二冲程航空活塞发动机空燃比控制

Air-fuel ratio control of two-stroke aviation piston engine

以某型号二冲程航空活塞发动机为研究对象,通过建立一维、三维发动机模型、喷油器模型和空燃比控制模型,辨析进气量和喷油量的主要影响参数,基于递归神经网络进气量预测和喷油模型,在变工况下对二冲程发动机空燃比控制进行研究。在节气门开度变化的瞬态工况下,将空燃比控制的超调量控制在4.6%以内,能在变工况停止后较短的时间0.3 s内将缸内混合气恢复至当量比。在不同海拔工况的仿真研究下,随着海拔的增高,空燃比控制模型的超调量和回调时间适当减小并逐渐稳定。

A two-stroke aviation piston engine was taken as the research object.By establishing one-/three-dimensional engine model,injector model and air-fuel ratio control model,the main influencing parameters of intake and injection were discriminated.Based on the recurrent neural network intake prediction and injection model,the air-fuel ratio control of two-stroke engine was studied under variable working conditions.Under the transient condition of throttle opening change,the overshoot of air-fuel ratio control was controlled within 4.6%,which can restore the cylinder mixture to the equivalent ratio within 0.3 s after the variable condition stopped.Under the simulation study of different altitude conditions,it was found that with the increase of altitude,the overshoot and callback time of air-fuel ratio control model appropriately decreased and gradually stabilized.