Exhaust catalyst monitoring arrangement

US6922985B2 · kind B2 · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Wei Wang · Cupertino, US
• Jason E Wielenga · Jackson, US
• Bill Leisenring · Tecumseh, US
• Douglas M. Stander · Grosse Pointe Woods, US
• Dave Carlson · Santa Clarita, US
• Mark J Poublon · Shelby Charter Township, US
• Chris J Booms · Milford, US
• Tom Stephens · Dearborn, US
• Craig Summers · Northville, US
• Danny K Schuelke · Marquette, US
• Richard K. Moote · Ann Arbor, US

Key dates

• Filing date: Jan 21, 2003
• Grant date: Aug 2, 2005
• Expiry date: Apr 5, 2023

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

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.