轴端无通孔时三轴转台相交度测试方法

Method for measuring axis line intersection of three-axis turntable without luminous hole at the ends of shaft

为解决中环轴没有通光孔时如何测量三轴转台轴线相交度的问题,在内环轴上三轴交汇中心附近设置一靶标,再利用齐次变换法推导出靶标在基准坐标系下的坐标,它是三轴相交度、三轴角位置以及靶标在内环轴坐标系下的偏移量的函数,据此设计三轴相交度误差的测量方法。利用经纬仪观测靶标,计算出靶标坐标的变化量,从而实现三轴相交度的测量,并进行相关的误差分析。分析结果表明:实测相交度满足测量精度要求,测量结果具有有效性。该测量方法可避免在没有通光孔的中环轴旋转至某些特殊角度时经纬仪视线被挡住的情况,使得测量更加方便。

The paper aims to find out ways to measure axis line intersection of three-axis turntable when its middle axis has no luminous hole. Firstly, fix a target on the inner axis in the vicinity of the intersecting center of three axis lines. Secondly, deduce the target＇s coordinates under the reference coordinate system with the homogeneous transformation method. The coordinate is the function of the offset of three axis intersection, three axis angular positions and the target in the inner axis coordinate system and then the method for the measurement of three axis line intersection error is designed on this basis. A theodolite is used to align with the target and the variable quantity of the target＇s coordinates are calculated, in which way the three-axis line intersection is measured and the relevant error is analyzed. The analysis results show that practically measured axis line intersection meets the requirements of measurement accuracy and proves the effectiveness of this method. This measurement method prevents the sight of the theodolite to be blocked when the inner axis without luminous holes rotates to certain angle, simplifying the measurement.