Research On Multi-base Station Transfer Method And Error Compensation Of Laser Tracker

Large-scale and high-performance components are widely used in major defense fields such as aerospace,marine exploration,and high-speed train manufacturing.With the rapid development of science and technology,the requirements for the processing of these components become higher,which have large size and require high processing precision.Generally,the machining accuracy requirements of millimeters or even millimeters are required in the range of 10 meters to several tens of meters,which poses a great challenge to the machining measurement process.At present,the proposal and application of coordinate measurement technology or three-dimensional measurement network construction technology in the field of large-scale manufacturing greatly improves the manufacturing and assembly efficiency of large-scale components.However,in the process of constructing the threedimensional measurement network,the measurement range,the measurement method,the measurement error,and the measurement complexity of the measuring instrument affect the measurement accuracy of the specific measurement network.Compared with GPS measurement technology,machine vision measurement technology,theodolite and other measurement equipment,laser tracker has become the main measuring instrument for constructing large-scale three-dimensional measurement network with its advantages of portability,high measurement accuracy,wide measurement range and strong measurement adaptability.Therefore,this paper proposes a method based on laser tracker to establish a threedimensional measurement control network,namely laser tracker transfer station measurement:(1)Research the basic measurement principle of laser tracker,trace the measurement error of laser tracker,construct the laser tracker transfer error model,and lay the foundation for improving the measurement accuracy of laser tracker transfer station;(2)Analyze the influence of the distribution pattern of common points on the measurement of the laser tracker's transfer station.Under the principle of measuring the envelope of the transfer station,the laser tracker beam adjustment method is used to adjust the adjustment of the common point measurement value,and the optimized transfer station parameters are improved.Transit accuracy,average transfer accuracy is 0.005mm;(3)In order to increase the accuracy of laser tracker station-transfer measurement of larger-scale metrology,in this paper,a station-transfer model was established,which is related to the measurement error of laser tracker such as random measurement and system measurement error.Firstly the source and precise form of measurement error of the laser tracker system is analyzed according to the measurement principle of the laser tracker.And a spatial point measurement model containing the laser tracker measurement error is established.Secondly,a station-transfer calculation model is established which is linked to random measurement error and systematic measurement error.Finally,an error compensation model of laser tracker station-transfer is established which is related to random measurement error and system measurement error by analyzing the station-transfer calculation model.(4)The results which are verified by Monte Carlo simulation show that,when the error of length measurement is 0.5?m/m and the error of angle measurement is 5?m+6?m/m,then the maximum station-transfer error is 0.1747 mm.While the maximum station-transfer error after compensation is 0.04 mm,and the accuracy of the transfer station is increased by 77%.A Multibase time-sharing station-transfer measurement experiment show that the direct station-transfer error is 0.0542 mm,the error of the station-transfer after compensation is 0.0331 mm,as a result the accuracy of the transfer station is increased by 38.9%.The measurement accuracy of laser tracker station-transfer has a significantly improvement after compensation.The research results of this paper provide effective thinking for the establishment of laser tracker 3D measurement network.The method of compensation and correction of laser tracker measurement error is extended,which provides a reliable idea for improving the direct measurement accuracy of laser tracker and the measurement accuracy of transfer station.