Method for determining the load signal of an internal combustion engine having external exhaust-gas recirculation

US5889203A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Ernst Wild · Oberriexingen, DE
• Manfred Pfitz · Leinfelden, DE
• Axel Stuber · Ludwigsburg, DE

Key dates

• Filing date: Jun 18, 1997
• Grant date: Mar 30, 1999
• Expiry date: Jun 18, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

The invention is directed to a method for determining a load signal of an internal combustion engine having an intake pipe with a pressure sensor, external exhaust-gas recirculation (EGR) and an EGR valve. A load signal (tl) is computed in a circuit arrangement which is proportional to the mass inducted per revolution of the engine. The computation is made in dependence upon measured intake-pipe pressure (ps) and the speed (n) of the engine in rpm. On the one hand, the method makes a simple adaptation possible, while, on the other hand, a correct load signal is formed also in steady-state operation and, in this way, reduced exhaust-gas emissions of the engine are made possible. The exhaust-gas mass flow flowing through the EGR valve is determined by converting the exhaust-gas mass flow into an rpm-dependent signal. The rpm-dependent signal is filtered in a filter simulating charging operations in the intake pipe. A corrective signal (scorr) proportional to the exhaust-gas mass inducted by the engine per revolution thereof is determined and this corrective signal (scorr) is subtracted from the load signal (tl) to generate and output the corrected load signal (tlcorr).