Patent ID: 8281572

Claim:
An apparatus for controlling NO x conversion in a selective catalytic reduction (SCR) system of an exhaust aftertreatment system coupled to an internal combustion engine, comprising: a duty cycle factor module configured to determine a duty cycle factor of the internal combustion engine, the duty cycle factor representing predicted driving conditions of a vehicle in which the internal combustion engine is housed; and a NO x conversion mode selection module configured to command NO x conversion in the SCR system according to a first NO x conversion mode if the duty cycle factor is within a duty cycle factor range and according to a second NO x conversion mode if the duty cycle factor is not within the duty cycle factor range, wherein operation in each of the first and second NO x conversion modes comprises generating a reductant injection command; wherein according to the first NO x conversion mode, the reductant injection command is generated based on a first model, and according to the second NO x conversion mode, the reductant injection command is generated based on a second model different than the first model.