| 摘要 |
PROBLEM TO BE SOLVED: To accurately determine a PM adhesion amount of a PM sensor detecting PM (particulate matters) discharged from an engine without dependence on engine operating conditions.SOLUTION: An ECU 30 calculates a PM adhesion amount in response to an output signal from a PM sensor 33 while referring to a PM adhesion amount map (a map specifying a relation between the output signal from the PM sensor 33 and the PM adhesion amount). At this time, a particle size distribution of PM discharged from an engine 11 changes depending on an air-fuel ratio of the engine 11, a particle size distribution of PM adhering to the PM sensor 33 changes accordingly, and a relation between a resistance value between electrodes of the PM sensor 33 and the PM adhesion amount (relation between the output signal from the PM sensor 33 and the PM adhesion amount) changes. The PM adhesion amount map is changed in response to the air-fuel ratio of the engine 11 at a time of calculating the PM adhesion amount on the basis of the output signal from the PM sensor 33 while paying attention to these characteristics, thereby correcting the PM adhesion amount in response to the air-fuel ratio of the engine 11. |
