Research On Single-probe Shear Scanning Measurement Of Guideway Straightness

Straightness error is one of the important geometric errors.In ultra-precision machining,the straightness error of the guideway affects the surface accuracy of the workpiece.With the continuous progress of ultra-precision machining technology,the requirement of measuring straightness of guideway is getting higher and higher.The methods of measuring the straightness of guideway include laser interferometer,optical flat scanning and so on.In this paper,the workpiece profile is measured based on the shear scanning method of single probe,and the straightness error of guideway is separated.The main research contents of this paper include:1.The limitations of multi-probe scanning measurement and the advantages of single-head shear scanning measurement are analyzed.A flexure hinge is designed to realize the single-head shear scanning function.Finite element analysis of flexure hinges,design and optimization of flexure hinges to meet the requirements of use.Then the stiffness of the flexure hinges are tested to verify the reliability of the flexure hinges and the correctness of the simulation results.2.The shearing platform control system was built,and the UMAC controller and TA330 linear driver were used to achieve high positioning accuracy and repeat positioning accuracy of the shearing stage.The performance study of the spectral confocal sensor was carried out,and the optimal sampling frequency for stable data output was obtained.3.The source of the single-head shear scan error is analyzed.The influence of the two-head method spacing error and the single-head two-point shear error on the measurement error is studied.The effects of environmental factors(temperature,noise,vibration isolation)on the spectral confocal sensor were also investigated.4.The single probe head scanning scanning measurement method is used to measure the workpiece contour,and the straightness error of the guideway is separated.The feasibility and accuracy of the proposed method are verified by comparison with dualfrequency laser interferometer measurement and optical flat scanning measurement.