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All List of Publications

Research Topics, Abstract, and Related Publications

• Digital Redesign Method in use of N-Delay Control
  
  
• Perfect Tracking Control Based on Multirate Sampling Control
  
  
• Advanced Control of Hard Disk Drive in use of Multirate Sampling Control
  
  
• Vibration Suppression and Repetitive Disturbance Rejection Control Based on Multirate Sampling Control (Applications to Hard Disk Drive and Visual Servoing of Robot Manipulator)
  
  

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  Digital Redesign Method in use of N-Delay Control

  (abstract) A novel digital redesign method is proposed for a feedback control system, by which the states in the continuous-time system are completely reserved in the redesigned sampled-data system. The features of the proposed method are 1) the N-Delay control is employed, and the l-th plant input is changed Nl times during one sampling period, 2) the states of the redesigned sampled-data system completely match those of the original continuous-time closed-loop system at every sampling period, and 3) the proposed redesign method can be applicable for a state-feedback and/or a dynamic controller. An illustrative example of position control using a DC servo motor is presented, and the advantages of redesign approach are demonstrated.

  (Journals)

  • Hiroshi Fujimoto, Atsuo Kawamura "New Digital Redesign Method in use of N-Delay Control", Trans. IEE of Japan, vol. 117-D, no. 5, pp. 645 -- 654, 1997.(in Japanese)
  • H. Fujimoto, A. Kawamura, and M. Tomizuka, "Generalized Digital Redesign Method for Linear Feedback System Based on N-Delay Control", IEEE/ASME Trans. Mechatronics , Vol. 4, No. 2, pp. 101 -- 109, 1999.
    

    (International Conference)

  • H. Fujimoto, A. Kawamura, and M. Tomizuka, "Proposal of Generalized Digital Redesign Method in use of N-Delay Control", in Proc. 1997 American Control Conference (ACC-97) , pp. 3290 -- 3294, Albuquerque, 1997.
  • H. Fujimoto and A. Kawamura, "New Digital Redesign Method by N-Delay Control and its Application", in Proc. Power Conversion Conference (PCC-97) , pp. 525 -- 530, Nagaoka, 1997.
  • H. Fujimoto and A. Kawamura, "Generalized Digital Redesign Method by N-Delay Control and its Application to Motion Control", in Proc. IEEE Power Electronics Specialists Conference (PESC98) , pp. 1835 -- 1841, Fukuoka, 1998.
    

    (Domestic Conference)

  • Hiroshi Fujimoto, Atsuo Kawamura "Proposal of Digital Redesign by Nl-Delay Control", 1996 National Convention Record I.E.E Japan, No. 685, pp. 3.234 -- 3.235, 1996.(in Japanese)
  • Hiroshi Fujimoto, Atsuo Kawamura "Proposal of Digital Redesign in use of N-Delay Control and its Application", IEE of Japan Technical Meeting Record, IIC-96-13, pp. 31 -- 40, 1996.(in Japanese)
  • Hiroshi Fujimoto, Atsuo Kawamura "New Digital Redesign Method in use of N-Delay Control", 1996 National Convention Record I.E.E Japan -- Industry Application Society --, No. 154, pp. 51 -- 56, 1996.(in Japanese) (Best Paper Award)
  • Hiroshi Fujimoto, Atsuo Kawamura "Digital Redesign Method in use of N-Delay Control", 1997 National Convention Record I.E.E Japan, pp. S.15-25 -- S.15-28, 1997.(in Japanese)

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  Perfect Tracking Control Based on Multirate Sampling Control

  (abstract) In this study, a new perfect tracking control method in use of the multirate sampling control is proposed, in which the concept of the two-degree-of-freedom control method is employed. In the proposed method, it is assumed that the usual single-rate robust feedback controller such as the disturbance observer or the $ H_{\infty} $ controller already exists, and the feedforward controller is obtained by using the multirate sampling control. The advantages of the proposed method are that 1) the controller can be designed without considering the unstable zeros of the discrete-time plant, 2) the states of the plant match the desired trajectories at every sampling period, 3) high robust performance is assured by the robust feedback controller. An illustrative example of position control using a dc servo motor is presented, and the advantages of this approach are demonstrated.

  (Journals)

  • Hiroshi Fujimoto, Yoichi Hori, and Atsuo Kawamura, "Perfect Tracking Control Method Based on Multirate Feedforward Control", Trans. SICE, vol. 36, no. 9, pp. 766--772, 2000.(in Japanese)
  • Hiroshi Fujimoto, Yoichi Hori, Atsuo Kawamura, "Perfect Tracking Control based on Multirate Feedforward Control with Generalized Sampling Periods", IEEE Trans. Industrial Electronics , Vol. 48, No. 3, pp. 636--644, 2001.
    

    (Report)

  • H. Fujimoto, A. Kawamura, and Y. Hori, "Proposal of Advanced Perfect Tracking Control Based on Generalized Multirate Sampling Control and Comparison with Zero Assignment Method", Annual Report of Engineering Research Institute, School of Engineering, University of Tokyo, Vol. 57, pp. 207 -- 214, 1998.(in Japanese)
    

    (International Conference)

  • H. Fujimoto and A. Kawamura, "Perfect Tracking Digital Control in use of Two-Degree-of-Freedom Multirate Feedforward Control for Mechatronics", in Proc. TITech COE/Super Mechano-Systems Workshop '98 , pp. 85 -- 93, Tokyo, 1998.
  • H. Fujimoto and A. Kawamura, "Perfect Tracking Digital Motion Control Based on Two-Degree-of-Freedom Multirate Feedforward Control", in Proc. International Workshop on Advanced Motion Control (AMC98) , pp. 322 -- 327, Coimbra, 1998.
  • H. Fujimoto, Y. Hori, A. Kawamura, "High Performance Perfect Tracking Control Based on Multirate Feedforward / Feedback Controllers with Generalized Sampling Periods", in Proc. 1999 IFAC World Congress , vol. C, pp. 61 -- 66, Beijing, 1999.
  • H. Fujimoto, Y. Hori, A. Kawamura, "Structure of Perfect Tracking Controller based on Generalized Sampling Periods", in Proc. International Power Electronics Conference , vol. 1, pp. 337 -- 342, Tokyo, 2000. (Student Encouragement Award)
    

    (Domestic Conference)

  • Hiroshi Fujimoto, Atsuo Kawamura "Perfect Tracking Control Based on Multirate Sampling Control", IEE of Japan Technical Meeting Record, IIC-97-16, pp. 47 -- 54, 1997.(in Japanese)
  • Hiroshi Fujimoto, Atsuo Kawamura "Proposal of Perfect Tracking Control Based on Multirate Input Sampling Control}", 1997 National Convention Record I.E.E Japan, No. 979, pp. 4-314 -- 4-315, 1997.(in Japanese)
  • Hiroshi Fujimoto, Atsuo Kawamura "Proposal of Robust Perfect Tracking States Control by Multirate Feedforward Control", 1998 National Convention Record I.E.E Japan, No. 875, pp. 4-265 -- 4-266, 1998.(in Japanese)
  • Hiroshi Fujimoto, Atsuo Kawamura, Yoichi Hori "Advanced Perfect Tracking Control Based on Multirate Feedforward / Feedback Controllers", 1998 National Convention Record I.E.E Japan -- Industry Application Society --, Vol.2, pp 166-169, 1998.(in Japanese)

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  Advanced Control of Hard Disk Drive in use of Multirate Sampling Control

  (abstract) In this study, new multirate two-degree-of-freedom controllers are proposed for digital control systems, where it is restricted that the speed of the A/D converters are slower than that of the D/A converters. The proposed feedforward controller assures the perfect tracking at M inter-sampling points. Moreover, the proposed feedback controller assures the perfect disturbance rejection at $ M $ inter-sample points in the steady state. Illustrative examples of position control for hard disk drive are presented, and the advantages of this approach are demonstrated.

  (Journals)

  • Hiroshi Fujimoto, Yoichi Hori, Takashi Yamaguchi, and Shinsuke Nakagawa, "Seeking Control of Hard Disk Drives by Perfect Tracking using Multirate Sampling Control", Trans. IEE of Japan, vol. 120-D, no. 10, pp. 1157--1164, 2000.(in Japanese)
  • Hiroshi Fujimoto, Yoichi Hori, "High Performance Servo Systems Based on Multirate Sampling Control", IFAC Journal on Control Engineering Practice. (to be published)
    

    (Report and Survey)

  • H. Fujimoto and Y. Hori, "Proposal of Inter-Sampling Perfect Tracking and Perfect Disturbance Rejection Controllers in use of Multirate Sampling Control -- Extensions to Systems with delay and Applications to the HDD Control -- , Annual Report of Engineering Research Institute, School of Engineering, University of Tokyo, Vol. 58, 1999.(in Japanese)
  • Hiroshi Fujimoto, Yoichi Hori, Takashi Yamaguchi, "Motion Control Based on Multirate Feedforward Control -- Application to Seeking Control of Hard Disk Drive --", Journal of SICE, vol. 39, no. 10, pp. 639--642, 2000.(in Japanese)
    

    (International Conference)

  • Hiroshi Fujimoto, Yoichi Hori, Takashi Yamaguchi, and Shinsuke Nakagawa, "Advanced Control of Hard Disk Drive by Perfect Tracking and Perfect Disturbance Rejection Control in use of Multirate Sampling Control", in Proc. 4th The Univ. of Tokyo -- Seoul Nat. Univ. Joint Seminar on Electrical Engineering, pp. 35 -- 40, Seoul, 1999.
  • Hiroshi Fujimoto, Yoichi Hori, Takashi Yamaguchi, and Shinsuke Nakagawa, "Proposal of Perfect Tracking and Perfect Disturbance Rejection Control by Multirate Sampling and Applications to Hard Disk Drive Control", in Proc. 38th IEEE Conference on Decision and Control , pp. 5277 -- 5282, Phoenix, 1999.
  • Hiroshi Fujimoto, Yoichi Hori, Takashi Yamaguchi, and Shinsuke Nakagawa, "Proposal of Seeking Control of Hard Disk Drives based on Perfect Tracking Control using Multirate Feedforward Control" in Proc. International Workshop on Advanced Motion Control (AMC2000) , pp. 74 -- 79, Nagoya, 2000.
    

    (Domestic Conference)

  • Hiroshi Fujimoto, Yoichi Hori, Atsuo Kawamura "Improvement of Feedback Characteristics for Perfect Tracking Control in use of Multirate Two-degree-of-freedom Control -- Proposal of Perfect Disturbance Rejection Control and Applications to HDD control -- IEE of Japan Technical Meeting Record, IIC-99-2, pp. 7 -- 14, 1999.(in Japanese)(Best Paper Award)
  • Hiroshi Fujimoto, Yoichi Hori, Takashi Yamaguchi, and Shinsuke Nakagawa, "Seeking Control of Hard Disk Drives by Perfect Tracking using Multirate Sampling Control", 1999 National Convention Record I.E.E Japan -- Industry Application Society --, Vol.3, pp. 535 -- 540, 1999.(in Japanese)

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  Vibration Suppression and Repetitive Disturbance Rejection Control Based on Multirate Sampling Control (Applications to Hard Disk Drive and Visual Servoing of Robot Manipulator)

  (abstract) In this study, novel multirate feedback controllers are proposed for digital control systems, where it is restricted that the speed of the A/D converters are slower than that of the D/A converters. The proposed controllers achieve vibration suppression and disturbance rejection even in the semi-Nyquist frequency region. First, the continuous-time vibration suppression controller is exactly discretized by the multirate sampling control based on the closed-loop characteristics. Second, the multirate repetitive controllers are proposed both by the feedback and feedforward approaches, in which the inter-sample response is optimized by the fast sampling method. Moreover, the initial value compensations for observer are proposed in order to prevent the overshoot. The proposed controllers are applied to hard disk drive and visual servo system, and the advantages of these approaches are demonstrated by simulations.
  

  (International Conference)

• Hiroshi Fujimoto, Yoichi Hori, "Vibration Suppression and Disturbance Rejection Control in Semi-Nyquist Frequency Region Based on a Novel Multirate Sampling Control with Initial Value Compensation", in Proc. International Conference and Exhibition on Power Electronics and Motion Control, vol. 6, pp. 190--196, Kosice (Slovakia), 2000.
• Hiroshi Fujimoto, Yoichi Hori, "Vibration Suppression and Optimal Repetitive Disturbance Rejection Control in Semi-Nyquist Frequency Region using Multirate Sampling Control", in Proc. 39th IEEE Conference on Decision and Control , pp. 3745--3750, Sydney, 2000.
• Hiroshi Fujimoto, Yoichi Hori, "Visual Servoing Based on Multirate Sampling Control -- Application of Perfect Disturbance Rejection Control --", in Proc. Int. Conf. Robotics and Automation (ICRA2001), pp. 711--716, Seoul, 2001. (Vision Paper Award, Finalist)
• Hiroshi Fujimoto, Yoichi Hori, "Visual servoing based on intersample disturbance rejection by multirate sampling control -- Time Delay Compensation and Experimental Verification --", in Proc. 40th IEEE Conference on Decision and Control , pp. 334--339, Orlando, 2001.
  

  (Domestic Conference)

• Hiroshi Fujimoto, Yoichi Hori, "Proposal of Vibration Suppression and Disturbance Rejection Control in Semi-Nyquist Frequency Region Based on Multirate Sampling Control" IEE of Japan Technical Meeting Record, IIC-00-23, pp. 133 -- 136, 2000.
• Hiroshi Fujimoto, Yoichi Hori, "Proposal of Vibration Suppression Control in Semi-Nyquist Frequency Region and High-Order Repetitive Disturbance Rejection Control Based on Multirate Sampling Control -- Optimization of Inter-sample Disturbance Rejection Performance --" IEE of Japan Technical Meeting Record, IIC-00-56, pp. 39 -- 46, 2000.
• Hiroshi Fujimoto, Yoichi Hori, " Proposal of Repetitive Disturbance Rejection Control using Multirate Sampling Control and Application to Visual Servo System", 2000 National Convention Record I.E.E Japan -- Industry Application Society --, Vol. 1, pp. 766--772, 1999.(in Japanese)
• Hiroshi Fujimoto, Yoichi Hori, "Vibration Suppression and Periodic Disturbance Rejection Control Based on Multirate Sampling Control", Dynamical System Theory Symposium, pp. 225--230, 2000.(in Japanese)
  
  
• Hiroshi Fujimoto, Yoichi Hori, "Visual Servoing Based on Multirate Sampling Control -- Stability Improvement by Intersample Observer and Periodic Disturbance Rejection --", Robotics Symposia, 2002. (in Japanese, to be presented)
  

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  Last modified: Mon Jan 07 11:28:09 2002
  fujimoto@vos.nagaokaut.ac.jp