超声波流量计中相关时差法的应用  

Application of Time-different Algorithm Based on Cross Correlation Theory in Ultrasonic Flowmeters

作　　者：陆敏恂[1] 朱列铭[1] 周爱国[1] 

机构地区：[1]同济大学机械工程学院,上海201804

出　　处：《仪表技术与传感器》2011年第12期105-107,共3页Instrument Technique and Sensor

基　　金：上海市委火炬计划项目(08Dz1120702)

摘　　要：介绍了一种基于互相关理论的时差法超声波流量测量算法。系统采用时差法声道布置,采集流体静止和有流速状态下的两组回波信号,通过计算相关函数的峰值得到两回波信号时间差,间接得出流量,提高了时差法渡越时间获取的精度。极性相关算法的引入,大大提高了系统运算速度,提高了实时性。采用伪随机信号作为超声激励信号,克服了算法测量范围小的缺陷,更可提高系统精度。实验表明该系统测量精度高,实时性好。This paper introduced a time-different ultrasonic flow measurement algorithm based on cross correlation theory.The system arranged ultrasonic transducers like the arrangement of the time difference method flowmeters,and collected stationary fluid condition and flowing fluid condition of echo signals in two groups.By calculating the correlation function peak of the two echo signals,it obtained the time difference,indirectly gained the flow of wind,which can improve the accuracy of the transit time difference accuracy.The application of polarity correlation algorithm can greatly improve the system operation speed and improve performance of real-time property.By using pseudo-random signal as the ultrasonic excitation signal,the algorithm overcomes the shortcomings of small measurement range,and improve the system accuracy.Experiments show that the system is of high precision,and good real-time property.

关 键 词：超声波 流量计 相关时差法 伪随机信号 极性相关算法 MATLAB 

分 类 号：TP216[自动化与计算机技术—检测技术与自动化装置]