基于相关原理的相位差测量改进算法及应用

An improved method for phase difference measurement based on correlation theory

为提高相关法在非整周期采样情况下的相位差测量精度,增强算法的动态响应能力,提出了一种基于相关原理的相位差测量改进算法。该算法利用原两路同频信号产生具有90°相移的两个参考信号,经零相位滤波后,将原两路信号分别与两路参考信号进行相关运算,再利用相关和正弦函数的一些性质得到相位差的计算公式。理论分析和实验结果表明,该算法具有不必预先知道信号频率的特点,测量精度不受采样是否整周期的影响,且能实现相位差的动态检测,与传统算法相比,该算法测量精度更高,更具鲁棒性和普适性。

In order to improve precision and dynamic response capacity of the correlation method for phase difference measurement in the case of asynchronous sampling,an improved method for phase difference measurement based on the correlation theory was proposed.Firstly,two reference signals having a 90°phase difference were introduced by using two original signals with the same frequency.Then,after filtering with zero phase,the correlation functions of the original signals and the reference signals were directly computed,some properties of correlation and sine functions were adopted to obtain the computational formula of phase difference.The theoretical analysis and test results showed that it is not necessary for the proposed algorithm to know the features of the signal frequency in advance,and the measuring accuracy for this method is not affected by synchronous sampling or asynchronous one,it can realize the dynamic measurement of phase difference;compared with the traditional methods,it has better accuracy,robustness and universality.