| 摘要 |
PROBLEM TO BE SOLVED: To execute air-fuel ratio control with excellent accuracy while taking in consideration of an adsorption condition in a catalyst. SOLUTION: When controlled objects from a fuel injection valve 20 through a downstream side air-fuel ratio sensor 29 are modelled, such a model is used as a catalyst model that is set while taking in consideration of the whole existence of the adsorption reaction of an inflow gas component in a catalyst 27, oxidation reduction reaction between the inflow gas component and an adsorbed material in the catalyst 27, the elimination reaction of the adsorbed material in the catalyst 27 and the non-reacted part of the inflow gas component. The present and past input/output to/from a control model including this catalyst model, are recognized as property, and state feedback is executed so that a catalyst downstream side air-fuel ratio λR detected by the downstream side air-fuel ratio sensor 29 is controlled in a target air-fuel ratio λTG, therefore, the injection amount of the fuel injection valve 20 is controlled and the air-fuel ratio is successively controlled. The catalyst model simplifies an operation process by representing a lean component and a rich component by the opposite positive and negative symbols in connection with amounts led to flow into and out from the catalyst 27, an eliminated amount and a non-reacted part amount. |
