【作者】 郑家移；

【导师】 倪江生；

【作者基本信息】 东南大学 ， 精密仪器及机械， 2006， 硕士

【摘要】 随着我国基础设施建设速度加快,各种大型建筑物不断涌现,人们对于大型工程结构的健康诊断也越来越关注。常规的监测方法越来越不能满足现有需求,而光纤传感器以其优异的抗干扰特性和传感信息以波长编码的特点,成为国内外工程领域广泛关注的重要研究课题。其中,光纤布拉格光栅(FBG)以其灵敏度高、光能利用率高、易复用、适用于工程等特点成为目前光纤传感领域的研究热点之一。本文首先系统地分析了光纤传感原理及FBG传感器的技术特点,并在此基础上提出了以可调光纤F-P滤波器为基础的通用解调方案。针对F-P滤波器的非线性特性的影响,分析了设置波长参考的必要性并提出了具体方法。由高速数字信号处理器(DSP)构成的数字处理系统对光路解调中提取出来的信号进行数字量化、分析,运用巴特沃斯数字低通滤波器对数据进行了滤波,并通过串行通讯接口将所得数据传送给PC机。论文对数字处理系统的软硬件进行了详细设计和调试,给出了系统调试结果并进行了讨论。为了提高系统性能,论文还提出了一种高精度的基于D/A输出控制F-P滤波器的解调方案。更多还原

【Abstract】 With the development of large-scale building and infrastructures in China, more and more attention is paid to the structure health diagnosis. The traditional monitoring method cannot satisfy the requirement of construction industry. As fiber optical sensors have a great deal of advantages over traditional ones, they become the important research topic in the area of sensor and instrument. In particular, the optical fiber Bragg grating (FBG) sensors are widely used in engineering in virtue of their prominent characteristics.This paper systematically analyzed the detecting principle of FBG sensor and discussed the relative technical problems firstly and then put forward a scheme of wavelength demodulation based on FFP tunable filter. A set of wavelength reference is involved in the system as calibration to correct non-ideal performance of the F-P filter. A digital signal process system based on high speed digital signal processor (DSP) converters and analyses the analog signal from the conditioning circuit. Then the data was filtered by Butterworth low-pass filter and sent to PC104 via serial communication interface or USB. The realization of the hardware and the software of the digital signal process system is presented and the results of debugs is given in this thesis. Furthermore, a high precision demodulation scheme by D/A converter is also proposed.更多还原