口腔教学评估系统旋转台转轴方位的确定  

Calculation Method of Turntable Spindle Orientation for Oral Teaching Evaluation System

作　　者：王小娟[1] 刘丙才[2] 

机构地区：[1]西安工业大学理学院,陕西西安710032 [2]西安工业大学光电工程学院,陕西西安710032

出　　处：《科技广场》2016年第2期30-35,共6页Science Mosaic

摘　　要：基于激光线扫描的口腔教学评估系统是通过投影光刀在预备牙体的牙齿表面调制变形信息的测量来实现牙齿窝洞和肩台的快速轮廓重建。为避免复杂的牙齿颌面形貌对激光光刀的遮挡,系统将旋转测量与双目立体视觉相结合,此时,旋转台转轴方位的确定将成为制约牙颌模型三维重建效果的关键。本文通过2个CCD摄像机从不同角度采集不同高度平面内标志点图像,通过特征点提取和椭圆拟合,获得各高度平面上旋转中心的像素坐标值;利用物像变换关系矩阵将其转换为物空间坐标值,直线拟合得到旋转台转轴的方向直线。实验表明,该方法不仅简单、易操作,而且具有较高的稳定性,通过旋转台转轴方位的确定,并对多次测量结果进行三维数据融合,获得了较好的牙齿肩台三维轮廓。Through the deformation measurement of the projection laser scalpel on the preparation teeth surface, the profile of dental cavity and shoulder can be reconstructed quickly by laser scanning oral teaching evaluation system. To avoid the shelter of laser scalpel from the complex teeth surface, the system combines the rotating measurement and binocular stereo vision. So the calculation of the turntable spindle orientation is an important factor in the 3D dental model reconstruction. This paper introduces the key technology for the calibration method of turntable spindle orientation. Images of the mark point are obtained by 2 CCD from different views at different height locations. The pixels of the rotating centers at each height are collected by feature points extraction and ellipse fitting, and their object space coordinates are calculated by image transform relation matrix. Then the turntable spindle orientation is calculated by 2 points line fitting. The test results show that the calculation method is simple and stable. Based on this turntable spindle orientation, three-dimensional profile of dental shoulder can be reconstructed well through multiple measurements data fusion.

关 键 词：转轴方位 双目立体视觉 特征点提取 直线拟合 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]