利用抽样率变换提高渡越时间测量精度方法  

The Method of Improving the Measurement Accuracy of Transition Time Based on Sampling Rate Change

作　　者：吴新杰[1] 刘石[2] 许超[1] 付荣荣[1] 胡晟[1] 

机构地区：[1]辽宁大学物理学院,沈阳110036 [2]华北电力大学能源与动力工程学院,北京102206

出　　处：《工业计量》2011年第3期1-3,共3页Industrial Metrology

基　　金：国家自然科学基金重点项目(50736002);辽宁省自然科学基金资助项目(20102082);华北电力大学电站设备状态监测与控制教育部重点实验室开放基金资助项目(2008-010)

摘　　要：为了克服低采样率对信号渡越时间测量精度的影响,提出一种互相关与抽样率变换相结合的渡越时间估计方法。首先对上下游传感器信号进行采样率变换,然后对它们进行傅立叶变换;并通过低通滤波器滤除多余的镜像,最后根据卷积定理求出上下游传感器信号的相关函数和渡越时间。仿真实验结果表明:文章方法得到的渡越时间估计值误差比较小,结果更可靠,这也降低了对数据采集卡的要求,为两相流速度测量提供一种有效的手段。To overcome the effect of low sampling rate on the measurement accuracy of transition time,a measurement method of transition time based on cross correlation and sampling rate change is proposed.Firstly the sample rates of upstream and downstream sensors signals are changed.Then the spectrums of upstream and downstream sensors signals are achieved by Fourier transform.The superfluous images of their spectrum are filtered by low-pass filter.Finally the correlation function and transition time are obtained according to the convolution theorem.The simulation results have shown that the measurement errors of transition time are smaller and more reliable.This method may reduce the requirements of data acquisition card,too.It also presents an effective means for the velocity measurement of two-phase flow.

关 键 词：两相流 互相关 抽样率变换 速度 

分 类 号：TP274.2[自动化与计算机技术—检测技术与自动化装置]