• Title/Summary/Keyword: DC-motor

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Design of pulsatile pump and performance test for pulsatile flow generation (맥동 유동 발생을 위한 맥동 펌프의 설계 및 특성 분석 연구)

  • Joo, Yoon-Ha;Kim, Kyung-Won;Lee, Yeon-Ho;Kwak, Moon-Kyu;Lee, Choon-Young;Lee, Jong-Min;Park, Cheol-Woo
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.2
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    • pp.149-155
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    • 2013
  • For in-depth research of blood flow, it is important to create pulsating flow like the blood flow from heart beat. In this study, we developed a heart mimicking pulsatile pump and evaluated its performances. Main body of pump was produced using a piston pump, and its rpm and duty ratio was modulated by DC motor and encoder. To determine the part dimensions, principle stress theory and simple fluidic pressure analysis were used. The performance of pulsating pump was evaluated by comparing the pressure values and their deviations according to experimental variables. For the results, the output value of pressure followed the distribution of pulsating flow and its deviation was negligible. Through this study, we expect the established pulsating pump can be widely used in study of blood flow produce easy ways to related researchers.

Nonlinear Friction Control Using the Robust Friction State Observer and Recurrent Fuzzy Neural Network Estimator (강인한 마찰 상태 관측기와 순환형 퍼지신경망 관측기를 이용한 비선형 마찰제어)

  • Han, Seong-Ik
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.18 no.1
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    • pp.90-102
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    • 2009
  • In this paper, a tracking control problem for a mechanical servo system with nonlinear dynamic friction is treated. The nonlinear friction model contains directly immeasurable friction state and the uncertainty caused by incomplete modeling and variations of its parameter. In order to provide the efficient solution to these control problems, we propose a hybrid control scheme, which consists of a robust friction state observer, a RFNN estimator and an approximation error estimator with sliding mode control. A sliding mode controller and a robust friction state observer is firstly designed to estimate the unknown infernal state of the LuGre friction model. Next, a RFNN estimator is introduced to approximate the unknown lumped friction uncertainty. Finally, an adaptive approximation error estimator is designed to compensate the approximation error of the RFNN estimator. Some simulations and experiments on the mechanical servo system composed of ball-screw and DC servo motor are presented. Results demonstrate the remarkable performance of the proposed control scheme.

Analsis of Preponderant Wear of Earth Brush for an Electrical Multiple Units(EMUs) (전동차용 접지브러쉬 편중마모에 대한 해석)

  • Park, Byung-Sup;Ku, Jung-Su;Kim, Gil-Dong
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.356-361
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    • 2005
  • Earth brush for electrical multiple units(EMUs) is a device through which the current of the EMU load's consumed power fed from the DC 1,500V overhead line (or from the AC 25.000V catenary) flows via axle to the rail(ground) and which prevents the electric corrosion of the axle bearings by preventing the current flow to the axle bearings caused by electric potential from the magnetic field when the bearings rotate together with the earthing function when a thunderbolt falls or a surge comes. The earth brush wear rates among cars, however, shows quite differences when the earth brushes after being separated from the holders are measured with vernier callipers every 6 months of maintenance period. Main causes of the earth brush wear are divided as mechanical, electric arc and electrical one, and the factors can be running speed, current, harmonics, connection state. spring tension, earth brush material, lubricant and so on. but only the earth brushes of the motor(M1) car show the highest wear rate and moreover maintenance difficulty occurs because of the wear rate differences among e earth brushes in one holder. The reason for these preponderant wear comes from the design concept of making preponderant current flow to some particular earth brushes and moreover the heat generated by the harmonics when the inverter starts to operate accelerate the wear. By defining these causes through experiments. I hope that the found results would be helpful for the future EMU design, safety, economy and maintenance.

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DEVELOPMENT OF THE SOFTWARE FOR 30INCH TELESCOPE CONTROL SYSTEM AT KHAO (경희대학교 천문대 30인치 주망원경 TCS 소프트웨어 개발)

  • Mun, B.S.;Kim, S.J.;Jang, M.;Min, S.W.;Seol, K.H.;Moon, K.S.
    • Publications of The Korean Astronomical Society
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    • v.21 no.2
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    • pp.81-86
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    • 2006
  • Even though 30inch optical telescope at Kyung Hee Astronomy Observatory has been used to produce a series of scientific achievements since its first light in 1992, numerous difficulties in operating of the telescope have hindered the precise observations needed for further researches. Since the currently used PC-TCS(Personal Computer based Telescope Control System) software based on ISA-bus type is outdated, it doesn't have a user friendly interface and make it impossible to scale. Also accumulated errors which are generated by discordance from input and output signals into a motion controller required new control system. Thus we have improved the telescope control system by updating software and modifying mechanical parts. We applied a new BLDC(brushless DC) servo motor system to the mechanical parts of the telescope and developed a control software using Visual Basic6.0. As a result, we could achieve a high accuracy in controlling of the telescope and use the user friendly GUI(Graphic User Interface).

The Analysis of Vibration Due to Magnetic Exciting Force in the Brushless DC Motor (다기 전력 시스템 동적 안정도 향상을 위한 분산 제어 기반 PSS 및 TCSC 제어기 설계)

  • Lee, Seung-Cheol;Seo, Jang-Cheol;Moon, Seung-Ill;Park, Jong-Keun
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.1
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    • pp.13-19
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    • 2001
  • This paper deals with decentralized control scheme and its application to multi-machine power systems. Decentralized control scheme has several practical advantages, because power system has geographically distributed characteristics. In this paper, decentralized observer-based optimal Power System Stabilizer(PSS) and Thyristor-Controlled Series Capacitor(TCST) controller are designed and tested in WSCC 9 bus system with one TCSC installed. Simulation results show that the proposed decentralized controller has satisfactory performances comparable to the centralized controller. In addition, using modal analysis, this paper shows that the proposed decentralized controller significantly affects only one pair of eigenvalues which have high participation with each generator, while slightly affects other eigenvalues. This result indicates that the application of the decentralized control scheme to enhance power system dynamic stability via excitation control have potential advantages because each low-damped mode occurs dominantly by each decentralized subsystem.

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Nonlinear Controller for the Velocity Tracking and Rejection of Sinusoidal Disturbances in Permanent Magnet Stepper Motors (영구 자석 스테퍼 모터의 속도 추종과 외란 제거를 위한 비선형 제어기)

  • Kim, Won-Hee;Gang, Dong-Gyu;Han, Jonh-Pyo;Chung, Chung-Choo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.3
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    • pp.632-638
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    • 2011
  • In this paper, a nonlinear controller is proposed to track the desired velocity and to cancel sinusoidal disturbances. The proposed method consists of a velocity tracking controller and internal model principles (IMPs). For the design of the velocity tracking controller, mechanical and electrical dynamic controllers are independently designed. For the mechanical dynamics, the velocity tracking controller generates the desired quadrature current to track the desired velocity. The current tracking controller is designed to guarantee the desired quadrature current and to regulate the direct current. Therefore, the proposed velocity tracking controller has a field-oriented control. Since the controllers of the mechanical and electrical dynamics are independently designed, the stability of the closed-loop system is demonstrated using passivity. Since both the cogging torque and DC current errors act as sinusoidal disturbances in PMSM, we use four add-on type IMPs that preserve the merits and performance of the pre-designed controller without sacrificing the closed-loop stability. The performance of the proposed method is validated via simulations.

A controller Design using Immune Feedback Mechanism (인체 면역 피드백 메카니즘을 활용한 제어기 설계)

  • Park, Jin-Hyun;Kim, Hyun-Duck;Choi, Young-Kiu
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.701-704
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    • 2005
  • PID controllers, which have been widely used in industry, have a simple structure and robustness to modeling error. But They are difficult to have uniformly good control performance in system parameters variation or different velocity command. In this paper, we propose a nonlinear adaptive PID controller based on a cell-mediated immune response and a gradient descent learning. This algorithm has a simple structure and robustness to system parameters variation. To verify performances of the proposed nonlinear adaptive PID controller, the speed control of nonlinear DC motor is performed. The simulation results show that the proposed control systems are effective in tracking a command velocity under system parameters variation.

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SRM Drive System Using 6-switch IGBT Module (6-Switch IGBT Module을 이용한 SRM 구동 시스템)

  • Kim Yuen-Chung;Yoon Yong-Ho;Lee Won Cheol;Lee Byoung-Kuk;Won Chung-Yuen
    • The Transactions of the Korean Institute of Power Electronics
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    • v.10 no.6
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    • pp.569-577
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    • 2005
  • In this paper, a new control scheme to use 6-switch IGBI module for 3-phase switched reluctance motors(SRM) is proposed. Compared with the conventional asymmetric bridge converter topology, it can minimize the entire system size and cost. Therefore, it may have a new topology lot SRM to compare the other ac motors, such as induction motors, brushless dc motors, and so on. The validity of the proposed method is verified by simulation, and experimental results.

Fault Detection and lsolation System for centrifugal-Pump Systems: Parity Relation Approach (원심펌프 계통의 고장검출진단시스템 : 등가관계 접근법)

  • Park, Tae-Geon;Lee, Kee-Sang
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.1
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    • pp.52-60
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    • 1999
  • This paper deals with a fault detection and isolation scheme for a DC motor driven centrifugal pump system. The emphasis is placed on the design and implementation of the residual generatorm, based on parity relation, that provides decision logic unit with residuals that will be further processed to detect and isolate three important faults in the system;brush fault, impeller fault, and the speed sensor fault. Two process faults are modelled as multiplicative type faults, while the sensor fault as an additive one. With multiplicative fault, the implementation of the residual generator needs the time varying transformation matrix that must be computed on-line. Typical implementation methods lack in generality because only a numerical approximation around the assumed fault levels is employed. In this paper, a new implementation method using well tranined neural network is proposed to improve the generality of the residual generator. Application results show that the fault detection and isolation scheme with the proposed residual generator effectively isolates three major faults in the centrifugal pump system even with a wide range of fault magnitude.

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Construction of the I-PD Control System by Multilayer Neural Network (다층 신경망에 의한 I-PD 제어계의 구성)

  • 고태언
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.1
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    • pp.74-79
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    • 2002
  • Many control techniques have been proposed in order to improve the control performance in discrete-time domain control system. In control system using these techniques, the response-characteristic of system is dependent on the gains of the controller. Specially, There is a need to readjust the gain of controller when the response of system is changed by disturbance or load fluctuation. In this paper, I-PD controller and pre-compensator are designed by multilayer neural network. The gains of I-PD controller and pre-compensator are adjusted automatically by back propagation algorithm when the response characteristic of system is changed under a condition. Applying this control technique to the position control system using a DC servo motor as a driver, the control performance of controller is verified by the results of experiment.

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