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:
Jul. 15, 2008
Filed:
Oct. 11, 2005
Nobuyuki Imai, Wako, JP;
Yutaka Takahashi, Wako, JP;
Tomohiro Shiraishi, Wako, JP;
Hajime Kondoh, Wako, JP;
Nobuyuki Imai, Wako, JP;
Yutaka Takahashi, Wako, JP;
Tomohiro Shiraishi, Wako, JP;
Hajime Kondoh, Wako, JP;
Honda Motor Co., Ltd., Tokyo, JP;
Abstract
A method and an apparatus accurately detect a rotor angle of a DC brushless motor by using a first-order difference of a detected value of a phase current. A periodic signal causing the total sum of output voltages in three control cycles to become zero is superposed over a drive voltage under current feedback control. The drive voltage is held at a constant level during the three control cycles. The phase difference between an actual value and an estimated value of a rotor angle is calculated, using the first-order differential current in each control cycle, and the estimated value of the rotor angle is calculated by follow-up computation of an observer, using the phase difference.