Research On The Method Of Improving The Accuracy Of Multi Station Measurement Of Laser Tracker

The five-axis machine tool,as the country's heavy weapon,occupies an important position in processing and industrial production,as well as national defense and military.The machining accuracy reflects the performance of the machine tool.Improving the machining accuracy of the CNC machine tool is a symbol of improving the national industrial strength.As a measuring tool for large measuring fields,the laser tracker has the excellent properties of high accuracy,high performance,high guarantee,and high stability.It is also an important technical tool for detecting machine tool errors.How to use the laser tracker to quickly and efficiently detect the machine tool Precision error is a problem that needs to be solved urgently.This paper takes five-axis machine tools and laser trackers as the target research objects,and aims to improve the measurement accuracy.Related research has been done on how to improve the measurement accuracy when the laser tracker adopts multi-station measurement.The main research contents are as follows:(1)Firstly,the research on the spatial error of machine tools is carried out,and the representation method of the spatial error of machine tools is defined.By analyzing the topological structure of machine tools,the sources of various errors of machine tools and the representation methods of various errors are summarized.In this paper,the multibody theory and rigid body transformation theory are used to substitute the actual machining errors,and the mathematical model expressions of the spatial errors of the machine models in the actual and theoretical machining are established.At the same time,the laser tracker is researched,the mathematical model of the transfer station is established and the error of the transfer station is analyzed.(2)The multi station measurement network model is established,the relationship between the number of stations and the number of measurement points is analyzed,and the most suitable number of stations is summarized.Instead of the angle data of the laser tracker,the high-precision ranging data is used to solve the coordinates of stations and measuring points.Using the experimental data and simulation data to solve and analyze,and put forward the mathematical model of optimizing the station,using genetic algorithm to optimize the target station,get the optimal four station instrument coordinates in the measurement space.(3)The coordinate establishment method in the calculation of transfer station is analyzed and established.This paper studies and analyzes the error sources of the transfer station,puts forward the accuracy evaluation method of the transfer station measurement,introduces several methods of solving the transfer station parameters in detail,and summarizes and evaluates the accuracy of the above methods based on the experimental data.Based on the establishment of the transfer station accuracy function,the quality factor of the transfer station accuracy evaluation index is quantified by extracting matrix parameters.Based on the experimental data,the common factors such as the distribution and number of public reference points are discussed and studied,and the influence of some factors on the quality factor and transfer station accuracy is analyzed.Finally,based on the experimental results,the selection principle of public reference point is summarized.