Method and apparatus for diagnosing engine exhaust gas purification system
US5802843A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 1995 |
| Grant date | Sep 8, 1998 |
| Priority date | — |
| Expiry date | Feb 10, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A diagnosis apparatus for diagnosing a catalytic converter of a motor vehicle as to whether the catalyst suffers deterioration by estimating a temperature of the catalyst or that of the exhaust gas in the vicinity of the catalyst on the basis of a plurality of engine parameters to thereby decide deterioration of the catalyst by using as an index the estimated temperature. The apparatus includes a unit for estimating the temperature of the catalyst in a steady state by making use of an engine speed and an engine load which represent typical parameters employed in fuel injection control of the engine. The steady-state temperature facility is realized by storing the engine speeds and the engine loads obtained experimentally in the steady state operation of the engine in the form of a two-dimensional data map. A unit for correcting the estimated temperature of the catalyst in the transient state is provided for correcting the catalyst temperature determined by the steady-state catalyst temperature estimating unit to thereby ensure correct estimation of the catalyst temperature even in the course of operation of the motor vehicle. In the transient temperature estimating unit, non-linear…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.