基于极大倾角光纤光栅的龙门架低频振动传感系统的性能研究

Study on Low Frequency Sensing Performance of Gantry Crane Based on Excessively Tilted Fiber Grating

摘要:

提出了一种光强解调型极大倾角光纤光栅(Excessively Tilted Fiber Grating,ExTFG)的龙门架低频振动传感器。首先分析Ex-TFG振动传感的基本原理和传感特性,实验分析Ex-TFG的偏振相关谐振峰的损耗强度与横向压力的关系;然后通过弹性膜片将PZT的振动信号转换为对传感器的横向压力;再通过光电探测模块把光信号转化为电信号;并且对输出信号进行FFT变换分析。实验结果表明,所设计的传感系统对正弦信号频率响应时间为0.045s,检测范围为1~10Hz,平均误差为0.085Hz,最大误差率为1.4%,幅度响应的线性度为96.46%,传感性能良好,其FFT变换主频分量占80%以上,对低频振动信号的传感与检测具有一定的指导意义。

Abstract:

A low frequency vibration sensor of Gantry crane based on excessively tilted fiber grating (ExTFG) is proposed by using light intensity demodulation. The basic principle and sensing characteristics of the ExTFG vibration sensing is analyzed, the linear relationship between the peak value of the polarization dependant resonant of ExTFG and the transverse pressure is verified. Vibration output signal of PZT to the lateral pressure on the sensor is transferred through an elastic diaphragm, photoelectric detection module is used to transform the light signal into the electrical signal, and the sensing signal is analyzed by FFT transform. The experimental results show that the response time of the designed sensor system is 0.045s, the detection range is 1~10Hz, the average error is 0.085Hz, the maximum error rate is 1.4%, the linearity of the amplitude response is 96.46%, and the sensing performance is good. The main frequency components of FFT transform of the sensor signal account for more than eighty percent. It has a certain guiding significance for the sensing and detection of low frequency vibration signals.