水平式激光发射系统光轴平行度误差分析

Analysis of optical axis parallelism error for the level mounting laser transmitter system

对于激光发射系统,激光轴与电视光轴的平行度是保证其指向精度的关键。相对于传统的光电经纬仪,该系统光轴平行度误差是一动态误差,变化规律较为复杂。为修正激光发射系统激光轴与电视光轴的平行度误差,建立了光轴平行度误差模型,由此掌握该系统光轴平行度误差的变化规律。在总结了影响光轴平行度的主要系统误差源的基础上,分析各项误差对光轴平行度的影响,利用矢量旋转与坐标变换,建立了激光轴经折返镜后在空间坐标系内的指向模型,由此得到两光轴平行度误差模型,通过电视跟踪系统测量两光轴平行度误差值,并采用最小二乘法拟合得到误差模型中各待定系数。实验结果表明:拟合后的光轴平行度达到2.6″,模型能够基本描述两光轴平行度误差的变化规律。

Parallelism error between laser axis and TV optical axis is a key factor influencing on the pointing accuracy of the level mounting laser transmitter system.Compared with the traditional photoelectric theodolite,the parallelism error of optical axis of the laser transmitter system is a dynamic error and its variation is much more complex.In order to correct the parallelism error between laser axis and TV optical axis,a new model was built,which was able to describe the change law between laser axis and TV optical axis.First,the opto-mechanical structure and the modeling theory were introduced,and the systematic errors were picked out.Then after constructing three dimensional coordinates in which the laser was considered as a unit vector,the parallelism error model was obtained by linear coordinate transformation and linear vector transformation.Finally,the TV tracking system was used to measure the parallelism error of the two optical axes.After least square fitting,the undetermined coefficients in the parallelism error model were obtained.Experimental results indicate that the fitting precision is up to.It could be basically confirmed that the parallelism error model can describe the variation law of the two optical axis.