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:
Jan. 08, 2019
Filed:
Jun. 19, 2017
Canon Kabushiki Kaisha, Tokyo, JP;
CANON KABUSHIKI KAISHA, Tokyo, JP;
Abstract
A position estimation unit of a motor control apparatus includes a counter electromotive voltage estimation unit configured to estimate a counter electromotive voltage generated in a motor based on generated voltage and current of the motor, and an arc tangent calculation unit configured to perform an arc tangent calculation using coordinate data on a two-dimensional plane based on the estimated counter electromotive voltage to calculate an angle of deviation. The arc tangent calculation unit includes a rotation calculation unit configured to repeatedly perform a rotation calculation of coordinate data on a fundamental wave and a harmonic; a rotation direction judgment unit configured to judge a rotation direction of a subsequent rotation calculation based on a result of the rotation calculation of the rotation calculation unit; and a deviation angle calculation unit configured to calculate a total of rotation angles obtained as a result of the rotation calculation.