用经纬仪测量大尺寸三维导轨垂直度的方法

Perpendicularity measurement method of 3-D large guideway with theodolite

基于经纬仪将运动直线引出来的原理,提出了一种测量大尺寸三维导轨垂直度的新方法。首先在水平直线移动的Y导轨的动基座上安装经纬仪并观察静止靶标水平角的微小变化,采用最小二乘法拟合出了经纬仪视准轴分别与运动X导轨和Y导轨平行时的水平角,继而测量了X-Y导轨间的垂直度误差。然后将经纬仪固定在地基上,通过观测水平移动导轨上靶标的竖直角的微小变化,采用最小二乘法拟合了X、Y导轨的水平度误差;通过观测与Z导轨固定的靶标水平角的微小变化,采用最小二乘法拟合了Z导轨的二维铅垂度误差,利用X,Y导轨的水平度和Z导轨的铅垂度换算出了Z-X间,Z-Y间导轨的垂直度误差。最终实现了三维导轨X-Y之间、Y-Z之间、X-Z之间的垂直度的检测,并对测量的垂直度误差进行了精度分析。在研制的月球软着陆系统垂直度的调试中进行了应用,证明了该方法能够满足测量的精度要求。

Based on the mechanism that theodolite leads to a moving line, a new method of measuring the perpendicularity of guideway was presented. Firstly, a theodolite is installed on the horizontal linear moving base of Y guideway and a crosshair target is fixed on the foundation. When the theodolite is on different positions and pointed to the target as the level guideway is moving, the horizontal angles of the target are acquired. So two horizontal angles of the theodolite can be computed using least square method twice when the two collimation axis lines of the theodolite are parallel to the moving lines of X and Y guideways respectively, then the perpendicularity between X and Y guideways is calculated. After that, the theodolite is fixed on the foundation, the slight vertical angle changes of the target fixed on the horizontal linear moving guideway are observed, and the levelness errors of X and Y guideways are fitted respectively using least square method. Later on, the horizontal angle changes of the target fixed on the vertical Z guideway are measured with the theodolite, and the 2-D plumb errors of the Z guideway are achieved also using least square method. Finally, all the X-Y, Y-Z, Z-X three guideway perpendicularities are obtained, and the measurement error analysis is conducted. This method was applied in adjusting and measuring the perpendicularities of a lunar soft landing simulation system. Results show that this method can meet the requirement of the measurement accuracy.