基于Hilbert变换的轴系扭振信号分析

Analysis for Torsion Vibration Signal of the Shaft Based on the Hilbert Transformation

扭转振动是轴系常见的振动形式之一,扭转振动将引起轴系材料的疲劳积累,最终导致轴系破损事故,所以扭振的测量非常重要.应用高精度光电编码器测取扭振信号,当扭振发生时,编码器输出的脉冲信号产生疏密变化,扭振信号对编码器输出的脉冲信号进行频率调制.用希尔伯特变换对调制信号进行解调,直观地得到了整个扭振信号的角位移与角速度波形.对调制信号进行了频谱分析,得出扭振频率与激励信号的频率相一致.研究结果为以后将轴系扭振信号用于回转系统状态监测与故障诊断提供了依据.

Torsion vibration is one of the common vibration forms of the shaft. Torsion vibration will cause the fatigue accumulation of the shaft material, and finally make the shaft damaged. So it is very important to measure the torsion vibration. The high-accuracy pho- toelectric encoder is used to pick up the torsion vibration signal. When torsion vibration happens, the torsion vibration signal will modu- late the pulse signal in frequency domain. Using Hilbert transformation, the signal is demodulated, and the angular displacement and the angular velocity waveform of the whole torsion vibration signal is obtained. Spectrum analysis of modulation signals shows that the frequency of torsion vibration corresponds with that of the stimulation. The results provide the basis for condition monitoring and fault diagnosis of rotating systems.