关键词: 柴油机, 特征提取, 相关分析, 敏感度系数, 故障诊断

Abstract: Aiming at the problem of failure diagnosis of diesel engine working status based on steady process and linear system statistical method,a fault diagnosis method of diesel engine based on feature extraction and correlation analysis is proposed.Firstly,the time domain,frequency domain and time-frequency characteristics of vibration signals of diesel engine cylinder head under different working conditions are extracted,and a standard characteristic matrix and an unknown characteristic matrix are established.Relevant analysis methods are used to analyze the correlation between different working condition signals.Finally,a model six diesel engine test bench was used to simulate the four conditions of normal,collision cylinder,misfire and small head tile wear respectively.The experimental results show that this method can accurately diagnose four operating conditions of normal,collision cylinder,misfire and small head tile wear,and prove the effectiveness of this method in diesel engine fault diagnosis.At the same time,sensitivity coefficients are used to evaluate and rank the fault features.The sensitive characteristics of the fault of the impact cylinder and the small head tile wear are mainly concentrated in the time domain,while the normal and misfire are also concentrated in the time and frequency domains.

Key words: diesel engine, feature extraction, correlation analysis, sensitivity coefficients, fault diagnosis