试析lpg发动机空燃比控制器的研究

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1、福建农业大学硕士学位论文LPG发动机空燃比控制器的研究姓名：林秀霞申请学位级别：硕士专业：农业机械化工程指导教师：黄敬党2003.5.1LPG发动机空燃比控制器的研究摘要本文采用开闭环豆相结合．粗、细、微调逐步精确喷气占空比的控毒4方式研制了LPG发动机空燃比控制器。该控制器能根据不同的工况快速反应并调整燃料喷射占空比，使过量空气系数a符台三效催化转化器有效工作范围(d=l±0．005)。开环阶段根据实时工况参数对事先制取的喷气占空比MAP图执行取值操作；闭环阶段根据氧传感器反馈信号通过增量逼近法或PI环节计算输出适合即时工况的喷气占空比值：为解决低速振荡现象，本文运用

2、固定增量法，对系统进行低速振荡微调。喷气占空比粗调阶段为对MAP图执行取值操作；细调阶段为执行增量逼近法的阶段：微调阶段为执行PI环节或执行低速振荡微调。实验证明当废氧浓度信号处于非振荡状态时，本控制器的调整时间约为3—5秒；当废氧浓度信号处于振荡状态时，调整时间约为8一lO秒。与WT615型增压天然气发动机的控制系统相比，本课题研究的空燃比控制器响应快速性有较大改善，稳定性结果相近：与BritishI．。yangdCFI发动机相比，本控制器的响应快速性比该控制系统差，而稳定性则得到较大改善。关键词：LPG发动机空燃比占空比控制婴垄垫垫皇垄些丝型堡塑堡茎Study011

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