| 摘要 |
PURPOSE:To optimumly control the air-fuel ratio over a wide operating range, by controlling either one of or both of the opening degree of the throttle valve and the fuel injection amount so that the actual fuel ratio takes a desired value, individually having the dynamic characteristic models of the fuel and air system. CONSTITUTION:Upon engine operation, a computing circuit 11 determines in which range B1, B2, B3 the running condition of the engine falls, in accordance with the rotational speed and load of the engine at that time. In the transition range B2 the injection amount of fuel and the opening degree of the throttle valve are calculated in view of the depressed amount of an accelerator pedal 9, etc., and therefore, a fuel injection valve drive circuit 12 and a throttle valve drive circuit 15 are controlled. Meanwhile, in the range B3, after the supply amount of fuel to an engine cylinder is calculated in view of the injection amount of fuel and the dynamic characteristic models of the fuel system, the fuel preference type control is made to determine the opening degree of the throttle valve in view of the amount of intake-air determined to allow the air- fuel ratio to take a desired value, and in view of the dynamic characteristic model of the air system. Further, in the range B2 the supply amount of fuel is determined by the air preference type control. |
