Research On Error Modeling And Calibration Of Laser Tracker

At present,laser tracker has been widely used in the fields of precision measurement of major equipment,installation and positioning of large parts and robot calibration attribute to its portability,high precision,fast measurement speed and wide measurement range.With the development of continuous refinement of laser tracking and measurement system and the improvement of quality control and traceability accuracy in the manufacturing process,higher requirements were put forward for the calibration technology and error compensation of laser tracker.However,the structure of laser tracker is complex and the error sources are widespread,and the current calibration methods and devices can’t meet the requirements of modern measurement.Therefore,the laser tracker is taken as the research object of this paper,its error sources and characteristics are analyzed,and the calibration methods of the individual error and complete instrument are studied to ensure the measurement accuracy of the laser tracker.Based on the measurement principle of laser tracker,error factors that affect the measurement accuracy of the instrument were analyzed in this paper.Aiming at the error that deviates from the ideal measurement model introduced in the process of instrument processing and assembly,each individual error theoretical model was established by using the geometric analysis method.Their influence mechanism on the instrument measurement error was distribution.And each error characteristic was intuitively displayed through simulation.Aiming at the individual error of laser tracker,including Home base reference distance error,shafting shaking error,encoder accuracy error and shafting position error,an error detection platform was built according to the characteristics of each error and the existing calibration standards.Through the corresponding data processing method,the mistake parameter of each error factor was accurately obtained,and the error compensation model was established to complete error compensation of the instrument.At the stage of complete instrument,according to the multi-station measurement principle of laser tracker,the multi-station measurement model and the algorithm model of transfer parameters were established.The distance constrained beam adjustment method was used to calibrate the position of the instrument and the position of the measuring common point.For the measurement points beyond the envelope of common points,the influence of random error and systematic error of measurement accuracy on was studied,and the compensation model of multi-station measurement was established to obtain the correction value of transfer parameters.The simulation results show that the transfer accuracy was improved by more than 50%,which shows the reliability of the error compensation method.Finally,through the simulation analysis of the layout of multi-station measurement stations and common points,an excellent layout of calibration network was recommended.In this paper,through the error analysis and calibration method research,a set of reliable error calibration model and method of laser tracker were established,which can effectively improve the measurement accuracy of laser tracker.This research provides a reference for the production and accuracy evaluation of the instrument,and has important engineering application value.