数字信号处理技术在科氏质量流量计中的应用

Applications of digital signal processing technology in Coriolis mass flowmeter

科氏质量流量计是目前应用范围最广、发展速度最快的流量计之一。数字信号处理技术是科氏质量流量计的核心技术,直接决定其测量精度、测量稳定性等性能指标;而流量传感器输出信号的数学模型是信号处理的依据和基础。国内外学者提出了多种信号处理方法,但是,没有根据不同的信号模型和不同的应用场合对各种信号处理方法进行比较和评价。为此,根据不同数字信号处理方法的特征量提取原理,分析了其具有的优缺点。针对科氏质量流量计单相流、批料流与气液两相流测量这3种典型应用场合中存在的关键技术问题,依据随机游动信号模型、突变信号模型和自回归滑动平均(ARMA)信号模型,分别从计算精度、响应速度、收敛性、抗干扰能力和对参数变化的敏感度等方面,对不同信号处理方法进行考核和对比,确定了3种典型应用场合下,解决关键技术问题,性能最佳的数字信号处理方法。

Coriolis mass flowmeter is one of the most widely used and fastest growing flowmeters. Digital signal processing technology is the core of Coriolis mass flowmeter and it directly determines the measurement accuracy, measurement stability and etc.. The mathematical model of sensor output signal is the basis of signal processing. Scholars at home and abroad have proposed many signal processing methods for Coriolis mass flowmeter. But there is a lack of comparison and evaluation for these signal processing methods based on different mathematical models and different applications. Therefore, the advantages and disadvantages of different signal processing methods are analyzed according to their feature extraction principles. The calculation accuracy, response rate, convergence, anti-jamming capability and sensitivity of different signal processing methods are compared and evaluated according to random walk model of single flow, mutant signal model of batch flow and ARMA signal model of gas-liquid two-phase flow. The optimized signal processing methods are determined for signal flow measurement, batch flow measurement and gas-liquid two-phase flow measurement to solve key technical issues.