航空活塞式发动机瞬态空燃比控制与实验研究

Experimental Research of Transient Air-Fuel Ratio Control of Aviation Piston Engine

针对航空活塞式直喷发动机瞬态空燃比难以精确控制、动态超调大等问题,采用PID神经网络控制策略对发动机瞬态工况空燃比进行控制.PID神经网络用于瞬态空燃比控制具有易于实现、较强自适应能力等优点.该策略包含前馈控制和反馈控制,并由前馈控制确定基本喷油量,PID神经网络作为反馈控制,实现瞬态工况的燃油补偿.在一台航空活塞式单缸机上进行了发动机瞬态空燃比控制实验,结果表明,瞬态工况下,相比于PID控制,PID神经网络控制下的过量空气系数超调量可以减小25%左右;节气门开度在5%~30%,之间以不同开度变化速率变化时,PID神经网络也能实现良好的控制效果.

The control of transient air-fuel ratio of aviation piston engine has some problems such as difficulty inprecise control and large dynamic overshoot.In order to control transient air-fuel ratio of engine accurately,thecontrol strategy based on the PID neural network is adopted.The PID neural network has the advantages of easyimplementation and strong adaptive ability while used in transient air-fuel ratio control.The control strategy includesfeed-forward control and feedback control.The feed-forward control determines the basic fuel injectionquantity,and the PID neural network is used as the feedback control which can realize fuel compensation undertransient conditions.The transient air-fuel ratio control experiments were carried out on a direct injection aviationpiston engine.The experimental results show that the excess air coefficient overshoot controlled by the PID neuralnetwork controller decreases by25%,compared with that by the PID controller.The PID neural network can alsoachieve good control effect at different change rate of throttle valve opening between5%,and30%,.