Research On Error Analysis Of Line Scan Gear Measuring Machine And Calibration Technology Of Reference Shaft

Gears are the basic transmission parts of industrial equipment and are widely used in the automotive,aerospace,industrial equipment and military industries.With the rapid development of manufacturing industry,gear measuring technology and instruments have also progressed,and line scan gear measuring machines have been created.Line scan gear measuring machine is a kind of measurement efficiency,can obtain tooth surface tooth profile complete information non-contact gear measuring instrument,which directly affects the gear measurement accuracy of the instrument calibration has become one of the hot spots in the field of gear measurement research.Instrument calibration mainly includes sensor calibration and gear reference axis calibration,where most of the existing gear reference axis calibration requires specific machining of high-precision standard parts,the calibration process is tedious,high cost and limited calibration accuracy,so this paper takes the line scan gear measuring machine as the object,using the method based on the plane target calibration of its line laser scanning system rotary reference axis calibration.Firstly,based on the mechanical structure and working principle of the line scanning gear measuring machine,the sources of measurement error and evaluation error are analysed,and the mathematical model of the influence of reference axis deviation on gear measurement results and the reliability of evaluation results is established and numerically simulated by combining the three-dimensional gear measurement model and the definition of gear measurement parameters.Secondly,based on the existing calibration technology of line laser scanning system,the camera calibration method and the existing rotary reference axis calibration method are analyzed and summarized,and Zhang Zhengyou’s camera calibration method is used for camera calibration.Then,based on the basic rotary datum axis calibration method,an improved rotary datum axis calibration method of the rotary table is proposed by fixing the plane checkerboard grid parallel to the precision rotary table and using the least squares method to fit the feature point plane to obtain the direction vector of the rotary datum axis.The rotation datum axis equation is obtained.Finally,the rotary reference axis calibration experiment of the rotary table was completed using the built up rotary axis calibration experimental platform and gear measurement center.The Rodriguez matrix was used to convert all the reference axis calibration results into the same coordinate system,and the results of the rotary reference axis calibration were compared with those of the gear measurement center to verify the feasibility of the reference axis calibration method.The experimental results show that the improved method reduces the reference axis tilt angle by 65.2271% and the eccentricity distance by 47.8752%,i.e.the improved method results in a more accurate calibration of the reference axis,proving that the rotational reference axis calibration method can be used for subsequent gear reconstruction experiments,providing a basis for accurate measurement and evaluation of the results of the linear laser scanning gear.