Method for optimizing the air/fuel ratio under non-steady conditions in an internal combustion engine

US4733358A · kind A · utility

Assignee

• Daimler-Benz AG · DE

Inventors

• Jorg Abthoff · Plüderhausen, DE
• Dieter H. P. Schuster · Wuppertal, DE
• Christoph Noller · Königsbrunn, DE
• Ferry Durschmidt · Friolzheim, DE
• Gunter Loose · Waiblingen, DE

Key dates

• Filing date: Jul 3, 1985
• Grant date: Mar 22, 1988
• Expiry date: Jul 3, 2005

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D41/1487
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A self-optimizing control method for optimizing the fuel/air ratio under non-steady conditions in an internal combustion engine is described; in this method, a probe is provided both before and after the catalyst. Control quantities and the time during which the post catalyst probe shows an undesirable fuel/air ratio are stored for certain specified engine-operating conditions in the non-steady range. When the same engine operating condition is repeated, reference is made to the stored control quantities and time and the control quantity is varied in the direction of the correct fuel/air ratio. The time now obtained is compared with the stored time and, if the time has decreased, the new control quantity and the new time are stored. The control values are iteratively corrected by repeating these procedures, when the same engine operating condition reappears, until the time reaches a minimum.