Air-fuel ratio control system for internal combustion engine
US7412820B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2007 |
| Grant date | Aug 19, 2008 |
| Priority date | — |
| Expiry date | Mar 14, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An air-fuel ratio control system for an internal combustion engine having a catalyst provided in an exhaust system of the engine for purifying exhaust gases and a first oxygen concentration sensor disposed upstream of the catalyst is disclosed. The air-fuel ratio control system controls an air-fuel ratio of an air-fuel mixture supplied to the engine. A degree of response deterioration of the first oxygen concentration sensor is detected. A response delay of the first oxygen concentration sensor is compensated according to the detected degree of deterioration to calculate a compensated sensor output. The air-fuel ratio is controlled so that a detected air-fuel ratio calculated from the compensated sensor output coincides with a target air-fuel ratio. A frequency characteristic of the compensation is adjusted according to the detected degree of deterioration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.