| 摘要 |
PROBLEM TO BE SOLVED: To correct the deviation of the EGR rate due to the change in atmospheric pressure without measuring the atmospheric pressure to exactly estimate the actual EGR rate whatever the environment is changed. SOLUTION: The valve lift amount LFT of an EGR valve is retrieved from the map by means of the engine speed NE and the throttle-opening THR, and when LFT≠O, the basic EGR rate STEGR is retrieved from the map by means of the throttle-opening THR and the valve lift amount LFT. Next, the exhaust pressure correction factor KEGRH is retrieved from the map by means of the engine speed NE and the intake pipe pressure PM, and the EGR rate EGRCAL is calculated by multiplying the basic EGR rate by the exhaust pressure correction factor KEGRH (EGRCAL=STEGR×KEGRH). Thus, the deviation of the EGR rate due to the change in atmospheric pressure can be corrected without measuring the atmospheric pressure, and the actual EGR rate can be exactly estimated whatever the environment is changed.
|
