| The rotation axis is the basis of the rotating motion of mechanical structure.The rotation axis is very important in aerospace,military equipment,high-end manufacturing,intelligent medical and other application fields,and the manufacturing accuracy and operation state of the rotation axis are very important for precision measurement,processing and control equipment,including roundness instrument,laser tracker,multi axis numerically controlled machine tool and multi degree of freedom manipulator.The straightness error of the rotation axis is an important error source in the working process of the rotation axis.The straightness motion error of the rotation axis is an important parameter about the working accuracy and safe operation of high-precision equipment.In order to measure the straightness error of the rotation axis,the laser interferometry method is introduced into the research of the straightness error measurement of the rotation axis.Laser interferometry has the characteristics of high sensitivity and high precision.It is easy to be affected by many error factors in the measurement process.In order to optimize the measurement scheme,this subject simulates and analyzes the error influence of optical devices such as light source,polarizer,polarized beam splitter,phase retarder and corner prism in the measurement system.Jones matrix and Zemax are used to establish the interferometric error model,The main error source is the angle and wavelength drift of the semiconductor laser.In the research project,an experimental scheme for monitoring the relevant parameters of the semiconductor light source is proposed,which is conducive to the correction and compensation of the laser interference measurement results of the straightness error of the rotation axis.The main research work of this dissertation is as follows:Firstly,the experimental scheme of rotation axis motion straightness error interferometry is proposed,the possible error factors are analyzed,and the method of analyzing the error factors by Jones matrix and Zemax is determined;Secondly,the error model of laser interferometry about the straightness error of the rotation axis is established by using Jones matrix on the platform of Matlab,and the measurement simulation optical path is built by Zemax.Through the above contents,the influence of optical devices such as non ideal laser light source,polarizer and polarization splitting prism in the optical system on the interference measurement results and the contrast of interference fringes is analyzed.Further,it can put forward reasonable suggestions for the selection of relevant equipment.The analysis results show that compared with other error factors,the measurement error caused by the wavelength drift of the light source has the greatest influence.The measurement accuracy of the straightness error of the rotation axis can be greatly improved by compensating and correcting the wavelength of the light source;Finally,in order to solve the influence of wavelength drift of semiconductor laser light source on the accuracy of interference measurement of straightness error of rotation axis motion,an experimental scheme for monitoring relevant parameters of semiconductor laser light source based on grating diffraction principle is designed.The experimental results show that when the ambient temperature changes by 0.55℃,the horizontal drift of the semiconductor laser light source is 0.06′′,the vertical drift is 1.09′′,the wavelength drift is 0.31nm,and the frequency stability of the semiconductor laser light source is 4.9×10-4.According to the simulation model,when the laser interference measurement range of the straightness error of the rotating axis is±1mm,After compensating the interferometric error caused by wavelength drift in this range,the interferometric error is reduced by 0.489μm.Since the resolution of the photodetector is40 nm,the compensation accuracy of the interferometric measurement results can reach31 nm. |
PDF Full Text Request