Abstract:For the four-channel ultrasonic gas flow-meter, a digital signal processing method based on variable threshold and zero-crossing detection is proposed to locate the echo signals quickly and accurately and improve the anti-interference ability of the system. And the working process that centralized sampling-centralized processing of data and the transceiver way that double emission double receive were designed. A transmitter of four-channel ultrasonic gas flow-meter was developed based on FPGA & DSP dual core structure. It realizes the double emission double receive transceiver way, controls the high-speed ADC & DAC and storages the data by taking the advantage of the parallel processing capacity and better logic control ability of FPGA, completing the centralized sampling of data. On the other hand, it realizes the real time digital signal processing method by using the high-speed computing capacity of DSP, completing the centralized processing of data. The gas calibration experiment results show that the four-channel ultrasonic gas flow-meter developed meets the needs of the related technical indicators of the 0.5-level precision ultrasonic gas flow-meter.
穆立彬,徐科军,刘博,田雷,李剑波,沈子文. 基于可变阈值和过零检测的四声道气体超声波流量变送器[J]. 计量学报, 2019, 40(2): 266-271.
MU Li-bin,XU Ke-jun,LIU Bo,TIAN Lei,LI Jian-bo,SHEN Zi-wen . Development of Four-channel Ultrasonic Gas Flow Transmitter Based on Variable Threshold and Zero-Crossing Detection. Acta Metrologica Sinica, 2019, 40(2): 266-271.
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