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:
Sep. 15, 1998
Filed:
Jul. 25, 1997
Toru Kitamura, Wako, JP;
Hiroshi Ohno, Wako, JP;
Yusuke Hasegawa, Wako, JP;
Yoichi Nishimura, Wako, JP;
Kenichiro Ishii, Wako, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A cylinder-by-cylinder air-fuel ratio-estimating system for an internal combustion engine includes an air-fuel ratio sensor arranged in the exhaust system of the engine, at a confluent portion of the exhaust system. The air-fuel ratio of a mixture supplied to each of the cylinders is estimated based the output from the air-fuel ratio sensor, by using an observer for observing the internal operative state of the exhaust system based on a model representative of the behavior of the exhaust system. The air-fuel ratio at the confluent portion is estimated by using a delay parameter representative of the response delay of the air-fuel ratio sensor, and the air-fuel ratio of the mixture supplied to each of the cylinders is estimated by using the estimated air-fuel ratio at the confluent portion. The estimated air-fuel ratio of the mixture supplied to each of the cylinders is subsequently used for estimating a value of the air-fuel ratio at the confluent portion of the exhaust system.