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:
Feb. 04, 2014
Filed:
Nov. 09, 2012
Yuya Yoshikawa, Chiryu, JP;
Yuya Yoshikawa, Chiryu, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, JP;
Abstract
An apparatus and method for detecting an abnormal air-fuel ratio variation between cylinders of a multi-cylinder internal combustion engine in which the output of an air-fuel ratio sensor is acquired at each sampling interval, a parameter correlated with the degree of fluctuation of the sensor output is calculated from a plurality of the acquired sensor outputs, and the presence or absence of the abnormal air-fuel ratio variation between cylinders is determined by comparing the parameter with a determination value. A cylinder air amount is estimated at each sampling interval. Every time the air-fuel ratio sensor output is acquired, the value of the cylinder air amount at the point earlier, by a transport delay time, than the point of the acquisition is determined based on the time-series data, and a corresponding determination value corresponding thereto is calculated. The determination value is determined based on a plurality of the calculated corresponding determination values.