• 제목/요약/키워드: Gap servo

검색결과 43건 처리시간 0.027초

Improvements of Performance of Multi-DOF Spherical Motor by Double Air-gap Feature

  • Lee, Ho-Joon;Park, Hyun-Jong;Won, Sung-Hong;Ryu, Gwang-Hyun;Lee, Ju
    • Journal of Electrical Engineering and Technology
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    • 제8권1호
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    • pp.90-96
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    • 2013
  • As the need of electric motor is increased rapidly throughout our society, the various application fields are created and the service market called robot gets expanded as well as the existing industrial market. Out of those, the joint systems such as humanoid that is servo actuator for position control or all fields which require multi-degree of freedom (multi-DOF) require the development of innovative actuator. It is multi-DOF spherical motor that can replace the existing system in multi-DOF operating system. But, multi-DOF spherical motor that has been researched up to date is at the stage which is insufficient in performance or mechanical practicality yet. Thus, first of all the research results and limitation of the previously-researched guide frame-type spherical motors were analyzed and then the feature of double air-gap spherical motor which was devised to complement that was studied. The double air-gap multi-DOF spherical motor is very suitable spherical motor for system applying which requires the multi-DOF operation due to its simple structure that does not require other guide frame as well as performance improvement due to its special shape which has two air-gaps. So, the validity of the study was verified by designing and producing it with 3D-FEM through the exclusive jig for multi-DOF spherical motor.

핵연료봉 프레팅마멸 시험기 개발 (Development of Fuel Rod Fretting Wear Tester)

  • 김형규;하재욱;윤경호;강흥석;송기남
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2001년도 제34회 추계학술대회 개최
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    • pp.245-251
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    • 2001
  • A fretting wear tester is developed for experimental study on the fuel fretting problem of light water reactor. The feature of the developed tester is it can simulate the existence of gap between spring and fuel rod as well as different contacting force including the just-contact condition (0 N on the contact). Used are a servo-motor, an eccentric cylinder and lever mechanism for driving system. A spacer grid cell is constituted with four strap segments (each segment has a spring). This fretting wear tester can also be used as a fatigue tester of a spacer grid spring with the frequency of more than 10 Hz. It is required to simulate the frequency of the vibrating fuel rod due to flow-induced vibration in a reactor. In fretting wear test, up to two span-length of a fuel cladding tube can be accommodated. A specimen of cladding tube of one span-length is specially designed, which can be extended for two-span test. For .fatigue test, a device for clamping the spring fixture is installed additionally, Presently, the tester is designed for the condition of air environment and room temperature. The variation of the reciprocal distance is measured to check the stability of input force, which will be exerted to the cladding (for fretting wear. test) and the spring (for fatigue test) specimen.

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A Novel High Precision Electromagnetic Suspension for Long-Stroke Movement and Its Performance Evaluation

  • Lee, Ki-Chang;Moon, Seokhwan;Ha, Hyunuk;Park, Byoung-Gun;Kim, Ji-Won;Baek, Jun-Young;Lee, Min-Cheol
    • Journal of Electrical Engineering and Technology
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    • 제9권2호
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    • pp.514-522
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    • 2014
  • A new type of high precision electromagnetic suspension (EMS) which can support heavy tray along long stroke rail is proposed in this paper. Compared with the conventional EMS, the suggested moving-core typed EMS has the levitation electromagnets (EMs) on the fixed rail. This scheme has high load capability caused by iron-core and enables simple tray structure. Also it does not have precision degradation caused by heat generation from EMs, which is a drawback of conventional EMS. With these merits, the proposed EMS can be an optimal contactless linear bearing in next generation flat panel display (FPD) manufacturing process if the ability of long stroke movement is proved. So a special Section Switching Algorithm (SSA) is derived from the resultant force and moment equations of the levitated tray which enables long stroke movement of the tray. In order to verify the feasibility of the suggested SSA, a simple test-setup of the EMS with 2 Section-changes is made up and servo-controlled in the simulation and experiment. The simulation shows the perfect changeover the EMs, and the experiment shows overall control performance of under ${\pm}40{\mu}m$ gap deviations. These results reveal that the newly suggested contactless linear bearing can simultaneously achieve high load capability and precision gap control as well as long stroke.

초음파 고도계를 이용한 지형지물 측정에 있어서의 잡음에 의한 오차 보정 방법 (A Correction Method of the Error in the Survey of Topography Using an Ultrasound Altitude Sonar)

  • 김시문;최종수;이종무;홍섭
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2001년도 추계학술대회 논문집
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    • pp.26-31
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    • 2001
  • In order to measure the distance from the bottom in the ocean we use ultrasound altitude sonars. The manganese nodule pick-up device developed by KRISO is also using an altitude sonar to control the gap between the pick-up head and sea bottom. This paper describes the performance of the altitude sonar by an experimental method. The experiment was performed with four ground models in a small basin, Manganese nodule models and water-bentonite mixture was used for setting up the ground models. Buttorworth filter was applied to remove the noise caused by a servo motor and its controller. The results show that the altitude sonar gives a good estimation of the types and slopes of the bottom as well as the distance.

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실시간 분산 열연 두께제어 시스템의 설계 및 현장적용 (A Real-time Distributed AGC System for a Hot Strip Mill)

  • 이호훈
    • 대한기계학회논문집A
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    • 제23권6호
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    • pp.922-930
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    • 1999
  • This paper describes a new 14-CPU real-time distributed automatic gauge control (AGC) system for POSCO's No. 2 Hot Strip Mill at Pohang Works. The new AGC system has adopted gaugemeter AGC, Monitor AGC, and roll gap disturbance compensators. The computer system for the new AGC system has been developed based on VMEbus computer systems and a commercial real-time operating system. A VMEbus computer system is also used for the position servo control of hydraulic cylinders. All the application programs and input/output signals have been reasonably distributed over the control computer systems for the maximum reliability and effectiveness of the system. The new AGC system has been successfully used for the No. 2 Hot Strip Mill.

턴널링 전류효과를 이용한 마이크로가속도 센서의 축전기부 해석 (Analysis in Capacitor of Microaccelerometer Sensor Using Tunnelling Current Effect)

  • 김옥삼
    • 동력기계공학회지
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    • 제3권4호
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    • pp.57-62
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    • 1999
  • The microaccelerometer using a tunnelling current effect concept has the potential of high performance, although it requires slightly complex signal-processing circuit for servo-system. The paddle of micro accelerometer is pulled to have the gap width of about 2nm which almost allows the flow tunnelling current. This paper demonstrates at capacitor of microaccelerometer the use of the coupled thermo-electric analysis for voltage, current, heat flux and Joule heating then tunnelling current flows. Two electrodes are applied to the microaccelerometer producing a unform difference of temperature gradient and electric potential between the paddle and the substrate.

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회전구동 정전형 마이크로 액추에이터를 이용한 고트랙밀도 HDD용 이단 구동 시스템 (Dual Stage Actuator System for High Density Magnetic Disk Drives Using a Rotary-type Electrostatic Microatuator)

  • 정성환;최재준;박지황;이창호;김철순;민동기;김영훈;이승희;전종업
    • 한국정밀공학회지
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    • 제22권10호
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    • pp.174-185
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    • 2005
  • This paper presents the design, fabrication, and testing results of a dual stage actuator system for a fine positioning of magnetic heads in magnetic disk drives. A novel rotary microactuator which is electrostatically driven and utilized as a secondary actuator was designed. The stator and rotor electrodes in the microactuator was revised to have the optimal shapes and hence produces much higher rotational torque compared with the conventional comb-shape electrodes. The microactuators were successfully fabricated using SoG(silicon on glass) processing technology, which is known as being cost-effective. The fabricated microactuator has the structural thickness of $45{\mu}m$ with the gap width of approximately $3{\mu}m$. The dynamic characteristic of microactuator/slider assembly was investigated, and its natural frequency and DC gain were measured to be 3.4kHz and 32nm/V, respectively. The microactuator/slider assembly was integrated into a HDD model V10 of Samsung Electronics Co. and a dual servo algorithm was tested to explore the tracking performance of dual stage actuator system where the LDV signals instead of magnetic head signals were used. Experimental results indicate that this system achieves the tracking accuracy of 30nm. This value corresponds to a track density of 85,000 track per inch(TPI), which is about 3 times greater than that of current hard disk drives.

근접장 광기록 시스템용 전자기구동 액추에이터의 설계 및 평가 (Design and Evaluation of An Electromagnetic Driven Actuator for Near-field Optical Recording System)

  • 김석중;이용훈;이철우;서중언
    • 대한기계학회논문집A
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    • 제24권11호
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    • pp.2732-2741
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    • 2000
  • Combination of magnetic recording technology and optical recording technology such as Near Field Optical Recording is watched recently. In order to accomplish this technology, the development of an electromagnetic driven mm-sized mirror shifting laser beam in track direction have to needed. In Near Field Optical Recording System, shifting laser beam in track direction mean as fine tracking and means as coarse tracking. Therefore in Near Field Optical Recording, 2-stage actuator is composed of servo controller in reading or recording information on disc layer. In our research, through design and simulation process of driven mm-sized mirror, we arrange systematically design process of driven mm-sized mirror having good frequency transfer characteristics. Design and simulation processes included modal analysis of spring, calculation of magnetic moment according to the number of turns and geometric configuration of coil and magnetic circuit analysis meaning that calculation of magnetic flux density in air gap of magnetic circuit. After that we design and make parts of driven mm-sized mirror, assemble and evaluate our electriomagnetic driven mm-sized mirror. we compared design values with actual characteristic values and present solution scheme. Through these processes we performed manufacturing of an electromagnetic driven mm-sized mirror having good frequency-domain characteristics and high sensitivity characteristics.

인쇄전자를 위한 롤투롤 시스템의 필름 정밀제어에 관한 연구 (Precision Film Control of Roll to Roll System for RFID Printing)

  • 김동민;최종근;김형선
    • 한국생산제조학회지
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    • 제19권6호
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    • pp.867-874
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    • 2010
  • RFID printing technology has emerged recently as an important tool for leading future IT. Therefore, many manufacturers concerning on low cost and mass production of the related products pay close attention to the printing technology. In order to realize printed electronics, the technologies for fine line-width/gap printing and registration are essential work. This study proposes a precise Roll to Roll control system that is capable of tilting two posts. Two controllable tilting posts can adjust film position at traverse direction for the precision registration. A mathematical model for representing the geometric features of each posts in Roll to Roll printing system is established first. Then an operating program is built to implement the system and to control film movement. For experimental test, a hard ware system is fabricated which is consisted of two AC servo motors, two posts tilting mechanisms, several guide rolls, and so on. The test results show the proposed system can control the film position precisely at transverse direction.

Design and Analysis of Rolled Rotor Switched Reluctance Motor

  • Eyhab, El-Kharashi
    • Journal of Electrical Engineering and Technology
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    • 제1권4호
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    • pp.472-481
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    • 2006
  • In the conventional SRM with multi-rotor teeth, the air gap must be very small in order to drive the SRM in the saturation region that is necessary for high output torque. However, this leads to the problem of overheating; particularly in the case of a small-size SRM This paper discusses the design of a new type of SRM, namely the rolled rotor SRM. This new type does not require more than a single region of a very small airgap. This solves the overheating problem in the small size SRM. Moreover, the use of the rolled rotor, instead of the conventional toothed rotor, grades the airgap region in a fashion that gives a smooth variation in the reluctance and smooth shapes of both current and torque. The latter functional behavior is required in many applications such as servo applications. The paper first addresses general design steps of the rolled rotor SRM then proceeds to the simulation results of the new SRM in order to evaluate the advantages gained from the new design. In addition, this paper compares the torque ripples obtained from the new design to its equivalent conventional one.