时差法超声波流量检测三步互相关算法研究

对时差法超声波流量检测中互相关算法计算量大的问题进行了研究，指出了减少计算量的3个方面——参与运算的数据容量、每次相关运算乘加次数和相关运算的累计次数，提出了一种采用预处理、粗相关和精相关三步相关算法，将计算量减少3~5个数量级；并以λ型超声波流量检测方法中的三步互相关算法为例，将整体运算时间控制在ms级，达到了实时性要求，为Z型、V型等时差法超声波流量检测的互相关算法大幅度减少计算量提供了一种有效的解决方案。

Study on three-step cross-correlation algorithm for ultrasonic flow detection by time-difference method

Based on the analysis of the problem of computing a large amount about cross-correlation algorithm for ultrasonic flow detection by time-difference method，the authors pointed out the three aspects of reducing the amount of calculation，firstly operation data quantity，secondly multiply-add operation quantity of each correlation operation，and lastly correlation operation quantity. A three-step cross-correlation algorithm was proposed，which is based on preprocessing，rough correlation and fine correlation. It can decrease the calculation quantity by 3~5 orders of magnitude；lambda type ultrasonic flow detection method was also applied as an example，the overall computation time was controlled in ms level，which has met the real-time requirement. Finally，it has provided an effective solution to greatly reduce computation of cross-correlation algorithm for Z type，V type time-difference method of ultrasonic flow detection.