基于悬臂梁调谐技术的光纤光栅无源振动监测

采用匹配光纤光栅设计了一种结构简单的振动信号无源监测装置.该装置利用悬臂梁调谐技术能够将微小振动信号转化为光电探测器可探测的光强信号,利用示波器实现实时监测.实验中对振幅为3mm的简谐振动信号进行了监测,测量结果与振动频率一致,可测量7～20Hz的振动,信噪比不低于14.9dB.监测频率受限是因为悬臂梁的性质,如采用金属材料或者采用齿轮组对转子进行减速,该装置可探测更高的频率.

Passive Fiber Bragg Grating Sensor for the Mechanical Vibration Monitoring Based on Cantilever Beam Tuning Technology

Utilizing a couple of fiber Bragg gratings, a simple structure device was presented for the passive monitoring vibration. Based on an isosceles triangle cantilever beam tuning technology, microvibrations could be converted into light intensity signal that could be detected by a photo-electro detector. Using an oscilloscope, the passive monitoring was attained; In the experiment, harmonic vibrations with 3 mm amplitude were monitored. The experiment results agreed with the real value.7～20 Hz vibrations could be detected and the SNR was more than 14.9 dB. The detect frequency was limited by the nature of the cantilever beam. If a metal beam or deceleration device was used, it was possible to detect higher frequency.