| 摘要 |
PROBLEM TO BE SOLVED: To secure control accuracy without being influenced by operating conditions when driving an actuator provided adjacently to a throttle valve and controlling to a throttle opening being a throttle ventilation flow target vague. SOLUTION: When pressure differential in front and behind a throttle valve is large, a pressure ratio RP between manifold pressure Pm and atmospheric pressure Pa is calculated, and when pressure difference in front and behind the throttle valve is small, the manifold pressure Pm is fixed to a differential pressure threshold value and the pressure ratio RP is calculated. A correction coefficient KP in the flow formula of an orifice is found out according to the value of the pressure ratio RP, and also a flow correction coefficient KC per range is found out, and a correction coefficient KF is found out by multiplying each other a constant term KT, a value that atmospheric pressure Pa is divided by one half power of atmospheric temperature Ta, and the correction coefficient KP. An effective opening area OA is calculated by dividing a throttle ventilation flow Qa by the multiplied value KC.KF of the flow correction coefficient KC and the correction coefficient KF, and an ETC indicated vague Sa is set from the effective opening area OA.
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