• 제목/요약/키워드: magnetic control

검색결과 2,267건 처리시간 0.026초

External Magnetic Field of Journal Bearing with Twined Solenoid

  • Zhang, Yanjuan;Wang, Jianmei;Li, Decai
    • Journal of Magnetics
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    • 제22권2호
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    • pp.291-298
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    • 2017
  • In this paper, the distribution of internal magnetic induction intensity of oil-film bearing twined solenoids was proposed. The magnetic field was generated by solenoids and magnetized bearing. The magnetized bearing was simplified as solenoid model. The mathematical model of magnetic induction intensity at any point of finite solenoid was deduced. Through experiment method, the distribution of the internal magnetic induction intensity of oil-film bearing and the magnetizing current formula of bearing was obtained. Further, the magnetic induction intensity distribution of magnetization bearing was solved successfully. The results showed that the magnetic induction was a second-degree parabola with open upwards along the axial plane and the distribution of magnetic induction intensity was opposite to the rule of magnetic induction intensity generated by solenoids. In addition, the magnetic flux density increased linearly with the increase of current.

Magnetic Field Analysis for Development of Magnetic Torquer

  • Yim, Jo-Ryeong;Lee, Seon-ho;Rhee, Seung-Wu
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2003년도 한국우주과학회보 제12권2호
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    • pp.63-63
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    • 2003
  • There are many actuators and sensors used for attitude control system for KOMPSAT such as Reaction Wheel Assembly, Magnetic Torque Assembly, Dual Thruster Module, Solar array Drive, Three Axis Magnetometer, Conical Earth Sensor, Fine Sun Sensor Assembly, Coarse Sun Sensor Assembly, Gyro Reference Assembly and so on. For KOMPSA T satellite it has been considered using the Magnetic Torquer (MTQ) generating the magnetic dipole moment. In general, the magnetic dipole moment for satellite attitude control system is used for dumping out the excessive reaction wheel momentum so that the reaction wheel speed is not saturated. The objective of this study is to analyze the magnetic field characteristics generated by the Magnetic Torquer using the Maxwell 2D Field Simulator software. Currently, the developing model (DM) of the MTQ is being developed and manufactured at a company under the supervision of KARL MTQ is an electromagnet consisting of a ferromagnetic cylindrical core on which an excitation coil is wound. A current is passed through the coil to produce a dipole momentum in the ferromagnetic core. The configuration of the MTQ will be introduced in the presentation. The 2 dimensional model of the MTQ is drawn as axisymmetric models in RZ plane, and each corresponding material is assigned to the each MTQ object, the core, coil, and background. After the boundary conditions, current sources, and solution parameters are set up, the magnetic field intensities, directions, and other values specified by users can be calculated by using the finite element analysis. The theoretical magnetic field quantities obtained by the Maxwell 2D Simulator can be used for the basis of the development of the MTQ.

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자기베어링계에서 외란 관측기를 갖는 슬라이딩모드 제어 (Sliding Mode Control with Disturbance Observer for An Active Magnetic Bearing System)

  • 강민식
    • 대한전기학회논문지:시스템및제어부문D
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    • 제53권6호
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    • pp.408-414
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    • 2004
  • In this paper, a disturbance observer based sliding mode control is proposed to attenuate disturbance responses in an active magnetic bearing system, which is subject to base motion. An algorithm which decouples disturbance observation dynamics from sliding mode dynamics is suggested. This algorithm preserves the robustness of the sliding mode control and satisfies reachability condition in the presence of external disturbance and parameter uncertainties. Along with experimental results, it is shown that the proposed control is effective in disturbance rejection without any additive disturbance measurement.

전자기 구동장치를 이용한 병렬형 6자유도 스테이지의 위치제어 (A Position Control for a Parallel Stage with 6 degrees of freedom Using Magnetic Actuators)

  • 이세한
    • 한국정밀공학회지
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    • 제22권7호
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    • pp.102-111
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    • 2005
  • In this paper, we address a position control for a parallel stage, which is levitated and driven by electric magnetic force. This consists of a levitating object (called platen) with 4 permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion by the vertical and horizontal force. A dynamic equation of the stage system is derived based on Newton-Euler method and it's special Jacobian matrix describing a relation between the limited velocity and Cartesian velocity is done. There are proposed two control methods for positioning which are Cartesian space controller and Actuator space controller. The control performance of the Cartesian space controller is better than the Actuator space controller in task space trajectory while the Actuator space controller is simpler than the Cartesian space controller in controller realization.

MR유체를 이용한 유량제어 밸브 (Development of Flow Control Valve Using MR Fluid)

  • 이형돈;배형섭;이육형;박명관
    • 제어로봇시스템학회논문지
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    • 제17권9호
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    • pp.888-891
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    • 2011
  • This paper presents development of flow control valve using MR fluid. Generally, since the apparent viscosity of MR fluids is adjusted by applying magnetic fields, the MR valves can control high level fluid power without any mechanical moving parts. In this paper, flow control valve using MR fluid on the behavior of the magnetic field influence on the numerical analysis of more accurate electromagnetic parameters were obtained, even if when magnetic field apply inside of surrounding MR fluid from electromagnet, more realistic designing way analysis of characteristic of whole magnetic field distribution is suggested by surrounding magnetic material. Also, comparison of flow rate inlet and outlet, behavior of MR fluid in experiments proposed. A new type of flow control valve using MR fluid is proposed by analysis of behavior of MR fluid in experiments.

마그네틱 콤파스 기반의 전 방향 로봇의 방위각 제어 (Azimuth Tracking Control of an Omni-Directional Mobile Robot(ODMR) Using a Magnetic Compass)

  • 이정형;정슬
    • 제어로봇시스템학회논문지
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    • 제15권2호
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    • pp.132-138
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    • 2009
  • In this paper, control of an omni-directional mobile robot is presented. Relying on encoder measurements to define the azimuth angle yields the dead-reckoned situation which the robot fails in localization. The azimuth angle error due to dead-reckoning is compensated and corrected by the magnetic compass sensor. Noise from the magnetic compass sensor has been filtered out. Kinematics and dynamics of the omni-directional mobile robot are derived based on the global coordinates and used for simulation studies. Experimental studies are also conducted to show the correction by the magnetic compass sensor.

Design and Analysis of a New Hybrid Electromagnetic Levitation System

  • Na, Uhn Joo
    • 한국산업융합학회 논문집
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    • 제22권1호
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    • pp.29-37
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    • 2019
  • A new permanent magnet biased hybrid maglev actuator is developed. Compared to the classical hybrid maglev actuators, the new maglev has unique flux paths such that bias fluxes are separated with control flux paths. The control flux paths have minimum reluctances only developed by air gaps, so the currents to produce control fluxes can be minimized. The consumed power to operate this maglev system can also be minimized. The gravity load can be compensated with the static magnetic forces developed by the permanent magnet bias fluxes while external disturbances are controlled with the bidirectional AC magnetic forces developed by control fluxes by currents. 1-D circuit model is developed for this model such that the flux densities and magnetic forces are extensively analyzed. 3-D finite element model is also developed to analyze the performances of the maglev actuator.

내면연삭기 고속 주축용 원추형 자기베어링시스템 설계 (Design of Cone-Shaped Magnetic Bearing Spindle System for High Speed Internal Grinding Machine)

  • 박종권;노승국;경진호
    • 한국정밀공학회지
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    • 제19권2호
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    • pp.213-219
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    • 2002
  • A cone-shaped active magnetic healing spindle system for high speed internal grinding with built-in motor that has 7.5kW power and maximum rotational speed of 50,000 rpm is designed and built. Using cone-shaped AMB(Active Magnetic Bearing) system, the axial rotor dick and magnets of conventional 5-axis actuating design can be eliminated. so this concept of design provides a simple magnetic bearing system. In this paper, the cone-shaped electromagnets are designed by magnetic circuit theory, and a de-coupled direct feedback PID controller is applied to control the coupled magnetic bearings. The designed crone-shaped AMB spindle system is built and constructed with a digital control system, which has TMS320C6702 DSP, 16 bit AD/DA, switching power amplifier and gap sensors. As the AMB system provides high damping ratio eliminating overshoot and resonance speed, this spindle runs up to 40,000 rpm stably with about 5${\mu}{\textrm}{m}$ of runout.

AF궤도회로에서 세라믹 코팅재에 의한 자계의 세기 변화에 대한 연구 (A Study on the Variation of Magnetic Field Intensity by Ceramics Coating Material in AF Track Circuits)

  • 김민규;김선동;고영환;김민석;이종우
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.1656-1662
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    • 2010
  • Automatic train control systems are divided into ATC, ATP and ATS systems etc. The ATP and ATS systems offer discontinuous information for train control. While the ATC systems provide continueous information for train control. There is a method for offering continuous information by AF track circuits. Magnetic fields are formed by current through rails in the AF track circuit systems. So, the continuous information is received by the magnetic fields on a on-board antenna. Coating materials on rails are researched to decrease defects such as head check, shelling, corrugation, squats and so on in Germany. Currently, a coating method of rail construction is proposed by using the ceramics in Korea. When deciding physical characteristic of ceramics, researches are required about variation of flux density by the ceramics. In case that the flux density is much lower than existing value, the information for train control is not transmitted to the on-board antenna. In this paper, inductance on rails is calculated and a model is presented about variation of the magnetic field intensity in the AF track circuit. Standard permeability of ceramics is proposed by analyzing the variation of magnetic field intensity. It is demonstrated by using Maxwell and Matlab program.

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