Robert Boschgmbh

Magnus Labbe

Eberhard Schnaibel

Erich Schneider

Christoph Woll

Klaus Hirschmann

Kersten Wehmeier

Bernd Kraewer

Thomas Kuhn

Richard Hotzel

Maik Unverricht

Simon Fass

Method for diagnosing at least one exhaust gas sensor () of an internal combustion engine () disposed in an exhaust duct (), where ambient air () is actively introduced into the exhaust duct () by means of a device (), when an operating state is present in which the internal combustion engine () does not produce an exhaust gas mass flow, and the diagnosis of the at least one exhaust gas sensor () disposed in the exhaust duct () is subsequently carried out.

Method and device for diagnosing at least one exhaust gas sensor of an internal combustion engine disposed in an exhaust duct

A method () is proposed for operating an internal combustion engine (), which comprises a lean-burn engine having compression-ignition, having a throttle valve () in an air path () upstream of the internal combustion engine () and an exhaust gas posttreatment system () downstream of the internal combustion engine (), comprising a control of the internal combustion engine () according to a present load demand () using metering of an amount of fuel in dependence on the present load demand; and if a load demand () is absent in a heating operating mode, further comprising partially closing () the throttle valve () and defining a minimum value for the amount of fuel, which is greater than zero. Furthermore, a computing unit and a computer program for carrying out such a method () are proposed.

Method, computing unit, and computer program for operating an internal combustion engine

The invention concerns a procedure to determine the oxygen storage capability of an emission control system with an exhaust gas sensor with discrete-level ability disposed in front of the emission control system. If in a period of time before the determination of the oxygen storage capability, the control intervention of the exhaust gas sensor is ascertained, and if this mean value is taken into consideration when calculating the fuel-delivery control phase during the determination of the oxygen storage capability of the emission control system, or if this mean value is used to correct the lambda value used to calculate the amount of oxygen stored, an improved measuring accuracy can be achieved while using a cost effective discrete level sensor. In that during the rich or lean operation of the cycle to determine the oxygen storage capability, the mean value of the control intervention is used for the calculation, pre-control errors are compensated for, as they can arise, for example, through dispersion of the injection valves or errors in the acquisition of cylinder fill. If the mean value is used to correct the lambda value, the amount of oxygen stored can be more accurately determined as a result of the measured air mass. In the procedure according to the invention, a cost effective step discrete-level sensor can be used in front of the emission control system.

Procedure to measure the oxygen storage capability of an emission control system

A method for controlling an internal combustion engine in which in each case the lambda value is ascertained by evaluating a measuring signal of a lambda probe. In this context, two combustion periods of the internal combustion engine are compared to each other. In the two combustion periods, in a single cylinder the lambda value is induced once in the direction of a lambda increase and once in the direction of a lambda decrease.

Method for controlling an internal combustion engine

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Moeglingen, Germany

Magnus Labbe