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:
Jun. 25, 2002
Filed:
Aug. 31, 2001
Scott Wilson Badenoch, Farmington Hills, MI (US);
Delphi Technologies, Inc., Troy, MI (US);
Abstract
A rear wheel steering control determines, when desired and actual lateral accelerations of a vehicle have the same direction, an instantaneous dynamic yaw center on a vehicle longitudinal axis in response to the measured vehicle speed. It further determines a cornering radius and an instantaneous Ackerman center as a point at the outer end of the cornering radius extended outward perpendicular to the vehicle longitudinal axis from the instantaneous Ackerman center. The control then directs a rear wheel of the vehicle to be perpendicular to a line connecting the instantaneous Ackerman center to the center of the wheel. The dynamic yaw center, and thus the instantaneous Ackerman center, is preferably shifted rearward with increasing vehicle speed to shift vehicle steering in a direction from oversteer at very low speeds for greater ease of steering in parking maneuvers to understeer for vehicle stability in high speed driving conditions. The method and apparatus preferably include a reverse lock routine to control the rear wheels when the desired and actual lateral accelerations of the vehicle have opposing directions, to control the vehicle in a four wheel drift; and the reverse lock routine may further adjust suspension damping.