基于入口端压力特征的喷油器喷油量预测研究

Research of Fuel Injection Quantity Prediction Based on the Inlet Pressure of Common Rail Injector

共轨喷油器的喷油量一致性影响柴油机各气缸之间的工作均匀性,从而影响车辆的舒适性和排放,该一致性主要由喷油器各参数的设计公差、零部件制造及装配工艺、喷油器老化等引起。对喷油器全生命周期喷油量闭环控制可以提高喷油器的喷油量一致性。研究了一种算法,通过采集喷油器入口端压力信号,对其进行一阶求导和二阶求导,找到喷射过程的特征点,拟合喷油规律,从而计算实际喷油量,采用编程的方式将数值计算得到的喷油量与实测喷油量进行对比。结果显示数值计算精度较高,证明通过入口端压力信号判断喷油器的实时喷油量的算法可行,为喷油器全生命周期喷油量闭环控制技术的进一步研究提供参考。

The consistency of common rail injectors affects the consistency among engine cylinders,thereby affecting vehicle comfort and emissions.The consistency of injectors is mainly related to the design tolerance of various parameters and the manufacturing and assembly process of parts.It can be improved by correcting the injector fuel.A method by collecting the inlet pressure signal and calculating the first and second derivatives,find the characteristic points to fit the fuel injection rate,then calculate the real fuel.The result is accurately by comparing the calculated value with the measured value.So the injector fuel can be calculated by the inlet pressure of the injector.This method to predict the injector fuel is reasonable.