改进型离子电流检测系统在汽油机爆震检测中的应用研究

The Applications of a Modified Ion Current Detecting System to the Detection of Gasoline Engine Detonation

采用一种改进型的串联式离子电流检测系统,在一台1.3L四缸增压汽油机上开展了离子电流信号的典型特性,尤其是爆震工况下特性的试验研究。结果表明:该检测系统离子电流的频率特性可较好地判定中强爆震工况,但在轻微爆震工况有一定的局限;离子电流积分值能进一步提高爆震工况判定的准确率,达到87.2%。针对爆震强度的识别,离子电流峰值和平均幅值与爆震强度有很强的正相关性,采用加权平均的数学方法能优化离子电流爆震关键值与爆震强度的相关系数,使其由0.811提高到0.843。

A modified serial-type of ion current detecting system is adopted to conduct an experimental studyon the typical characteristics,in particular,the characteristics in detonation condition of ion current signals in a 1.3Lfour-cylinder supercharged gasoline engine. The results show that with the detecting system, the frequencycharacteristics of ion current can better judge the detonation of m e d i u m intensity but has certain limitation for lightdetonation. Using the integral value of ion current can further enhance the judgment accuracy of detonation conditionup to 87. 2 % . In terms of the identification of detonation intensity,the peak value and the average amplitude of ioncurrent have very strong positive correlation with detonation intensity, and by optimization using weighted averagem e t h o d,the correlation coefficient between ion current key value and detonation intensity can be raised from 0.811to 0.843.