The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 18, 2008
Filed:
Jan. 15, 2004
Reza Aliakbarzadeh, Regensburg, DE;
Gerd Rösel, Regensberg, DE;
Milos Tichy, Regensburg, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
The invention relates to a method for diagnosing a regulated exhaust gas catalyst, according to which regulating the catalyst results in control cycles, catalyst diagnosis being performed at a predetermined oxygen concentration per control cycle. A fuel mixture can be adjusted fat or lean according to a specific lambda control factor. A fat or lean exhaust gas is detected, the lambda control factor being incrementally decreased when a lean exhaust gas is detected. The lambda control factor is modified by a P step following a detected change from a fat to lean exhaust gas or from a lean to a fat exhaust gas, the lambda control factor being set to a minimum value during a first loading period following a detected change from a fat exhaust gas to a lean exhaust gas while being set to a maximum value during a second loading period following a detected change from a lean exhaust gas to a fat exhaust gas. The first and the second loading period are adjusted such that the oxygen concentration reaches the predetermined oxygen concentration in each control cycle.