초록 ▼

A reductant injection control strategy for controlling an amount of nitrogen oxide reducing agent injected upstream of a selective reduction catalyst uses a NOx sensor located downstream of the catalyst. An open loop injection quantity is first determined based on operation conditions. Nitrogen oxid

A reductant injection control strategy for controlling an amount of nitrogen oxide reducing agent injected upstream of a selective reduction catalyst uses a NOx sensor located downstream of the catalyst. An open loop injection quantity is first determined based on operation conditions. Nitrogen oxide conversion efficiency of the catalyst is controlled by controlling the reductant injection based on after catalyst NOx sensor reading and engine out nitrogen oxide concentration.

대표청구항 ▼

[ We claim:] [1.]1. A method for controlling a reductant injection upstream of a catalyst coupled to an internal combustion engine, the method comprising the steps of:generating a reductant injection quantity based on a nitrogen oxide concentration entering the catalyst;determining a nitrogen oxide

[ We claim:] [1.]1. A method for controlling a reductant injection upstream of a catalyst coupled to an internal combustion engine, the method comprising the steps of:generating a reductant injection quantity based on a nitrogen oxide concentration entering the catalyst;determining a nitrogen oxide conversion efficiency of the catalyst;generating a desired NOx conversion efficiency value based on a catalyst temperature and said nitrogen oxide concentration entering the catalyst; andadjusting said injection quantity to obtain said desired NOx conversion efficiency value.