AIR FUEL RATIO CONTROLLING APPARATUS

摘要

The invention pertains to an air fuel ratio controlling apparatus in which, even if a LAF sensor is not installed on the upstream of a catalyst, optimization of an air fuel ratio can be achieved and reduction of the cost of the system and application of air fuel ratio control to a motorcycle or the like can be promoted. The invention further pertains to a predictor for predicting an air fuel ratio on the downstream side of a catalyst calculates a predicted air fuel ratio DVPRE at least based on an actual air fuel ratio SVO2 from an oxygen sensor and a history of a first correction coefficient DKO2OP. The air fuel ratio controlling apparatus includes an adaptive model corrector which determines the deviation between the actual air fuel ratio SVO2 and the predicted air fuel ratio DVPRE as a prediction error ERPRE, and then superposes a second correction coefficient KTIMB on the first correction coefficient DKO2OP so that the prediction error ERPRE may be reduced to zero.