基于模型的发动机空燃比控制策略研究与仿真

Model-based Research and Simulation of Engine Air/Fuel Ratio Control Strategies

空燃比的精确控制是现代车用汽油机控制最为关键的技术。发动机平均值模型由于其模型简单、计算时间短、使用方便,且能满足控制设计的要求而被广泛应用。基于模型的空燃比控制技术是当前国内外研究的热点。在建立某型汽油发动机空燃比平均值数学模型的基础上设计了稳态工况下模糊自适应PID控制器,并与传统的PID控制器空燃比控制效果进行了对比。设计了瞬态工况下燃油前馈补偿控制器并进行仿真。仿真结果表明在稳态工况下模糊自适应PID控制策略不仅能够满足实际控制需要,而且比传统的PID控制策略控制效果更好。前馈补偿控制策略能满足瞬态工况下空燃比的控制要求。

Accurate air/fuel ratio control technique is the key control technology for modern automotive gasoline engine.Because of its simple model,short calculation time,easy usage,and being able to meet the control requirement,mean value model for engines has a wide range of application.Air/fuel ratio control technique based on model is research hotspot at home and abroad currently.A stable operating condition fuzzy adaptive PID Controller and a transient condition fuel feed-forward compensation controller were designed on the basis of a certain type gasoline engine air/fuel ratio mean value mathematics model.The architectures of these models and the general simulating processes are described.Results showed that fuzzy adaptive PID control strategy not only can meet the practical control requirements,but can also improve the control accuracy compared with the traditional PID control method on the stable operating condition.Fuel feed-forward compensation control strategy can meet A/F control requirement on transient condition.