High-speed measurement system and method for few-spectrum sampling points of white-light interference fiber-optic F-P sensor

Abstract

The invention relates to a low-spectrum sampling point high-speed measuring system and method for a white light interference type optical fiber Fabry-Perot sensor, belonging to the technical field ofoptical fiber sensing. The system comprises a broadband light source, an optical circulator, a wavelength division multiplexer, a photoelectric detection group, a high-speed parallel acquisition subsystem and a demodulation calculation subsystem. The method comprises the steps of (S1) using the wavelength division multiplexer, the photoelectric detection group and the high-speed acquisition subsystem to decomposes a broad spectrum outputted by the optical fiber Fabry-Perot sensor into N paths of finite narrow-spectrum signals, (S2) constructing N paths of noise-free ideal interferometric spectrum signals and constructing a probability density function from a difference between the noise-free ideal interferometric spectrum signals and actual signals obtained in step (S1), and (S3) solving an estimator that maximizes the probability density function and obtaining a maximum likelihood estimator with the cavity length L. The invention starts from the spectrum acquisition and data processing method of less sampling points and software algorithm and hardware, the resource occupation of data collection and processing is greatly reduced, and therefore, the bottleneck of a measurement speedis broken.

Description

Technical field [0001] The invention belongs to the technical field of optical fiber sensing, and relates to a low-spectrum sampling point high-speed measurement system and method of a white light interference type optical fiber Fabry-Perot sensor. Background technique [0002] For rotating machinery and equipment such as steam turbines and water turbines, generators and engines, centrifuges and machine tools, the high-speed dynamic online monitoring of the micro-displacement / clearance of moving parts is of great significance for new product development and operational safety assurance. Due to the advantages of optical fiber sensors, such as small size, anti-electromagnetic interference, and no charge at the sensor end, they are paid attention to in the high-speed dynamic online monitoring of such micro-displacement / gap. Among all kinds of optical fiber sensors, white light interference optical fiber sensors have the advantages of high measurement accuracy, strong anti-interferen...

AI Technical Summary

Problems solved by technology

[0008] Although the research from the two aspects of spectral sampling and data demodulation and calculation can improve the speed of the existing white light interference fiber-optic F-P sensor demodulation system to a certain extent, the improvement is limited and cannot fundamentally solve the problem of high-speed and high-precision sensing. measurement needs

[0009] 2. Root cause of the problem

[0011] From the analysis of the above problems, it can be seen that in the white light interferometric optical fiber sensor, the original wide-spectrum interferometric data with a large amount of data requires intensive spectral signal sampling and processing calculations, which is not only the key to ensuring its high-precision demodulation, but also the limitation The key to its demodulation speed

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