• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

1994 Fiscal Year Final Research Report Summary

Development of a Vibration Control System for the Coil Drum of MRI equipment

Research Project

Project/Area Number 04555052
Research Category

Grant-in-Aid for Developmental Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 機械力学・制御工学
Research InstitutionTohoku University

Principal Investigator

TANI Junji  Tohoku University, Institute of Fluid Science, Professor, 流体科学研究所, 教授 (30006192)

Co-Investigator(Kenkyū-buntansha) QIU Jinhao  Tohoku University, Institute of Fluid Science, Research Professor, 流体科学研究所, 助手 (60241585)
JIANG Zhongwei  Tohoku University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (60225357)
TAKAGI Toshiyuki  Tohoku University, Institute of Fluid Science, Associate Professor, 流体科学研究所, 助教授 (20197065)
SHINDO Yasuhide  Tohoku University, Faculty of Engineering, Professor, 工学部, 教授 (90111252)
CHONAN Seiji  Tohoku University, Faculty of Engineering, Professor, 工学部, 教授 (20005424)
Project Period (FY) 1992 – 1994
KeywordsVibration Control / Electromagnetic Force / MRI equipment / Coil Drum
Research Abstract

High level noise induced in MRI equipments has been a main obstacle for their wide application in medical diagnosis. The noise is caused by the vibration of the cylindrical shell used to support the gradient magnetic field coils in MRI.A model of the coil drum with reduced size is made from polymer films and piezoelectric films. In the control of the shell vibration, two parts of the piezoelectric films is used as bending actuators so that no external actuators are needed. The disturbance cancellation method is used since the shell is excited by pre-determined forces. The relation between the size, position and output magnitude of the actuators and control effect is also discussed. Experiment and simulation were carried out when the shell was excited at resonance frequencies of three main modes. The results shows that the minimum amplitude of controlled vibration varies for different modes.
Next, a method was proposed to control the vibration of a cylindrical shell system. The cylindric … More al shell system consists of a polymeric film in the middle and one piezoelectric film on each side. The piezoelectric films are divided into several parts, some of which function as distributed actuators.Analysis of the shell vibration under periodic excitation is performed by means of the modal expansion method. A controller is designed based on H_* control theory and the results of modal analysis. Numerical simulation and experiment were carried out using the designed controller and the results show good agreement, as well as the effectiveness of this method in suppression of forced vibration.
At last, a study on vibration control of a cylindrical shell using distributed piezoelectric sensors and actuators which are parts of the shell wall. Modal expansion method is used in estabishment of the state equation of the system. The robust control including H_* control theory and mu synthesis method are applied to the design of the controller which satisfies given control performance and robust stability. Simulation and experiment are carried out when the shell is excited at the resonance frequency of a controlled mode. The results shows good agreement between simulation and experiment, as well as the effectiveness of the method using distributed sensors and actuators, and H_* control theory and mu-synthesis method. Less

  • Research Products

    (12 results)

All Other

All Publications (12 results)

  • [Publications] 裘 進浩、谷 順二、大友 規矩雄: "MRI装置用勾配コイルドラムのインテリジェント化" 日本機械学会論文集、C編. 予定 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] J.Qiu, J.Tani, T.Takagi: "Suppression of Intemal Noise Induced by the Vibration of a Cylindrical" Proc. 1993 JSME Int. Conf. on Advanced Mechatronics. 38-43 (1993)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] J.Qiu, J.Tani: "Vibration Control of a Cylindrical Shell Using Distributed Piezoelectric Sensors and Actuators" Proc. 2nd Int. Conf. on Intelligent Materials. 1003-1014 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 谷 順二、裘 進浩、三浦 英久: "円筒殻の圧電フィルムによる振動制御" 日本機械学会論文集、C編. 60. 443-449 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 裘 進浩: "円筒殻の衝撃応答解析" 第6回計算力学講演会講演論文集. 285-286 (1993)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 谷 順二: "知的複合材料と適応設計" インテリジェント材料. 3. 6-11 (1993)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] J.Tani, H.Miura, J.Qiu and K.Ohtomo: "Vibration Control of an Arch System Using Piezoelectric Actuators" Trans.JSME,Ser.C. Vol.60. 74-78 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] J.Tani, J.Qiu and H.Miura: "Vibration Control of a Cylindrical Shell System Using Piezoelectric Film" Trans.JSME,Ser.C. Vol.60. 79-85 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] J.Qiu, J.Tani and T.Takagi: "Dynamic Characteristic of a Cylindrical Shell under Excitation of Lorentz Force" The Reports of the Institute of Fluid Science, Tohoku University. Vol.6. 33-41 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] J.Tani, J.Qiu and H.Miura: "Vibration Control of a Cylindrical Shell Using Piezoelectric Actuators" to be published in J.Intelligent Material Systems and Structures. Vol.5. (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] J.Qiu and J.Tani: "Vibration Control of a Cylindrical Shell Used in MRI Equipment" J.Smart Materials and Structures. Vol.4. 1-7 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] "Intelligent Coil Drum with Electromagnetic Force Cancellation for MRI Equipment" to be published in Trans.JSME,Ser.C. Vol.61. (1995)

    • Description
      「研究成果報告書概要(欧文)」より

URL: 

Published: 1996-04-15  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi