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. 13, 2014
Filed:
May. 10, 2011
Shan Tang, Irvine, CA (US);
Jianjun LI, Rancho Santa Margarita, CA (US);
Jianguo Zhou, Foothill Ranch, CA (US);
Wei Xi, Mission Viejo, CA (US);
Shan Tang, Irvine, CA (US);
Jianjun Li, Rancho Santa Margarita, CA (US);
Jianguo Zhou, Foothill Ranch, CA (US);
Wei Xi, Mission Viejo, CA (US);
Western Digital Technologies, Inc., Irvine, CA (US);
Abstract
A method of evaluating a dual stage actuator (DSA) servo loop in a disk drive is disclosed. The disk drive comprises a dual stage actuator (DSA) servo loop operable to actuate a head over a disk surface. A first sinusoidal signal Ais added to a VCM control signal Bgenerated by a VCM servo loop. A response of the VCM control signal Bto the first sinusoidal signal Ais measured, and a closed loop response of the VCM servo loop is computed in response to Aand B. A second sinusoidal signal Ais added to a microactuator control signal Bgenerated by a microactuator servo loop. A response of the microactuator control signal Bto the second sinusoidal signal Ais measured, and a closed loop response of the microactuator servo loop is computed in response to Aand B