中文摘要：

针对当前涡街流量计量程比较低、低流速下测量精度不高的问题,提出一种采用FFT（fast Fourier transformation）谱分析与多重互相关算法相结合的数字信号处理方法.该方法首先使用FFT谱分析法得到信号的频率范围,然后选取适当周期个数的数据,使用多重互相关算法进行数据分析和处理,得到比较理想的信号频率.经仿真和实际验证：使用多重互相关算法能有效地提高涡街信号的信噪比,将淹没在噪声中的微弱涡街信号检测出来,扩展涡街流量计的测量下限.

英文摘要：

In vortex flow meters,measurement precision at lower velocities and turndown ratios is low.To address this problem,a digital signal processing method that combines a fast Fourier transform（ FFT） spectrum analysis algorithm and a multiple cross-correlation algorithm is proposed.First,the frequency range of the signal is calculated using the FFT,spectrum analysis algorithm,and then the appropriate cycle＇s data are selected.The multiple cross-correlation algorithm is used to process the data to obtain ideal signal data.Simulation and experimental results show that the signal-to-noise ratio of the vortex signal can be effectively improved and the weak vortex signal that is drowned in the noise can be detected using the multiple cross-correlation algorithm.Thus,the value of vortex flowmeter measurement at lower velocity is extended.