柴油机燃油系统电磁阀闭合始点及反馈控制策略  

Diesel Fuel System Solenoid Closure Start-point and Feedback Control Strategy

作　　者：陈林[1] 刘磊[1] 杨福源[1] 李建秋[1] 张科勋[1] 欧阳明高[1] 

机构地区：[1]清华大学汽车安全与节能国家重点实验室,北京100084

出　　处：《机械工程学报》2010年第18期108-114,120,共8页Journal of Mechanical Engineering

基　　金：国家重点基础研究发展计划资助项目(973计划;2007CB210003)

摘　　要：高速电磁阀是柴油机电控燃油喷射系统的关键部件,其闭合时间的精确评估直接影响喷射定时和喷油量的控制精度。以电控组合泵电磁阀为研究对象,通过建立由磁路、电路和阀芯动力学模型组成的电磁阀机理模型对电磁阀闭合过程进行研究。利用电磁阀闭合前后磁阻变化率突变的特性,设计出适合于电磁阀闭合时刻的检测的电路驱动逻辑,使电磁阀驱动电流曲线在闭合时刻呈现明显的转折点。在此基础上,始点识别算法通过对驱动电流进行监测实时提取电磁阀闭合时刻信息,燃油喷射控制策略依据该闭合始点的信息对燃油喷射进行实时反馈控制,修正实际电磁阀控制定时和控制脉宽,以消除电磁阀特性引起的喷油差异。试验结果表明,改进后的电路驱动逻辑能使电磁阀闭合始点在其驱动电流上表现出清晰的特征,始点识别算法能根据该特征精确地检测出电磁阀的闭合时刻,配合燃油喷射始点反馈控制策略可以消除因电磁特性引起的各缸喷油量不均匀的问题,从而提高燃油喷射的控制精度。High speed solenoid is a key component of electronically controlled diesel fuel injection system.Accurate evaluation of the solenoid closure time has direct influence on the control precision of both injection timing and quantity.The electronically controlled combination pump solenoid is taken as the research object.A solenoid mechanism model composed of dynamic models of magnetic circuit,electric circuit and spool is built for the research of the solenoid closing process.The electric circuit driving logic suitable for detecting the solenoid closure instant is designed by utilizing the mutation characteristic of magnetoresistance change rate before and after the solenoid closure,so that the solenoid driving current curve shows an obvious turning point.On this basis,the start point recognition algorithm,through the monitoring on driving current,extracts in real time the information on solenoid closure instant.Based on the information,the fuel injection control strategy carries out real-time feedback control on the fuel injection,corrects the actual solenoid control timing and pulse width,so as to eliminate injection variance caused by the solenoid characteristic.The test result shows that the improved circuit driving logic can make the solenoid closure start-point show the characteristic clearly on its driving current.Based on this,the start-point recognition algorithm can accurately detect the solenoid closure instant,and in coordination with the feedback control strategy,can solve the problem of uneven fuel injection from the cylinders,thus improving the control precision of fuel injection.

关 键 词：柴油机 电控组合泵 电磁阀闭合始点 喷射反馈控制 

分 类 号：U27[机械工程—车辆工程]