设计并搭建了一套声光移频式的激光外差振动测量系统，包括光路部分和信号处理部分，并对该振动测量系统进行了实验验证。实验结果表明，当频率在10～100 Hz、100～1000 Hz、1～10 kHz 频段内时，其测量相对误差分别小于0．15％、0．07％和0．03％，并且相对误差随着频率的增加而减小；解调信号幅值随着驱动电压的增大而增大，显示出了很好的振幅响应特性。此外，对该系统在小型旋转机械故障监测中的应用进行了实验探究。对一小型旋转机械故障前、后的振动进行了测量，记录了其波形以及频谱信息。测量结果表明，当该旋转设备存在故障时其振动时域波形图发生明显变化；频谱分析结果显示，在175～250 Hz 频段内，频谱幅值相对变小；在250～350 Hz 频段内产生了新的频谱成分，从而验证了将该系统应用于小型旋转机械故障监测中的可行性。%An acousto-optic laser heterodyne vibration measurement system is designed and built,which is made up of an optical part and a signal processing part.This system is verified experimentally,and the results show that relative errors for the vibration frequency at 10 ~100 Hz,100 ~1000 Hz,1 ~10 kHz band are less than 0.15%,0.07% and 0.03% respectively,and it decreases with the increasing of frequency.The output signal amplitude increases with the increasing of driving voltage amplitude,showing a good amplitude response.In addition,the vibration waveform and spectrum are measured and recorded of small rotating machinery in the condition of normal and fault.The measure-ment results show that when this rotating machinery operates with a failure,the vibration waveform shows a significant change.The spectrum analysis results show that the spectrum amplitude is smaller in the 175 ~250 Hz band and new spectral components are produced in 250 ~350 Hz band,these results show the the feasibility of this system in the mo-nitoring of fault for small rotating machinery.
展开▼
