基于结构光的微细管孔内表面三维重建

3D Reconstruction of Small-diameter Pipes Inner Surface Based on Structural Light

介绍了一种适于空间曲线型微细管孔内表面三维重建的系统。该系统主要由管道机器人、形貌检测器和曲率检测器等部分组成。形貌检测器在管道机器人的带动下潜入管孔内部进行内壁截面图像采集,曲率检测器负责测量管孔中心轴线在检测器采样位置处的局部几何性质。对管道内壁截面图像进行适当的处理,结合形貌传感器的标定参数和结构参数,可以计算出在检测器局部坐标系下的管道截面三维轮廓;同时,根据传感器采样位置处的管道中轴线局部几何性质、管道机器人的前进步长,建立局部坐标系与全局坐标系的关系,从而将被测全部截面的局部坐标转化为全局坐标,实现管道内表面的三维重建。实验结果表明,利用该技术检测的管道内表面三维形貌与实际情况是一致的。

A 3D reconstruction system for the interior surface of small-diameter pipes is developed. The system consists of an in-pipe micro-robot, a profile detector and a curvature sensor. The profile detector captures sectional pictures of the inner surface when it moves in a pipe driven by the robot. At the same time, the curvature sensor gets the local geometric information of the central axis of the pipe in the sampling position. The image coordinates of points in the sectional pictures are obtained through adaptive image processing. Then three- dimensional coordinates of the points in the profile detector＇s local coordinate system can be calculated according to the calibration and structure parameters of the detector. Meanwhile, the relationship between every local coordinate and the global one can be derived based on the corresponding local geometric information of the central axis and the step of the robot. The coordinates of the points in all the measured sections can be transformed into global ones and the 3D profile of the inner surface of the pipe can be reconstructed easily by reverse engineering. As shown by the experiments, the reconstructed 3D profile is coincident with the actual facts.