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:
Sep. 08, 2009
Filed:
Dec. 03, 2004
Hideyuki Kobayashi, Maebashi, JP;
Toru Sakaguchi, Maebashi, JP;
Takeshi Hara, Maebashi, JP;
Sakae Nejo, Maebashi, JP;
Hideyuki Kobayashi, Maebashi, JP;
Toru Sakaguchi, Maebashi, JP;
Takeshi Hara, Maebashi, JP;
Sakae Nejo, Maebashi, JP;
NSK Ltd., Tokyo, JP;
Abstract
An electric power steering device changes the discontinuous non-linear characteristics in the duty ratio of the PWM signal versus motor current generated during steering wheel handle return into linear characteristics to suppress noise and provides a smooth and natural feeling steering. The electric control circuit () provided a current reference value calculator (A) to calculate I, a current controller (B) to obtain V, a compensation adder () to obtain a duty D, and a current discontinuity compensator () in order to obtain a duty D. A motor drive circuit () including an H bridge circuit whose upper stage FET () is driven by the duty D, and whose lower stage FED () paired with the upper stage FET (), is driven by the duty Dto allow forming a continuous linear characteristic in the duty ratio of the PWM signal versus the motor current.