Research of a fast and accurate measuring method for guide planes of ultra precision machine

为了准确测量平面度，需要建立平面度标准。在本研究中，重力方向是用水银表面来表示的，它被用来作为平面度的标准。为了提高空间波长分辨率，提出了一种新的数据处理方法，即两点法。研究结果如下：在所研制的光学水平仪中，水平仪的两个方向的倾斜是由一个由LED和光电二极管阵列构成的光学系统感测。研制的液位计动态范围为30 min。(arc)分辨率为2秒。（弧）。它的尺寸是30 x30 x50（mm），立方厘米，重量为300克。当水平仪的两支腿间距为20 mm时，其分辨高度的精度可达0.4 μ m。两点法的采样间隔不受测量直线度时常用的伸缩链法测量的难点--腿间距的限制，可根据所需的空间波长和采样定理的要求确定采样间隔，利用二维水平仪，可以比光电自准直仪更容易和快速地测量水平面的平坦度。在测量中，水平仪的三个支撑腿的三角形被逐步放置在被测量平面上的连续三角形上。

In order to measure flathess accurately, it is necessary to establish a standard of flat plane. In this research, gravitational direction which is represented by a mercurial surface is used as a standard of flatness. Resolutional ability in spacial wave length can be improved by a data processing method which has been developed in the research, and named 2-points method. Results obtained by the research are as follows:In the developed optical level meter, the two directional inclination of the level is sensed by an optical system constructed by a LED and a photodiode array. The developed level meter has the dynamic range of 30 min.(arc) and resolutional ability of 2 sec.(arc). And its dimensions are 30x30x50 (mm) in cubic lengthes and 300 g in weight. If a span of 20 mm is given between two supporting legs of the level, the accuracy of resolution in heihgt attains 0.4 micro meter. Using the 2-points method, sampling intervals is not restricted by the span of legs, which has been a difficult point of the succesive chained method usually used in the measurement of the straightness.In the 2-points method the sampling intervals can be determined in correspondent with necessary spacial wave length and requirement of the sampring theorem.Using the two dimensional level meter, the flatness of a horizontal plane can be measured more easily and speedily than by the optoelectoronic autocollimater. In the measurement the triangle of the three supporting legs of the level, is placed step by step on successive triangles which are meshed on the plane to be measured.