| 摘要 |
<p>PURPOSE: To provide an air-fuel ratio control device which 15 so constituted as to easily and accurately detect abnormality of a fuel feed system as feedback control of an air-fuel ratio is conducted on an internal combustion engine using a graduation type controller. CONSTITUTION: Based on the output of a wide area air-fuel ratio sensor 17 and an optimum feedback gain based on the dynamic model of an engine 1, an adaptive correction factor KSTR is calculated, and an adaptive correction factor KSTR is smoothed by a low-pass filter block B24. An average value KFBCHKAVE of the smoothed adaptive correction factor (a filter output value) KSTRLO is calculated, and based on the average value KFBCHKAVE, abnormality of the fuel feed system of the engine 1 is detected.</p> |
