| 摘要 |
PROBLEM TO BE SOLVED: To provide an engine control device which can exactly obtain an oxygen concentration of an EGR gas which is supplied to an air intake passage, and can properly control a flow rate of the EGR gas on the basis of the result.SOLUTION: An engine control device comprises: an air-fuel ratio sensor 34 for detecting an exhaust oxygen concentration; exhaust oxygen concentration estimation means 41 for estimating an exhaust oxygen concentration; delay time calculation means 42 for calculating a detection delay time; estimated exhaust oxygen concentration correction means 43 for correcting an estimation result of the exhaust oxygen concentration estimation means on the basis of a detection result of the air-fuel ratio sensor 34 and the detection delay time; air intake oxygen concentration estimation means 44 for estimating an air intake oxygen concentration on the basis of a correction result of the estimated exhaust oxygen concentration correction means 43; and exhaust circulation control means 45 for controlling flow rate adjustment means on the basis of the estimation result of the air intake oxygen concentration estimation means 44. |
