Method and device for operating an exhaust gas aftertreatment device of an engine system including an internal combustion engine

A control unit for operating an engine system including an internal combustion engine and an exhaust gas aftertreatment device, the control unit being configured to:

• carry out a fill level control to control a fill level of the exhaust gas aftertreatment device as a function of a predefined fill level setpoint value;
• operate a pilot control for the fill level control;
• adapt the pilot control as a function of a deviation between a measured lambda value and a modeled lambda value;
• wherein the modeled lambda value is generated using a system model which includes an input emission model, a catalytic converter model, and an output emission model, the input emission model converting an input lambda value, from an input-side exhaust gas sensor at an input side of the exhaust gas aftertreatment device, to variables representing concentrations of at least three individual components of exhaust gas in an area of the input-side exhaust gas sensor, the catalytic converter model modeling, using the variables from the input emission model, concentrations of individual components of exhaust gas on an output side of the exhaust gas aftertreatment device, and the output emission model converting the modeled concentrations of the individual components from the catalytic converter model to the modeled lambda value.

A non-transitory machine-readable memory medium on which is stored a computer program for operating an engine system including an internal combustion engine and an exhaust gas aftertreatment device, the computer program, when executed by a processing unit, causing the processing unit to perform:

• carrying out a fill level control to control a fill level of the exhaust gas aftertreatment device as a function of a predefined fill level setpoint value;
• operating a pilot control for the fill level control;
• and
• adapting the pilot control as a function of a deviation between a measured lambda value and a modeled lambda value;
• wherein the modeled lambda value is generated using a system model which includes an input emission model, a catalytic converter model, and an output emission model, the input emission model converting an input lambda value, from an input-side exhaust gas sensor at an input side of the exhaust gas aftertreatment device, to variables representing concentrations of at least three individual components of exhaust gas in an area of the input-side exhaust gas sensor, the catalytic converter model modeling, using the variables from the input emission model, concentrations of individual components of exhaust gas on an output side of the exhaust gas aftertreatment device, and the output emission model converting the modeled concentrations of the individual components from the catalytic converter model to the modeled lambda value.