基于数字相关原理的相位差测量新方法

提出了一种基于数字相关原理的相位差测量新方法，该方法直接对两被测信号作互相关运算，并利用相关和正弦函数的一些性质，使部分噪声分量被有效地与有用信号相分离，从而提高了抗随机干扰能力和测量的准确度。理论分析和数字仿真结果表明：该方法具有不必预先知识正弦信号频率、抗随机干扰能力强等特点；其测量准确度和信号的信噪比和数据采集卡的位数有关，可通过调节总采样样本点数减小它们的影响。

A New Method for Phase Difference Measurement Based on Digital Correlation Theory

In order to overcome the shortcomings of the previous method for phase difference measurement, a new method based on digital correlation theory is presented. Cross correlation functions of the two measured signals are directly computed and some properties about correlation and sine function are adopted to separate the part noise and the useful signal. And so the capability to resist random disturbance and the measurement accuracy are improved. The conclusions are supported by the results of theoretical analysis and emulating experiments. The characters of this method are strong anti disturbance capability and it is not necessary to know the signal frequency in advance. The measuring accuracy for this method is related to SNR of signal and the resolution of data acquired board, whose effects to the accuracy are diminished by regulating the total numbers of acquired data.