Patent Number: 7,398,854

Title: Method for controlling an electric power steering system

Abstract: A method for controlling an electrical power steering system for a vehicle includes an electrical servomotor, a steering device for entering a reference value (.theta..sub.S) of a steering angle into a control andlor regulation device, a moment sensor and an angle sensor for the steering device, a device for estimating the moment (M.sub.v) at the steering device and an angle sensor for determining the angle (.theta..sub.A) of a power take-off of the electrical servomotor. In order to control the electrical power steering system, which makes a non-critical behavior possible in the event of a malfunction or failure of a moment sensor at the steering device, provisions are made so that an offset value (.DELTA..sub..theta.) is constantly formed from the reference value (.delta..sub.S) of the steering angle and the actual value .theta..sub.I of the steering angle, and a virtual moment (M.sub.v) of the steering device is determined on the basis of the offset value (.DELTA..sub..theta.) and is used to control the electrical servomotor.

Inventors: Heilig; Arnulf (Schwaebisch Gmuend, DE), Bischofberger; Michael (Schwaebisch Gmuend, DE)

Assignee: ZF Lenksysteme GmbH

International Classification: B62D 5/04 (20060101); B62D 6/00 (20060101)

Expiration Date: 2020-07-15 0:00:00