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. 02, 2005
Filed:
Jan. 21, 2003
Wei Wang, Troy, MI (US);
Jason E Wielenga, Jackson, MI (US);
Bill Leisenring, Tecumseh, MI (US);
Douglas M Stander, Grosse Pt. Woods, MI (US);
Dave Carlson, Williamston, MI (US);
Mark J Poublon, Shelby Township, MI (US);
Chris J Booms, Milford, MI (US);
Tom Stephens, Dearborn, MI (US);
Craig Summers, Northville, MI (US);
Danny K Schuelke, Grass Lake, MI (US);
Richard K Moote, Ann Arbor, MI (US);
Wei Wang, Troy, MI (US);
Jason E Wielenga, Jackson, MI (US);
Bill Leisenring, Tecumseh, MI (US);
Douglas M Stander, Grosse Pt. Woods, MI (US);
Dave Carlson, Williamston, MI (US);
Mark J Poublon, Shelby Township, MI (US);
Chris J Booms, Milford, MI (US);
Tom Stephens, Dearborn, MI (US);
Craig Summers, Northville, MI (US);
Danny K Schuelke, Grass Lake, MI (US);
Richard K Moote, Ann Arbor, MI (US);
DaimlerChrysler Corporation, Auburn Hills, MI (US);
Abstract
In a motor vehicle having an engine with an exhaust catalyst and an oxygen sensor upstream of the catalyst and an oxygen sensor downstream of the catalyst, a method for detecting whether the catalyst has aged. Over a test block period of time, the method periodically obtains upstream data points from an oxygen sensor located upstream of the catalyst and from and oxygen sensor located downstream of the catalyst. Absolute differences are calculated between consecutive pairs of the upstream data points and the downstream data points. A ratio between the sums of absolute differences is then calculated, and the ratio is used to determine whether the catalyst has aged.