Passive model-based EGR diagnostic
US6763708B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2001 |
| Grant date | Jul 20, 2004 |
| Priority date | — |
| Expiry date | Jan 10, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A process for computer based, wholly passive, diagnosis of an automotive vehicle exhaust gas recirculation system is disclosed. Use is made of any suitable math model of the vehicle's air intake system to estimate the absolute pressure in the intake manifold, MAP, assuming both a healthy EGR system, MAPHE, and a faulty EGR valve, MAPFE. Both estimated values are compared with the actual normally measured manifold pressure, MAPmeas. Both comparisons are repeated over many calculations and the differences analyzed to reliably determine whether there is a real restriction to recirculated exhaust flow. A preferred math model of the intake system uses as input variables: mass air flow, barometric pressure, the position command for the EGR valve and engine speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.