| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem of an engine adopting an EGR (exhaust gas recirculation) that accuracy in estimating an EGR rate real-time is deteriorated especially during a transitional state which causes torque fluctuation and deterioration of exhaust gas. <P>SOLUTION: An engine control system is provided with a sensor 12 for directly detecting an EGR flow rate in an EGR path 9 and the EGR rate and in-cylinder oxygen concentration are calculated from its output value. As this EGR rate calculation method is used while being switched between a steady operation state characterized by a low load and small rotational fluctuations and a transitional operating state including acceleration and deceleration, the EGR rate and the in-cylinder oxygen concentration can be correctly estimated under a wide range of engine operation conditions, and torque fluctuation and deterioration of exhaust gas can be prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT |
