Robert Boschgmbh

Torsten Handler

Dirk Samuelsen

Lothar Diehl

Tobias Pfister

Klaus Winkler

Stefan Wickert

Bernhard Kamp

Henrik Schittenhelm

Christian Walz

Michael Kolitsch

Katharina Schaenzlin

Eckehard Knoefler

Klaus Mueller

Thomas Wahl

Jens Wagner

Wolfgang Ripper

Detlef Heimann

Rainer Strohmaier

Enno Baars

Andreas Fritsch

Thomas Zein

Thomas Seiler

Michael Gerlach

Ralf Wirth

Matthias Loehr

Goetz Reinhardt

Helge Schichlein

Andreas Genssle

Harry Braun

Werner Christl

Bjoern Alexander Schuetz

Heribert Haerle

Dieter Lindauer

Sabine Rösch

Andreas Sturm

Sven Boeffert

Dietmar Seizinger

Sabine Gräbe

Markus Willimowski

A method for monitoring a gas sensor () which comprises two electrochemical measuring cells () and which is arranged in an exhaust tract () of an internal combustion engine (), wherein the sensor elements () exhibit a substantially identical sensitivity towards a first gas component and a different sensitivity towards a second gas component and are insensitive towards further gas components. In an operating state in which an exhaust gas stream at the gas sensor () contains less of the second gas component than of the first gas component a concentration of the first gas component is calculated from each of the sensor signals from the sensor elements () and a defect in a sensor element () is deduced from the concentrations of the first gas component.

Method for monitoring a gas sensor

The invention relates to a method for monitoring a NOx sensor () having an oxygen-ion-conducting solid electrolyte and having at least one cavity (), wherein at least one cavity () of the NOx sensor is flooded with a defined oxygen concentration during a self-diagnosis of the NOx sensor. The gradient of a pump current resulting therefrom is evaluated and, in the case of a deviation in comparison with reference values, possibly impaired dynamics of the NOx sensor are inferred.

Method for the dynamic monitoring of a NOx sensor

A method is presented for checking the functional capability of a nitrogen oxide sensor () which has a first chamber () and a second chamber (), wherein the first chamber has a first oxygen pump cell () and the second chamber has a second pump cell (), in a normal operating mode of the nitrogen oxide sensor (), an oxygen concentration level in the first chamber is reduced to a predetermined first value with the first pump cell, and an oxygen concentration level in the second chamber is reduced to a second value with the second pump cell, said second value being lower than the first value.

Method for checking the functional capability of a nitrogen oxide sensor

A method for diagnosing a sensor element for detecting at least one fraction of a gas component of a gas in a measuring gas chamber, in particular a sensor element for detecting oxygen in an exhaust gas of an internal combustion engine. The sensor element includes at least one first electrode, to which the gas may be applied, and at least one second electrode, the first electrode and the second electrode being connected via at least one solid electrolyte. A diagnostic signal is applied between the first electrode and the second electrode, a response signal being detected between the first electrode and the second electrode.

Method and device for diagnosing electrodes in sensor elements

The present invention relates to a method for monitoring a pollutant conversion capacity of a catalytically coated, oxidizing exhaust gas aftertreatment component () in an exhaust gas system () of an internal combustion engine (). A nitrogen oxide sensor () is disposed in each case in the flow path of the exhaust gas upstream of and downstream of the oxidizing exhaust gas aftertreatment component (), a capacity of said oxidizing exhaust gas aftertreatment component () for converting NO to NObeing ascertained from a comparison of the two signals (Z', Z&#x2033;) of the nitrogen oxide sensors (). Additional independent claims relate to an open-loop and/or closed-loop control device (), a computer program and a computer program product.

Method for monitoring a pollutant conversion capacity in an exhaust gas aftertreatment system

A method for monitoring the capability of a catalytic converter to convert nitrogen monoxide into nitrogen dioxide in the exhaust gas of an internal combustion engine, the catalytic converter being arranged in an exhaust gas duct of the internal combustion engine and the catalytic converter being followed downstream by a collecting particle sensor. It is in this case provided that, in a monitoring cycle, a decrease in the particle loading of the particle sensor during the operation of the internal combustion engine under predetermined operating conditions is taken to conclude an adequate capability of the catalytic converter to convert from nitrogen monoxide to nitrogen dioxide.

Method for monitoring a catalytic converter

A procedure to diagnose a particle filter disposed in an exhaust gas area of an internal combustion engine as well as a device to implement the procedure is proposed. Provision is made to ascertain the degree of efficiency of the particle filter on the basis of the upstream particle flow occurring upstream in front of the particle filter and on the basis of the downstream particle flow occurring downstream behind the particle filter. The ascertainment of the degree of efficiency of the particle filter allows for an On-Board-Diagnosis of the particle filter, with which compliance with specified exhaust gas threshold values can be assured.

Procedure to diagnose a particle filter and device to implement the procedure

A method for operating an internal combustion engine in whose exhaust-gas region at least one SCR catalytic converter is disposed, which is acted upon by a reagent contributing to the NOx conversion in the SCR catalytic converter, and a device for implementing the method. The reagent level in the SCR catalytic converter is controlled or regulated to a predefined reagent setpoint level, which is specified to at least a maximum value, which corresponds to an SCR catalytic converter completely filled with reagent. In this way the SCR catalytic converter is always operated at the highest possible efficiency at which the highest possible NOx conversion takes place.

Method for operating an internal combustion engine and device for implementing the method

Method for diagnosing a NOx readings recorder which acquires a NOx concentration in an exhaust gas tract of an internal combustion engine and comprises two measuring chambers (), wherein the exhaust gas to be measured is supplied to the first measuring chamber () and an oxygen concentration is set by means of a first oxygen ion pump current (I), wherein the second measuring chamber () is connected to said first measuring chamber () and wherein both measuring chambers are disposed in a solid electrolyte, the oxygen content in the second measuring chamber () is determined; the oxygen content is additionally determined by a separate device; the two values characterizing the oxygen concentration are compared and a defective sensor is then suggested if the oxygen concentration value determined in the second measuring chamber () deviates from the oxygen concentration value determined by the separate sensor device by a predeterminable magnitude.

Method for diagnosing a NOx readings recorder

A method for metering a reagent which an emission control device situated in the exhaust duct of an internal combustion engine requires for removing at least one exhaust gas component from the exhaust gas and a device for executing the method are described. The fluid level of the reagent stored in a reagent tank is measured. The measured change in the fluid level is compared to at least one measure for the change in the fluid level calculated as a function of consumption. An error signal is output when the comparison result exceeds a predefined threshold value. This approach enables reliable information to be provided about the fluid level of the reagent in the reagent tank.

Method for metering a reagent for the emission control of internal combustion engines and device for executing the method

The invention relates to a method for diagnosing a particle filter used for filtering particles out of the exhaust gas of an internal combustion engine, wherein a collecting particle sensor is disposed downstream of the particle filter in the direction of flow of the exhaust gas and wherein a measurement for the loading of the particle sensor is determined from an output signal of the particle sensor. Provision is thereby made for the temporal integral of a parameter correlating to the particle emissions of the internal combustion engine to be formed during a measurement cycle, for the measurement for the loading of the particle sensor to be associated with the integral at least one measurement point in time during the measurement cycle and for a defective particle filter to be suggested if the measurement for the loading of the particle sensor is higher than a loading threshold value associated with the integral or if the integral is lower than an integral threshold value associated with the measurement for the loading of the particle sensor. The invention further relates to a device for carrying out the method. The method and the device allow for the diagnosis of the functionality of a particle filter in the exhaust gas of an internal combustion engine during any operating conditions passed through by the internal combustion engine.

Monitoring of a particle limit value in the exhaust gas of an internal combustion engine

A method for operating a sensor for recording particles in an exhaust gas flow and a device for carrying out the method are provided, in which at least one measure of the exhaust gas flow is ascertained and in which the measure of the exhaust gas flow is taken into consideration in the valuation of the particle sensor signal made available by the particle sensor. The procedure is based on the knowledge that the exhaust gas flow, for instance, the exhaust gas volume flow, has an influence on the particle sensor signal made available by the particle sensor, especially when the measuring effect is based on the depositing of particles on a sensor surface. Using the procedure, a possibly present cross sensitivity of the particle sensor with respect to different exhaust gas flows is taken into consideration, so that the measuring accuracy is increased.

Method for operating a sensor for recording particles in a gas stream and device for implementing the method

The invention concerns a procedure to determine a mass of particles or a particle mass flow in an exhaust gas system of an internal combustion engine, whereby at least one resistive particle sensor is disposed in the exhaust gas system of the internal combustion engine. The measured signal change of the particle sensor is compared with a predicted signal change of the particle sensor ascertained from an engine model. If the measured signal change of the particle sensor and/or the predicted signal change of the particle sensor are corrected while taking into account the influencing variables on the transverse sensitivities of the particle sensor, it is possible when ascertaining the predicted signal change of the particle sensor that a compensation for the transverse sensibilities can result even during dynamic operating point changes of the internal combustion engine, which occur faster than the actuation of the particle sensor. This is the case because the correction can even be implemented for small predicted signal changes, such as those occurring during a currently transpiring operating point of the internal combustion engine. Because the predicted signal changes are ascertained from a set of characteristic curves of the engine model, these measurement intervals capable of being assigned to very short times and for that reason to individual operating points of the internal combustion engine can be determined with the very small predicted signal changes, which are required for this purpose.

Exhaust gas sensor

A method for operating an internal combustion engine, in whose exhaust region, in the direction of flow of the exhaust gas, there are situated a first broadband lambda sensor which makes available a first lambda signal, an NOx adsorption catalyst and a second broadband lambda sensor which makes available a second lambda signal, in which the NOx adsorption catalyst cyclically stores the NOx emissions of the internal combustion engine, and is regenerated within the scope of a nominal regeneration by the operation of the internal combustion engine using a rich/stoichiometric air/fuel mixture, and a device for carrying out the method are provided. An intensified regeneration, compared to a nominal regeneration, of the NOx adsorption catalyst is undertaken, which supports a better setting of the thermodynamic equilibrium in the exhaust gas compared to the nominal regeneration. At the end of the intensified regeneration, at a still rich/stoichiometric air/fuel mixture, a plausibility check/correction of the first lambda signal using the second lambda signal is provided.

A method for operating an internal combustion engine; in the exhaust area of this engine there is at least one catalytic converter and downstream from the catalytic converter there is an NOx sensor. A device for carrying out this method is also provided. The NOx sensor has a cross-sensitivity to a reagent needed in the catalytic converter. In predefined operating states of the internal combustion engine, e.g., idling and/or overrun, a selection signal is supplied; when this selection signal occurs, the sensor signal supplied by the NOx sensor is interpreted as at least a measure of the reagent leakage.

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Stuttgart, Germany

Torsten Handler