Abstract:To meet the special requirement of the transient air-fuel ratio control for lean burn engine, a sliding mode-neural network control scheme was presented. The sliding variable structure control strategy has been provided as feedback to control the air-fuel ratio. At the same time, the neural network method was applied to build the intake air flow observer and realize the instantaneous fuel compensation as feedforward. By way of employing the engine control system that developed by ourselves, the lean burn engine air-fuel ratio control experiments were carried out on a lean burn gasoline engine. The experiments results showed that the maximal overshoot of air-fuel ratio is one AFR unit and the longest transient period is less than 3 seconds when the throttle body moves rapidly. The more slowly the engine worked, the more rapidly the throttle body moved; the bigger the overshoot of air-fuel ratio was, the longer the transient period would be.