| 摘要 |
<p>PURPOSE:To prevent the generation of the phase difference of a control value during feedback of an air-fuel ratio at each cylinder group by detecting the control position difference of each cylinder group and correcting a control constant the control period of which is regulatable according to a phase difference. CONSTITUTION:Through feedback control of the air-fuel ratio of each cylinder group, the phase difference of a control value at each cylinder group is produced. Thus, since a phase difference is produced between the detecting values of first and second air-fuel ratio sensors 14 and 15, based on the phase difference of a detecting value, the phase difference of a control value is detected by a control phase difference detecting means. By correcting a control constant the control period of which is regulatable, correction is effected in a direction in which a phase difference is removed through correction of a control period, and a control period is also corrected. In this case, if a control phase difference detecting means is constituted to detect the phase difference of the control value based on a time difference with which the output value of an air-fuel ratio detecting means at each cylinder group passes a reference value and the fluctuation direction of an output value, it is discriminated whether the phase of other cylinder group is an advance phase or a delay phase based on a reference cylinder group and from the phase difference, the magnitude of the phase difference can be determined.</p> |
