为了动态、实时地测量光电编码器在变速转动情况下的细分误差，提出了一种莫尔条纹信号的非均匀采样分析与处理方法。利用傅里叶级数原理构造了实际情况下的莫尔条纹信号方程，根据编码器在不同转速下的实时采样，揭示了莫尔条纹信号的非均匀采样特征。鉴于信号采样的非均匀性，采用曲线拟合的最小二乘法重构莫尔条纹信号，利用离散傅里叶变换算法分析重构信号并求出波形参数。通过信号参数与细分误差的关系式，测量了编码器动态细分误差。采用该方法对21位绝对式光电编码器莫尔条纹信号进行了分析和处理，两次测试得到其动态细分极值误差为+3.21″、-4.69″和+3.45″、-4.81″。实验结果表明，该方法可以有效地分析和处理编码器在非匀速转动下产生的变频莫尔条纹信号，精确地测量编码器的动态细分误差，为工作现场编码器误差的实时检测与修正奠定了基础。

To measure the dynamic real-time interpolation error of an optical encoder in non-uniform rotation, a method for analysis and processing the Morié fringe signals based on non-uniform sampling was presented. The real Morié fringe signal equation was constructed by Fourier series principle. According to real-time sampling on the encoder at different speeds, the characteristics of non-uniform sampling for Moiré signals was revealed. On the basis of the non-uniformity of the signal sampling, the Morié fringe signals were reconstructed by using the least square curve fitting.Reconstructed signals were analysed by Discrete Fourier Transform algorithm and the waveform parameters were obtained. With the relationship between interpolation error and signal parameters, the measurement of encoder dynamic error was achieved. The Moiré fringe signal of a 21 bit absolute optical encoder was analysed and processed and the twice extreme dynamic interpolation errors are +3.21 "; -4.69" and +3.45 "; -4.81",respectively.Experiment result shows that this method effectively processes Morié fringe signal of variable frequency in the encoder with non-uniform rotation ,and accurately measures the dynamic interpolation error of the encoder,which provides foundation for real-time detection and correction of encoder error at the actual work site.