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:
Aug. 04, 2009
Filed:
Oct. 09, 2007
Eijirou Yamada, Hekinan, JP;
Eijirou Yamada, Hekinan, JP;
DENSO Corporation, Kariya, JP;
Abstract
When detecting the data showing an output characteristics of an air-fuel ratio sensor, the air-fuel ratio (feed air-fuel ratio) supplied to each cylinder is alternately changed to rich or lean by a predetermined ratio (X %). And then, the average value of the detected air-fuel ratio λ in the rich side and the lean side is respectively computed. A ratio between the variation width of the air-fuel ratio and the detection variation of the air-fuel ratio sensoris computed as an output-characteristics correction value for correcting the dispersion in the output characteristics of the air-fuel ratio sensor. By correcting the air-fuel ratio detection of the air-fuel ratio sensor with this output-characteristics correction value, the dispersion in the output characteristics due to manufacturing tolerances, aged deterioration, etc. of the air-fuel ratio sensor is corrected.