| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent damage of a catalyst regeneration type filter due to overheating, by preventing a control error of a catalyst bed temperature when regenerating the filter. <P>SOLUTION: During a setting period of an initial target catalyst bed temperature, a quantity of integral control QI corresponding to a difference between a quantity of post injection Qpst and an actual quantity of post injection is learned, based on an offset target catalyst bed temperature Tofst that is lower than a normal target catalyst bed temperature (S142). A highly accurate quantity of integral control QI is calculated because the target catalyst bed temperature is stable at the offset target catalyst bed temperature Tofst during setting the initial target catalyst bed temperature. Accordingly, thereafter, by setting a target catalyst bed temperature at the time of normal regeneration as the target catalyst bed temperature, even in a transient period, since the quantity of post injection Qpst is controlled by using the highly accurate quantity of integral control QI previously learned, highly the catalyst bed temperature is precisely controlled. When the catalyst bed temperature reaches the target catalyst bed temperature, because heating of the quantity of integral control QI including a large error with overshoot is not applied, the damage of the DPF due to overheating is prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
