| 摘要 |
PROBLEM TO BE SOLVED: To estimate the atmospheric pressure with a high precision without being influenced by the detection error of throttle valve opening even when it is large. SOLUTION: When a throttle opening is a prescribed value or less (S1), and an internal combustion engine is in steady state or constant traveling state (not in accelerating or decelerating state) (S2), the average valueα1 of feedback correction quantityαin air-fuel ratio feedback control within a prescribed period is calculated (S4) in the state where EGR is forcedly started (S3). The average valueα2 of feedback correction quantityαin air-fuel ratio feedback control within a prescribed period is calculated (S6) in the state where EGR is forcedly stopped (S5). Thereafter, on the basis of the deviation (α2-α1) of the average values of feedback correction quantity changed by ON/OFF of EGR, the atmospheric pressure Pa is estimated in reference to a map or by arithmetic operation (S7).
|
