| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device of an internal combustion engine capable of maintaining both an NOx clean-up rate and exhaust gas characteristics at high levels by supplying a just enough amount of reducing agent to a selective reduction catalyst even when the NOx clean-up rate of the selective reduction catalyst is changed by various causes. <P>SOLUTION: This exhaust emission control device 1 comprises a urea selective reduction catalyst 7, a urea injection device 10, an exhaust gas concentration sensor 22, and a ECU 2. The ECU 2 calculates a filtered value Yf from a signal value Vex detected by the exhaust gas concentration sensor 22, calculates a moving average value Cr of a product Z of the filtered value and a reference input value Ref, calculates a control input value Uc such that the moving average value Cr becomes equal to 0, and adds a reference input value Ref to the control input value to calculate a FB injection amount Gurea_fb. The ECU 2 calculates an FF injection amount Gurea_ff with a predetermined feedforward control algorithm, and adds the FF injection amount Gurea_ff to the FB injection amount Gurea_fb, to thereby calculate a urea injection amount Gurea. <P>COPYRIGHT: (C)2009,JPO&INPIT |
