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:
Feb. 05, 2019
Filed:
Feb. 26, 2015
Mitsubishi Electric Corporation, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
In an electric power steering device assisted by a brushless motor, an induced voltage from a brushless motor is detected when a main power supply is off. The motor is determined to be in a high rpm state when the induced voltage is in a first transient state from a voltage≤a high rpm detection threshold Th1 to a voltage≥Th1, thereby setting an intermittent excitation cycle of a revolution angle sensor connected to the motor to a short cycle. The motor is determined to be in a low rpm state when the induced voltage becomes a voltage≥a high rpm detection threshold Th2 after a wait period corresponding to an electrical angle between peaks or valleys of an output voltage has elapsed in a second transient state from a voltage≥Th1 to a voltage≤Th2, thereby setting the cycle to a long cycle.