| 摘要 |
PROBLEM TO BE SOLVED: To detect a change in an air-fuel ratio of exhaust gas in a combustion chamber earlier than an air-fuel ratio sensor disposed upstream of a catalyst, and to appropriately feedback control the air-fuel ratio even in a transient operation state. SOLUTION: Main injection only is performed during a normal period. During catalyst regeneration control, after injection is performed in addition to the main injection. During the catalyst regeneration control, the total amount of fuel injected FI (the amount of fuel by the main injection and the amount of fuel by the after injection) is calculated so that the air-fuel ratio is matched with a target air fuel ratio in consideration of the amount of fuel correctedΔF based on a displacement rate (a peak position displacement rateΔCP) of "the actual peak position CPa in the transient operation state acquired based on transition of pressure of a combustion chamber acquired from a cylinder inner pressure sensor" with respect to "a steady peak position CPs in a steady operation state with the air-fuel ratio maintained to the target air-fuel ratio" and a feedback correction amount DFi acquired by applying a PID process to a deviation between an air-fuel ratio AFsen detected by the air-fuel ratio sensor and the target air-fuel ratio. COPYRIGHT: (C)2011,JPO&INPIT
|
