基于多参考波的多径超声气体流量计设计

Design of Multipath Ultrasonic Gas Flowmeter Based on Multiple Reference Wave

超声波气体流量计中使用了多种技术,如多普勒、相关性等,基于实验和基于测量传输时间的方法已经证明了它的优点并变得更加流行。在可用于确定超声波飞行时间(TOF)的技术中,包括阈值检测,互相关算法和其他数字信号处理算法,当接收到的超声信号受到严重干扰时,互相关算法具有更多优势。然而在多径流量计的应用中,参考波的选择变得困难。对此,在分析引入超声波噪声和波形畸变的影响因素的基础上,提出了一种有助于确定参考波的实用方法。在多路超声波气体流量计的应用中,超声波的每个路径的分析需要其自己的参考波。在案例研究中,设计并测试了6通道超声波气体流量计,其中气流通过管道。结果表明,与使用随机参考波相比,使用平均参考波可以显着提高TOF的流速精度和重复性。

There are many technologies used in ultrasonic gas flowmeter, such as Doppler and correlation. Experimental and time-based methods have proved their advantages and become more popular. In the technology used to determine the time of flight(TOF), including threshold detection, cross-correlation algorithm and other digital signal processing algorithms, cross-correlation algorithm has more advantages when the received ultrasonic signal has been seriously disturbed. Based on the analysis of the factors that influence the introduction of ultrasonic noise and waveform distortion, a practical method to determine the reference wave has been proposed. In the application of multi-channel ultrasonic gas flowmeter, the analysis of each channel of ultrasound needs its own reference wave. In the case study, a six-channel ultrasonic gas flowmeter has been designed and tested, in which the gas flow passed through the pipeline. The results show that compared with the random reference wave, the average reference wave can significantly improve the accuracy and repeatability of TOF.