基于DFT的自调整累积误差消除相位检测系统

DFT-based self-adjusting cumulative error elimination phase detection system

基于离散傅里叶变换(DFT)的测量方法计算量大且必须要求整周期采样,文中针对这些问题提出了一种基于DFT的自调整累积误差消除相位检测算法。通过A/D采样电路采集波形数据,应用算法自动调整采样频率实现整周期采样并滤除由频率偏移带来的累积误差,然后结合FFT技术实现快速相位计算。该方法有效减小了由非整周期采样产生的计算误差和频率偏移带来的累积误差,能够准确稳定的得到输入信号的相位。

The measurement method based on Discrete Fourier Transform(DFT)has a large amount of calculation and requires full-cycle sampling.Aiming at these problems,the article proposes a DFT-based self-adjusting cumulative error elimination phase detection algorithm.The waveform data is collected through the A/D sampling circuit,and the algorithm is used to automatically adjust the sampling frequency to achieve full-cycle sampling and filter out the cumulated error caused by the frequency offset,and then combine with FFT technology to achieve fast phase calculation.This method effectively reduces the calculation error caused by the non-integer period sampling and the cumulative error caused by the frequency offset,which can accurately and stably obtain the phase of the input signal.