CBVCT系统中心标定方法

CBVCT（Cone Beam Volume CT）系统在无损检测和逆向工程等领域具有不可替代的优越性。而系统设计时射线源焦点投影不能枝准将严重影响其精度。采用实验的方法，利用标准钢丝样本和直尺样本，先采用DR成像的方法大致确定投影中心的位置，然后利用黄金分割点逼近准确位置。在计算钢丝位置时，则采用最小半径法确定钢丝的中心。系统标定后，时钢丝样本重新进行了重建实验，实验结果表明，标定后的系统精度提高5倍以上。在理论和实践上为CBVCT系统的研发提供了切实可行的中心标定方案。

Research on the method of center calibration of CBVCT system

The Cone Beam Volume CT(CBVCT) system has the non-substitutable superiority in the field of non-damage detection and reverse engineering.Yet the focus projection of ray origin can not be calibrated will seriously affect its accuracy.The experimental method was adopted,and the standard steel wire sample and ruler sample were utilized.Firstly determine approximately the position of projection center by adopting the method of DR imagery,and then approaches the accurate position by means of point of golden section.When computing the position of steel wire,however the wire center was determined by the adoption of method of minimum radius.After the system is being calibrated,the reconstruction experiment was carried out again on the wire sample.The result of experiment shows that the accuracy of system after calibration raised over 5 times.This paper provided a practical and feasible scheme of center calibration for the development of CBVCT system in theory and in practice.