传统的同步扫描三角测量模型假设旋转镜厚度为零,从而建立了三维扫描点的轨迹圆模型。本文将旋转镜厚度也作为系统参数进行考虑,提出一种同步扫描三角法在展开光路中的几何参数模型,通过14个参数精确地描述各个功能部件的位置姿态和几何光学参数,并建立了三维空间点与系统参数的关系。仿真分析表明:1 mm厚的旋转镜会产生200mm的系统误差。对接受透镜位置参数的建模使得三维点具有动点旋转特性,与传统的轨迹圆模型相比,更精确地描述了旋转中心的轨迹变化。构建了原型系统,并通过实验验证了方法的正确性。
Synchronized scanning triangulation inserts the scanning mirrors in the projected light path and the received light path, thus the changed angles for the projected light and the received light are the same when the scanning mirrors are rotated. This synchronized scanning mechanism expands the tt field and is adopted in the large distance measurement. In the model of traditional synchronized scanning triangulation measurement system, the thickness of rotated mirror is assumed to be zero and the trajecto- ry of the 3D scanning point is modeled as a circle. However,this simplified assumption deteriorates the precision of the system. In this paper, the thickness of the rotated mirror besidesf other geometry param- eters is considered. The 3D measured point is established with the 14 parameters,which describe the po- sition and pose of different parts. Through the simulation,we find that the system's error could achieve 200 mm,when the thickness of the rotating mirror is 1 mm. This error can not be omitted for measuring general objects. In addition,the modelrs 3D point for the same pixel position is a circle with the moving center instead of a constant position. This model describes the trajectory more precisely than traditional model. Finally,the prototype system is designed and the experimental results show that the method is feasible.