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.

Date of Patent:
Mar. 17, 2015

Filed:

May. 17, 2012
Applicants:

Seiji Watanabe, Wako, JP;

Tooru Sekiguchi, Wako, JP;

Hiroyuki Ando, Wako, JP;

Atsuhiro Miyauchi, Wako, JP;

Takeshi Aoki, Wako, JP;

Michinori Tani, Wako, JP;

Soichiro Goto, Wako, JP;

Inventors:

Seiji Watanabe, Wako, JP;

Tooru Sekiguchi, Wako, JP;

Hiroyuki Ando, Wako, JP;

Atsuhiro Miyauchi, Wako, JP;

Takeshi Aoki, Wako, JP;

Michinori Tani, Wako, JP;

Soichiro Goto, Wako, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B60T 7/12 (2006.01); G05D 1/00 (2006.01); G06F 7/00 (2006.01); G06F 17/00 (2006.01); F02D 41/14 (2006.01); F02D 41/28 (2006.01);
U.S. Cl.
CPC ...
F02D 41/1456 (2013.01); F02D 41/1495 (2013.01); F02D 2041/288 (2013.01);
Abstract

An apparatus for controlling an air-fuel ratio of an internal-combustion engine includes an air-fuel ratio detector, a fluctuation signal generating device, an air-fuel ratio fluctuation device, a 0.5th-order frequency component strength calculator, a fluctuation frequency component strength calculator, a reference component strength calculator, and an imbalance fault determining device. The reference component strength calculator is configured to calculate strength of a reference component in accordance with strength of a first frequency component and strength of a second frequency component. The imbalance fault determining device is configured to make a determination of an imbalance fault in which air-fuel ratios of a plurality of cylinders vary beyond a tolerance limit on a basis of a relative relationship between strength of the 0.5th-order frequency component and the strength of the reference component.


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