基于离子电流与缸压信息融合的HCCI发动机不完全燃烧提前诊断

Advanced Diagnosis of Incomplete Combustion in HCCI Engine Based on Information Fusion of Ion Current and Cylinder Pressure

由于随机出现的非正常燃烧现象,均质压燃(HCCI)发动机的应用受到阻碍。本文中以一台压缩比及配气系统经过改造的2.0 L四缸发动机为平台,以负阀重叠期的缸压和离子电流为信号,研究了HCCI发动机的不完全燃烧提前诊断方法。结果表明:负阀重叠期缸压峰值相位与离子电流峰值可作为不完全燃烧的诊断依据;单独使用缸压峰值相位或离子电流峰值进行诊断时,大部分不完全燃烧循环可被提前判断,诊断灵敏度分别可达93.8%和95.6%,但部分正常循环会被误判为不完全燃烧循环。使用缸压和离子电流信号相结合进行诊断时,可大幅提高诊断准确率至90.0%,同时诊断灵敏度保持为91.4%。

Due to the random abnormal combustion,the application of HCCI engine is hindered.In this paper,based on the platform of a 2.0 L four-cylinder engine with modified compression ratio and valve mechanism,taking the cylinder pressure and ion current in the period of negative valve overlap as signals,the method of advanced diagnosis of incomplete combustion in HCCI engine is studied.The results show that the peak phase of cylinder pressure and the peak value of ion current during NVO can be used as the basis for incomplete combustion diagnosis.When the peak phase of cylinder pressure or the peak value of ion current is used alone for diagnosis,most of the incomplete combustion cycles can be judged in advance,with the diagnostic sensitivity of 93.8%and 95.6%respectively;but some of the normal cycles can be misjudged as incomplete combustion cycles.When using the combination of cylinder pressure and ion current signal for diagnosis,the diagnostic accuracy can be greatly improved to 90.0%,and the diagnostic sensitivity can be kept at 91.4%.