Patent Number: 7,786,687

Title: Apparatus and method for control of an active front steering (AFS) system

Abstract: A motor control strategy for a motor in a front steering system for a vehicle that reduces vibrations from the motor being transferred to a vehicle hand-wheel. The control strategy also includes operating the electric motor in a commutation freeze mode if a position error signal is less than a first predetermined threshold by sending signals to coils of the motor to prevent to the motor from rotating, operating the electric motor in a commutation normal mode if the position error signal is greater than a second predetermined threshold that is greater than the first predetermined threshold, and operating the electric motor in an angle step mode if the position error signal is between an intermediate threshold and the second threshold where the angle step mode provides a signal to the motor to move the motor forward or backward a predetermined number of motor steps, one step at a time.

Inventors: Namuduri; Chandra S. (Troy, MI), Gopalakrishnan; Suresh (Farmington Hills, MI), Bolio; Robert R. (Clarkston, MI), Feller; Ross (Ann Arbor, MI), Murty; Balarama V. (West Bloomfield, MI)

Assignee: GM Global Technology Operations, Inc.

International Classification: H02P 1/04 (20060101); H02P 6/04 (20060101)

Expiration Date: 8/31/12018