The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 24, 2005
Filed:
Jun. 23, 2003
Applicants:
Masahito Kobayashi, Ushiku, JP;
Hidehiko Numasato, Odawara, JP;
Atsushi Okuyama, Chiyoda, JP;
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B019/04 ;
U.S. Cl.
CPC ...
Abstract
In a positioning control device for a two-stage actuator having a coarse-movement actuator and a fine-movement actuator, a notch filter having a cutoff frequency fn is provided to a coarse-movement control loop, and the fine-movement actuator is driven by a sine wave of the frequency fn. At the frequency fn, a head position signal becomes identical with an output signal of the fine-movement actuator, by which the gain of the fine-movement actuator can be estimated by an adaptive identification unit with high accuracy based on the control input to the fine-movement actuator and the head position signal.