内燃机
內燃機
내연궤
INTERNAL COMBUSTION ENGINES
2012年
1期
55-58
,共4页
EMD%内燃机%瞬时转速%故障诊断
EMD%內燃機%瞬時轉速%故障診斷
EMD%내연궤%순시전속%고장진단
Empirical mode decomposition%Internal-combustion engine%Instantaneous speed%Fault diagnosis
针对内燃机瞬时转速信号的非平稳性特点，将EMD方法用于瞬时转速信号的时频分析，将其自适应分解为几个基本模式分量和剩余值序列；对各个基本模式分量进行Hilbert变换得到Hilbert谱，从而得到瞬时频率和振幅随时间的变化规律，并进一步得到了EMD边界谱。实验测量6-135型柴油机正常和故障状态下瞬时转速信号，对其进行EMD分析表明：瞬时转速EMD边界谱可以指示有无故障发生，而瞬时频率和分解剩余值序列可以指示故障缸位置，二者结合可以较好地实现内燃机的故障诊断，为基于瞬时转速的内燃机故障诊断提供了一条新的思路。
針對內燃機瞬時轉速信號的非平穩性特點，將EMD方法用于瞬時轉速信號的時頻分析，將其自適應分解為幾箇基本模式分量和剩餘值序列；對各箇基本模式分量進行Hilbert變換得到Hilbert譜，從而得到瞬時頻率和振幅隨時間的變化規律，併進一步得到瞭EMD邊界譜。實驗測量6-135型柴油機正常和故障狀態下瞬時轉速信號，對其進行EMD分析錶明：瞬時轉速EMD邊界譜可以指示有無故障髮生，而瞬時頻率和分解剩餘值序列可以指示故障缸位置，二者結閤可以較好地實現內燃機的故障診斷，為基于瞬時轉速的內燃機故障診斷提供瞭一條新的思路。
침대내연궤순시전속신호적비평은성특점，장EMD방법용우순시전속신호적시빈분석，장기자괄응분해위궤개기본모식분량화잉여치서렬；대각개기본모식분량진행Hilbert변환득도Hilbert보，종이득도순시빈솔화진폭수시간적변화규률，병진일보득도료EMD변계보。실험측량6-135형시유궤정상화고장상태하순시전속신호，대기진행EMD분석표명：순시전속EMD변계보가이지시유무고장발생，이순시빈솔화분해잉여치서렬가이지시고장항위치，이자결합가이교호지실현내연궤적고장진단，위기우순시전속적내연궤고장진단제공료일조신적사로。
Internal-combustion engine instantaneous speed is nonstationary signal, so the empirical mode decomposition（EMD） method is used in time-frequency analysis of instantaneous speed signal in this paper, and the signal is decomposed into several intrinsic mode functions and residual trend terms. Hilbert transform is made for each of intrinsic mode function to obtain instantaneous frequency and amplitude （Hilbert spectrum）, and boundary-spectrum is obtain from Hilbert spectrum. The instantaneous speed are measured of 6-135 type diesel in normal status and fault status, and the EMD analysis outcome shows that the boundary-spectrum may indicate fault＇s exist, and the instantaneous frequency and residual trend terms may indicate which cylinder have fault. So the EMD method can achieve the fault diagnosis very well, and offer a new method for internal-combustion engine fault diagnosis based on instantaneous speed.
