Adaptive compensation for position error signal nonlinearity

Author

Cooper, Evert ; Hampshire, Randall

Author_Institution

Adv. Technol. Center, Lockheed Martin Space Syst. Co., Palo Alto, CA, USA

Volume

38

Issue

3

fYear

2002

fDate

5/1/2002 12:00:00 AM

Firstpage

1593

Lastpage

1602

Abstract

The magnetoresistive (MR) magnetic head is a poor positioning transducer for a disk file´s servo control system because its positioning response is nonlinear with radial displacement. This paper shows how the MR head´s poor positioning properties are alleviated by a self-adjusting adaptive algorithm that allows a disk file to linearize its own servo position error signal (PES). The adaptive linearizer uses a nonlinear state estimator whose nonlinearity adjusts to match the nonlinearity of the PES. As the match between the two nonlinearities adaptively improves, the state estimator gives increasingly accurate estimates of the true actuator position

Keywords

adaptive control; adaptive estimation; error compensation; least mean squares methods; limit cycles; linearisation techniques; magnetic heads; magnetoresistive devices; motion control; nonlinear estimation; position control; servomechanisms; state estimation; adaptive compensation; adaptive control; adaptive estimation; adaptive linearizer; disk drives; disk file; least mean square methods; limit cycles; magnetic disk recording; magnetoresistive magnetic head; motion control; nonlinear state estimator; polynomial coefficients; position error signal nonlinearity; self-adjusting adaptive algorithm; servo control system; Actuators; Disk drives; Disk recording; Magnetic heads; Motion control; Position measurement; Servomechanisms; Servosystems; State estimation; Tunneling magnetoresistance;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.999135

Filename

999135