点燃式发动机瞬态空燃比自适应控制策略研究

摘要

阐述发动机稳态工况闭环控制的特点，分析导致瞬态空燃比匹配不当的原因，设计空燃比加性误差与乘性误差模型，提出自适应补偿的方案，最后基于Matlab/Simunlink建立空燃比控制系统模型并验证自适应补偿控制策略。结果表明：当出现误差时，自动改变空燃比修正值调整燃料喷射量，空燃比波动约1%。%The closed-loop control characteristics of engines under steady-state operating conditions are explained in this paper. First, the causes of mismatched transient air -fuel ratio are investigated. Second, an additive error model and a multiplicative error model of air-fuel ratio is designed. Third, an adaptive compensation scheme is proposed accordingly. According to Matlab/Simulink, a simulation model of air-fuel ratio control system is established and the adaptive compensation scheme is verified. The results show that when an error occurs, the fluctuation in air-fuel ratio is lower than 1% after the modified value of air-fuel ratio correction value is automatically changed to adjust fuel injection.