电喷汽油机进气管空气动态模型的仿真与试验研究

Simulation and Experimental Study of EFI Gasoline Engine's Manifold Filling Dynamic Model

由理想气体状态方程、质量守恒方程、能量守恒方程和速度密度方程建立了电控燃油喷射汽油机进气歧管空气动态的均值模型。为满足基于模型进行空燃比实时控制的要求,基于以下两个假设对模型进行了简化:(1)假设进气流量与模型所建立的关于节气门开度和进气压力的表达式的乘积成线性关系;(2)充量系数和进气压力的乘积与进气压力成线性关系。在MATLAB/Simulink仿真环境中对模型进行了仿真分析,得到了模型的主要参数。最后分别在稳态和瞬态工况下将仿真结果与台架试验结果进行了对比,结果表明:模型中所作的假设成立,稳态和瞬态工况下模型的误差分别在2%和3%以内,说明模型具有较高的精度,且结构简单,能够满足控制过程实时性的要求。

With regard to electronic fuel injection gasoline engines, this paper presented an intake manifold filling dynamic mean value engine model by the ideal gas law, the mass and energy conservation and the speed-density equations. In order to satisfy the real-time control of air/fuel ratio, this model was simplified based on two supposals as follows. （1） the intake air mass flow rate has a linear form with the product of the two established expressions, the throttle angle expression and the intake air pressure expression; （2） the product of volumetric efficiency and intake air pressure has a linear form with intake air mass pressure. Then the model was simulated in Matlab/Simulink and main parameters of the model were obtained. At last, comparison was made between the simulation results and the bench experiment results both in steady and transient states. The comparison results show that the supposals are feasible and the errors of steady and transient state are within 2% and 3% separately; the model established in this paper has a high accuracy and a simple form and can satisfy the real-time control.