25 Hz相敏轨道电路相位差测量非整周期采样误差校正算法

Non-integer-period sampling error correction algorithm in phase difference measurement of 25 Hz phase-sensitive track circuit

针对25 Hz相敏轨道电路接收器相位差测量过程中非整周期采样带来的误差问题,设计了一种基于希尔伯特数据重采样的校正算法。该算法从25 Hz相敏电路待测信号频率波动范围有限的实际出发,结合希尔伯特变换计算出待测信号的实际周期值,然后依据估测的周期值对采样信号的值进行更新,排除频率漂移的影响,提高测量精度。用仿真软件量化观察校正方法的效果,实验结果表明,在有无噪声的情况下相位和幅值的精度都很好,相位角测量误差不大于0.3°。

To correct the non-integer-period sampling error of phase difference measurement in 25 Hz phase-sensitive circuit, an algorithm based on data resampling was proposed. Based on the fact that the frequency of tested signal from 25 Hz phase-sensitive circuit is within a certain range, the actual value of a cycle was estimated by means of the Hilbert transform.Then the sampling value was updated according to the estimated cycle value to eliminate the influence of frequency drift and improve the accuracy of measurement. Simulation software was used to observe the effect of correction quantitatively.Experimental results show that the precision of phase is good regardless of the presence or absence of noise, and the error of phase angle measurement is less than or equal to 0. 3°.