Research On Angle Measurement Error Compensation Technology For Accurate Laser Positioning System

In recent years,with the rapid development of China’s equipment field,the demand for precision manufacturing and assembly of large components is increasing,which in turn has higher and higher requirements for large-size precision measurement technology involved in the manufacturing and assembly process.Accurate Large-scale Positioning System(ALPS),as a new type of large-size measurement equipment,has the features of several meters to tens of meters measurement range,multi-point parallelism and sub-millimeter positioning,etc.It gradually replaces the traditional large-size measurement equipment and is widely used in large-space precision measurement occasions.At present,although the static measurement accuracy of ALPS system can reach ±0.2 mm,the system measurement stability and anti-interference are poor due to the random fluctuation of goniometric error of the base station and the influence of external environment.Therefore,it is important to analyze the system error source,study the field base station goniometric fast evaluation method,and explore the base station goniometric accuracy improvement and error compensation method based on this method to improve the system measurement accuracy and stability.This paper analyzes the error influencing factors,and focuses on the technical research of base station performance optimization methods,error compensation and goniometric accuracy evaluation methods.The main research contents are as follows:1)On the basis of analyzing the system working principle of ALPS,measurement model and factors affecting system measurement accuracy,study the mechanism of measurement station error generation;simulate the system measurement process through 3D modeling software,analyze the influence of single station goniometric error on the final system measurement accuracy,study the system measurement error distribution,and design the method of implementing base station goniometric accuracy.2)To further improve the system measurement accuracy,the rotation speed fluctuation and spindle swing optimization are analyzed,and the base station dynamic performance optimization method is proposed to achieve the single station angle measurement accuracy from ±18″ to±5″.In order to evaluate the accuracy of the base station angle measurement,a threedimensional model is established by Creo to extract the simulated initial values,analyze the fitting relationship between the initial values of the multi-tooth indexing table,the laser tracker and the transmitting base station,study the high-precision angle measurement evaluation method based on the multi-tooth indexing table in the laboratory and the rapid angle measurement evaluation method based on the laser tracker in the field,and verify the feasibility of the two evaluation methods by comparing the initial values and the fitted values.The feasibility of the two methods was verified by comparing the initial and fitted values.3)Based on the analysis of the optimization of the dynamic performance of the base station,the study of the base station goniometric error compensation method based on reference sensing,the establishment of the error compensation model,and the design of the compensation receiver set and ZYNQ-based multi-channel high-speed error compensation processing platform,by adding compensation units to the signal channels,time domain matching and compensation processing,to achieve real-time compensation of the short-time proximity spatial disturbance error and compensation of the measurement system error caused by long-term environmental changes,reducing the base station goniometric error fluctuations.4)To verify the feasibility of the optimization method of angle measurement accuracy of the base station proposed in this paper,a laboratory evaluation platform based on multi-tooth indexing table and a field rapid evaluation platform based on laser tracker were built,and the accuracy verification experiments of compensation receiving unit,compensation method performance and evaluation method were carried out respectively,and the maximum angle measurement error of single base station was verified by multi-tooth indexing table comparison to be 1.044 arc second,and the maximum angle measurement error of laser tracker comparison to be 1.296 arc second,which meets the requirement of ±1.5″ angle measurement accuracy.