• 제목/요약/키워드: Magnetic positioning

검색결과 139건 처리시간 0.043초

퍼지 추론 시스템을 이용한 아날로그형 자기위치 장치의 위치 정밀도 향상 (Positioning Accuracy Improvement of Analog-type Magnetic Positioning System using Fuzzy Inference System)

  • 김정민;정경훈;정은국;조현학;김성신
    • 한국지능시스템학회논문지
    • /
    • 제22권3호
    • /
    • pp.367-372
    • /
    • 2012
  • 본 논문은 아날로그형 자기위치 장치(magnetic positioning system)의 개발과 퍼지 추론 시스템(FIS: fuzzy inference system)을 통한 정밀도 향상에 관한 것이다. 자기위치 장치는 무인운반차(AGV: automatic guided vehicle)의 자기-자이로 유도장치(magnet-gyro guidance system)에 사용되는 장치로, 바닥에 매설된 자석의 위치를 계측하는 장치이다. 기존의 판매되고 있는 자기-자이로 유도 장치는 외국에서 독점 판매되고 있어, 국내에서는 가격이 매우 비싸다. 또한, 자기위치 장치에 디지털 타입의 단극성 홀센서를 이용하기 때문에 위치측정 정밀도가 낮다. 이에, 본 논문에서는 자기위치 장치를 직접 개발하였고 퍼지 추론 시스템을 통해 자기위치 장치의 정밀도 향상시켰다. 실험은 직접 개발한 아날로그형 자기위치 장치를 이용하였으며, 기존의 위치측정 방법과 제안된 방법의 성능을 비교하였다. 실험 결과, 제안된 방법이 자기위치 장치의 정밀도를 향상시킴을 확인하였다.

Effect of sensor positioning error on the accuracy of magnetic field mapping result for NMR/MRI

  • Huang, Li;Lee, Sangjin
    • 한국초전도ㆍ저온공학회논문지
    • /
    • 제17권3호
    • /
    • pp.28-32
    • /
    • 2015
  • Nowadays the magnetic field mapping is widely used in the design and analysis of the NMR/MRI magnet system, and the accuracy of mapping result has become more and more important. There are several factors affecting the accuracy of the mapping such as the mapping method, the precision of the sensor, the position of the measurement points, the calculation accuracy, and so on. In this paper the error due to the misalignment of the measurement points was discussed. The magnetic field in the central volume was mapped using an indirect method in an MRI magnet system and the magnetic field was fitted to a polynomial. Considering the misalignment between the original measurement points and the practical measurement points, there must be some errors in the mapping calculation and we called it positioning error. Several comparisons of the positioning error have been presented through the theoretical estimates and the exact magnetic field values. Finally, the allowable positioning errors were suggested to guarantee the accuracy of the magnetic field mapping within a certain degree for an example case.

초정밀 자기부상 스테이지의 위치제어를 위한 영구자석형 선형 자기베어링의 개발 (Permanent Magnet Biased Linear Magnetic Bearing for High-Precision Maglev Stage)

  • 이상호;장지욱;김의석;한동철
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2001년도 춘계학술대회논문집B
    • /
    • pp.164-169
    • /
    • 2001
  • The active magnetic bearing has many advantages - an active positioning, no contact and lubrication free motion - and is widely used in high precision motion stages. But, the conventional magnetic bearings composed of electromagnets only are power consuming due to their bias current and have the excessive heat generation, which can make the repeatability of the positioning system worse. To overcome this drawback, we developed a novel permanent magnet (PM) biased linear magnetic bearing for a high precision magnetically levitated stage. The permanent magnets provide a bias flux and generate a bias force, and the electromagnet increases or reduces a flux of the permanent magnets and gives a levitation force. This paper presents a theoretical magnetic circuit analysis, FEM analysis and experimental data from the 1-DOF tests, and compares the theoretical power consumption of the electromagnetic bearings and the PM biased linear magnetic bearings. The PM biased linear magnetic bearing presented in this paper gives better load capacity but lower power consumption than a conventional electromagnetic bearing and will be adopted in our 6-DOF high precision linear positioning maglev stage.

  • PDF

면외 방향의 자기력을 이용한 자기 서스펜션 시스템의 위치결정기구로의 적용 가능성 (Feasibility Study of Positioning Device Using Magnetic Suspension System of Out of Plane Direction Forces)

  • 이상헌;백윤수
    • 대한기계학회논문집A
    • /
    • 제27권11호
    • /
    • pp.1941-1948
    • /
    • 2003
  • This paper is about feasibility study of positioning device using magnetic suspension system which uses only vertical magnetic forces. The proposed system has inherited advantages from contact-free system, simple structure, and high expansibility in operating range different from conventional positioning devices. In this paper, the structure and operating principle are described and the linearized magnetic force and dynamic model are obtained. With the linear control theory, the experiments are executed. finally, the experimental results are shown.

Sliding Mode Control based on Disturbance Observer for Magnetic Levitation Positioning Stage

  • Zhang, Shansi;Ma, Shuyuan;Wang, Weiming
    • Journal of Electrical Engineering and Technology
    • /
    • 제13권5호
    • /
    • pp.2116-2124
    • /
    • 2018
  • Magnetic levitation system with the advantages of non-contact, no friction and no wear can satisfy the requirement of high precision and high speed positioning. In this paper, magnetic levitation positioning stage which mainly consists of planar coil and HALBACH permanent magnet array and its control and driving system are designed. Magnetic levitation system is a highly nonlinear and strongly coupled complex system and its control performance can be influenced by the uncertainty and external disturbance. So exact feedback linearization method is used to realize exact linearization and decoupling, and a strategy of sliding mode control based on disturbance observer is proposed to compensate the uncertainty and external disturbance. Detailed proofs of observer's convergence property and system stability are derived. Both the simulation and experiment results verify the effectiveness of sliding mode control algorithm based on disturbance observer.

능동 자기 베어링을 이용한 비접촉식 선형 구동기 (Contact-free Linear Actuator Using Active Magnetic Bearing)

  • 이상헌;백윤수
    • 한국정밀공학회지
    • /
    • 제20권7호
    • /
    • pp.91-98
    • /
    • 2003
  • In the field of precision manufacturing demanding high positioning performance, the mechanical friction in positioning device deteriorates the quality of the product and increases the cost of production for positioning devices. Therefore, we propose a contract-free linear actuator using active magnetic bearing. The structure and operating principle of the proposed system are explained, and the magnetic forces are analyzed by magnetic circuit theory to design magnetic bearings and linear actuator. With the derived equation of motion, the stability is identified. Experimental results are presented to show the feasibility.

전자기력을 이용한 3 자유도 정밀 위치결정기구에 관한 연구 (A Study on Three Degree-of-Freedom Fine Positioning Device Based on Electromagnetic Force)

  • 이기하;최기봉;박기환;김수현;곽윤근
    • 한국정밀공학회지
    • /
    • 제15권11호
    • /
    • pp.199-207
    • /
    • 1998
  • This paper presents the design and the control of three degree-of-freedom(DOF) fine positioning device based on an electro-magnetic force. The device is designed by use of a magnetic circuit theory and it is capable of fine motion due to the electro-magnetic force. The device consists of permanent magnets, yokes and coils. The magnetic fluxes generated from the permanent magnets constitute magnetic paths through steel, whereas the coils are arranged into the gap between two surfaces of the yokes. Therefore, by supplying current to the coils, the coils are capable of some motions due to Lorentz forces. For the optimal design of the actuating system, the system parameters are defined and investigated under the given constraints. From the system modeling in small displacement, three decoupled equations of motion are obtained. To get better performance of the system, a PID controller is implemented. Experimental results are presented in terms of time response and accuracy.

  • PDF

마그네틱 마커를 이용하는 이동로봇을 위한 위치인식 센서 시스템 (Positioning sensor system for mobile robots using magnetic markers)

  • 김의선;김원호
    • 센서학회지
    • /
    • 제19권3호
    • /
    • pp.221-229
    • /
    • 2010
  • In recent studies, many methods have been studied for mobile robot using magnetic markers on its pathway. This is not influenced by the weather conditions, and makes possible to develop controller with low level processors and simple algorithms. However, the interval between magnets is restricted by the magnetic field intensity and it is impossible to get road information ahead. This paper suggests a method of widening markers and expressing the road information ahead using magnetic markers, and explains a sensor arrangement considering suggested methods. Also, magnetic field analysis was done to investigate the effects of widening magnetic markers with various environments. A small mobile robot was made to figure out the performance of suggested methods, and driving experiments were performed on the straight and curved road with magnetic markers. The results show that the robot moved the prearranged pathway with 0.5 cm lateral displacements and stopped at a stop line using magnetic information on the road.

원추형 자기 베어링 지지 무마찰 구동장치의 위치제어 (Position control of the frictionless positioning device suspended by cone-shaped active magnetic bearings)

  • 정호섭;이종원
    • 제어로봇시스템학회논문지
    • /
    • 제2권3호
    • /
    • pp.181-187
    • /
    • 1996
  • A frictionless positioning device using cone-shaped active magnetic bearings(AMBs) is developed, which is driven by a brushless DC motor equipped with resolver. The cone-shaped AMB feature that the structure is simple and yet the five d.o.f. rotor motion is controlled by four magnet pairs. A linearized dynamic model, which accounts for the relationship between input voltage and output current in the cone-shaped magnet, is developed and the azimuth motion of the frictionless positioning device is modeled as the second order system. The feedback controller is designed by using linear quadratic regulator with integral action optimal control law so that the cone-shaped AMB system is stabilized and the frictionless positioning device gets the zero steady state. It is observed that the linearized dynamic model is adequate and the frictionless positioning device can achieve the tracking accuracy within the sensor resolution.

  • PDF

Performance Enhancement and Countermeasure for GPS Failure of GPS/INS Navigation System of UAV Through Integration of 3D Magnetic Vector

  • No, Heekwon;Song, Junesol;Kim, Jungbeom;Bae, Yonghwan;Kee, Changdon
    • Journal of Positioning, Navigation, and Timing
    • /
    • 제7권3호
    • /
    • pp.155-163
    • /
    • 2018
  • This study examined methods to enhance navigation performance and reduce the divergence of navigation solutions that may occur in the event of global positioning system (GPS) failure by integrating the GPS/inertial navigation system (INS) with the three-dimensional (3D) magnetic vector measurements of a magnetometer. A magnetic heading aiding method that employs a magnetometer has been widely used to enhance the heading performance in low-cost GPS/INS navigation systems with insufficient observability. However, in the case of GPS failure, wrong heading information may further accelerate the divergence of the navigation solution. In this study, a method of integrating the 3D magnetic vector measurements of a magnetometer is proposed as a countermeasure for the case where the GPS fails. As the proposed method does not require attitude information for integration unlike the existing magnetic heading aiding method, it is applicable even in case of GPS failure. In addition, the existing magnetic heading aiding method utilizes only one-dimensional information in the heading direction, whereas the proposed method uses the two-dimensional attitude information of the magnetic vector, thus improving the observability of the system. To confirm the effect of the proposed method, simulation was performed for the normal operation and failure situation of GPS. The result confirmed that the proposed method improved the accuracy of the navigation solution and reduced the divergence speed of the navigation solution in the case of GPS failure, as compared with that of the existing method.