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:
Sep. 30, 2003
Filed:
Dec. 06, 1999
Ichiro Watanabe, Kawasaki, JP;
Takayuki Kawabe, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A learning control unit is provided between a feedback calculating unit and a driving unit. When a period for one medium rotation period is assumed to be T , an unknown drive current function Irepeat(t) which repeats for a period of time from a start time t=0 for one medium rotation period to an end time t=T is obtained by a learning algorithm as an approximated function I{circumflex over ( )}repeat(t) that is approximately presumed by a set of the heights C of N rectangular functions having interval numbers i=0˜ (N−1) whose time widths are obtained by dividing the period for one medium rotation period into N intervals. After the learning, a learning control signal I{circumflex over ( )}repeat is outputted synchronously with the medium rotation and a feed-forward control is performed. The learning control unit can be provided between a position signal detecting unit and a feedback calculating unit and can learn a position function TESrepeat(t) as an approximated function TES{circumflex over ( )}repeat(t) in a similar manner.