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:
Apr. 22, 2003
Filed:
Sep. 25, 2002
Andrew A. Adamczyk, Dearborn, MI (US);
Christian Thomas Goralski, Jr., Ypsilanti, MI (US);
Eva Thanasiu, Trenton, MI (US);
Ford Global Technologies, L.L.C., Dearborn, MI (US);
Abstract
A method and system are provided for monitoring exhaust gas conversion efficiency of a catalytic converter during operation of an internal combustion engine coupled to the catalytic converter. The system includes an upstream exhaust gas sensor interposed the engine and the catalytic converter for generating a first signal based on the exhaust gas upstream of the converter. A downstream exhaust gas sensor is interposed the catalytic converter and atmosphere for generating a second signal based on the exhaust gas downstream of the converter. A phase shift detector is provided for estimating a phase shift between the first and second signals. A processor is provided for aligning the first and second signals such that the resulting phase shift between the first and second signals is substantially an integer multiple of &pgr; radians and for determining conversion efficiency of the catalytic converter based such phase aligned first and second signals. With such method and system, average error of the calculated index ratio using such system and method and the theoretical average error in index ration (IR) is minimized when the phase shift between the upstream and downstream sensor signals is substantially an integer multiple of &pgr; radians.