Research On Compensation Method Of Sinusoidal Error Of Grating Moiré Signal

The quality of the grating moiré signal directly affects its subdivision effect.In the actual grating measurement system,due to processing technology,mechanical installation and other factors,there are DC drift,equal amplitude error,phase error and sinusoidal error components in the grating moiré signal generated.Among them,since the sinusoidal error is quantized in the frequency domain,compared with the other three errors,the compensation is more complicated.Therefore,research on the sinusoidal error compensation technology of grating moiré signal is of great significance to improve the measurement accuracy and resolution of the grating sensor.Based on the quantitative analysis of the subdivision error introduced by the sinusoidal error of the grating moiré signal,this paper establishes an error compensation model;improves the method of sinusoidal error compensation of the grating moiré signal based on particle swarm optimization(PSO),and aims at the compensation scheme.The key links of this paper are analyzed and the specific implementation plan is given;the FPGA circuit system is designed,and the compensation algorithm is implemented on this platform,and finally the application in the actual grating measurement system is realized.The main research contents include:1.Establishing a sinusoidal error compensation model for grating Moire signals: A mathematical model is established for the grating moiré signal sinusoidal error.The subdivision error introduced by the sinusoidal error is quantitatively analyzed,and a sinusoidal error compensation method based on the angle compensation idea is proposed.2.Improve the sinusoidal error compensation method based on PSO algorithm: Aiming at the problem of non-quantified indicators in the traditional waveform modeling process,through the establishment of model derivation and analysis,a set of innovative waveform modeling methods with quantized indicators was proposed.Aiming at the problem of the complexity of the algorithm in the application process of PSO algorithm,the two key parameters of inertial weight w and the number of particles N are determined through experiments to ensure the effectiveness of the algorithm and reduce the complexity of the algorithm to the maximum extent.3.Complete sinusoidal error compensation algorithm circuit design:FPGA is used as the hardware circuit platform to develop a circuit board for receiving and processing the actual grating moiré signal.The PSO algorithm module and the error compensation module are built on the FPGA platform to realize the sinusoidal error compensation of the grating moiré signal.In this paper,the sinusoidal error compensation technology of grating moire signal is studied.The research results can obviously improve the subdivision accuracy of grating moire signal,and provide strong technical support for the research of high-precision grating measurement system.