Patent · US Expired

Air-fuel ratio control system for internal combustion engines

US5732689A · kind A · utility

13Cited by
3References
21Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 23, 1996
Grant dateMar 31, 1998
Priority date
Expiry dateFeb 23, 2016

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF02D41/2477
  • WIPO fieldEngines, pumps, turbines
  • WIPO sectorMechanical engineering

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 i…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.