Two-stage fast identification method for strain and temperature of Brillouin fiber optic sensor based on Bayesian update and stochastic simulation

Abstract

The present invention proposes a two-stage rapid identification method for Brillouin optical fiber sensor strain and temperature based on Bayesian update and stochastic simulation. Brillouin gain spectrum, through the parameter identification method based on Bayesian update and stochastic simulation methods, a large number of samples that obey the joint distribution of parameters in the Brillouin gain spectrum are obtained, and the upper and lower limits of the frequency sweep range in the next stage are statistically estimated. Intensive frequency sweeping of the range is carried out to obtain sufficiently accurate identification results of the Brillouin fiber gain spectrum parameters, and finally the structural strain or temperature information is obtained according to the functional relationship between the Brillouin fiber frequency shift and the structural strain and temperature. The invention can quickly and accurately process the data obtained by the Brillouin optical fiber sensor, and the result is the mean value and standard deviation estimated value of the structural strain or temperature at each measuring point of the Brillouin optical fiber, which has a good reference for practical engineering applications value.

Description

technical field [0001] The invention belongs to the technical field of Brillouin optical fiber sensing and structural health monitoring, in particular to a two-stage fast identification method for strain and temperature of a Brillouin optical fiber sensor based on Bayesian update and stochastic simulation. Background technique [0002] In today's era, with the rapid development of our country, large-scale infrastructure such as bridges, tunnels, oil and gas pipelines, and high-speed rail tracks are being rapidly constructed. The massive construction of these projects will also bring about structural safety and reliability issues. In response to such engineering status, structural health monitoring becomes very important as the structure encounters different degrees of damage. Structural health monitoring often requires the collection of structural strain and temperature information, and distributed Brillouin fiber optic sensing technology can provide a very effective solutio...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem that in the process of measuring the strain or temperature of the sensing optical fiber by the traditional distributed optical fiber strain and temperature tester, due to the uncertainty of the strain or temperature distribution range of the optical fiber to be tested, the detection light needs to carry out a large-scale intensive continuous frequency sweep And multiple averages, such a process will obtain a lot of useless information, and will consume more time, resulting in low efficiency

Images