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:
Sep. 05, 2000
Filed:
Jun. 28, 1999
Robert Joseph Jerger, Livonia, MI (US);
Christopher Kirk Davey, Novi, MI (US);
Michael I Kluzner, Oak Park, MI (US);
Donald Fenwick Dickison, Sterling Heights, MI (US);
Ford Global Technologies, Inc., Dearborn, MI (US);
Abstract
A system and method for monitoring catalytic converter efficiency monitor the switch ratio of upstream and downstream exhaust gas oxygen sensors based on an acceptable temperature range of the catalytic converter. In one embodiment, catalytic converter temperature is determined based on exhaust gas temperature. The exhaust gas temperature may be used to infer the temperature of the catalytic converter mid-bed. The efficiency may be determined based on a correspondence with a number of mass air flow ranges. The system and method may also use vehicle speed and EGR to assure that the monitor samples data during repeatable, robust load-speed-temperature conditions. Switch data is stored in keep-alive memory to increase the confidence of the efficiency determination due to a larger data collection phase. A filter having a cycle based constant may be used to filter a current switch ratio before incorporating it into an average switch ratio.