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:
Oct. 06, 2009
Filed:
Sep. 12, 2008
Reina Fukagai, Aichi, JP;
Norikazu Ieda, Ichinomiya, JP;
Masahiro Tanaka, Kasugai, JP;
Hiroshi Inagaki, Komaki, JP;
Masaki Hirata, Hamamatsu, JP;
Takahiro Suzuki, Hamamatsu, JP;
Reina Fukagai, Aichi, JP;
Norikazu Ieda, Ichinomiya, JP;
Masahiro Tanaka, Kasugai, JP;
Hiroshi Inagaki, Komaki, JP;
Masaki Hirata, Hamamatsu, JP;
Takahiro Suzuki, Hamamatsu, JP;
NGK Spark Plug Co., Ltd., Nagoya-shi, JP;
Suzuki Motor Corporation, Hamamatsu-shi, JP;
Abstract
A gas sensor diagnostic method includes the steps of counting the reversal number of times that a target air-fuel ratio for an air-fuel mixture to be supplied to an internal combustion engine reverses from a rich side to a lean side or from the lean side to the rich side through a specific air-fuel ratio defined as a boundary of the rich and lean sides; obtaining a detection signal of gas sensor at constant time intervals during a diagnosis period between a timing when the count for the reversal number is started and a timing when the reversal number reaches a predetermined number; calculating a first moderated signal by applying a first moderation calculation to the detection signal, and a second moderated signal by applying a second moderation calculation to the detection signal; calculating a deviation between the first and second moderated signals; and determining whether the gas sensor is in the abnormal state on the basis of the deviation obtained during the diagnosis period.