| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem of reductions in acquisition accuracy of an air-fuel ratio based on output signals of A/F sensors 58a and 58b due to in output-signal perturbations of the A/F sensors 58a and 58b caused by exhaust pulsations and the problem of reductions in the controllability of an air-fuel ratio by air-fuel-ratio feedback control. <P>SOLUTION: A cutoff frequency is set as a frequency corresponding to one rotation of a crankshaft 36. A low-pass filter computed on the basis of the cutoff frequency fc is used to perform filter processing on output signals of the A/F sensors 58a and 58b. An average air-fuel ratio based on filter-processed output signals of the A/F sensors 58a and 58b is taken as a control variable of average F/B control. <P>COPYRIGHT: (C)2011,JPO&INPIT |
