중공사막 모듈에 대한 제습특성 연구)

  • Jeong, Eun-A;Khan, Haroon Ahmad;Lee, Kee-Yoon;Yun, So-Nam
    • Journal of Drive and Control
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    • v.16 no.4
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    • pp.65-73
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    • 2019
  • In this study, flow analysis and fluid-solid interaction analysis were conducted on a hollow fiber membrane module used for analysis of dehumidification characteristics. To ensure the reliability of the flow analysis results, the dehumidification experiment was performed under the temperature of 30℃ and relative humidity of 30% RH. The results of the dehumidification experiments were compared with the flow analysis results. The results of dehumidification experiments and flow analysis had a difference of approximately 5%. A 1-Way fluid-solid interaction analysis with various materials was conducted. From the results, it was found that the baffle with the largest shape deformation (polyethylene material) was subjected to 2-way fluid-solid interaction. The analysis of fluid flow and dehumidification characteristics were analyzed according to the shape deformation of the baffle.

Design of Network Controller for Proportional Flow Control Solenoid Valve (비례유량제어밸브 네트워크 제어기 설계)

  • Jung, G.H.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.8 no.4
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    • pp.17-23
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    • 2011
  • Proportional control solenoid is a type of modulating valve that can continuously control the valve position with magnetic force of solenoid. Recent microcontroller based digital servocontroller for proportional valve is being developed toward the smart valve with additional features such as enhanced control algorithm for finer process and intelligent on-board diagnosis for maintenance. In this paper, development of servocontroller network control with CAN bus which is free from problems of security and network traffic jam is presented. Design of network control system includes modes of communication between master and slave, assignment of 29bit message identifier and message objects, transaction of communication sequence, etc. Monitoring function and control experiments for remote valve through CAN network prove the extended function of smart valve control system.

Force Control of Electro-Hydraulic Servo System using Direct Drive Valve for Pressure Control (압력제어용 직동 밸브를 이용한 전기.유압 서보시스템의 힘 제어)

  • Lee C.D.;Lee J.K.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.1 no.3
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    • pp.14-19
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    • 2004
  • The Direct Drive Valve used in this study contains a pressure-feedback-loop in itself, then it can eliminate nonlinearity such as the square-root-term in flow rate calculation and the change of bulk modulus of hydraulic oil. In this study, assuming that the dynamic characteristic of the DDV is modelled as a first order lag system, an parameter identification method using the input data and the output data is applied to obtain DDV's mathematical model. Then, a state feedback controller was designed to implement the force control of hydraulic system, and the control performance was evaluated.

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