| 摘要 |
<P>PROBLEM TO BE SOLVED: To highly precisely estimate a total NOx trapping amount to be used for determining the timing of regenerating a NOx trapping catalyst even upon transient operation. <P>SOLUTION: A NOx exhaust amount per unit output and unit time is computed in accordance with an inlet air amount (S1, S2), a NOx trapping amount per unit time is computed by multiplying it by an engine output (S3), and the NOx trapping amount per unit time, which is corrected after multiplied by a final correction coefficient kNOx obtained by integrating a correction coefficient kNOx<SB>-</SB>eoe with a NOx exhaust amount per unit time (S4), a correction coefficient kNOx<SB>-</SB>tbed with a catalyst carrier temperature (S5) and a correction coefficient kNOx<SB>-</SB>trap with a current total NOx trapping amount (S6), is integrated. Thereby, the total NOx trapping amount of the NOx trapping catalyst is highly precisely estimated. <P>COPYRIGHT: (C)2004,JPO |
