调制度测量轮廓术中高度映射与相机同时标定的方法

A Method of Both Height Mapping and Camera Calibration at the Same Time in Modulation Measuring Profilometry

传统的调制度测量轮廓术在进行系统的标定时,需要将标准平面多次精密移动,以建立调制度与实际物理高度的映射关系,同时还要对摄像机进行单独的标定。提出一种新的用于调制度测量轮廓术系统的高度映射与相机同时标定的方法。该方法用一个含有多个台阶的标定模块代替传统的调制度测量轮廓术标定方法中使用的标准平面及复杂的平移定位系统,多个高度相同但空间离散分布的台阶构成多个虚拟校准平面,虚拟平面上的调制度分布是通过一个拟合过程实现的,同时多个台阶的中心点还可以作为立体靶标用于相机标定。这种标定方法的特点是:只需要一次扫描测量过程就可以完成系统的标定,包括建立调制度与高度的映射关系和对相机的标定。阐述了该标定方法的原理,并给出实验结果说明了该标定方法的有效性。

In the calibration process for traditional modulation measuring profilometry,a standard plane needs to be moved several times to establish the mapping relationship between modulation and actual physical height.And the camera calibration process needs to be done separately.A new calibration method for modulation measuring profilometry is proposed,which can implement height mapping and camera calibration at the same time.In this method,a standard block is used instead of the standard plane and the complex translation stage system in the traditional methods.Several separated stages with the same height but whose spatial distribution is discrete are used to form a virtual calibration plane,on which the modulation distribution is obtained by fitting process,and the multistages can also be used in the lateral coordinates calibration process.The characteristics of this method are that only one scanning process is required for setting up the mapping relationship between the modulation and height and calibrating the lateral coordinates.The theory analysis of the proposed method is given and experiment proves the feasibility of the method.