基于柴油机曲轴瞬时转速信号EEMD分解的失火故障诊断  

Fire Fault Diagnosis Based on Signal EEMD of Diesel Engine Crankshaft Instantaneous Speed

作　　者：黄英[1] 李准 王健 刘辰 胡博睿 HUANG Ying;LI Zhun;WANG Jian;LIU Chen;HU Borui(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《北京理工大学学报》2025年第4期384-390,共7页Transactions of Beijing Institute of Technology

摘　　要：对于十缸V型柴油机单缸失火和双缸失火这两类故障,提出了基于曲轴瞬时转速信号的集合经验模态分解的故障诊断策略.该策略考虑到多个转速工况对失火故障诊断的影响,根据柴油机喷油提前角将实车实时采集到该转速下的数据划分为正常、单缸失火和双缸失火这三个工况区间.通过多循环平均方法对三个工况区间数据进行预处理,并通过集合经验模态分解方法分解,该方法能自适应地将曲轴转速信号分解为若干个本征模态函数.通过集合经验模态分解得到每个本征模态函数幅值的异常波动,确定包含故障信息的本征模态函数,为了进一步提取特征,需对该本征模态函数进行快速傅里叶变换,根据主频分量的幅值,得到故障特征.最后在多个转速工况下进行上述诊断流程,得出各个转过速工况的诊断准确率,实现了诊断算法的转速工况敏感性分析.实验结果表明该方法能有效提取故障特征,实现了十缸柴油机基于多个瞬时转速的失火故障诊断.A fault diagnosis strategy was proposed based on ensemble empirical mode decomposition of crankshaft instantaneous speed signals to handle the faults of single-cylinder fire and double-cylinder fire for a ten-cylinder V-type diesel engine.This strategy was arranged to analyze the impact of multiple speed conditions on fire fault diagnosis.Firstly,the real-time data collected from the engine at various speeds were categorized into three operating conditions,normal,single-cylinder fire,and double-cylinder fire,based on the diesel engine's fuel injection advance angle.Preprocessing the data of three operating conditions with the multi-cycle averaging method and decomposing the data with the ensemble empirical mode decomposition method,the fault diagnosis system was designed to decompose adaptively the crankshaft speed signal into several intrinsic mode functions.And then,according to the abnormal fluctuations in the amplitude of each intrinsic mode functions obtained with ensemble empirical mode decomposition,the intrinsic mode functions with fault information was identified.In order to further extract features,the intrinsic mode functions was processed with fast Fourier transform to obtain the fault characteristics based on the amplitude of the dominant frequency component.Finally,the diagnostic process was conducted under multiple speed conditions to derive the diagnostic accuracy for each speed condition,enabling a sensitivity analysis of the diagnostic algorithm to different speed conditions.The experiment results show that this method can effectively extract fault features and achieve fire fault diagnosis in a ten-cylinder diesel engine based on multiple instantaneous speed measurements.

关 键 词：柴油机 失火故障诊断 集合经验模态分解(EEMD) 曲轴瞬时转速 特征提取 本征模态函数(IMFs) 快速傅里叶变换(FFT) 

分 类 号：TK428[动力工程及工程热物理—动力机械及工程]