双轴转台的八位置调平及失准角估算

重力梯度旋转平台调制实验时要求旋转平台台面的水平失准角在一定范围之内。使用两位置正交方法对双轴转台进行调平时,能保证正交两个方向上水平精度,但无法保证在多个方向上的水平精度。对此,提出了一种八位置调平方法,即将整周360°分为八个位置,两个相邻位置的夹角为45°,依次测量八个位置的水平失准角,取最大值和最小值之和的二分之一作为中值,每个位置失准角与中值求差,通过差值的符号并结合八位置图确定调高或调低相应的地脚。同时,给出了一种通过匀速旋转调制来估算台面最大水平失准角的方法。实验表明:在目前实验条件下,八位置调平方法能将转台台面最大失准角控制在3″以内,旋转调制估算的水平失准角为2.9″。

Estimation algorithm of eight-position leveling and horizontal misalignment for two-axis turntable

The gravity gradient rotary platform modulation experiments require the horizontal misalignment be within a certain range.The two-position orthogonal algorithm in two-axis turntable leveling can satisfy the level alignment of two orthogonal directions,but it can’t satisfy the horizontal misalignment angle in multi-directions.So,this paper presents an eight-position leveling method whose circularity is divided into eight areas and the angle between two adjacent positions is 45°.The level misalignments of eight positions are measured in turn,and the half sum of the max and min misalignments is taken as mean value.The differences of the misalignments and the mean value are calculated,and their sign of "+" and "-" could be used to determine the corresponding level adjustment of the three underlay,i.e.raising or lowering.Meanwhile,a level misalignment estimation algorithm by uniform-motion rotating modulation is presented for eight-position leveling.The horizontal misalignment can be limited to 3″in the presented experiment conditions by the eight-position leveling method,and the estimated level misalignment is 2.9″ by the rotation modulation method.