| 摘要 |
The invention relates to a method for determining the reducing agent slip of an exhaust gas treatment device (23) said method having at least the following steps: determining a difference (5) of the sensor signals (3 4) of a second nitrogen oxide sensor (29) and of a device (41) for determining a nitrogen oxide quantity in the exhaust gas flow direction (31) upstream of the SCR catalytic converter (25); determining a control deviation (7) from the difference (5) and a target value (6) of the control element (2); determining a gradient (21) of the integrating control component (20); and establishing reducing agent slip if the control deviation (7) exceeds a first threshold value (9) and the gradient (21) exceeds a second threshold value (10). The method according to the invention and a correspondingly designed and equipped device allow the reliable establishment of a reducing agent slip and the use of a very fast control element. |
