基于粒子群优化极点配置的空燃比输出反馈控制

摘要

There exists the oil-film wet wall effect during gasoline engine operating processes , which reduces accuracy of air-fuel ratio (AFR ) control , and then degrades combustion performance in transient cases .In order to control the AFR near ideal values ,this paper uses the state space model based on fuel oil-film subsystem to design state feedback controllers by adopting the pole placement method ,which combines an observer to estimate the state and design an output feedback controller .By the particle swarm optimization (PSO) online algorithm ,the poles are placed optimally and the optimized poles are computed in order to precisely control AFR of gasoline engines .Finally ,the simulation experiments are showed that the designed controller has better tracking and control effect and satisfy the requirement of AFR control .%汽油发动机运行过程中存在油膜湿壁效应,导致汽油机瞬态工况下的空燃比控制精度变差,燃烧性能下降.为了能快速、精确的控制空燃比在理想数值附近,基于燃油油膜子系统状态空间模型,采用极点配置状态反馈控制方法,加入观测器估计状态量,设计输出反馈控制器.通过粒子群优化算法在线优化极点配置,求得最优极点,实现汽油发动机空燃比的精确控制.最后通过仿真实验,验证了设计的控制器具有较好的跟踪控制效果,满足空燃比控制要求.