Robert Boschgmbh

Richard Hotzel

Kersten Wehmeier

Eberhard Schnaibel

Erich Schneider

Christoph Woll

Andreas Koring

Klaus Hirschmann

Ronaldi Rusli

Ralf Buehrle

Lanouar Chouk

Magnus Labbe

Kersen Wehmeier

A procedure and device for diagnosing the increasing speed and the dead time of an exhaust gas probe includes carrying out the diagnosis by comparing a modeled and a measured signal after a default change of a fuel air ratio of an air fuel mixture that is supplied to a combustion engine. The signal is an output signal of the exhaust gas probe or a modeled or measured signal that is derived from the output signal. The device for diagnosing the velocity and the dead time of an exhaust gas probe also includes a comparing unit for comparing the modeled signal with the measured signal for diagnosing the velocity and the dead time of the exhaust gas probe after a default change of a fuel air ratio of an air fuel mixture that is supplied to the combustion engine.

Procedure and device for diagnosing an exhaust gas probe

The invention concerns a procedure and a device for diagnosing the dynamic of an exhaust gas sensor, which is arranged in an exhaust gas duct of a combustion engine and with which a parameter of the gas mixture that is supplied to the combustion engine is regulated by a control loop. It is thereby provided according to the invention that during a diagnosing period a temporal deflection of a regulation correcting variable for the parameter that is derived from an output signal of the exhaust gas sensor or a temporal course of the output signal of the exhaust gas sensor is used for the diagnosis and that the dynamic of the exhaust gas sensor is assumed in an evaluation algorithm. Thereby an improvement of the on-board diagnosis of the dynamic of the exhaust gas sensor can be achieved and in particular lambda probes, which provide a slowing down of their responding behavior, can be detected early on.

Procedure and device for diagnosing the dynamic of an exhaust gas sensor

A method for regulating the fuel/air ratio of a combustion process which is operated alternatingly with excess air and air deficiency, and having at least one catalyst volume in the exhaust gas of the combustion process which stores oxygen when there is excess oxygen in the exhaust gas and gives it off when there is oxygen deficiency, in which method the oxygen charges into the catalyst volume taking place when there is excess air, and the oxygen discharges from the catalyst volume taking place when there is air deficiency determined, and in which the fuel/air ratio is regulated in a first control loop such that the sum of the oxygen charges and oxygen discharges determined in a predefined interval takes on a predetermined value, wherein the combustion process is operated using oxygen excess or oxygen deficiency, respectively, at least until these appear at an oxygen-sensitive Nernst probe downstream from the catalyst volume.

Method and device for regulating the fuel/air ratio of a combustion process

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 and device for operating an internal combustion engine, which diagnose and/or adapt the exhaust-gas recirculation system for, in particular, multibranch internal combustion engines. In this context, the internal combustion engine includes at least one adsorption catalyst in at least one exhaust branch. In addition, at least one exhaust-gas recirculation duct is provided, which is equipped with an exhaust-gas recirculation valve and feeds exhaust gas from the at least one exhaust branch back into at least one air-supply duct, a level of pollutant stored in the at least one adsorption catalyst being ascertained in a first operating state of the internal combustion engine when the exhaust-gas recirculation valve is at least partially open, so that a first value for the pollutant level is produced. In a second operating state of the internal combustion engine, a second value for the pollutant level in the at least one adsorption catalyst is ascertained when exhaust-gas recirculation valve is closed. The first value of the pollutant level is compared to the second value of the pollutant level. A diagnosis and/or an adaptation of an exhaust-gas recirculation system formed by the at least one exhaust-gas recirculation duct, along with its exhaust-gas recirculation valve and its drive circuit, is carried out as a function of the comparison result.

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Stuttgart, Germany

Richard Hotzel