激光跟踪仪多基站转站精度模型与误差补偿

Model establishment and error compensation of laser tracker station-transfer

为实现大空间域激光跟踪仪的高精度测量,本文针对由转站误差导致的激光跟踪仪分时多基站测量精度难保证的问题,提出了基于多站位下单台激光跟踪仪测量误差的转站误差模型与转站参数修正的补偿方法。首先分析了激光跟踪仪测量误差的来源以及具体形式,阐述了激光跟踪仪测量误差影响空间任意点测量精度的具体形式;其次分析了激光跟踪仪的随机测量误差和系统测量误差对多基站转站参数求解精度的影响。在此基础上,建立了考虑随机、系统测量误差的激光跟踪仪多基站转站误差模型和转站参数误差补偿模型。蒙特卡洛仿真结果表明:当激光跟踪仪的长度测量误差为0.5μm/m,角度测量误差为5μm+6μm/m时,最大转站误差为0.174 7mm,补偿后最大转站误差为0.04mm,转站精度提高了77%。分时多基站转站测量实验结果表明:直接转站测量时最大转站误差为0.054 2mm,补偿后转站误差为0.033 1mm,转站精度提升了38.9%。激光跟踪转站补偿后测量精度有明显的提高。

A station-transfer model was established in this study to improve the accuracy of laser tracker station-transfer measurement in larger-scale metrology. The accuracy of the laser tracker is related to the measurement errors, such as random and system measurement errors. First, the source and precise form of measurement error of the laser tracker system was analyzed according to the measurement principle of the laser tracker. Moreover, a spatial point measurement model containing the laser tracker measurement error was established. Second, a station-transfer calculation model was established, which was linked to random and systematic measurement errors. Finally, an error compensation model of the laser tracker station-transfer was established, which is similarly related to the random and system measurement errors, by analyzing the station-transfer calculation model. The results are verified by Monte Carlo simulation and show that when the error of length measurement is 0.5 μm/m and the error of angle measurement is 5 μm + 6 μm/m, and the maximum station-transfer error is 0.174 7 mm. Hence, the maximum station-transfer error after compensation is 0.04 mm, and the accuracy of the transfer station is increased by 77%. A multi-base time-sharing station-transfer measurement experiment shows that the direct station-transfer error is 0.054 2 mm, the error of the station-transfer after compensation is 0.033 1 mm, and the accuracy of the transfer station is increased by 38.9%. Thus, the measurement accuracy of the laser tracker station-transfer exhibits significant improvement after compensation.