选带细化频谱分析在超声波流量测量中的应用  

The Application of ZOOM-FFT Technology in Ultrasonic Flow Measurement

作　　者：伍昕[1] 刘岩[1] 何耀[2] 冯冠平[1] 

机构地区：[1]深圳清华大学研究所,深圳518057 [2]上海汽轮机有限公司,上海200240

出　　处：《测试技术学报》2006年第2期109-112,共4页Journal of Test and Measurement Technology

摘　　要：通过中频调制为基础提取流体速度方向信息,引入选带细化频谱分析技术对解调后多普勒信号进行高精度的频谱估计,该方法主要有三个方面的优点:能判断流速的方向;降低流速测量下限;提高了流速测量的动态响应速度、实时性以及稳定性.在此基础上,以数字信号处理器(DSP)为平台设计了超声流量计,实验分析表明1 024点ZOOM-FFT算法在选定频带范围内与16 384点FFT有相近的分辨率.This paper adopted the intermediate frequency modulation to extract the flow direction, and introduced the ZOOM-FFT technology to precisely estimate the frequency spectrum of demodulated Doppler signal. This method has three primary advantages： judging the flow direction, reducing the lowest measurement limit of the low flow velocity, raising the dynamic response speed, real-time characteristic and the stability of flow velocity measurement. On this basis, the authors designed an ultrasonic Doppler flow-meter by digital signal processor （DSP）. The experiment results indicated that the 1024-point ZOOM-FFT has the similar resolution to the 16384-point FFT within a certain frequency range.

关 键 词：超声多普勒 流量测量 频谱分析 选带细化 中频解调 数字信号处理器 

分 类 号：TH814.92[机械工程—仪器科学与技术]