车用汽油机过渡工况空燃比动态补偿仿真

A Simulation of Dynamic Compensation for Air Fuel Ratio of Automobile Gasoline Engine under Transient Condition

为解决汽车汽油机处于过渡工况时,汽油机缸内空燃比受进气管内油膜影响产生的较大偏离理论空燃比,造成汽油机排放性能下降的问题。该文通过对进气管内油膜特性的分析,提出一种进气管油膜动态模型和基于该模型的燃油补偿方法,以精确控制过渡工况空燃比。采用SIMULINK对汽油机2种过渡工况进行了仿真,给出了仿真结果并与基于Aquino动态油膜模型的燃油补偿方法进行了对比分析,结果表明,该文提出的动态油膜模型及补偿方法能够将空燃比控制在理论空燃比附近,精度优于传统动态油膜模型,适用于汽油机过渡工况的空燃比补偿,具有精度高、适用范围广的特点。

In order to solve the problem that the air fuel ratio of the gasoline engine is affected by the air fuel ratio of the gas inlet and the gas inlet pipe, the air fuel ratio of the gasoline engine is greatly deviated from the theoretical air fuel ratio,resulting in the decrease of the performance of the gasoline engine. In this paper, a dynamic model of intake pipe oil film and a fuel compensation method based on the model are put forward by analyzing the characteristics of oil film in the intake pipe.Using SIMULINK to simulate two kinds of transition conditions for the gasoline engine, simulation results are given and fuel compensation method based on dynamic oil film model of Aquino were made the comparative analysis with the simulation results. The results show that the dynamic oil film model and compensation method can control the air fuel ratio near to the airfuel ratio in theory, its accuracy is better than the traditional dynamic oil film model, this dynamic oil film model is suit to the compensation of the air fuel ratio for the engine transient condition, which has the characteristics of high precision and wide range of application.