| 摘要 |
PROBLEM TO BE SOLVED: To properly perform air-fuel ratio learning in a state of current application to an electromotive force cell.SOLUTION: An O2 sensor 16 has a sensor element 31 including a solid electrolyte layer 32 and a pair of electrodes 33, 34, and outputs a signal of an electromotive force corresponding to an air-fuel ratio of exhaust emission with the exhaust emission of an engine as a detection object. A microcomputer 41 comprises: characteristic control means which performs current application by a constant current circuit 43 on the basis of a requirement value of an application current applied to the sensor element 31, and shifts a characteristic of the electromotive force of the sensor element 31; correction value acquisition means which acquires a requirement displacement correction value equivalent to a displacement amount of a requirement injection amount which occurs accompanied by the current application; injection amount control means which performs the current application, and controls a fuel injection amount by using the requirement displacement correction value in a state that air-fuel ratio feedback control is performed; and air-fuel ratio learning means which permits the learning of an air-fuel ratio by the feedback correction value in a state that the correction of the fuel injection amount by the requirement displacement correction value is performed.SELECTED DRAWING: Figure 2 |
