The Improvement Of Adjustment System For Grating’s Eccentricity Of Encoder Based On Machine Vision

High-precision optical encoder is an important part of photoelectric anglemeasuring instrument and angle measuring technology, the main applications ofwhich are in the aerospace, automotive, defense industry, high-precision machinetools, and other important areas of aviation. Currently, the eccentricity of encodergrating mainly rely on manual adjustment or semi-automated adjustment in thedomestic, which has plenty of deficiencies in adjustment accuracy, efficiency,stability, influences of man-made factors, the degree of automation. To make up thedeficiencies above, this thesis designed and built a system for automaticallyadjusting the eccentricity of encoder grating based on machine vision, completingthe optimization of the original device of grating eccentricity adjusting inaccuracy, efficiency, stability etc, formatting the system of high precisiongrating eccentricity adjusting based on machine vision, data and signalprocessing, intelligent integrated control.First of all, the accuracy optimization of the machine vision system is achievedrespectively through the preferred machine vision image acquisition device, imageprocessing program, pixel size calibration on the basis of the analysis ofgrating eccentricity adjusting precision influence factors. The accuracy optimizationof coaxial calculating solution is achieved through the analysis, comparison andselection of the coaxial calculating solutions. The accuracy optimization of controlsystem is achieved by optimizing control system equipment, improving controlprocess, designing control programs.Secondly, the software of grating eccentric adjustment system is developedbased on VC++/OpenCV environment with a brief introduction and comparativeadvantages over original software functionality development environment, a detailedanalysis of the efficiency optimization of the control system. The control flowchartsand programs of grating eccentric adjustment mode and coaxial detection modewere developed.Thirdly, according to the technical requirements of industrial practice, the stability optimization of grating eccentric adjustment system is completed, includingoptimization of image acquisition, processing, eccentricity data processing andcontrol system stability.Finally, this thesis designed five experiments, including the accuracy test ofplatform for micro adjustment, parameter optimization test, adjustment efficiencytest, concentricity detection efficiency test, eccentricity test from third-party system.Experimental results show that the accuracy, efficiency and stability of adjustmentsystem for grating’s eccentricity of encoder have reached the design specifications,being able to meet the needs of practical application within10μm range gratingadjustment accuracy and30s range of adjustment time.The content of this thesis provides a theoretical basis and engineeringexperiments for the development of high accuracy and resolution absolute gratingrotary encoder, with significant engineering significance.