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:
Aug. 26, 2003
Filed:
Feb. 26, 2001
Koichiro Nagata, Mito, JP;
Toshiaki Okuyama, Tokai, JP;
Hiroshi Fujii, Chiba, JP;
Shigetoshi Okamatsu, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electric motor is rotated at a velocity &ohgr; . After that, during &Dgr;t seconds, the 1st acceleration is executed at a rate (&ohgr; −&ohgr; )/&Dgr;t . During this acceleration, the torque &tgr; is calculated so as to execute the time integration. After the lapse of &Dgr;t , the integrated result is stored. Next, the velocity is set to be &ohgr; . After that, during &Dgr;t seconds, the 2nd acceleration is executed at a rate (&ohgr; −&ohgr; )/&Dgr;t . At the 2nd acceleration, although the integration-starting and the integration-terminating velocities are each equal to those at the 1st acceleration, the acceleration rate is modified (&ohgr; =&ohgr; , &ohgr; =&ohgr; , &Dgr;t ≠&Dgr;t ). During this acceleration, the torque &tgr; is calculated so as to execute the time integration, after the lapse of &Dgr;t , storing the integrated result. The inertia J is calculated using the 1st and 2nd integrated results.