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:
Mar. 31, 1998
Filed:
Feb. 23, 1996
Hiroshi Ohno, Wako, JP;
Koichi Saiki, Wako, JP;
Yukio Noda, Wako, JP;
Shusuke Akazaki, Wako, JP;
Yoshitaka Takasuka, Wako, JP;
Yusuke Hasegawa, Wako, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An air-fuel ratio control system for an internal combustion engine has an air-fuel ratio sensor arranged in an exhaust passage of the engine for detecting an air-fuel ratio of exhaust gases emitted from a plurality of cylinders. An output from the air-fuel ratio sensor is sampled whenever the engine rotates through a predetermined crank angle, and sampled values of the output from the air-fuel ratio sensor are sequentially stored. An output characteristic of the air-fuel ratio sensor is detected. One of the sampled values of the output from the air-fuel ratio sensor is selected at least depending on the output characteristic of the air-fuel ratio sensor. An air-fuel ratio of a mixture supplied to each of the cylinders is estimated, separately from other ones of the cylinders, based on selected ones of the sampled values of the output from the air-fuel ratio sensor and a model representative of a behavior of the exhaust passage. The air-fuel ratio of the mixture supplied to the each of the cylinders is controlled in a feedback manner responsive to the estimated air-fuel ratio of the mixture such that the estimated air-fuel ratio of the mixture supplied to the each of the cylinders is converged to a desired air-fuel ratio.