Patent ID: 8429898
Filing Date: 2013-04-30
Classification: F01N,Y02A,Y02T

Abstract:
1. A dosing control system for a vehicle, comprising: a first electronic circuit configured to determine an estimated amount of ammonia stored by a selective catalytic reduction (SCR) catalyst; a second electronic circuit configured to determine a predicted amount of nitrogen oxides (NOx) that will be measured by a first NOx sensor located downstream of the SCR catalyst; a third electronic circuit configured to trigger a reduction of an actual amount of ammonia stored by the SCR catalyst to zero at a time when a first amount of NOx measured by the first NOx sensor is greater than the predicted amount; a fourth electronic circuit configured to, after an estimated time when the actual amount of ammonia stored by the SCR catalyst should be equal to zero, determine whether the estimated amount at the time when the third electronic circuit triggered the reduction was one of greater than or less than the actual amount of ammonia that was stored by the SCR catalyst at the time; and a fifth electronic circuit configured to selectively delay increasing the actual amount of ammonia stored by the SCR catalyst after the determination based on a comparison of the first amount of NOx with a second amount of NOx measured by a second NOx sensor located upstream of the SCR catalyst.