Study On A Laser Multi-degree-of-freedom Precision Measurement Method Based On The Faraday Effect

The simultaneous measurement of a laser multi-degree-of-freedom motion parameters has advantages with high accuracy and high detection efficiency,and it is widely used in precision fields,such as the integrated circuit manufacturing,the ultra-precision machining and the robot calibration.Therefore,it is of great significance to carry out the study of simultaneous measurement of the laser multi-degree-of-freedom motion parameters.This thesis is supported by the project "Study on a laser multi-degree-of-freedom precision motion parameter measurement method based on the Faraday effect(No:51605445)" of the National Natural Science Foundation of China.The simultaneous measurement method of the laser five-degree-of-freedom precision motion parameters based on the Faraday effect is studied,the influence mechanism of the coupling between angle error and the accurate measurement of straightness is analyzed.The simultaneous measurement system of the laser five-degree-of-freedom with angle error compensation straightness is designed to realize the high-precision simultaneous measurement of the laser five-degree-of-freedom motion parameters.The simultaneous measurement system of the laser five-degree-of-freedom precision motion parameters has been studied based on the Faraday effect.The theoretical study of the simultaneous measurement of the five-degree-of-freedom is carried out,the mathematical model of the influence of the coupling between yaw angle and pitch angle error and straightness is established,and the simulation research is carried out by MATLAB.The simultaneous measurement optical path structure of the five-degree-of-freedom is designed based on SolidWorks.The signal processing systems of laser heterodyne interference and position sensitive detector are designed.The measurement software of the laser five-degree-of-freedom upper computer is developed based on VB.NET.The error factors affecting the accuracy of straightness measurement are analyzed.The simultaneous measurement system of the laser five-degree-of-freedom based on the Faraday effect is constructed,and the related experiment studies are carried out.A series of experimental studies are carried out through the measurement system of the laser five-degree-of-freedom based on the Faraday effect to verify the feasibility of the five-degree-of-freedom measurement and the validity of the angle error compensation straightness measurement:(1)The static stability test experiment of laser.The experiments show that within one hour,the maximum deviation of the stability of the laser horizontal straightness is 0.44?m,the minimum deviation is-0.30?m and the standard deviation is 0.14?m,and the maximum deviation of the stability of the laser vertical straightness is 0.34?m,the minimum deviation is-0.20?m and the standard deviation is 0.09?m.The experimental results show that the laser has little effect on the straightness measurement.(2)The influence experiment of temperature on straightness measurement.The experiments show that within two hours,the temperature change is about 0.054°C and it has an effect on horizontal straightness with 0.011?m and an influence on vertical straightness with 0.003?m.(3)The verification experiments of angle and straightness measurement.The angle measurement experimental results show that in the measurement range of 0.06°,the maximum deviation,the minimum deviation and the standard deviation between the angle measurement value and the turret angle value of M-038.DG1 precision turntable are 2.12 arc sec,-0.91 arc sec,0.73 arc sec.This experiment verifies the effective of angle measurement.The straightness measurement experimental results show that in the measurement range of 0.75 mm,the maximum deviation,the minimum deviation and the standard deviation between the measurement value and the displacement value of the XML350 linear stage are 0.4?m,-0.79?m,0.35?m.This experimental verifies the straightness measurement has high measurement accuracy.(4)The repeatability experiment of the straightness measurement.The horizontal straightness measurement results show that the three times measurement values of the measured guide way are 15.02?m,15.17?m and 15.35?m,respectively.The vertical straightness measurement results show that the three times measurement values of the measured guide way are 8.71?m,8.44?m and 8.71?m,respectively.The constructed horizontal and vertical straightness measurement system has good repeatability.(5)The effectiveness experiment of angle error compensation straightness measurement.The experiment result shows that when the M-038.DG1 precision turntable is rotated from 0° to 0.06°,the maximum deviation of the horizontal straightness is-14.71?m with the standard deviation is 4.56?m.After the angle error compensation,the maximum error and the standard deviation of the straightness are reduced to 0.68?m and 0.25?m,respectively.The experiment result verifies that the coupling of angle error affects the accuracy of the straightness measurement,and the angle error compensation can improve the accuracy of the straightness measurement.(6)The comparison experiment of the straightness measurement.The experimental results show that the maximum deviation and the standard deviation between the straightness measurement value before the angle error compensation and the measurement result of Agilent heterodyne interferometer are 16.38?m and 5.85?m,respectively.The maximum deviation and the standard deviation between the straightness measurement result after the angle error compensation and the measurement result of Agilent heterodyne interferometer are 3.42?m and 1.58?m,respectively.The comparison experiment verifies the effectiveness of the angle error compensation straightness measurement method.(7)The static stability experiment with simultaneous measurement of the five degrees of freedom motion parameters.The experiments show that within one hour,the standard deviations of the axial displacement,the horizontal straightness,the vertical straightness,the yaw angle,and the pitch angle measurement are 0.003?m,0.303?m,0.47?m,0.08 arc sec and 0.072 arc sec.The static stability experiment results verify that the simultaneous measurement system of five-degree-of-freedom that has better static stability.(8)The simultaneous measurement experiments of the five-degrees-of-freedom motion parameters.The experimental results show that the maximum deviations of the three times measurement values of the rail displacement,the horizontal straightness,the vertical straightness,the yaw angle and the pitch angle are 0.2?m,0.05?m,0.22?m,0.52 arc sec and 0.68 arc sec.The simultaneous measurement experiment results verify that the constructed simultaneous measurement system of the five-degree-of-freedom has good repeatability.