摘要
利用振动信号测量发动机转速是一种不解体检测的重要方法,但其对发动机振动频率要求较高,因此转速急剧变化时,对测量精度影响较大。提出了基于希尔波特包络和自相关的新方法;利用小波变换消除基线漂移,再通过短时时间窗进行类稳态分析,并采用希尔伯特包络和三次自相关对信号进行时域分析,计算短时窗内的发动机转速,通过移窗法得到连续的发动机转速。通过在发动机台上进行变工况试验,同步采集振动信号和转速传感器信号进行对比分析,在急加速条件下转速测量最大误差小于1.4%,能够有效的满足柴油发动机转速的实时性和精确性要求,在车辆不解体检测和无负荷测功方面有很大应用前景。
It is an important method to measure the engine speed by using vibration signals. Engine vibration frequency has a great influence on the measurement accuracy when the speed changes dramatically. A new method based on Hilbert envelope and autocorrelation was proposed. Wavelet transform was used to eliminate the baseline drift firstly. Then the quasi-steady-state analysis was carried out by means of a short-time window,and the Hilbert envelope and three autocorrelations were used in time domain analysis to calculate the rotational speed of the engine in a short-time window. Finally,the continuous engine speed was obtained by the moving window method. Through a variable working condition experiment on the engine bench,the synchronous acquisition vibration signal and the rotating speed sensor signal were compared and analyzed,and the maximum error of speed measurement under the condition of rapid acceleration was less than 1. 4 %. It can effectively meet the requirements of real-time and accuracy of diesel engine ＇s speed,and has great application potential in the field of non-disassembly tests and unloaded power detection.
出处
《振动与冲击》
EI
CSCD
北大核心
2017年第22期252-256,共5页
Journal of Vibration and Shock
基金
国防预研项目(40407030401)
关键词
柴油发动机转速
振动信号
基线漂移
短时窗
希尔伯特变换
自相关
diesel engine speed
vibration signal
baseline drift
short-time window
Hilbert transform
autocorre-lation
