Abstract: The invention relates to a method for operating an internal combustion engine comprising at least one turbocharger, at least one catalytic converter and a variable valve train, a valve overlap parameter being determined in at least one operating mode of the internal combustion engine and being used to set the valve train. According to the invention, the valve overlap parameter is adapted on the basis of at least one parameter for the condition of the catalytic converter and/or at least one parameter for the condition of the turbocharger, prior to being used to set the valve train. The invention also relates to an internal combustion engine.

Abstract: The invention relates to a method for operating an internal combustion engine comprising at least one turbocharger, at least one catalytic converter and a variable valve train, a valve overlap parameter being determined in at least one operating mode of the internal combustion engine and being used to set the valve train. According to the invention, the valve overlap parameter is adapted on the basis of at least one parameter for the condition of the catalytic converter and/or at least one parameter for the condition of the turbocharger, prior to being used to set the valve train. The invention also relates to an internal combustion engine.

Abstract: In a method for operating an internal combustion engine a compression ratio is set to a setpoint compression ratio by means of an adjustment device, wherein in a normal operating mode of the internal combustion engine the setpoint compression ratio is determined as a function of an, operating variable of the internal combustion engine. The internal combustion engine is at least temporarily operated in a predictive operating mode in which the setpoint compression ratio is determined on the basis of an anticipated estimated operating variable which is estimated on the basis of the instantaneous gradient of the operating variable over time.

Abstract: A method and a device operate an internal combustion engine having a plurality of cylinders with which are associated respective injection valves for metering fuel, and having an exhaust gas probe which is arranged in an exhaust gas tract and the measurement signal of which is characteristic of the air/fuel ratio in the respective cylinder, and having a crankshaft angle sensor the measurement signal of which is representative of a crankshaft angle of the crankshaft. Within a predefined operating range of the internal combustion engine, and when at least one predefined condition is fulfilled, a rough-running based cylinder-individual diagnosis (CYBL-HOM) with regard to harmful emissions is carried out before activation of a cylinder-individual lambda control (CILC) is enabled.

Abstract: A method is disclosed for performing an individual cylinder diagnosis with respect to pollutant emissions within a predefined operating range of an internal combustion engine, meeting at least one predefined condition. During the performing of the individual cylinder diagnosis, a forced activation, by means of which a predefined air/fuel ratio to be set is activated, is prescribed in a manner synchronous to the cylinder segment. The excitation is carried out such that each individual cylinder is subjected during subsequent working cycles to a mixture that is either richer or leaner in comparison to the predefined air/fuel ratio to be set due to the forced excitation. Depending on the forcibly activated air/fuel ratio to be set, the corresponding injection valves are actuated.

Abstract: In a method for operating an internal combustion engine a compression ratio is set to a setpoint compression ratio by means of an adjustment device, wherein in a normal operating mode of the internal combustion engine the setpoint compression ratio is determined as a function of an, operating variable of the internal combustion engine. The internal combustion engine is at least temporarily operated in a predictive operating mode in which the setpoint compression ratio is determined on the basis of an anticipated estimated operating variable which is estimated on the basis of the instantaneous gradient of the operating variable over time.

Abstract: A method is disclosed for performing an individual cylinder diagnosis with respect to pollutant emissions within a predefined operating range of an internal combustion engine, meeting at least one predefined condition. During the performing of the individual cylinder diagnosis, a forced activation, by means of which a predefined air/fuel ratio to be set is activated, is prescribed in a manner synchronous to the cylinder segment. The excitation is carried out such that each individual cylinder is subjected during subsequent working cycles to a mixture that is either richer or leaner in comparison to the predefined air/fuel ratio to be set due to the forced excitation. Depending on the forcibly activated air/fuel ratio to be set, the corresponding injection valves are actuated.

Abstract: An association unit is designed to determine cylinder-individual lambda signals on the basis of a lambda probe signal and to determine lambda deviation signals for the respective cylinders based on the lambda signals in relation to an averaged lambda signal. Furthermore, an observer has a sensor model of the lambda probe that is arranged in a feedback branch. The lambda deviation signals are fed to the input side and observer output quantities in relation to the respective cylinder are representative of the injection characteristics deviations from predetermined injection characteristics. A parameter detection unit impresses a predetermined interference pattern from cylinder-individual mixture deviations. It further changes at least one sensor model parameter as a detection parameter in response to the respectively predetermined interference pattern for as long as the observer output quantities represent the portion of the interference pattern associated with the cylinders thereof in a predetermined manner.

Abstract: An association unit is designed to determine cylinder-individual lambda signals on the basis of a lambda probe signal and to determine lambda deviation signals for the respective cylinders based on the lambda signals in relation to an averaged lambda signal. Furthermore, an observer has a sensor model of the lambda probe that is arranged in a feedback branch. The lambda deviation signals are fed to the input side and observer output quantities in relation to the respective cylinder are representative of the injection characteristics deviations from predetermined injection characteristics. A parameter detection unit impresses a predetermined interference pattern from cylinder-individual mixture deviations. It further changes at least one sensor model parameter as a detection parameter in response to the respectively predetermined interference pattern for as long as the observer output quantities represent the portion of the interference pattern associated with the cylinders thereof in a predetermined manner.

Abstract: A method and a device operate an internal combustion engine having a plurality of cylinders with which are associated respective injection valves for metering fuel, and having an exhaust gas probe which is arranged in an exhaust gas tract and the measurement signal of which is characteristic of the air/fuel ratio in the respective cylinder, and having a crankshaft angle sensor the measurement signal of which is representative of a crankshaft angle of the crankshaft. Within a predefined operating range of the internal combustion engine, and when at least one predefined condition is fulfilled, a rough-running based cylinder-individual diagnosis (CYBL-HOM) with regard to harmful emissions is carried out before activation of a cylinder-individual lambda control (CILC) is enabled.