三维测量系统中基于圆锥拟合的旋转台轴线标定新方法

A Turntable Calibration Method Based on Conic-fitting for 3D Measurement System

旋转台是三维测量系统的重要组成部件,其轴线的标定精度直接影响多视角测量数据的拼合效果。本文提出了一种基于圆锥拟合的高精度旋转台轴线标定新方法。该标定方法考虑了转台轴线与水平面不垂直的情况,把传统的旋转台标定参数由3个提高到6个。采用标准陶瓷圆柱作为标定物,通过将圆柱测量点云轴线进行最小二乘圆锥拟合、圆锥曲线方程标准化求解标定参数;仿真实验、旋转台标定实验、圆柱测量实验与航空叶片测量实验表明,圆锥拟合模型相比传统的圆柱拟合能获得更高的拟合精度。在圆柱标定实验中测量误差由0.042 mm降低到了0.032 mm,验证了本文方法在标定精度上的优势。

The turntable is an important component of 3D measurement system. The calibration accuracy of its axisdirectly affects the merging accuracy of multi view data. This paper presents a new method of axis calibration forhigh precision turntable based on conic-fitting. The calibration method takes into account the situation that the axis of turntable is not perpendicular to the horizontal plane,and unlike in traditional ways of calibration,parameters considered are increased from 3 to 6. The standard ceramic cylinder is used as the calibration object,and theaxis calibration parameters are solved by the least square conic fitting of the point cloud measured on top of theconical curve equation standardization. The simulation experiment,the turntable calibration experiment,thecylindrical measurement experiment and the Aero -blade measurement experiment show that the conical fittingmodel is more efficient than traditional cylinder fitting. The higher fitting accuracy is obtained with measurementerror reduced from 0.042mm to 0.032mm,which verifies the superiority of this method in calibration accuracy.