摘要：AbstractBased on a 1.0 L turbocharged GDI engine and product-level ion current detection system, the potential of using ion sensing technology for transient EGR control is studied. Firstly, ion sensing performance under steady-state EGR condition is studied. The result shows that the correlation coefficient between mean value of Imax, Isum and IMEP is over 0.96 under steady-state condition, but the cyclic variation of ion current signal is too high for control. Thus, the moving average method is used to effectively reduce the cyclic variation of ion current signal to the same level as cylinder pressure signal. Based on that, ion sensing and UEGO sensor performance under transient EGR condition is compared. The weighted moving average method is proposed optimized from the moving average method to shorten the response delay of ion current signal. The response delay could be reduced by 30% in the case study. Finally, the applicability of ion current signal under different operating conditions is studied. The result shows that ion current signal could be used for transient EGR control. However, if the variation of ion current signal is within the cyclic variation range of ion current signal, the variation of EGR is hard to be distinguished.
