Modeling and deterioration diagnosis of catalyst for automobile exhaust gas by on-line identification method with variable forgetting factor

Yasushi Okada, Hiroyuki Okuda, Shuichi Adachi, Shinji Niwa, Mitsunobu Kajitani, Seiji Hashimoto

Research output: Contribution to journalArticle

3 Citations (Scopus)


The majority of the conventional system purifying exhaust gas is composed of a three-way catalyst and an electronic fuel injection. However, harmful pollutants are increasingly emitted when the catalyst becomes aged.Therefore, it is necessary to detect the deterioration of the catalyst by means of on board diagnosis. In this paper, we propose a diagnosis method of the aged catalyst using recursive system identification method with variable forgetting factor. We focus on the parameter of identified model which represents a characteristic of the catalyst, and possibility to describe the diagnosis of the aged catalyst.

Original languageEnglish
Pages (from-to)1637-1644+6
Journalieej transactions on industry applications
Issue number12
Publication statusPublished - 2006 Dec 21



  • Catalyst
  • Deterioration diagnosis
  • Recursive least squares method
  • System identification
  • Variable forgetting factor

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering

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