互相关算法在气体超声波流量计中的应用

Application of cross-correlation algorithms in ultrasonic gas flowmeters

针对当前大口径气体超声波流量计存在抗干扰能力差和测量精度低的问题,设计了一种利用互相关算法提高测量精度的气体超声波流量计.即以STM32F407作为核心控制器,采用时差法为测量方法,利用互相关波形匹配算法对信号进行定位处理.通过STM32主控芯片和TDC_GP22计时芯片测量的时间值与互相关算法得到的时间值进行对比参照,得到了精确的测量时间.进而搭建了试验样机并进行了试验测试和数据仿真.结果表明,该算法提高了流量计测量精度,增强了稳定性和抗干扰能力.

A new ultrasonic gas flowmeter was designed by using the cross-correlation algorithm to improve measurement accuracy.The core controller of the design was a STM32F407.Flow velocity was determined by the time-difference method;and the signal location was realized by the cross-correlation waveform matching method.By comparing the time measured with STM32 main control chip and TDC_GP22timing chip to that calculated by the cross-correlation algorithm,the accurate time difference was obtained.Simulation work was performed on a prototype.The results of the experimental tests and simulations show that the cross-correlation algorithm can improve the measurement accuracy and enhance stability and anti-jamming capability.