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:
Apr. 17, 2001
Filed:
Jul. 14, 1998
Jeffrey Joseph Dobbek, San Jose, CA (US);
Peter Kui Ho, Morgan Hill, CA (US);
Louis Joseph Serrano, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A direct access storage device (DASD) servo control system includes a servo controller that makes an estimate of disk actuator arm position and velocity as for a regular, expected PES signal sample time, and then alters the estimate for an odd sample time using a simplified estimation function. The altered estimate is generated after determining the amount of time by which the odd sample time is longer than the regular sample time. An odd sample time event is recognized and the odd sample time is forced longer than the regular sample time by skipping a disk control signal computation interval. In this way, the estimated position and velocity of the disk arm is improved for odd sample times, even where the change in one PES sample time may be unrelated to the change in any subsequent PES sample times.