Research On Theory And Key Technology Of Multi-parameter Heterogeneous Fiber Sensor Network

This paper reviews the current research status of multi-parameter optical fiber sensor network(MOFSN).For the shortcomings of the MOFSN,such as simple network structure,weak data concurrent acquisition and processing ability,and low precision of wavelength demodulation,we propose a polymerized multi-parameter heterogeneous optical fiber sensor network(MHFSN),a real-time parallel data acquisition and big data processing method,a wavelength demodulation precision optimization method based on fiber optical Fabry-Perot tunable filter.In order to meet the requirements of multiparameter heterogeneous sensing in complex environment,the embedded application software based on MHFSN is designed and developed to realize the composite monitoring of temperature,strain,pressure and vibration.The following work is done in this paper:1.For quasi-distributed temperature and strain sensor networks and the discrete pressure and vibration sensor networks,we proposed a heterogeneous structure of multi-parameter optical fiber sensor network.This network can multiplex different types of optical fiber sensor subnet,can automatically identify the types of subnet access networks.Two light source distribution structures are designed and their robustness is analyzed.2.For the fiber Bragg grating temperature sensing system,we proposed a wavelength demodulation precision optimization method based on optical fiber Fabry-Perot tunable filter.The algorithm used the original sampling data collected by the data acquisition card to dynamically calibrate the transmission wavelength of the F-P etalon real-time in each scanning cycle,and used the calibration value to calculate the central wavelength of the reflection of the fiber Bragg grating sensor.It effectively weakens the perturbation effect caused by the non-linearity and nonreproducibility of the narrow-band light source generated by the fiber F-P tunable filter,reduces the numerical error,effectively eliminates the pseudo-peak of the fp standard,and greatly improves the measurement accuracy of the system.The experimental results show that the temperature demodulation accuracy can reach 0.2 oC,and the wavelength demodulation accuracy is 3pm.3.We studied the real-time acquisition and data processing mode of MHFSN,and proposed a real-time parallel data acquisition and big data processing method.This method can multiplex different types of fiber sensor networks and quickly complete the simultaneous sampling of thousands of sensors on hundreds of channels in four-parameter heterogeneous fiber sensor network,its sampling frequency is up to 6.4MHz,and the data throughput is up to 13.8MB/s.4.The embedded application software,MSVP,based on MHFSN is designed and developed,proposes the reason of using My SQL database,analyzes the basis of database design,and designs and develops database of the MSVP.The overall framework of MSVP network communication and the humanized interface are analyzed and designed.MSVP have realized the high-capacity,large-scale and high-precision measurement of the composite parameters of temperature,strain,pressure and vibration.