基于相关原理的非整周期信号相位差测量算法

Research on phase difference measurement for non-integer period sampling signal 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,提出一种基于相关原理的非整周期信号相位差测量算法:首先采用自适应格型陷波器进行滤波,以求信号频率;然后利用滤波后的原2路同频信号产生具有90°相移的2个参考信号;将原2路同频信号分别与2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。同时,针对引入两参考信号相移不是90°的情况,进行了误差分析并给出了相应的补偿措施。理论分析表明,该算法测量精度不受采样是否整周期的影响,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,抗噪性能更强。仿真分析与工程应用均证实了该算法的有效性和可行性。

In order to improve the accuracy of phase difference measurement under non-integer period sampling circumstance with correlation method,a new phase difference measurement method for non-integer period sampling signal based on correlation theory is proposed.Firstly,lattice adaptive notch filter is applied to filter the signals and estimate the frequency of the signal.Then,two reference signals that have 90 degree phase shift are generated from the two filtered signals with same frequency.And then,the correlation functions of the original signals and reference signals are directly computed; certain properties of correlation and sine function are adopted to obtain the computational formula for phase difference.At the same time,aiming at the situation where the phase shifts of the two reference signals are unequal to 90 degrees,error analysis is carried out and relevant compensation method is presented.Theoretical analyses show that the measurement accuracy for this method is not affected by the condition whether the signal is integer period sampling or not;and the method can also measure dynamic phase difference.Compared with traditional methods,the proposed method is superior in accuracy and robustness.Simulations and engineering applications verify the feasibility and effectiveness of the proposed method.