Parallel distributed computing-based multi-channel optical fiber grating vibration signal intelligent sensor system

Abstract

The present invention provides a parallel distributed computing-based multi-channel optical fiber grating vibration signal intelligent sensor system. The system includes a strain measurement Bragg grating, a semiconductor laser which is used for providing broadband laser to the Bragg grating, an optocoupler which is connected with the semiconductor laser and the Bragg grating, a beam splitting system which is connected with the optocoupler, receives Bragg reflected spectral signals and completes the spatial spreading and focusing of the spectral signals, a line-array image detector which is connected with the beam splitting system, carries out light intensity detection on the spectral signals of each pixel position in a high-speed scanning manner and outputs corresponding optoelectronic signals in a serial manner, a signal conditioning amplification and analog-to-digital conversion circuit which is connected with the line-array detector, an FPGA-based embedded demodulator which is connected with the signal conditioning amplification and analog-to-digital conversion circuit, realizes the fitting and interpolation operation of an spectral curve to obtain the peak coordinates of the spectral signals, and a bus interface module which provides a variety of kinds of digital buses.

Description

technical field [0001] The invention relates to the field of optical fiber sensing, in particular to a multi-channel fiber grating vibration signal intelligent sensor system with an embedded fiber grating demodulator that can realize fiber grating peak finding and vibration parameter calculation at the sensor end. Background technique [0002] Fiber Bragg Grating (FBG) sensor is a wavelength-modulated sensor. The refractive index in its core changes periodically along the axial direction, and it will reflect laser light of a specific wavelength. The period of reflection wavelength and refractive index change related to length. FBG sensors can effectively measure temperature, strain, vibration, etc. [0003] However, the FBG sensor's perception of environmental variables is realized through the precise measurement of the wavelength, and the analog value can only be obtained after a certain amount of data demodulation. The complex signal demodulation mechanism and algorithm l...

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Problems solved by technology

[0003] However, the FBG sensor's perception of environmental variables is realized through the precise measurement of the wavelength, and the analog value can only be obtained after a certain amount of data demodulation. The complex signal demodulation mechanism and algorithm limit the FBG sensor's ability to quickly change signals. Most of the current applications are limited to the monitoring of slowly changing signals such as temperature and strain

[0004] The existing high-end fiber grating demodulation module can achieve a demodulation rate of more than 30kHz, but due to the large amount of data, it needs to use the Gigabit Ethernet interface to transmit data. Due to the limitation of the processing speed of the host computer, it is difficult to achieve real-time measurement

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