Research On Multi-degree-of-freedom Measurement Method For Precision Engineering

With the development of aerospace,instrument and other high-tech fields,preci-sion benchmark measurement and precision measurement of geometric quantities have become more and more important.In many fields,it is often required to monitor the position and posture of workpieces,parts and target objects in space at the same time,which has ensured processing accuracy,installation accuracy and detection accuracy.Traditional single-degree-of-freedom angle or displacement measurement efficiency is low,and it has been unable to meet the needs of rapid and high-precision measurement.Therefore,the research on the simultaneous measurement method of multiple degrees of freedom and the development of corresponding instruments and equipment are urgent problems that need to be solved at present,which plays an important role in promoting the development of traditional precision measurement technology.In this paper,the multi-degree-of-freedom measurement requirement of the pre-cision stepping stage of gene sequencing as the application background.The easy-to-integrate degree of freedom measurement method is summarized.On this basis,two kinds of multi-degree of freedom measurement methods are proposed.A corresponding measurement device is built,and experimental research is carried out verify the feasibil-ity of the proposed measurement method.In summary,the main work and innovation of this thesis are as follows:1.A three-degree-of-freedom measurement method based on self-collimation is proposed,which can realize simultaneous measurement of pitch,yaw and roll.The principle of each degree of freedom measurement is analyzed,and the corresponding mathematical model is established.According to the proposed measurement principle,the optical design and structure design are carried out.And a three-degree-of-freedom simultaneous measurement prototype based on self-collimation is developed.The mea-surement resolution and measurement range of the system are analyzed,and the image processing method of the reticle crosshairs is introduced.Finally,the performance of the prototype is evaluated under laboratory conditions.Compared with the industrial theodolite,the angle measurement range±600 ",the standard deviation of the pitch is 2.72";The standard deviation of the yaw is 2.36";The standard deviation of the roll is 13.28".2.A five-degree-of-freedom measurement method based on polarization splitting is proposed,which can simultaneously measure the pitch,yaw,roll,horizontal and verti-cal translation.Compared with the laser collimation method,This method can improve the resolution of roll angle and horizontal translation at the same time.The measurement principle of each degree of freedom is analyzed,and the corresponding mathematical model is established.The measurement resolution and measurement range of the sys-tem are analyzed,and the image processing method of the laser spot is introduced.The corresponding optical device is built,and the effectiveness of the method is verified through a series of experiments.Compared with theodolite,the standard deviations of the pitch and yaw are 1.21 " and 1.74 " respectively.Compared with the photoelectric autocollimator,the standard deviation of the roll is 1.96 ";Compared with the RLE laser ruler,the standard deviations of the horizontal and vertical translation are 2.83 ?m and 3.18?m,respectively3.The error of the multi-degree-of-freedom measurement system is analyzed and compensated.For the problem of system light drift,the method of real-time measure-ment and compensation of the common optical path is adopted,and the experiment ver-ifies the effectiveness of the compensation method.The influence of the manufacturing and installation errors of the optical components on the measurement of each degree of freedom is analyzed,and the corresponding mathematical model is established.The crosstalk error in the simultaneous measurement of multiple degrees of freedom is ana-lyzed,and a crosstalk error compensation method based on the calculation of the corner cube midpoint is proposed.The corresponding compensation model is established,and the effectiveness of the model is verified by experiments.Compared with the RLE laser ruler,the maximum deviation before horizontal translation compensation is 97.7?m,the maximum deviation after compensation is reduced to 3.2?m,and the standard de-viation is 1.78?m.The maximum deviation before vertical translation compensation is-210.2 ?m,the maximum deviation after compensation is reduced to-3.8 ?m,and the standard deviation is 1.67 ?m.