Abstract:Aiming at the problem that the accuracy of the waveform equation establishment in the sinusoidal error compensation process of the grating Moiré signal affects the error compensation effect, a waveform modeling method is proposed according to the requirement of actual subdivision number. On the basis of explaining the sinusoidal error compensation principle of grating Moiré signal based on PSO algorithm, the importance of the signal waveform equation establishment is expounded. Aiming at the problem of harmonic selection during the waveform equation establishment, the angle errors induced by the DC drift and harmonic contents are quantified, which provides a reference for the establishment of the waveform equation. Simulation experiments were used to verify the effectiveness of the model establishment. On the FPGA platform, the signal waveform parameter solution was achieved with the PSO algorithm and the influence of waveform equation on resource occupancy under different dimensions was compared. Finally, a grating system platform was established to verify the effectiveness of the proposed method. The results show that the proposed compensation method can effectively reduce the sinusoidal error component in the signal. The subdivision error is reduced from 074″ to 030″.