非整周期低信噪比科氏流量计相位差测量研究  

Research on phase difference measurement of Coriolis flowmeter with non-integer period and low signal-to-noise ratio

作　　者：李昊宇 黄丹平 罗凡[2] Li Haoyu;Huang Danping;Luo Fan(School of Mechanical Engineering,Sichuan University of Science and Engineering,Yibin 644000,China;National Institute of Measurement and Testing Technology,Chengdu 610000,China)

机构地区：[1]四川轻化工大学机械工程学院,宜宾644000 [2]中国测试技术研究院,成都610000

出　　处：《国外电子测量技术》2023年第11期89-96,共8页Foreign Electronic Measurement Technology

基　　金：过程装备与控制工程四川省高校重点实验室开放基金科研项目(GK202209);自贡市科技局重点项目(2019YYJC12)资助。

摘　　要：科氏流量计相位差计算易受噪声信号干扰、非整周期采样等因素影响,导致计算精度差,不能满足测量领域要求。针对该问题,并在分析非整周期信号误差产生的基础上,提出一种基于信号非整周期采样、低信噪比环境下的相位差高精度测量方法。该方法采用周期相移算法,极大抑制频谱泄漏,其核心在于对采样信号整周期化与全相位对齐;为减小噪声信号对相位差计算的影响,提出将Sign-LMS算法替代自适应陷波器中原有迭代部分,对采样信号进行滤波处理。进行了不同采样长度下端点效应抑制、滤波器效果、稳定性分析等相关实验验证,与主流相位差算法进行了实验对比,同时通过质量法水流量标准装置进行测试,其相位差平均误差在纳秒以内,同时实际工程中平均称重误差小于10 g,证明了所提出周期相移算法以及Sign-LMS自适应陷波器的有效性。The phase difference calculation of Coriolis flowmeters is susceptible to interference from noise signals and factors such as non-integer cycle sampling,resulting in poor calculation accuracy and inability to meet the requirements of the measurement field.To address this issue,based on the analysis of the errors caused by non-integer cycle signals,a high-precision phase difference measurement method is proposed that is based on signal non-integer cycle sampling and low signal-to-noise ratio environments.This method uses a periodic phase shift algorithm to greatly suppress spectrum leakage,with its core being the whole-phase alignment and whole-cycling of the sampled signals.In order to reduce the impact of noise signals on phase difference calculation,the Sign-LMS algorithm is proposed to replace the iterative part of the adaptive notch filter for filtering the sampled signals.This paper conducts relevant experimental verifications on endpoint effect suppression,filter effect,and stability analysis under different sampling lengths.The proposed method is experimentally compared with mainstream phase difference algorithms,and it is also tested using a quality-type water flow standard device.The average error of the phase difference is within nanoseconds,and the average weighing error is less than 10 grams in practical engineering,which proves the effectiveness of the proposed periodic phase shift algorithm and Sign-LMS adaptive notch filter.

关 键 词：科氏流量计 信号预处理 非整周期采样 周期相移算法 

分 类 号：TH814[机械工程—仪器科学与技术]