发动机精确空燃比控制方法的研究

Research on Accurate Air-Fuel Ratio Control Strategy of SI Engines

提高电控汽油机的空燃比（α）控制精度，是改善发动机经济性、动力性和降低尾气排放的关键环节。通过对发动机稳态和过渡工况下出现空燃比控制偏差的机理进行分析，实现了一种较为精确的空燃比控制方法。该方法根据所建立的发动机物理模型，利用宽域空燃比传感技术，通过调整喷油脉宽来反馈控制发动机的空燃比。

The improvement of air - fuel ratio(α) control accuracy for electrically - controlled SI engine is the key link for engine fuel economy, low emission and good driveability. The mechanism of air -fuel ratio control error under both transinent condition and steady condition has been investigated in order to find an accurate control strategy for air - fuel ratio. Based on establised engine physical model and by using wide - range air - fuel ratio sensor, this strategy can be used to have feedback control on engine air - fuel raio through adjusting the injection pulse width.