小波分析在发动机失火监测中的应用  

Monitoring Method for Engine Misfire Based on Wavelet Analysis

作　　者：杜灿谊[1,2] 杨志坚[1] 丁康[1] 

机构地区：[1]华南理工大学机械与汽车工程学院,广州510641 [2]广东技术师范学院机电学院,广州510635

出　　处：《振动．测试与诊断》2011年第3期318-322,395,共5页Journal of Vibration,Measurement & Diagnosis

基　　金：国家自然科学基金资助项目(编号:51005078);华南理工大学自然科学青年基金资助项目

摘　　要：针对现时发动机失火监测方法的不足,研究了利用小波分析方法进行失火监测。对某发动机缸盖振动加速度信号作频谱分析,可知单缸失火状态的0.5和1谐次振动幅值与正常状态相比有显著增长。采集发动机稳速工况下失火故障瞬间前后一段时间的振动信号,利用小波分析方法,对其进行多尺度近似分解,获得低频逼近信号。由于失火引起低阶次振动幅值变化,观测获得的低频逼近信号的振动幅值波动,可明显分辨出故障发生的时间,再进行加速和减速工况分析。结果同样表明,通过小波变换分析方法,能有效监测发动机失火发生的时间。Aimed at the disadvantages of present monitoring methods for engine misfire,a wavelet analysis method for engine misfire monitoring is studied.Firstly,by analysis of vibration acceleration signal spectrum on cylinder head,it can be known that amplitudes of 0.5 and 1-order have much more growth under single-cylinder misfiring situation than normal one.Collecting the signal around the time of engine misfiring occurred under constant-speed condition.Then,multi-scale approximate decomposition is performed by wavelet analysis method for the vibration acceleration signal,and the low-frequency approximate signal is obtained.And the fault can be easily identified by vibration amplitude fluctuation.Similarly,the same analysis results are gained under acceleration and deceleration conditions.The result shows that wavelet analysis method can effectively monitor the occurrence of engine misfire fault.

关 键 词：失火监测 振动 阶次 小波分析 

分 类 号：TK418[动力工程及工程热物理—动力机械及工程] TH113.1[机械工程—机械设计及理论]