Design And Research Of High-speed Data Acquisition System For FBG Based On FPGA

Data acquisition technology plays an important role in the process of industrial intelligence.Data acquisition system(DAS)is required to obtain external information accurately and quickly in order to make real-time analysis and judgment in many large-scale industrial production control.A data acquisition system with FPGA as controlling core is designed to solve the problems of high-speed acquisition,real-time processing and accurate display to optical fiber sensor signals,which is of great significance in scientific research and engineering applications.The data acquisition system designed in this paper takes ADC+FPGA+USB as the framework,based on the modular design idea of FPGA,completes the acquisition,storage,digital filter processing and transmission of the fiber Bragg grating(FBG)reflected signal in turn through the clock management module,First,the front-end signal conditioning circuit and A/D conversion circuit are designed to complete the collection of weak FBG reflected signals;the stability of the system is improved by designing ping-pong storage structure to shunt the collected data;the linear accumulation average algorithm is implemented in the Quartus ?compilation environment by using Verilog hardware description language,which completes the filtering and denoising of the collected signal and greatly improves the signal-to-noise ratio(SNR),moreover the real-time performance of the system is also guaranteed;Finally,the USB serial communication between the host computer and FPGA is completed in Lab VIEW software by combining the VISA library function,and a good human-machine interface is designed to complete the waveform display and storage of the collected signals.After completing the joint debugging of the hardware subsystem and the software subsystem,Taking fiber Bragg grating as temperature sensor to measure external temperature,the demodulated signal collected by the system is compared with the data measured by the spectrometer.The result shows that the average error of the center wavelength is 0.006nm,and the average temperature error is 0.44?,which verifies the feasibility and correctness of the system.