激光跟踪仪转镜倾斜误差的标定及修正

Error calibration and correction of mirror tilt in laser trackers

为了提高激光跟踪仪的测量精度,分析了跟踪仪的几何结构误差,重点研究了其转镜倾斜误差的标定和修正方法。利用矢量分析和坐标转换相结合的方法建立了跟踪仪转镜倾斜误差模型,推导出了跟踪仪几何空间坐标修正公式,并基于自准直仪、多面棱体和可调反射镜建立了高精度误差标定装置。利用标定装置分析了误差标定方法,通过系统仿真研究了转镜倾斜误差对系统测角误差及最终坐标测量误差的影响。利用误差标定实验检测出的系统转镜倾斜误差约为4″,将其带入坐标修正公式,并与修正前的坐标进行了比对分析。对比结果显示,经误差修正后系统空间坐标测量误差可减小约2×10-6,验证了转镜倾斜误差标定和误差修正方法的有效性,表明利用该方法可在不改变系统硬件结构的基础上提高测量系统的测量精度。

To improve the measuring accuracy of laser trackers,the geometric errors of a tracker were analyzed,and the error calibration and error correction methods for a tilted mirror in the tracker were explored.An error model for the titled mirror was established based on vector analysis and coordinate transformation,and the error correction formulation for geometric space coordinate of the tracker was deduced.Then,a high precision error calibration device was built based on a multi-mirror polygon,an adjustable reflected mirror and autocollimators.The calibration device was used to analyze the error calibration method,and the system simulations were used to research the influence of mirror tilt error on angle and coordinate measurement errors.The error calibration test shows that the mirror tilt error is 4″.The tested error was induced to the coordinate correction formulation,and the spatial length measurement errors of the system before and after correction were tested.The results indicate that the measuring error of the laser tracker decreases by about 2×10-6,which shows that the error calculation and error correction methods are effective.The method improves the measuring accuracy without changing the hardware structure of the system.