| 摘要 |
PROBLEM TO BE SOLVED: To secure estimation accuracy of throttle upstream pressure while making adaptation man-hour of a model used for estimation of throttle upstream pressure unnecessary or reducing the same. SOLUTION: This time throttle upstream pressure Pthrup(i) is operated with substituting previous time throttle upstream pressure Pthrup(i-1) for one of two terms of throttle upstream pressure Pthrup(i) included in an expression of an intake system model in a non-critical pressure zone where pressure ratio Pm/Pthrup(i-1) of intake air pressure Pm (throttle downstream pressure) detected by an intake air pressure sensor and the previous time throttle upstream pressure Pthrup(i-1) is greater than a predetermined value B. This time throttle upstream pressure Pthrup(i) is operated with regarding a physical value f (Pm/Pthrup(i)) including pressure ratio Pm/Pthrup(i) of the intake pressure Pm and this time throttle upstream pressure Pthrup(i) as a parameter as a constant value fc in critical pressure zone where the pressure ratio Pm/Pthrup(i-1) is not greater than the predetermined value B. COPYRIGHT: (C)2009,JPO&INPIT
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