| 摘要 |
PURPOSE:To control the air-fuel ratio accurately by a method wherein a fluctuation due to the temperature, aging variation or the like of an air-fuel ratio sensor, in which the output signal thereof a changed continuously with respect to the air-fuel ratio, is compensated by another air-fuel ratio sensor in which the output thereof is inverted at the vicinity of a logical air-fuel ratio. CONSTITUTION:The air-fuel ratio sensor 5, in which the output signal thereof is inverted at the vinicity of the logical air-fuel ratio, and the air-fuel ratio sensor 7, in which the output signal thereof is changed continuously with respect to the air-fuel ratio, are provided on an exhaust tube 6, which the output signals thereof are inputted into an air-fuel ratio control circuit 4. During conrolling an air-fuel ratio regulating means 2 by the feedback in accordance with the output signal of the sensor 7, the output of the sensor 7 is read at a time when the output of the air-fuel ratio sensor 5 is inverted, and the error of the output signal relative to the regular signal upon the logical air-fuel ratio is obtained. Subsequently, the value of said error is subtracted from a detected value, whereby, the feedback control having a small error may be effected in all operating conditions. |
