In order to realize the detection for dynamic interpolation error in high-precision optical encoder with non-uniform rotation

a method of analysis based on mori fringe photoelectric signals with non-uniform sampling is presented.First

the real signal waveform is reconstructed with collecting non-uniform signal data of encoder in the method of least squares curve fitting.Then

according to the discrete Fourier transform algorithm analyzing reconstructed signal

meanwhile deducing the calculation expression of frequency

amplitude and phase.The feasibility of the algorithm is assessed with software emulation.Finally

the precise code signal of a 21-bit absolute rotary optical encoder is analyzed.Dynamic interpolation error is obtained based on relationship between the signal parameters and interpolation error.Interpolation extreme errors are +2.41 and -3.08.Experiment result shows that

the signal parameters are obtained with using signal reconstruction and Fourier transform algorithm

that reflects the real mori signal quality.This method can effectively measure the dynamic interpolation error while the encoder is non-uniform rotation

which establishes foundation of real-time detection of encoder error at the actual work site.