Abstract
Global emission legislation becomes more stringent and requires drastic reduction of NOx emission. Future legislation has a focus on real-world, in-use emissions. Calibrating urea SCR systems has become complex and time consuming. A model-based approach is presented which cuts development time and costs. A phenomenological SCR model fitted on engine dyno experiments is used for off-line simulation and on-line urea dosing control. A control strategy which incorporates the real-time model for NH3 storage control is demonstrated to accomplish good NOx conversion and low NH3 slip. The addition of a feedback sensor allows correction for system deviations in a closed-loop manner.
