| 摘要 |
<p>PROBLEM TO BE SOLVED: To accurately estimate a catalyst temperature even in a transient period during which an exhaust temperature changes. SOLUTION: In this system, an exhaust temperature or a temperature at a specific part of a catalyst unit 8 disposed in an exhaust passage 4 of an internal combustion engine 1 are detected or estimated by temperature detection means 14. Then, exhaust flow rate in the exhaust passage 4 is detected or estimated by exhaust flow rate detection means 10. Then, an average time based on the exhaust flow rate is set by average time setting means 21. A short-term average temperature is calculated by first averaging means 22 by averaging temperatures within the average time. Further, a catalyst temperature is calculated by second averaging means 23 by moving-averaging plurality of continuous short-term average temperatures.</p> |
