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:
Jun. 16, 2015
Filed:
Jun. 19, 2012
Tooru Sekiguchi, Wako, JP;
Atsuhiro Miyauchi, Wako, JP;
Takeshi Aoki, Wako, JP;
Michinori Tani, Wako, JP;
Takashi Yanagiura, Wako, JP;
Seiji Watanabe, Wako, JP;
Tooru Sekiguchi, Wako, JP;
Atsuhiro Miyauchi, Wako, JP;
Takeshi Aoki, Wako, JP;
Michinori Tani, Wako, JP;
Takashi Yanagiura, Wako, JP;
Seiji Watanabe, Wako, JP;
HONDA MOTOR CO., LTD., Tokyo, JP;
Abstract
An air-fuel ratio control system for an internal combustion engine has a perturbation control which oscillates the air-fuel ratio with a first frequency. A first difference signal is generated indicative of a difference between a present value and a first past value from an air-fuel ratio sensor detected at a timing of a first specific period which is set to reduce a specific frequency component corresponding to a specific frequency different from the first frequency. A first frequency component is extracted. A second difference signal is generated indicative of a difference between a present value and a second past value detected at a timing of a second specific period which is set to reduce the first frequency component. The specific frequency component is extracted. A failure of the control system is determined by a relationship between intensities of the first frequency component and the specific frequency component.