Individual cylinder air/fuel ratio control based on a single exhaust gas sensor
US6382198B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2000 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | Nov 20, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2041/1416
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An improved internal combustion engine fuel control wherein a single oxygen sensor responsive to the combined exhaust gas flow of several engine cylinders is used both to control the overall or average air/fuel ratio, and to trim the air/fuel ratio in the individual engine cylinders. The oxygen sensor output is sampled in synchronism with the engine firing events, but at twice (or higher) the frequency, and filtered by an engine speed dependent high-pass filter to form a measure of the air/fuel ratio imbalance with respect to time. The imbalance signal, in turn, is parsed into an array of imbalance values that are associated with individual engine cylinders based on engine operating conditions, and the imbalance values are then used to develop correction factors for the respective engine cylinders that reduce the imbalance while preserving the overall or average air/fuel ratio of the engine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.