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:
Nov. 11, 2014
Filed:
Apr. 11, 2013
Hitachi Automotive Systems Steering, Ltd., Saitama, JP;
Takumi Hisazumi, Atsugi, JP;
Atsushi Yoshitake, Ebina, JP;
Hitachi Automotive Systems Steering, Ltd., Saitama, JP;
Abstract
In a power steering system, at least one of phase open relays in which a contact weld (an abnormality) occurs is detected. That is to say, the power steering system comprises an abnormality monitor section () configured to output vector control command signals to supply only a d-axis current in a positive side direction toward the motor, with all of phase open relays () in an interruption state, and to determine an abnormality in at least one of the phase open relays in a case where a current value is detected by a current detection circuit which detects a current flowing into an inverter. In a case of three phase open relays installed between respective three phases of motor windings, a potential difference is detected at a neutral position of a star connection to determine the abnormality of at least two of the phase open relays.