激光光束入射角度变化对角锥棱镜测量精度的影响

Effect of incident laser beam angle varying on cube corner retro-reflector measurement accuracty

为了掌握光束入射角变化对激光跟踪仪中角锥棱镜测量精度的影响规律,详细分析了角锥棱镜的工作原理和反射特性,计算了角锥棱镜在不同入射角下的实际有效反射面积,并建立了角锥棱镜有效反射面积随光束入射角变化的理论公式,进而得到角锥棱镜测量精度随光束入射角变化的规律。实验结果表明:角锥棱镜测量精度随入射角增大而减小,在最大允许入射角处发生突变。在最大允许入射角为±35.26°时,其测量误差达到0.050 mm;而在±20°内时,其测量精度优于0.010 mm;入射角在±15°内其测量精度最高,稳定性最好。所得结论证明了当角锥棱镜入射角在±20°内工作时能满足了激光跟踪仪的测量精度要求,这对角锥棱镜设计和实际测量工作具有指导意义。

In order to describe the relationship between the incident angle of Cube Corner Retro-reflec tor （CCR） and the measurement accuracy of CCR used in laser tracker system, the working principle and reflective characteristic of CCR were analyzed. A novel approach was proposed to determine the effective reflection area of CCR with an arbitrary incident angle and then the formula of ray cross section of CCR with varying incident angle was derived according to the effective reflection area. Accordingly, the relationship between CCR measuring accuracy and incident angle was established. The experimental results demonstrate that the CCR measuring accuracy reduces as the increase of incident angle, the CCR measuring error is the largest when the maximal incident angle is reached. The measuring error of CCR at maximal incident angle of ±35.26° is 0. 050 mm, but the measuring accuracies of CCR are better than 0. 010 mm when the incident angle are within ±20°, and the measuring accuracy and the stability are best only when the incident angles are within ±15~. The results show that CCR can maintain the manufacture specifications of laser tracking system only when the incident angles are within ±20°, which provides a very useful guidance for design and application for CCR.