| Summary: | In the demodulation process of Fiber Bragg Grating（FBG）sensing system,the accuracy of the system is affected by the noise seriously.In order to improve the measurement accuracy of the system,denoising is an indispensable part in the demodulation.In this paper,we construct a new threshold function with much better denoising performance based on typical wavelet threshold denoising algorithm with soft and hard threshold function,and threshold functions in the existing literature.Through the de-noising experiment for the noisy FBG reflected signal,the result shows that the proposed threshold function can increase the average signal-to-noise ratio by 3<sup>5</sup>dB,and reduce the root mean square error by 0.1<sup>0</sup>.3,when comparing with the typical soft and hard threshold function.Finally,we apply the proposed method to the FBG temperature sensing system to demonstrate the feasibility of the method.The experiment results show that the demodulation accuracy is less than5 pm,which meet the accuracy requirement of the FBG sensing system.
|
|---|