自准直仪对安放在光电编码器轴系上的多面体进行检测是目前检测光电编码器的测角精度的常用方法之一。为了提高检测效率, 根据自准直仪检测原理, 对多面体塔差对自准直仪读数的影响进行理论分析; 其次, 依据偏心产生的原理, 分析了多面体安装偏心对检测光电编码器精度的影响, 得出了多面体塔差或多面体安装偏心在光电编码器精度检测中, 因自准直仪的读数方式不同造成的影响不同。用23面体检测某种型号21位绝对式光电编码器, 采用沿自准直仪y轴读数的方式, 多面体安装偏心造成的检测误差为Vp-p=7.9″, 多面体塔差造成的检测误差Vp-p=0.8″。实验结果表明, 自准直仪读数方式不同, 多面体塔差和安装偏心造成的检测误差不同, 为提高检测效率提供了一定的理论指导。

In a common method for precision detecton of photoelectric encoders, a polyhedron is joined with a photoelectric encoder and light from an autocollimation setup is reflected by the polyhedron; the precision of photoelectric encoder is then measured by reading the numerical value of the autocollimation. A feasible method to improve measurement efficiency was investigated with respect to the main factors that affect photoelectric encoder detection. Firstly, according to the principle of autocollimator detection, a theoretical analysis was conducted by analyzing polyhedron pyramidal error as it effects the reading of the numerical value of autocollimation. Secondly, according to the principle of installation eccentricity of a polyhedron pyramidal, the impact factors that affect the measurement precision of a photoelectric encoder were analyzed in detail. Pyramidal error and installation eccentricity are the main external factors, which are determined by the numerical value reading of autocollimation. A 21-bit photoelectric absolute encoder was detected using a 23-sided polyhedron; the numerical value of autocollimation is read along the y-axis, the detection error of polyhedron pyramidal error is 7.9″, and the detection of installation eccentricity is 0.8″. The testing results indicate the effects of pyramidal error and installation eccentricity on the precision are based on the reading of the numerical value of autocollimation, which offers an guidance to improve detection efficiency.