基于相关理论的相位差算法的误差研究

Research on Error of Phase Difference Algorithm Based on Correlation Theory

为了提高电信号相位差的测量精度,提出了基于双相关算法的相位差测量新方法.对于同一对正弦波信号,利用此方法进行相位差仿真测量,当采样频率、采样精度和噪声源参数发生改变时,测量误差会有所不同.仿真结果表明,信号的采样频率和噪声源对测试结果影响较大,最大相对误差可达到1%,而采样精度对测量结果的影响较小,约0.1%.该算法已应用于某导弹舵机的测试系统中,经过多年使用,测试性能稳定,结果符合要求.

In order to improve the measurement precision of phrase difference of electrical signals,a new method is put forward based on double correlation algorithm.Numerical simulations have been done to measure the phase difference of the same couple of sine signals by using this method.The measurement error varies with the sampling frequency,parameters of noise source and sampling bits.The simulation results show that the sampling frequency and parameters of noise source affect the measurement precision much more than the sample bits do by 1% vs.0.1%.The algorithm has been applied to a missile steering engine testing system.After several years＇ operation,the performance of the system keeps reliable and meets the user＇s requirements.