自研角度计量转台在圆分度器件校准中的应用

为了实现亚角秒级圆分度器件的高精度校准，建立了基于角度计量转台和自准直仪的角度测量系统，研究了基于无实物基准的圆分度误差检测方法和控制测量系统引入误差的策略。简要介绍了基于真空预载气浮支承和超声马达驱动的自研转台的结构，搭建了整个测量系统。利用圆封闭原理和最小二乘原理分析了圆分度误差的测量算法，讨论了测量过程的误差来源，并分析了抑制各误差源的方法。最后，在构建的测量系统上测量了多齿分度台的圆分度误差，并对测量不确定度进行了分析。实验结果表明：自研计量转台和被校多齿分度台的最大圆分度误差分别为0.12″和0.15″，测量不确定度为0.05″（k=2）。通过比对，表明测量系统能够实现亚角秒级圆分度误差的高精度校准。

Calibration of circular division artifacts using a self-developed angle comparator

In order to achieve high-precision calibration of circular division artifacts with sub-arcsecond level, an angular measuring system based on a high-precision angle comparator and an autocollimator was established. A nonphysical circular indexing error detection method was studied, and the scheme to control measurement error was investigated. Firstly, the structure of self-developed angle comparator based on vacuum preloaded air bearings and ultrasonic motors, and the construction of the whole measurement system were introduced. Secondly, the measurement algorithm for circular indexing error detection was analyzed by the circular closed principle and the least squares principle. Thirdly, the sources of error in the measurement process were discussed and the methods for eliminating error sources are analyzed. Finally, based on the measurement system, the circular indexing error of the multitooth indexing table was measured, and the measurement uncertainty was analyzed. The experimental results show that the maximum circular indexing error of the self-developed angle comparator and the indexing table is 0.12″ and 0.15″, respectively; the measurement uncertainty is 0.05″(k=2). Thus, it shows that the measurement system satisfies the high-accuracy calibration of circular indexing error with sub-arcsecond level.