| 摘要 |
PURPOSE:To improve the response performance and stability in feedback control in transition state and improve operation performance of an engine by properly varying integration constant value according to the magnitude of the deviation of the present air-fuel ratio from an aimed air-fuel ratio. CONSTITUTION:A voltage signal Vi indicating the present air-fuel ratio is input into a differentiation means 21 from an air-fuel ratio detecting circuit 11. Into an integration-constant setting means 22, DELTAV is input as the differance betwen the variation rate dVi of the present air-fuel ratio and an aimed air-fuel ratio from a differential-value calculating means 14. Said values are compared in comparators 26-27 and 23-25, and outputted into an integration-constant determining circuit 28, where the integration constant C is set, and outputted into a correction coeffficient setting circuit 16, and fuel feeding amount is determined in a fuel-amount calculating circuit 17. When the present air-fuel ratio deviates from the aimed air-fuel ratio in transition state, the integration constant value C is increased, and response performance is improved, and the air-fuel ratio is speedily shifted to the aimed value, and when the value becomes close to the aimed value, the integration constant C is reduced, and stability is improved. |
