基于结构光立体视觉的激光再制造工件的测量  

Measurement of Laser Remanufacturing Workpieces on Structured Light Stereo Vision

作　　者：高贵[1,2] 杨洗陈[1] 张海明[1] 

机构地区：[1]天津工业大学激光工程中心,天津300160 [2]天津工业大学理学院,天津300160

出　　处：《南开大学学报（自然科学版）》2011年第1期36-42,共7页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：天津市科技支撑计划重点项目(08ZCKFGX02300)

摘　　要：为了实现激光再制造工件的快速准确测量,提出了1套与激光再制造机器人耦合的视觉系统.该视觉系统由2个摄像机、1个激光投射器和计算机组成.摄像机和激光投射器组成扫描测头,由6自由度机器人手持实现多视角扫描.并自动完成数据拼接,消除‘死角'.首先,通过MATLAB编程完成系统标定,分别标定出单目摄像机内外参数矩阵,双目相机关系矩阵和机器人手眼关系矩阵.然后,两摄像机同时采集带有结构光信息的左右图像,采用重心法精确提取亚像素级结构光条纹中心.最后,依据极线几何约束,完成左右结构光条纹数据的匹配,根据匹配得到的数据对计算出3维空间坐标.系统具有低速高精度扫描(<5 mm/s)和高速普通扫描(<50 mm/s)两种模式.以气缸门芯为例,完成了3维扫描与测量,并与常规测量方法结果做了对比.实验结果表明,高精度模式最大误差小于0.1 mm,最大相对误差为0.7%,高速模式扫描时间3～5 s,能够满足激光再制造机器人对测量精度和测量速度的要求.In order to achieve measurement quickly and accurately,a stereo vision system coupled with laser remanufacturing robot is designed.The system is made up by two cameras, a laser structured light projector and a PC.The scanning head with two cameras and the projector is hand-held by six DOF robot,which can achieve multi views scanning and splicing the data from different views together automatically.First,the system is calibrated by MATLAB programming.Internal and external parameters of single camera,relationship matrix between stereo camera and hand-eye relationship matrix are got.Then,images with structured light information are collected from two cameras,and the structured light center is extracted by gravity method with sub-pixel accuracy.Finally,structured light data extracted from left and right cameras are matched based by the epipolar geometry,and then calculate the 3D data.System has high-precision scanning mode at low-speed（5 mm/s） and normal-precision scanning mode at high-speed（50 mm/s）.In experiment,for example,intake valve is scanned into 3D model and measured,and compared the result with conventional measurement method.The results show that the maximum error of high-precision scanning mode is less than 0.1 mm,the maximum relative error is 0.7%,and the scanning time of high-speed scanning mode is 3～5 s. The results meet the accuracy and speed requirement of laser remanufacturing robot.

关 键 词：机器视觉 双目立体视觉 结构光 匹配 激光再制造 

分 类 号：TP242.62[自动化与计算机技术—检测技术与自动化装置] TN249[自动化与计算机技术—控制科学与工程]