基于小波阈值去噪的离子电流信号研究  

Research on Ion Current Signal Based on Wavelet Threshold De-Noising Method

作　　者：孟祥文[1] 吴筱敏[1] 高忠权[1] 高辉[1] 李根[1] 黄佐华[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049

出　　处：《内燃机工程》2011年第4期60-64,共5页Chinese Internal Combustion Engine Engineering

基　　金：国家重点基础研究发展规划资助项目(2007CB210006);国家自然科学基金项目(50876087)

摘　　要：在发动机上利用火花塞检测电极间离子电流信号,应用小波阈值收缩去噪方法对实测离子电流信号进行滤波去噪,去噪后的信号能够清晰地分离点火、火焰前锋区和焰后区,且由点火产生的峰值在上止点前5-6°CA,前锋区峰值在上止点附近,焰后区峰值与压力峰值位置相差〈1°CA。当相对空燃比在0.9-1.2变化时,去噪后离子电流前锋区峰值和焰后区峰值均随相对空燃比的增加而下降。On a spark ignition engine,ion current signals across two electrodes of spark plug were measured.Filtered and de-noised by wavelet threshold shrinkage de-noising method,the measured ion current signals can clearly distinguish ignition,flame front and post-flame zones,furthermore,the peak originated from ignition pulse is at 5~6 °CA BTDC,the position of flame front zone peak is near TDC,and the position of post-flame zone peak is close to the position of pressure peak（differs less than 1 °CA）.When relative air-fuel ratio varies between 0.9 and 1.2,both the flame front zone peak and post-flame zone peak of de-noised ion current decrease as the air-fuel ratio increasing.

关 键 词：内燃机 小波阈值去噪 离子电流 电感式点火系统 相对空燃比 

分 类 号：TK411.2[动力工程及工程热物理—动力机械及工程]