激光再制造机器人待加工零件形貌三维重建

3D Reconstruction of Parts to be Processed by Laser Remanufacturing Robot

采用双目摄像机结合结构光组成主动视觉测量系统,并与机器人耦合,构建了一种具有视觉功能的智能激光加工机器人,能够感知各种复杂曲面轮廓,重建三维形貌。系统由六自由度机器人、双目摄像机和结构光发射器组成。机器人带动双目摄像机和结构光发射器运动,既实现多视角测量,消除测量中的"死角",重建工件的完整三维形貌,又将测量到的点云数据转换到机器人坐标系。阐述了测量原理和数学模型,进行了单摄像机内外参数的标定,双目摄像机相对关系的标定,双目摄像机与机器人之间的手眼关系标定,得到摄像机内参数矩阵,手眼关系矩阵,机器人与世界坐标系关系矩阵。对双目图像进行大步距图像分割,提取目标区域,平滑降低图像噪声,重心法提取亚像素级结构光条纹中心,根据极线约束进行左右条纹配准,三维算法得到空间点坐标,可方便地转换到世界坐标系,实现全局坐标的统一。

An intelligent laser processing robot with active vision composed of binocular stereo camera and structure light is developed in this paper.It can measure a variety of complex surface and reconstruct its 3D shape.The system consists of a robot with six degrees of freedom,binocular cameras and structure light.Cameras and structure light emitter are fixed on the robot and follow the robot movement,which accomplishes multi-angle measurement to eliminate ＂dead space＂,as well as transforms point cloud data to the robot coordinate.In this paper,measurement principle and mathematical model are described.Inside and outside parameters of single-camera calibration,the relative relationship between binocular camera calibration,binocular camera and robot hand-eye relationship calibration are carried out to obtain the parameters of camera matrix,hand-eye matrix,robot-world matrix.The target is extract by big step segmentation,and the image is smoothed to reduce noise.Sub-pixel center of structure light is extracted by gravity algorithm,and the left and right image is registrated according to the epipolar constraint.Point coordinate calculated by 3D algorithm,can be easily converted to the world coordinate to achieve the unity of the global coordinates.