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:
Nov. 02, 1999
Filed:
Jan. 21, 1997
Michael I Kluzner, Oak Park, MI (US);
Christopher Kirk Davey, Novi, MI (US);
David Robert Nader, Farmington Hills, MI (US);
Robert Joseph Jerger, Livonia, MI (US);
Ford Global Technologies, Inc., Dearborn, MI (US);
Abstract
A system and method for monitoring efficiency of a catalytic converter count switches of at least one upstream sensor interposed the engine and the converter and count switches of a downstream sensor, interposed the converter and atmosphere, during a definite time period after a switch of the at least one upstream sensor to account for propagation delay of exhaust gases traveling between the at least one upstream and downstream sensor. Upstream sensor switches may optionally be counted only if predetermined entry conditions are satisfied while downstream switches occurring during respective definite time periods after an upstream switch are counted without regard to the entry conditions. A switch ratio based on the number of switches of the at least one upstream sensor and switches of the downstream sensor is used to monitor conversion efficiency of the catalyst. The system and method may include selecting a current air flow range from a plurality of air flow ranges and associating sensor switches and/or switch ratios with corresponding air flow ranges to compensate for the propagation delay. In inferred sensor signal base on dual upstream sensors may be used to trigger the definite time periods and calculate the switch ratio(s).