Abstract: A device and method for determining a temperature variable, in particular a temperature variable that characterizes the condition of an exhaust-gas treatment system of a combustion engine, are described. The temperature is specified on the basis of variables that characterize the mass flow in the exhaust-gas treatment system, and/or of a second temperature variable that characterizes the temperature upstream from the exhaust-gas treatment system.

Abstract: A method and a device for monitoring a signal, in particular a pressure signal that characterizes the pressure differential at the input and output of an exhaust after-treatment system, are described. Errors are recognized on the basis of the occurrence of oscillations in the sensor signal.

Abstract: A method and a device for monitoring an exhaust gas aftertreatment system, in particular an oxidation catalytic converter, are described. An error is recognized if an operating parameter does not change as expected, when a particular operating state is present.

Abstract: A method and a device for controlling an internal combustion engine, in which a first quantity characterizing the flow resistance of a first component of the exhaust-gas treatment system is determined based on a first measured quantity and a volumetric-flow quantity, and the volumetric-flow quantity is determined based on a second quantity which characterizes the flow resistance of a second component of the exhaust system.

Abstract: A method and a device for controlling an exhaust gas aftertreatment system, in which a first state variable characterizes the state of the exhaust gas aftertreatment system. A second state variable takes into consideration additional influences on the special operating state. A special operating state is initiated as a function of the first and the second state variable.

Abstract: A device and method for determining a temperature variable, in particular a temperature variable that characterizes the condition of an exhaust-gas treatment system of a combustion engine, are described. The temperature is specified on the basis of variables that characterize the mass flow in the exhaust-gas treatment system, and/or of a second temperature variable that characterizes the temperature upstream from the exhaust-gas treatment system.

Abstract: A device and a method for monitoring a sensor for an exhaust-gas after-treatment system, in particular a temperature sensor. In specified operating states, a first signal from the first sensor to be monitored may be compared to a second signal from a second sensor. Errors may be detected when at least the two signals differ from one another by more than a value.

Abstract: A method and a device for controlling an internal combustion engine having an exhaust gas aftertreatment system are described. A quantity which characterizes the state of the exhaust gas aftertreatment system is determined based on at least one characteristic operating quantity of the internal combustion engine.

Abstract: A method for determining the loading of a particle filter, in particular in a particle filter for filtering the exhaust gases of an internal combustion engine. A variable characterizing the flow resistance of the particle filter is determined on the basis of the temperature in the particle filter and the pressure in the particle filter, and a conclusion is drawn regarding the loading of the particle filter on the basis of the flow resistance.

Abstract: A device and a method for monitoring a sensor for an exhaust-gas aftertreatment system, in particular a temperature sensor, are described. In specified operating states a first signal from the first sensor to be monitored is compared to a second signal from a second sensor. Errors are detected when at least the two signals differ from one another by more than a value.

Abstract: A method and a device for controlling an internal combustion engine are described. The internal combustion engine includes an exhaust-gas aftertreatment system. The control and/or regulation of the air quantity supplied to the internal combustion engine are/is implemented as a function of a variable characterizing the exhaust-gas aftertreatment system.

Abstract: A method and a device for monitoring an exhaust gas aftertreatment system, in particular an oxidation catalytic converter, are described. An error is recognized if an operating parameter does not change as expected, when a particular operating state is present.

Abstract: A method and a device are described for controlling an exhaust gas aftertreatment system, in particular of an internal combustion engine. A special operation is intermittently carried out. The control and/or monitoring of the special operation is carried out as a function of a first quantity (O1) which characterizes the oxygen concentration in the exhaust gas upstream from the exhaust gas aftertreatment system, and a second quantity (O2) which characterizes the oxygen concentration in the exhaust gas downstream from the exhaust gas aftertreatment system.

Abstract: A method and a device for controlling an exhaust gas aftertreatment system are described. A first state variable characterizes the state of the exhaust gas aftertreatment system. A second state variable takes into consideration additional influences on the special operating state. A special operating state is initiated as a function of the first and the second state variable.

Abstract: A method and a device for monitoring a signal, in particular a pressure signal that characterizes the pressure differential at the input and output of an exhaust after-treatment system, are described. Errors are recognized on the basis of the occurrence of oscillations in the sensor signal.

Abstract: Described are a device and a method for correcting a temperature signal, in particular, a temperature signal which characterizes the temperature of the gases which are fed to the internal combustion engine and/or which are emitted by the of an internal combustion engine. A first correction takes into account the response of the sensor. A second correction takes into account the dynamic behavior of the internal combustion engine and/or of the associated components.

Abstract: A method and a device for controlling an internal combustion engine, in which a first quantity characterizing the flow resistance of a first component of the exhaust-gas treatment system is determined based on a first measured quantity and a volumetric-flow quantity, and the volumetric-flow quantity is determined based on a second quantity which characterizes the flow resistance of a second component of the exhaust system.

Abstract: A method and a device for controlling an internal combustion engine having an exhaust gas aftertreatment system are described. A quantity (B) which characterizes the state of the exhaust gas aftertreatment system is determined based on at least one characteristic operating quantity of the internal combustion engine.

Abstract: A method and a device are described for controlling an exhaust gas aftertreatment system, in particular of an internal combustion engine. A special operation is intermittently carried out. The control and/or monitoring of the special operation is carried out as a function of a first quantity (O1) which characterizes the oxygen concentration in the exhaust gas upstream from the exhaust gas aftertreatment system, and a second quantity (O2) which characterizes the oxygen concentration in the exhaust gas downstream from the exhaust gas aftertreatment system.