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:
Aug. 21, 2001
Filed:
Jan. 20, 2000
Richard Andrew Booth, Canton, MI (US);
Brent Edward Sealy, Dearborn, MI (US);
Kenneth John Behr, Farmington Hills, MI (US);
Michael John Cullen, Northville, MI (US);
Ford Global Technologies, INc., Dearborn, MI (US);
Abstract
A method and system for controlling the air/fuel ratio in an internal combustion engine having a first group of cylinders and a second group of cylinders. The first group of cylinders is coupled to a catalyst and at least one oxygen sensor, which provides a first feedback signal. The second group of cylinders is coupled to a catalyst and a post-catalyst oxygen sensor, which provides a second feedback signal. A controller uses the first and second feedback signals to calculate a short-term air/fuel bias value for the second group of cylinders. The controller also calculates a new long-term air/fuel bias value corresponding to the current engine speed and engine. The new long-term air/fuel bias value is based on a previously-calculated long-term air/fuel bias value calculated for the same engine load and speed. A total air/fuel bias value is calculated based on the short-term air/fuel bias value and the long-term air/fuel bias value. The new long-term air/fuel bias value is stored for future calculations.