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. 02, 2008
Filed:
Nov. 17, 2006
Chandra S. Namuduri, Troy, MI (US);
Robert R. Bolio, Clarkston, MI (US);
Willard A. Hall, Dryden, MI (US);
Chandra S. Namuduri, Troy, MI (US);
Robert R. Bolio, Clarkston, MI (US);
Willard A. Hall, Dryden, MI (US);
GM Global Technology Operations, Inc., Detroit, MI (US);
Abstract
An active front steering system includes a motor controller configured to compute a position error from a commanded position value and an actual position value, and then enter one of two modes—a commutation enable mode and a commutation freeze mode—depending upon the value of this position error. The commutation freeze mode applies when the absolute value of the position error is less than a predetermined threshold, and involves sending a set of signals to the motor's phase inputs such that commutation of the motor is prevented and a substantially constant motor hold torque is produced. The commutation enable mode applies when the absolute value of the position error is greater than or equal to the predetermined threshold, and corresponds to normal commutating operating mode.