基于球体几何关系的球标靶特征提取算法

摘要

A circle can be defined as the intersection of a sphere and a plane,where the plane is determined by three arbitrary points.Then the line passes through the center of the circle and the sphere is perpendicular to the circle's plane.In this paper,we propose a spherical target extraction approach based on these spherical geometry relations.Our algorithm extracts several intersection circles from the point cloud under the predefined constraints,then the center and radius of the spherical target can be determined by minimizing the sum of the distances from the sphere center to the normal vectors of the circles.Experimental comparison with other approaches based on least squares,total least squares and weighted least squares,shows that our spherical target extraction approach is able to achieve higher accuracy and robustness.%利用“球面上任意3点确定的平面与球的相交曲线为圆,该截面圆心与球心的连线(球截面圆心法线)垂直于圆平面”的几何关系,提出一种基于球体几何关系的球标靶特征提取算法.通过对球标靶点云构建多组截面圆,对截面圆设定约束条件,构造球心到球截面圆心法线距离平方和的目标函数,以此目标函数最小为条件求解球标靶的球心坐标.通过实验比较本文方法、最小二乘方法、整体最小二乘方法、加权整体最小二乘方法和稳健加权整体最小二乘方法对球标靶的处理效果,结果表明本文方法具有较高的准确性和稳健性.