| 摘要 |
PURPOSE:To enhance the accuracy of air-to-fuel ratio control and the purifying performance of exhaust gas over a wide range of the load on the engine etc. by setting a map for the constant of feedback control made by an air-to-fuel ratio sensor according to the characteristics of the sensor and by reading this map for making the optimum feedback control. CONSTITUTION:Output from the air-to-fuel ratio sensor to sense the oxygen density is related to the air-to-fuel ratio feedback correction factor f(A/F) through treatment including an integral process, to provide such feedback constants as reversing delay times TDL, TDR, skip widths RSL, RSR, integral constants KIL, KIR, etc. The ratio of the amount of taken-in-air a (16) to the revolving speed of engine N (22) shall be mapped with respect to the speed N with at least one of the abovementioned constants, for example time TDL, being matched previously with the characteristics of the air-to-fuel ratio sensor 36, and be put in memory in the ROM66 of the control circuit 50. Accordingly, the basic injection time for the fuel can be corrected by determining the abovementioned factor f(A/F) through read-out of the time TDL on accordance with the condition of loading a/N of the engine to be followed by output processing of the sensor 36. Thus the injector 44 and idling speed control valve 48 are feedback controlled. |
