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:
May. 20, 2014
Filed:
Aug. 02, 2012
Tooru Sekiguchi, Wako, JP;
Atsuhiro Miyauchi, Wako, JP;
Takeshi Aoki, Wako, JP;
Michinori Tani, Wako, JP;
Seiji Watanabe, Wako, JP;
Tooru Sekiguchi, Wako, JP;
Atsuhiro Miyauchi, Wako, JP;
Takeshi Aoki, Wako, JP;
Michinori Tani, Wako, JP;
Seiji Watanabe, Wako, JP;
Honda Motor Co., Ltd., Tokyo, JP;
Abstract
An oscillation signal is generated to oscillate the air-fuel ratio with a set frequency which is different from a 0.5th-order frequency (half of the frequency corresponding to a rotational speed of the engine). Air-fuel ratio perturbation control is performed to oscillate the air-fuel ratio according to the oscillation signal. An intensity of the 0.5th-order frequency component and the set frequency component contained in the detected air-fuel ratio signal are calculated. A determination parameter applied to determining an imbalance degree of air-fuel ratios corresponding to the plurality of cylinders is calculated according to the two intensities and determines an imbalance failure that the imbalance degree of the air-fuel ratios exceeds an acceptable limit. A predicted imbalance value, indicative of a predicted value of the imbalance degree, is calculated, and an amplitude of the oscillation signal is set according to the predicted imbalance value.