Patent · US Expired

Method of judging deterioration of emission gas control catalyst device

US6449944B1 · kind B1 · utility

15Cited by
9References
33Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 17, 2001
Grant dateSep 17, 2002
Priority date
Expiry dateJan 17, 2021

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02T10/40
  • WIPO fieldEngines, pumps, turbines
  • WIPO sectorMechanical engineering

Abstract

A first exhaust gas sensor 5 (air-fuel ratio sensor) and a second exhaust gas sensor 6 (O2 sensor) are disposed respectively upstream and downstream of a catalytic converter. An exhaust system E which ranges from the exhaust gas sensor 5 to the exhaust gas sensor 6 and includes the catalytic converter 3 is regarded as an object exhaust system E, and a behavior of the object exhaust system E is modeled. When an internal combustion engine 1 is in operation, parameters to be set of the model of the object exhaust system E are sequentially identified based on the data of outputs of the exhaust gas sensors 5, 6. A deteriorated state of the catalytic converter 3 is determined based on the data of the identified values. Concurrent with the determination of the deteriorated state, a target air-fuel ratio for the internal combustion engine 1 is sequentially determined in order to converge the output of the exhaust gas sensor 5 to a given target value, and the air-fuel ratio of the internal combustion engine 1 is controlled to converge the output (the detected value of the air-fuel ratio) of the first exhaust gas sensor 5 to the target air-fuel ratio, for thereby allowing the catalytic conve…

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