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. 05, 2014
Filed:
Aug. 08, 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 an electrically driven power steering system having a blushless three phase motor, an abnormality of a control unit is detected on a basis of a direct current bus bar current of an inverter detected by a current sensor and an estimated primary current. The estimated primary current is calculated from, for example, the following equation, namely, Iu×Du+Iv×Dv+Iw×Dw)/100%, wherein Iu denotes a current of a U phase of the motor, Du denotes a PWM duty signal of the U phase, Iv denotes a current of a V phase of the motor, Dv denotes the PWM duty signal of the V phase of the motor, Iw denotes a current of a W phase of the motor, and Dw denotes the PWM duty signal of the W phase.