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. 17, 2003
Filed:
Nov. 06, 2001
William Chin-Woei Lin, Troy, MI (US);
Yuen-Kwok Chin, Troy, MI (US);
Weiwen Deng, Sterling Heights, MI (US);
Scott P. Sherman, Fenton, MI (US);
Paul A. Grougan, Novi, MI (US);
Eugene A. Rodden, Gilbert, AZ (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A method is disclosed for controlling the rear wheel angle in a four-wheel steering vehicle such as a pickup truck. The front wheels are steered using the conventional operator handwheel linked to the front wheels. The rear wheels are actuated with a reversible electric motor and the rear wheel angle controlled using a computer with inputs of vehicle velocity, operator handwheel position and correlated front wheel angle, and handwheel turning rate. Control of rear wheel angle starts with a correlation of ratios of rear wheel angle to front wheel angle, R/F, vs. vehicle velocity suitable, determined under steady state front steering angle and velocity conditions, to maximize the contribution of the rear wheels while avoiding side-slip of the vehicle. It is found that driver steering feel and vehicle maneuverability is improved by imposing a minimum front wheel angle requirement before rear wheel steering is permitted and by modifying the current value of R/F with gain factors base d on the hand wheel angle and rate of motion.