To precisely meter a reducing agent to a catalyst by setting a characteristic quantity for determining the quantity of the reducing agent to be supplied on the basis of a load quantity and an operation parameter, and correcting the characteristic quantity depending on a second operation parameter.
A catalyst 100 is exposed to the exhaust gas of an internal combustion engine 100. In the front of the catalyst 110, a reducing agent is metered depending on an operating point by a metering unit 130. The reducing agent to be metered is set by the metering unit 130 as described below. The characteristic quantity for determining the quantity of the reducing agent to be supplied is set on the basis of a load quantity and at least one first parameter. The first parameter is, for example, the rotating speed, and the load quantity is advantageously a fuel quantity signal. The characteristic quantity can be corrected with at least one second operation parameter, and at this time, the basic quantity of the reducing agent to be supplied is set on the basis of the fuel signal and the rotating speed of the internal combustion engine.
BERND MAHR
HUPFELD BERND
STEFAN UNGER
