Adaptive inverse control for pickup head flying height in near-field optical disk drives

Near-field optical disk drives represent a novel technique for optical data recording. To achieve high precision in focusing for near-field data recording, it is essential to develop servo systems that can maintain a constant flying height. This study uses a piezoelectric bender can compensate the vibration of rotating optical disk. Due to the hysteresis phenomenon in piezoelectric material, adaptive inverse control is developed to overcome the nonlinear effect. The control scheme is implemented with least mean square sensed adaptive filter. Using a laser Doppler vibrometer for sensing, experimental results demonstrate that the present method results in only 2% displacement error in tracking command signals.

[1]  V. Hayward,et al.  Reduction of major and minor hysteresis loops in a piezoelectric actuator , 1998, Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171).

[2]  Jun-Hee Lee,et al.  Optical flying head mounted on four-wire type actuator , 2004 .

[3]  Bernard Widrow,et al.  Adaptive inverse control based on linear and nonlinear adaptive filtering , 1996, Proceedings of International Workshop on Neural Networks for Identification, Control, Robotics and Signal/Image Processing.

[4]  Kenjiro Watanabe,et al.  An Optical Configuration Based on Flying Head Structure for Near-Field Recording , 2004 .

[5]  Vincent Hayward,et al.  An approach to reduction of hysteresis in smart materials , 1998, Proceedings. 1998 IEEE International Conference on Robotics and Automation (Cat. No.98CH36146).

[6]  C. Johnson,et al.  Theory and design of adaptive filters , 1987 .

[7]  Gang Tao,et al.  Parametrizations for adaptive control of multivariable systems with actuator nonlinearities , 2000, Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334).

[8]  M Ohtsu,et al.  High-density speed optical near-field recording reading with a pyramidal silicon probe on a contact slider. , 2000, Optics letters.

[9]  A. Kaelin,et al.  On the use of a priori knowledge in adaptive inverse control , 2000 .

[10]  Timothy N. Chang,et al.  Control of hysteresis in a monolithic nanoactuator , 2001, Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148).

[11]  Ping Ge,et al.  Tracking control of a piezoceramic actuator , 1996, IEEE Trans. Control. Syst. Technol..

[12]  M. Kurita,et al.  Flying-height adjustment of a magnetic head slider with a piezoelectric micro-actuator , 2003, Digest of INTERMAG 2003. International Magnetics Conference (Cat. No.03CH37401).

[13]  Quan Zhou,et al.  Modelling of a piezohydraulic actuator for control of a parallel micromanipulator , 1999, Proceedings 1999 IEEE International Conference on Robotics and Automation (Cat. No.99CH36288C).

[14]  Peter C. Müller,et al.  Nonlinearity estimation and compensation by linear observers: theory and applications , 2000 .

[15]  K. Egiazarian,et al.  A transform domain LMS adaptive filter with variable step-size , 2002, IEEE Signal Processing Letters.

[16]  Elias B. Kosmatopoulos,et al.  Parametric and nonparametric adaptive identification of nonlinear structural systems , 2000, Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334).

[17]  B. Widrow,et al.  Adaptive inverse control , 1987, Proceedings of 8th IEEE International Symposium on Intelligent Control.

[18]  Tomoyoshi Yamada,et al.  Microactuator control for disk drive , 1996 .

[19]  Gregory L. Plett,et al.  Adaptive inverse control of unmodeled stable SISO and MIMO linear systems , 2002 .