摘要
考虑发动机断火之后对振动信号的影响,基于4层小波包分解重构信号能量,构造了小波包能量商无量纲指标。通过该指标提取发动机断火前后信号的能量特征作比商,充分考虑了断火之后振动信号能量的阶跃特性,定量分析断火后信号能量变化的程度。采集东风EQ6100汽油发动机缸体正常、活塞敲缸异响、活塞销异响以及曲轴轴承异响等4种工况的振动信号,并应用小波能量商指标对试验信号进行分析,取得很好的效果。试验结果表明,小波能量商可以对发动机不同故障准确地识别分类。
With the consideration of the effects of off-ignition on the vibration signals of engine, a dimen-sionless indicator-wavelet energy quotient （WEQ） is proposed based on the energy of signal reconstructed by fourlayers wavelet packet decomposition. The energy features of signals before and after off-ignition are extracted respec-tively to calculate the quotient, and the changing extent of signal energy is quantitatively analyzed. Tests are conducted on Dongfeng EQ6100 gasoline engine, with vibration signals in four working conditions （normal, piston knocking fault, and the faults with abnormal sounds of piston pin and crankshaft bearing） collected and analyzed by WEQ. The results demonstrate that by using WEQ, different faults of engine can be accurately identified and classified.
出处
《汽车工程》
EI
CSCD
北大核心
2009年第2期193-196,共4页
Automotive Engineering
关键词
发动机
故障诊断
断火
小波能量商
engine
fault diagnosis
off-ignition
wavelet energy quotient
