Design and Application of High-Precision Frequency Measurement System Based on FPGA
Aimed at the need that quartz crystal microbalance(QCM)sensors are used to measure high-precision frequency in gas detection,a high-precision frequency measurement system based on field programmable gate array(FPGA)is designed.An equal-pre-cision frequency measurement method based on phase-locked loop is proposed to reduce the theoretical relative error of frequency measurement,and design the overall architecture of the frequency measurement system.According to this architecture,the hardware circuit of the high-precision frequency measurement system based on FPGA is completed.The embedded software is also designed,which includes the modules of frequency measurement,communication,and firmware programming.The integration of the high-pre-cision frequency measurement system based on FPGA is achieved,which is applied in the QCM-based carbon dioxide gas concentration detection.Experimental results show that the absolute error of the frequency system measurement does not exceed 0.35 Hz,with an average error of 0.268 Hz and a maximum relative error of 3.5X 10-8.The frequency measurement resolution can reach 0.1 Hz.The system has the advantages of low measurement error,good stability,and better application prospect in the QCM-based carbon dioxide concentration detection.
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维普
