一种天然气发动机空燃比控制策略的研究

Research on a CNG Engine Air Fuel Ratio Control Strategy

提高电控天然气发动机的空燃比控制精度,是改善发动机经济性、动力性和降低尾气排放的关键环节。本文将模糊神经网络与PI控制技术相结合构成一种模糊神经解耦混合控制器。新控制器在控制过程中借助模糊神经网络的自学习算法实现控制参数的在线调整。将该算法应用于天然气发动机空燃比控制中,利用宽域空燃比传感技术,通过调整喷射脉宽控制发动机的空燃比,取得了较好的控制效果。

The improvement of air-fuel ratio control accuracy for electrically-controlled CNG engine is the key link for engine feul emissi on,low emission and good driveablity.Integrating fuzzy neural network and PI controller,we ob-tained a fuzzy neural decoupled hybrid controller.The param eters of new controller can be adjusted on line based on the ability of fuzzy ne ural network.By using wide-range air-fuel ratio sensor,the controller can b e used to have feedback control on engine air-fuel ratio adjusting the injectio n pulse width.The transient test result shows that it has better perfor-mance.