Research On Grating Moiré Signal Acquisition And Subdivition Technology

Angle is an important basic physical quantity,and angle measurement is an important part of measurement technology.As the advantages of high accuracy and high resolution,circular grating has been widely used in angle measurement.In the field of high resolution angle measurement,it is difficult to meet the requirement of measurement resolution and accuracy only depending on the resolution of the grating itself.Therefore,it is of great significance to carry out the research on the subdivision of the grating moiré signal.In this paper,the digital amplitude segmentation algorithm is studied based on the analysis of the existing subdivision technology.By analyzing the influence of DC error,amplitude error and quadrature error of actual moiré signal on the amplitude subdivision algorithm,the necessity of error compensation in the implementation of amplitude subdivision algorithm is expounded.According to the characteristics of moiré signal,the error compensation method was proposed and established the model between ADC parameters,moiré signal error compensation and subdivision.Aiming at the requirement of digital amplitude subdivision algorithm for signal sampling quality,the system circuit design are completed on the FPGA platform with the sampling speed and sampling precision as an indicator,and completed the signal acquisition and digital amplitude subdivision on the platform.The main research contents include:1.Grating moiré signal acquisition at high speed: the 8 way parallel circuit is used to match the layout of multi grating reading heads.According to the requirement of signal frequency characteristics and subdivision,the 80 Mbps high-speed analog to digital conversion function module is studied on the FPGA platform.2.Real-time compensation for moiré short period error: established a quantitative model between each short period error and the subdivision of moiré Signal,and developed digital circuit module to realize real-time compensation of DC,amplitude and quadrature error.3.Digital amplitude division and subdivision: research on moiré signal digital subdivision method on FPGA platform,and carry out quantitative research on ADC parameter,DC error compensation,amplitude error compensation and subdivision.In this dissertation,the method of grating moiré signal acquisition and subdivision are studied.The expected results can provide a little bit of technological accumulation for grating moiré signal subdivision technology,which will have a positive impact on promoting multi-grating read-heads measurement at high precision angle measurement.