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:
Oct. 28, 1997
Filed:
Jun. 05, 1995
Davorin Hrovat, Dearborn, MI (US);
Minh Ngoc Tran, Dearborn, MI (US);
Craig John Simonds, Dearborn, MI (US);
John Loring Yester, Bloomfield, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A vehicle traction controller includes engine control and brake control routines to improve vehicle traction. The engine control routine reduces average slip of driven wheels of the vehicle by retarding spark timing and by reducing air flow into the engine via an electronically controlled throttle. The engine control routine is entered if the average wheel speed of the driven wheels is above a predetermined threshold speed. Control of spark timing is performed by a Proportional-Differential (PD) control technique. The electronically controlled throttle is controlled by a Proportional-Integral-Differential (PID) control technique. The brake control routine operates to reduce the rotational speed of the driven wheel which has the highest rotational speed. The brake control routine is entered if one of the driven wheels has a rotational speed which is greater than a maximum desired speed and if the difference in speed between the driven wheels is greater than a maximum difference value. A PD control technique is employed to determine the amount of braking force generated by the brake control routine. Braking force generated by the brake control routine is gradually reduced when the rotational speed of each of the driven wheels falls below a threshold value.