| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an air-fuel ratio control apparatus for an internal combustion engine capable of properly calculating control input used for feed-back control based on an output value and a target value of an air-fuel ratio sensor while properly compensating for the output characteristic of the air-fuel ratio sensor even if the output characteristic is asymmetric to the target value, and capable of improving control accuracy of the air-fuel ratio. <P>SOLUTION: An air-fuel ratio control apparatus 1 converts an output deviation SVO2P as a difference between an O2 output value SVO2 of an O2 sensor 21 having an output characteristic which is nonlinear with respect to an exhaust gas air-fuel ratio A/FEX and a target value SVO2CMD to a first predetermined value EREF1 if the O2 output value SVO2 is on a richer side of a target value SVO2CMD, and converts the output deviation SVO2P to a second predetermined value EREF2 (=-EREF1) if the O2 output value is on a leaner side. A target air-fuel ratio KCMD to feedback-control the O2 output value SVO2 is calculated such that the converted output deviation SVO2P will be zero, and the calculated target air-fuel ratio KCMD is used to control the exhaust gas air-fuel ratio A/FEX. <P>COPYRIGHT: (C)2012,JPO&INPIT |
