Abstract: Cross-correlation is the common arithmetic in pulse-echo ultrasonic measurement distance. In the routine arithmetic, the quantity of the data to be treated is too large as all of the sampled data is involved in computing, and hence it is hard to be carried out in real time, especially in the embedded system. The optimization algorithm based on the pre-processing of the sampled data, including the fast calculations of the correlation coefficients by the recursive algorithm, is described in this paper. The algorithm can meet the precision of the time of echo ultrasonic measurement while reducing the computation burden remarkably. As a result, the algorithm is easy and reliable to be carried out, especially suitable for embedding system.

Key words: ultrasonic measurement distance, optimization algorithm, recursive algorithm, embedding system

摘要： 相关函数的时延估计方法是脉冲回波测距常用的算法。常规的算法直接以回波采样数据为样本处理，运算处理的数据量过于庞大，在嵌入式系统中实现困难且实时性差。提出将采样数据预处理，并以面向该应用采取的递归算法，快速获取相关系数的优化算法。可满足回波时间测量的精度，并显著降低数据存储器的需要量和数据的处理量。实现方法简便可靠，具有较高实用性。

关键词: 超声测距, 优化算法, 递归算法, 嵌入式系统